Search Subject Areas | Preprints.org

Preprint ARTICLE | doi:10.20944/preprints202404.0532.v1

Natural Hydrogen in North Perth Basin, WA Australia: Detection in Soil Gas for Early Exploration

Vitaly Vidavskiy, Reza Rezaee, Nikolay Larin, Rance Dorrington, Martin Spivey, Vladimir Vidavskiy

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Natural hydrogen; White hydrogen; Primordially Hydridic Earth; Clean Energy; Hydrogen exploration

Online: 8 April 2024 (11:42:01 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202403.1492.v1

Timing and Setting of Gold Mineralization in the Maljavr Oc-Currence, NE Part of the Fennoscandian Shield

Arkadii A. Kalinin, Nickolay M. Kudryashov, Yevgeny E. Savchenko

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Archean conglomerate; greenstone belt; alteration; gold; bismuth; ehrigite; U-Pb age; zircon.

Online: 26 March 2024 (08:19:47 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202403.1275.v1

The Zoning Rule and Forming Mechanism of Tectonite-Mineralized Alteration Lithofacies of “Black/Fracture Zone” of the Daliangzi Pb-Zn Deposit in Southwest Sichuan of China

Lingjie Li, Runsheng Han, Jianbiao Wu, Zhixing Feng

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: “ black/fracture zone” ; ; tectonite-mineralized alteration lithofacies; strike-slip structure + diapirism (cryptoexplosion); Daliangzi Pb-Zn deposit; Sichuan-Yunnan-Guizhou Pb-Zn metallogenic province

Online: 22 March 2024 (03:28:20 CET)

Show abstract| Download PDF| Share

As one of the typical deposits in Sichuan-Yunnan-Guizhou Pb-Zn metallogenic province, the Daliangzi Pb-Zn deposit has a close genetic relation with the structural system of “black/fracture zone” formed under the action of NWW-approx. EW strike-slip structures in the metallogenic province, but the mechanism of rock and ore-controlling action of the structural system remains unclear. Based on detailed analysis of tectonite-mineralized alteration lithofacies of R1 “black/fracture zone”, the tectonite-mineralized alteration lithofacies zones can be divided into 4 types in succession outward from the Pb-Zn mineralization center, i.e., ① brecciated and stockwork-like Pb-Zn mineralization-complex breccia facies zone, ② stockwork-like Pb-Zn mineralization-simple breccia and cataclasite facies zone, ③ veined pyrite-sulfide-dolomitic cataclasite facies zone, and ④ fine-veined calcite-black carbonized dolomite facies zone; Cl- and SO42--rich high-temperature oxidizing ore-bearing fluid mixes with reducing fluid in Zone ① while migration and precipitation occur in Zone ④. With the evolution of ore-forming fluid, the homogenization temperature decreases from Zone ① to Zone ④, the salinity increases from Zone ① to Zone ② and then decreases to Zones ③ and ④, and the fluid density has little change on the whole; the contents of Zn, Pb, Cu, Ga, Ge, Cd, Ag, and other metallogenic elements, the Zn/Pb ratio, and the CaO/MgO mole ratio decrease gradually from Zone ① to Zone ④; and REE fractionation, calcilization, silicification, and pyritization enhance gradually from Zone ① to Zone ④. This series of changes are the product of diapirism (cryptoexplosion) of strike-slip structures and “black/fracture zone”, among which the second-order structures (F5, F100, and other faults) derived from NWW-approx. EW striking dextral shear-tension faults F1 and F15 control the brecciated and stockwork-like Pb-Zn mineralized complex breccia facies zones and the stockwork-like Pb-Zn mineralized simple breccia and cataclasite facies zones. Therefore, this paper establishes the zoning mode of tectonite-mineralized alteration lithofacies of “black/fracture zone” and proposes that Zones ① and ② are important prospecting criteria. conclusions.

Preprint ARTICLE | doi:10.20944/preprints202402.1202.v1

Modern River-Sand Geochemical Mapping in the Manufahi Municipality and its Surroundings, Timor-Leste: Implications for Provenance

Vital Cruz Malai Araujo Vilanova, Tomoyuki Ohtani, Satoru Kojima, Kazuma Yatabe, Nene Valente Soares Cristovao, Aniceta Araujo

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: geochemical mapping; lithological mapping; river sands; principal component analysis; provenance; alteration; silicification; low-grade metamorphism; secondary mineral assemblage.

Online: 22 February 2024 (01:35:42 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202401.1790.v1

Hydrogeochemical Behavior of Shallow Groundwater around Hancheng Mining Area, Guanzhong Basin, China

Xiaomei Kou, Zhengzheng Zhao, Lei Duan, Yaqiao Sun

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Groundwater·; Hydrogeochemistry·; Coal mine·; Water-rock interactions

Online: 25 January 2024 (09:37:35 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202401.1242.v1

Evidence of Elliptical Intrusions and Sr, Hf, Pb, O Isotopes of the Khanbogd Alkali Granite Pluton: Constraction of Under-plating Magma Associated with the Duplex Thrust

DASH BATULZII, HOLK GREGORY, SERJLKHUMBE AMARAMGALAN

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: alkali granite; satellite image; elliptic shape; δ18O isotope; duplex thrust; underplating

Online: 16 January 2024 (12:29:14 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202401.0876.v1

The Solubility of Antimony (Sb) in Liquid Hydrocarbons and Its Im-Plication for the Ore-Forming Process of Orogenic Antimony-Gold Deposits in Southern Tibet

Yue Su, Xiaoming Sun, Zhengpeng Ding

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Antimony; Liquid hydrocarbons; Thiol; Ore-forming fluid; Orogenic antimony-gold deposits; Southern Tibet

Online: 11 January 2024 (07:36:02 CET)

Show abstract| Download PDF| Share

Orogenic antimony-gold deposits contribute significantly to the global antimony resource base. China's orogenic antimony-gold deposits are primarily in southern Tibet. Investigations indicate that antimony combines and migrates with sulfur hydroxides in ore-forming fluids. Previous research on fluid inclusions in orogenic antimony-gold ores with sedimentary rock accommodation revealed the presence of organic inclusions, including liquid hydrocarbons, alongside common components such as CO2, H2O, CH4, and NaCl. However, the impact of liquid hydrocarbons on antimony migration and mineralization is still de-batable. To investigate the transportability of antimony by liquid hydrocarbons in orogenic antimony ores, we selected n-dodecanethiol and n-dodecane as the subjects. We measured the solubility and occurrence form of antimony in these compounds at various temperatures and durations. The results indicate that after 5 and 10 days of reaction at 100 °C, the antimony concentrations in the n-dodecanethiol and n-dodecane groups were 67.44±7.62 ppm, 75.15±16.74 ppm, 1.40±1.02 ppm, and 3.02±3.09 ppm, respectively. At 150 °C for 5 and 10 days, the respective concentrations were 50.58±5.39 ppm, 77.26±45.20 ppm, 2.66±3.08 ppm, and 2.41±2.03 ppm. At 200 °C for 5 and 10 days, the corresponding concentrations were 339.76±71.94 ppm, 218.97±25.03 ppm and 6.53±7.17 ppm, 2.27±0.82 ppm (n=3). The measured solubility of antimony in the n-dodecanethiol group increased gradually with rising temperature. The solubility of antimony in the n-dodecane group was low and notably inferior to that observed in the n-dodecanethiol group. X-ray photoelectron spectroscopy (XPS) analysis demonstrated a distinct thiol (R-SH) peak at 163.31 eV and compound peaks of antimony reacting with thiols at 162.06 and 160.87 eV. This suggests that antimony predominantly forms complexes with thiols for migration. Our findings suggest that specific liquid hy-drocarbon components, predominantly thiols, can interact with antimony at metallogenic temperatures and persist in ore-forming fluids, facilitating migration and mineral enrichment. Earlier experimental studies on gold and crude oil have indicated that liquid hydrocarbons also play an essential role in the transportation and enrichment of gold during the formation of gold deposits, thus indicating that liquid hydrocarbons possess the considerable potential to act as an ore-forming fluid during orogenic antimony-gold deposit formation in southern Tibet.

Preprint ARTICLE | doi:10.20944/preprints202401.0561.v1

The Dynamic Evolution Model of Chemical and Carbon Isotopic Composition of C_1-3 during the Hydrocarbon Generation Process

Heng Zhao, Yanjie Li, Wenhui Liu, Guchun Zhang, Yanjun Wang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: dynamic evolution model; yield; carbon isotope; hydrocarbon genereation; C1-3; geochemistry

Online: 8 January 2024 (06:51:02 CET)

Show abstract| Download PDF| Share

A new approach is presented for dynamic modeling of chemical and isotopic evolution of C1-3 during the hydrocarbon generation process. Based on systematic data obtained from published papers for pyrolysis of various hydrocarbon sources(type I kerogen/source rock, type II kerogen/source rock, type III kerogen/source rock, crude oil, asphalt, etc), the empirical evolution framework of chemical and isotopic composition of C1-3 during the hydrocarbon generation process was built. Although the empirical framework was built only by fitting large amount of pyrolysis data, the chemical and isotopic composition of C1-3 derived from the pyrolysis experiments all follow the evolution laws, convincing us that it is applicable to the thermal evolution process of various hydrocarbon sources. Based on the simplified formula of the isotopic composition of mixed natural gas at different maturities (δ13Cmixed) δ13Cmixed=(X〖*n〗_iA 〖*δ〗^13 C_iA+Y〖*n〗_iB 〖*δ〗^13 C_iB)/(X〖*n〗_iA+Y〖*n〗_iB ), it can be derived that the cumulative isotopic composition of alkane generated in certain maturity interval can be expressed by the integral of the product of instantaneous isotopic composition and instantaneous yield at certain maturity point, and then divided by the cumulative yield of alkane generated in corresponding maturity interval. Thus, the cumulative isotopic composition(A(X)), cumulative yield(B(X)), instantaneous isotope(C(X)),and instantaneous yield(D(x)) in the dynamic model comply with the following formula during the maturity interval of (X0-X) A(X)=(∫_(X_0)^X▒〖C(X)*D(X)dx〗)/(B(X)), where A(X) and B(X) can be obtained by fitting of pyrolysis data, and D(x) can also be obtained from the derivation of B(X). The dynamic model was applied on the pyrolysis data of Pingliang Shale to illustrate the quantitative evolution of cumulative yield ,instantaneous yield, cumulative isotope and instantaneous isotope of C1-3 with increasing maturity.The dynamic model can quantify the yield of methane, ethane and propane as well as δ13C1, δ13C2 and δ13C3 respectively during the hydrocarbon generation process, which is of great significance to evaluate the natural gas resources of hydrocarbon source rock with different maturity and to identify the origin and evolutionary process of hydrocarbons by chemical and isotopic data. Moreover, this model provides an approach to study the dynamic evolution of isotope series of C1-3 (including reversed isotopic series), which is hopeful to reveal the mechanism responsible for isotopic reversal when combined with post-generation studies.

Preprint ARTICLE | doi:10.20944/preprints202401.0163.v1

Peraluminous Rare Metal Granites in Iberia: Geochemical, Mineralogical, Geothermobarometric and Petrogenetic Constraints

Francisco Javier López-Moro, Alejandro Díez-Montes, Susana Maria Timón Sánchez, Teresa Llorens González, Teresa Sánchez García

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: intensive variables; parental magma; exsolved fluid phase; albitization; Nb/Ta ratio; columbite group minerals; Iberian Massif

Online: 3 January 2024 (07:53:36 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202312.2290.v1

Occurrence Characteristics of Gold in Crude Oil and Its Geological Significance

Zhiyong Ni, Wen Zhang, Jie Liu, Shenbao Shi, Xue Wang, Yang Su

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: crude oil; gold; affinity; organic acid

Online: 29 December 2023 (16:44:55 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202312.1898.v1

Regional-Scale Paleo–Proterozoic Heating Event on Archean Acasta Gneisses in Slave Province, Canada: Insights from K–Ar and 40Ar/39Ar Chronology

Megumi Sato, Hironobu Hyodo, Kei Sugiura, Tatsuki Tsujimori, Tetsumaru Itaya

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: K-Ar age; 40Ar/39Ar age; biotite; amphibole; Acasta gneiss; Wopmay orogen; Canada

Online: 26 December 2023 (07:47:18 CET)

Show abstract| Download PDF| Supplementary Files| Share

Slave Province in Canada is an Archean granite-supracrustal terrane at the northwestern corner of the Canadian Shield. It is bordered by the Thelon–Taltson orogen (2.0 to 1.9 Ga) to the south-east and the Wopmay orogen (1.9 to 1.8 Ga) to the west. Acasta gneisses exposed in the western-most Slave province and the Wopmay rocks close to the gneisses were collected systematically for K-Ar and laser step-heating 40Ar /39Ar analyses of the biotite and amphibole. The K-Ar biotite ag-es of the four Wopmay samples range from 1816 ± 18 Ma to 1854 ± 26 Ma, which is within the reported U-Pb zircon age range of the Wopmay orogen. The K-Ar biotite ages of the fifteen Acasta gneisses range from 1779 ± 25 Ma to 1877 ± 26 Ma, except for a younger sample (1711 ± 25 Ma). The 40Ar/39Ar biotite analyses of the three samples from the Wopmay orogen give the plateau ages of 1826 ± 21 Ma, 1886 ± 13 Ma, and 1870 ± 18 Ma. On the other hand, the 40Ar/39Ar analyses of the biotite crystals from the Acasta gneiss show a variety of ages. Three samples show the plateau ages of 1877 ± 8 Ma, 1935 ± 14 Ma, and 1951 ± 11 Ma. These plateau ages are a little older than the total gas ages. The 40Ar/39Ar analyses of the amphibole crystals show more varied age rela-tions. The two samples show consistent age relations between the plateau ages (1814 ± 22 Ma and 1964 ± 12 Ma) and the total gas ages (1789 ± 23 Ma and 1967 ± 11 Ma), respectively. Some sam-ples have the apparent old age of 2000 Ma in the middle temperature fractions. These old frac-tions are due to that the originally existed amphibole crystals formed in Archean were affected by the thermal events during the Wopmay orogeny. but did not fully reset. The results suggest that the K-Ar system ages of the biotite and amphibole of the Archean Acasta gneiss that is aged from 4200 to 2600 Ma of zircon U-Pb ages were rejuvenated in the Paleo–Proterozoic ages. The heat source that rejuvenated the K-Ar system ages may have arisen due to the asthenospheric intrusion into the wedge mantle, which took place because of the subduction rollback.

Preprint ARTICLE | doi:10.20944/preprints202312.1879.v1

Formation of natural Magnesium Silica Hydrate(M-S-H) and Magnesium Alumina Silica Hydrate(M-A-S-H) cement

Håkon Austrheim, Depan Hu, Niels H Andersen

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Serpentinization; weathering; CO2 sequestration; Feragen and Leka ultramafic complexes; brucite; natural (M-(A)-S-H) cement; duricrust

Online: 25 December 2023 (15:58:21 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202312.0889.v1

Cold and Thermal Waters Circulation Systems at the Makaresh Carbonate Karst Massif (Central Albania)

Romeo Eftimi, Isabella Serena Liso, Mario Parise

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: karst; hydrogeology; thermal waters; Albania.

Online: 13 December 2023 (03:19:08 CET)

Show abstract| Download PDF| Share

Carbonate rocks occupy about 6490 km2 in Albania (23% of the country) and the total exploitable karst water resources are estimated in 2.84*109 m3/year (about 65% of the total exploitable groundwater resources in the country, and about 70% of those used for water supply). In addition, karst massifs are very rich in thermal waters, related to the ascending fluids which are essential for the development of hypogenic karstification in the outer Albanides. This type of karst facilitates the circulation regime of deep fluids, which are revealed at the surface through both numerous phenomena of hypogene karst and hot springs. The relatively small Kruja Tectonic Zone is characterized by the presence of SE-NW oriented carbonate structures, rich in thermal sources, and contains more than the 80% of Albania thermal springs. One of its most interesting carbonate structures, for the presence of both cold and thermal waters, is the small karst structure of Makaresh, with a surface of 22 km2. The purpose of this article is to describe the characteristics and factors that affect the quantitative and qualitative formation of cold and thermal groundwater in this massif. Based on the physico-chemical characteristics, groundwaters of the study area are classified in cold and thermal waters. The former are mainly of HCO3-Ca or HCO3-Ca-Mg type (Electrical Conductivity 580-650 μS/cm, Temperature 13.9-16.6° C). Thermal waters are mainly of the Cl-Na-Ca type (EC 7200-7800 μS/cm, T 18.5-22.5° C); further, they are characterized by high hydrogen sulphide concentration, up to about 350 mg/l. The presence of two groundwater types in the Makaresh massif is connected to the presence of two groundwater circulation systems. The main factors of the groundwater physic-chemical quality are the solution of rocks and minerals therein contained, the presence of hypogenic speleogenesis, and the mixing of the groundwater of the two systems. The hydrogeological studies proved that karst rocks contain considerable fresh water resources; the capacity of water wells used for the drinking water supply reaches up to about 50 l/s. Thermal waters are not currently exploited due to their temperature, but they are potentially suitable for thermal uses, by drilling boreholes at depth of about 1000 m.

Preprint ARTICLE | doi:10.20944/preprints202312.0866.v1

Reconciling Top-down and Bottom-up Methane Emissions Estimates in the Delaware Basin

Stuart N. Riddick, Mercy Mbua, Arthur Santos, Wendy Hartzell, Daniel J Zimmerle

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Methane; Inventory; Bottom-up; Reconciliation; Oil and Gas

Online: 12 December 2023 (09:53:12 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202311.1550.v1

Mineralogy and Geochemistry of the Paleocene-Eocene Palana Formation in Western Rajasthan, India: Insights for Sedimentary Paleoenvironmental Conations and Volcanic Activity

Mohammed Hail Hakimi, Alok Kumar, Abdullah Alqubalee, Alok Singh, Mohammed Almobarky, Afikah Rahim, Mohammad Alqudah, Aref Lashin, Khairul Azlan Mustapha, Waqas Naseem

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: organic-rich shale; bioproductivity; anoxia conditions; organic accumulation; Rajasthan; western India

Online: 24 November 2023 (02:40:59 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202311.0972.v1

Geochemistry of Cenozoic Basaltic Rocks from Anhui Province, China: Implications for Their Petrogenesis and Mantle Processes

Yung-Tan Lee, Meng-Lung Lin

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Anhui province; petrogenesis; mantle processes; metasomatism

Online: 15 November 2023 (16:34:31 CET)

Show abstract| Download PDF| Share

Based on the major, trace element, and isotope data of the Cenozoic basalts in the study area, it is indicated that the basalts in this region can be classified into three distinct magma systems: alka-li basalts, tholeiite basalts, and Nushan alkali basalts. The geochemical characteristics observed in the studied basalts indicate that the mantle source in this region might have experienced met-asomatic processes prior to partial melting, which could be linked to an ancient subduction pro-cess. Combining the geochemical characteristics in the studied basalts with previous research, we propose that the underlying mantle source in Anhui province may have undergone metaso-matism due to the carbonatitic melts. These melts are believed to have originated from car-bonated eclogite, derived from subducted Pacific slab materials present in the deeper mantle. According to the Sr-Nd isotope data, it is suggested that the mantle source in the Nushan region could be derived from a depleted asthenospheric mantle, while the basaltic composition in the Niugang area may be representative of the mantle's end components associated with the EM-I enriched mantle source present in this study area. Therefore, we propose that the Anhui basalts may have originated from the partial melting of a mantle source representing a mixing of two end-members: DMM (Depleted MORB Mantle) and EM-Ⅰ (Enriched Mantle 1). The Anhui basal-tic magmas may have originated from the partial melting of EM-Ⅰ, potentially influenced by upwelling asthenospheric mantle or asthenospheric diapirism processes. The mantle source in the study area experiences partial melting at 1-5%, 15%, and 1-10%, resulting in the formation of parent magmas for alkali basalt, tholeiitic basalt, and Nushan alkali basalt. Subsequently, the parent magmas experienced fractional crystallization processes, which included minerals like olivine, pyroxene, and plagioclase. This led to the formation of various types of basalt in the study area.

Preprint ARTICLE | doi:10.20944/preprints202311.0705.v1

Geochronology, Petrogenesis and Tectonic Setting of the Late Triassic syenite porphyry from the Western Part of the North Qinling Orogenic Belt

Shuqin Li, Zuochen Li, Xianzhi Pei, Hao Lin, Li Qin, Shang Ji, Yajie Yang, Jinghong Ren

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: North Qinling orogen belt; Late Triassic; tectonic setting; petrogenesis; geochronology; syenitic porphyries

Online: 10 November 2023 (11:33:26 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202311.0490.v1

Geochemical Characteristics and Environmental Implications of the Paleocene-Eocene in the Jiangling Depression, Southwestern Jianghan Basin

Kai Yan, Chunlian Wang, Renyi Chen, Jiuyi Wang, Ruiqin Li, Lihong Liu

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Jiangling depression; Paleocene-Eocene saline lake; climate; redox conditions; salinity

Online: 8 November 2023 (08:39:15 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202311.0404.v1

Nb-Ta-Sn Oxides From Lithium-Beryllium-Tantalum Pegmatite Deposits of the Kolmozero-Voronja Belt, NW Russia: Implica-Tions for Tracing Ore-Forming Processes and Mineralization Signatures

Dmitry Zozulya, Lyudmila Morozova, Kåre Kullerud, Ayya Bazai

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: columbite group minerals; pyrochlore; cassiterite; pegmatite; lithium; beryllium; NW Russia

Online: 7 November 2023 (06:34:15 CET)

Show abstract| Download PDF| Supplementary Files| Share

In this paper we present textural and compositional data for columbite group minerals (CGM) and associated Nb-Ta-Sn oxides from lithium-beryllium-tantalum pegmatite deposits of the Kolmozero-Voronja belt, NW Russia, with the aim of deciphering the above mentioned features for minerals from deposits with different mineral signatures and lithium ore grade. Minerals from four deposits, including two of world-class (Kolmozero and Polmostundra), are examined. It is shown that the main controlling factors are the diversity and rate of magmatic fractionation, hydrothermal overprint and mineral paragenesis followed from the specific geochemical signature of the different pegmatite deposits. CGM from Kolmozero include several mineral species (columbite-(Fe), columbite-(Mn), tantalite-(Fe), tantalite-(Mn)) showing large compositional variations, mainly controlled by Nb-Ta fractionation (Ta/(Ta+Nb) = 0.16-0.70; Mn/(Mn + Fe) = 0.45-0.63). Textural patterns are extremely various (oscillatory, homogeneous, patchy, spongy, somewhere with over-growing Ta-rich rims) and indicate the involvement of numerous magmatic and hydrothermal processes. The Polmostundra CGM are represented by columbite-(Fe) with Ta/(Ta+Nb) ranging from 0.05 to 0.39 with homogeneous, mottled, oscillatory, patchy and irregular reverse textures. The Okhmylk CGM are irregular normal, patchy and homogeneous columbite-(Fe) and columbite-(Mn) with Ta/(Ta+Nb) = 0.09-0.24 and Mn/(Mn + Fe) = 0.29-0.92, indicating the suppressed magmatic fractionation and iron drop due to precipitation of Fe minerals. Columbite-(Fe) and columbite-(Mn) from the Be-Ta Shongui deposit are less evolved with Ta/(Ta+Nb) = 0.07-0.23 and Mn/(Mn + Fe) = 0.31-0.55. The minerals are characterized by progressive normal, oscillatory, homogeneous and ir-regular reverse patterns. Associated pyrochlore minerals occur both as early magmatic (Kolmozero) and late hydrothermal (Polmostundra, Okhmylk). Cassiterite is found only in the Okhmylk dykes and is apparently of hydrothermal origin. CGM from Li pegmatites have impurities of Ti (0.01-0.05 apfu) and W (up to 0.02 apfu), whereas CGM from Be pegmatites contains elevated Ti (up to 0.09 apfu). The mineral systems analysis presented here is relevant for exploration.

Preprint ARTICLE | doi:10.20944/preprints202311.0074.v1

Apatite as an Indicator of Pge Mineralization Formation as Exemplified by Anorthosites of the Kievey Deposit, Fedorova-Pana Layered Complex, Kola Peninsula

Artyom Sushchenko, Nikolay Groshev, Tatyana Rundkvist, Alena Kompanchenko, Yevgeny Savchenko

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: apatite; disseminated sulfides; platinum group elements; layered intrusions; Fedorova-Pana Complex; Kola Peninsula

Online: 2 November 2023 (01:26:39 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202310.1410.v1

Post-Fracture Production Prediction with Production Segmentation and well logging: Harnessing Pipelines and Hyperparameter Tuning with GridSearchCV

Yongtao Sun, Jinwei Wang, Tao Wang, Jingsong Li, Zhipeng Wei, Aibin Fan, Huisheng Liu, Shoucun Chen, Zhuo Zhang, Yuanyuan Chen, Lei Huang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Post-fracture production prediction; Production segmentation; well logging; Pipelines; GridSearchCV; Machine learning

Online: 23 October 2023 (08:08:27 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202310.1320.v1

Diagenesis of the Permian Fengcheng Formation Shale Series in the Mahu Sag, Junggar Basin, China

Bin Bai, Jiwei Liang, Chaocheng Dai, Wenjun He, Zhenkun Yu, Ying Bai, Xiaobin Chang, Meng Zheng, Hanlin Li, Hao Zong

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: alkaline diagenesis; shale series; Fengcheng Formation; Mahu Depression; Junggar Basin; China

Online: 20 October 2023 (08:33:44 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202310.1254.v1

Deep-penetrating Geochemical Prospecting Experiment of Mahuagou Gold Deposit in the Core of Huangling Anticline, Western Hubei

Weihang Zhou, Li Lei, Yin Gong, Demin Liu, Shuyun Xie, Zhijun Chen, Qinglin Xia, Mengqi Wang, Salah Fadlallah Awadelseid, Oraphan Yaisamut

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: overburden prospecting; deep-penetrating geochemical indicator; chemical form analysis of gold; heat-released mercury survey; Huangling Anticline

Online: 19 October 2023 (09:34:41 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202310.0617.v1

Discussion on Genetic Types and Sources of Natural Gas in Y5 Well Area on the North Slope of Baiyun Sag

Guangrong Peng, Jun Liu, Xudong Wang, Lili Zhang, Cong Chen, Hui Sun, Jijun Li, Yuping Huang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Baiyun Sag; thermal simulation experiment; hydrocarbon generation kinetics; carbon isotope fractionation; natural gas genesis

Online: 16 October 2023 (02:48:19 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202310.0520.v1

Gemological, Spectral, and Chemical Features of Canary Yellow Chrysoberyl

Yujie Gao, Xu Li, Yansheng Cheng, Tiantian Huang, Kongliang Li, Bo Xu, Ruobin Tang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: chrysoberyl; Raman; trace elements; CIELab

Online: 10 October 2023 (03:19:18 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202310.0258.v1

Characteristics and Provenance of High Content Volcanogenic Compositions in Shanxi Formation of Daniudi Gas Field, Ordos Basin and Tectonic Implications

Xuejiao Qu, Qiao Wang, Tao Lei, Hao Chen, Jia Wang, Wei Jiang, Wei Zhang, Long Luo, Jianping Liu, Nan Jiang, Xuanbo Gao, Xianfeng Tan

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: volcanogenic compositions; provenance; tectonic evolution; Shanxi Formation; Ordos Basin

Online: 5 October 2023 (06:36:05 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202310.0186.v1

Study on the Dissolution Behavior of Typical Minerals in Continental Deposited Reservoirs During CO2 Geological Storage

Kai Wang, Weifeng Lv, Zemin Ji, Ninghong Jia, Shumin Ni, Wen Jiang, Jinhong Cao, Moxi Zhang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: salinity aquifer; CO2-water-rock (mineral) reaction; CO2 storage; dawsonite

Online: 4 October 2023 (11:17:28 CEST)

Show abstract| Download PDF| Share

A single geological carbon dioxide (CO2) storage within salinity aquifer as a paramount stratagem in the context of forthcoming CO2 sequestration initiatives. Within the expansive tapestry of terrestrial salinity aquifers in China, replete with nuances in mineral composition and structural diversity, a paradigm distinct from the marine sedimentary basins of North America, a labyrinthine stratigraphic environment of elevated complexity unfolds. Consequently, conspicuous lacunae and insufficiencies manifest within the existing knowledge reservoir pertaining to CO2-water-rock (mineral) reaction mechanisms. Notably, a conspicuous dearth of insights prevails concerning the dissolution kinetics inherent to individual minerals embroiled in these reactions. The present investigation undertakes a scrupulous exploration into the dissolution and erosive processes manifest within four emblematic terrestrial minerals in conjunction with CO2. Furthermore, the study meticulously scrutinizes the evolution of ionic composition and pH within the formation water throughout the trajectory of the geochemical reactions. To accomplish this, a simulation apparatus is configured to emulate conditions germane to temperature, pressure, and mineralization characteristics characteristic of a prototypical salinity aquifer reminiscent of the Daqing oilfield in China. The findings that emerge from this scrutiny reveal that the erosive action of CO2 fluid begets varying degrees of dissolution within the four minerals under investigation. Moreover, our meticulous inquiry lays bare that, in the terminal phases of the reaction process, feldspar precipitates secondary minerals, characterized primarily by dawsonite, in response to the aquatic milieu typifying the profound salinity stratum of terrestrial sedimentation. This milieu is notably enriched with Na+ ions and NaHCO3. This phenomenon suggests that feldspar, under these specific conditions, assumes the mantle of a mineral amenable to carbon sequestration, thus enriching the reservoir for CO2 mineralization within the salinity stratum of terrestrial sedimentation.

Preprint ARTICLE | doi:10.20944/preprints202310.0090.v1

Impact of Hydrocarbon Emissions from Oil and Gas Deposits on δ13С Variability in Pine Tree Rings

Olga V. Churakova (Sidorova), Georgy Batalin, Bulat Gareev, Gazinur Mingazov, Andrey Terekhin, Denis Tishin, Dilyara Kuzina, Danis Nurgaliev

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: CO2; CH4; δ13С in wood; tree-ring; Pinus sylvestris; iWUE; ci/ca; temperature; precipitation; evapotranspiration; cloud fraction; Tatarstan Republic; Russia

Online: 3 October 2023 (09:20:36 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint REVIEW | doi:10.20944/preprints202309.2133.v1

Amp-TB2 Protocol and Its Application to Amphiboles from Recent, Historical and Pre-historical Eruptions of Bezymianny Volcano, Kamchatka

Filippo Ridolfi, Renat Almeev, Alexey Yu Ozerov, Francois Holtz

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: amphibole; thermobarometry; equilibrium crystallization; volcanoes; magma chamber; magma feeding system; seismic tomography

Online: 30 September 2023 (07:10:58 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202309.1908.v1

Dehydration of Diaspore and Goethite during low-Temperature Heating as Criterion to separate Unheated from Heated Rubies and Sapphires

Michael S. Krzemnicki, Pierre Lefèvre, Wei Zhou, Judith Braun, Georg Spiekermann

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: ruby; sapphire; low-temperature heating; diaspore; goethite; Raman

Online: 27 September 2023 (15:11:57 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202309.1383.v1

Permian Granitic Plutons from the Northern Margin of the North China Craton: Implications for the Tectonic Evolution of the Central Asian Orogenic Belt

Jingsheng Chen, Dexin Tian, Bin Li, Zhonghui Gao, Weiwei Li, Chao Zhang, Yan Wang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Permian granitoids; Zircon U-Pb Geochronology; Geochemistry; Tectonic evolution; Northern Margin of the North China Craton

Online: 21 September 2023 (03:15:09 CEST)

Show abstract| Download PDF| Supplementary Files| Share

As the largest accretionary orogen in the world, the Central Asian Orogenic Belt (CAOB) has continuous juvenile crustal growth in the Phanerozoic. The northern margin of the North China Craton(NCC) and its adjacent area is the eastern segment of the CAOB, and is a key area to study the geological evolution of Paleo-Asian Ocean (PAO). In the Permian, the west of the northern margin of NCC belongs to a post-collision extensional environment, and the east belongs to a subduction stage. But, As a connecting area, the Permian evolution of PAO in the middle of northern margin of NCC has not been systematically studied. In order to fill the blank and understand the temporal and spatial continuous evolution process of PAO, this paper focused on the Permian granitic rocks in the Chifeng area, zircon U-Pb dating and the geochemical analysis of the whole rock main and trace elements were conducted in order to build a granite chronological framework, discuss the genesis and tectonic background of the granite rocks as well as the magma-tectonic evolution history in the Chifeng area. Zircon U-Pb dating results of 8 samples are 269±1 Ma, 268±3 Ma, 260±4 Ma, 260±1 Ma, 260±1 Ma, 255±2 Ma, 254±2 Ma, 256±1Ma, which showed that the Permian granitic rocks had undergone three stages of emplacement: (1) The monzogranite and syenite (294-284 Ma); (2) The monzogranite (269-260Ma) and (3) The monzogranite and syenite (256-254Ma). The Middle Permian magmatism (269-260Ma) was represented by the monzogranite assemblages with different grain sizes. The geochemical characteristics showed that they were high-potassium calc-alkaline-potassium dossonite series of granites formed in compressional environment, indicating there was a collision between the Xing’an-Mongolian Orogenic Belt (XMOB) and the North China Craton (NCC). During the Late Permian-Early Triassic (256-248Ma), the granites in the Chifeng area are dominated by the A-type and I-type granites of high-potassium calc-alkaline series formed under an extensional environments, which constituted typical "bimodal" rock assemblage combined with the coeval basic rocks, suggesting the study area was in an extensional environment where the subducting slab is fragmented during the collision between the XMOB and the NCC. According to emplacement time and occurrence location, the plutons are interpreted to have been generated by the subduction-collision of the Paleo-Asian oceanic crust beneath the NCC. This study provides strong evidence for Permian tectonic evolution and the characterization of the eventual closure of the Paleo-Asian Ocean in the Chifeng City at the northern margin of the NCC.

Preprint ARTICLE | doi:10.20944/preprints202309.1379.v1

Revisiting The Raman Spectra of Carbonate Minerals

Julliana F. Alves, Howell G. M. Edwards, Andrey V. Korsakov, Luiz Fernando C. De Oliveira

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Carbonate Minerals; calcite; aragonite, magnesite; dolomite; Raman spectroscopy

Online: 20 September 2023 (13:42:52 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202309.0575.v1

Instructional Mask AutoEncoder: A Powerful Pretrained Model for Hyperspectral Image Classification

Weili Kong, Baisen Liu, Xiaojun Bi

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Self-supervised; Pretrained Model; Transfer learning; Metric Learning; Transformer; Mask AutoEncoder; Hyperspectral Image Classification

Online: 8 September 2023 (07:42:04 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202309.0089.v1

Zircon as a Monitoring Tool for the Magmatic-Hydrothermal Process in the Granitic Bedrock of Shitouping Ion-Adsorption HREE Deposit, South China

Liangxin Gong, Xianguang Wang, Defu Zhang, Wen Zhong, Mingxuan Cao

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Ion-adsorption HREE deposits; Zircon; Magmatic-hydrothermal evolution; Highly fractionated granite

Online: 1 September 2023 (16:34:36 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint REVIEW | doi:10.20944/preprints202308.2185.v1

The use of newly formed minerals to characterize geothermal reservoirs and their cap rock: examples from intracontinental extensional basins and volcanic islands in subduction context

Béatrice A. Ledésert

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: geothermal reservoirs; cap-rocks; exploration; clay minerals; quartz; carbonates; fluid inclusions; chlorite geothermometers; flow pathways

Online: 31 August 2023 (15:03:50 CEST)

Show abstract| Download PDF| Share

Preprint TECHNICAL NOTE | doi:10.20944/preprints202308.2152.v1

87Sr/86Sr Isotope Ratio as a Tool in Archaeological and Environmental Investigation: Limits and Risks

Mattia Rossi, Paola Iacumin, Gianpiero Venturelli

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: 87Sr/86Sr; archaeology; environment; mineral dissolution; bio-available Sr

Online: 31 August 2023 (09:47:16 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint COMMUNICATION | doi:10.20944/preprints202308.2067.v1

Discovery of the Mafic Granulites in the Muzhaerte area, SW Tianshan, China

Jun Yan, Ying Cui

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: mafic granulites; Tianshan; Muzhaerte; high-temperature metamorphism; geothermobarometry

Online: 30 August 2023 (14:11:45 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202308.1463.v1

The Coal-Forming Environment at the End of the Late Permian and Its Control on Trace Elements: A Case Study of the C3 Coal Seam of the Xuanwei Formation in Eastern Yunnan, China

Juan Wang, Longyi Shao, Xuetian Wang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Late Permian coal; trace element geochemistry; coal facies; depositional environment; Xuanwei Formation

Online: 22 August 2023 (04:47:31 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202308.0428.v1

Geochemistry and Mineralogy of the Clay-Type Ni-Laterite Deposit of San Felipe (Camagüey, Cuba)

Esperança Tauler, Salvador Galí, Cristina Villanova de Benavent, Alfonso Chang-Rodriguez, Kenia Nuñez-Cambra, Giorgi Khazaradze, Joaquin Antonio Proenza

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: weathering; laterite; nickel; smectite; serpentine; clay-type; Cuba

Online: 4 August 2023 (10:40:27 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint REVIEW | doi:10.20944/preprints202307.1808.v1

A Review on Carbon Dioxide Sequestration Methodology

Gregory Tarteh Mwenketishi, Nejat Rahmanian, Hadj Benkreira

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Aquifer; Carbon Subsurface storage (CSS); CO2 Sequestration; Environment; Geological storage; Carbon Capture and Storage (CCS)

Online: 27 July 2023 (08:21:57 CEST)

Show abstract| Download PDF| Share

Carbon subsurface storage (CSS) has already been recognised as a critical, urgent, and essential method for reducing anthropogenic CO2 emissions and mitigating the severe effects of climate change. CSS is the last stage in the carbon capture and storage (CCS) cycle and is accomplished chiefly via oceanic and subterranean geological sequestration, as well as mineral carbonation. The injection of supercritical CO2 into geological formations causes a disruption in the subsurface's existing physical and chemical conditions; changes can occur in the pore fluid pressure, temperature state, chemical reactivity, and stress distribution of the reservoir rock. This paper aims to present a comprehensive review on the current advances in CSS, particularly CO2 storage methods and the challenges encountered during the implementation of each methods and analyses on how key uncertainties in CSS can be reduce. CSS sites are essentially unified systems; yet, given the scientific context, these systems are typically split during scientific investigations based on the physics and temporal/spatial scales involved. Separating the physics by using the system as a boundary condition is a strategy that works effectively for a wide variety of physical applications. Unfortunately, the separation technique does not accurately capture the behaviour of the larger important system in the case of water and gas flow in porous media. This is due to the complexity of geological subsurface systems, which prevents the approach from being able to effectively capture the behaviour of the larger relevant system. This consequently give rise to different CSS methods. A good CSS application method can further improve the efficiency of greenhouse gas emission and their environmental impact, promoting the process sustainability and helping to tackle some of the most important issues that human being is currently accounting, global climate change. Though this technology is already large-scale development for the last decade, some issues and uncertainties are identified. Special attention was focused on the basic findings achieved in CO2 storage operational projects to date.

Preprint ARTICLE | doi:10.20944/preprints202307.1255.v1

Mineral and Geochemical Features of Sulfide in Jade Hydrothermal Field of Okinawa Trough

Yujie Wang, Zhigang Zeng

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Massive sulfide; Mineralization stage; Jade hydrothermal field; Okinawa Trough

Online: 19 July 2023 (09:14:57 CEST)

Show abstract| Download PDF| Share

Preprint REVIEW | doi:10.20944/preprints202307.1120.v1

Criteria for Selecting Carbon Subsurface and Ocean Storage Site in Developing Countries: A Review

Gregory Tarteh Mwenketishi, Nejat Rahmanian, Hadj Benkreira

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: CCUS Site Selection; Carbon dioxide capture and storage (CCS); CO2 Sequestration; CCS Governmental Regulation; CO2 Environment Impact; Geological storage

Online: 18 July 2023 (05:40:27 CEST)

Show abstract| Download PDF| Share

Important first phases in the process of implementing CO2 subsurface and ocean storage projects include selecting of best possible location(s) for CO2 storage, site selection evaluation. Sites must fulfil a number of criteria that boil down to the following basics: they must be able to accept the desired volume of CO2 at the rate at which it is supplied from the CO2 source(s); they must as well be safe and reliable; and must comply with regulatory and other societal requirements. They also must have at least public acceptance and be based on sound financial analysis. Site geology; hydrogeological, pressure, and geothermal regimes; land features; location, climate, and access, etc. can all be refined from these basic criteria. In addition to aiding in site selection, site characterization is essential for other purposes, such as foreseeing the fate and impacts of the injected CO2, and informing subsequent phases of site development, including design, permitting, operation, monitoring, and eventual abandonment. According to data from the IEA, in 2022, emissions from Africa and Asia's emerging markets and developing economies, excluding China's, increased by 4.2%, which is equivalent to 206 million tonnes of CO2 and were higher than those from developed economies. Coal-fired power generation was responsible for more than half of the rise in emissions that were recorded in the region. The difficulty of achieving sustainable socio-economic progress in the developing countries is entwined with the work of reducing CO2 emissions, which is a demanding project for the economy. Organisations from developing countries, such as Bangladesh, Cameroon, India, and Nigeria, have formed partnerships with organisations in other countries for lessons learn and investment within the climate change arena. The basaltic rocks, coal seams, depleted oil and gas reservoirs, soils, deep saline aquifers, and sedimentary basins that developing countries (Bangladesh, Cameroon, India, and Nigeria etc) possesses all contribute to the individual country's significant geological sequestration potential. There are limited or no carbon capture and storage or clean development mechanism projects running in these countries at this time. The site selection and characterization procedure are not complete without an estimate of the storage capacity of a storage location. Estimating storage capacity relies on volumetric estimates because a site must accept the planned volume of CO2 during the active injection period. As more and more applications make use of site characterization, so too does the body of written material on the topic. As the science of CO2 storage develops, regulatory requirements are implemented, field experience grows, and the economics of CO2 capture and storage improve, so too will site selection and characterisation change.

Preprint ARTICLE | doi:10.20944/preprints202307.1017.v1

Studies on the source and phase characteristics of oil and gas: evidence from hydrocarbon geochemistry in the Pingbei Area of Xihu Sag, the East China Sea Shelf Basin, China

Wei Li, Jianfa Chen, Kaixuan Liu, Rao Fu, Cong Chen, Yinxun Wang, Xinjian Zhu, Xiaodong Chen, Tonglei Zhang, Liwen He

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: sources of oil and gas; phases of oil and gas; hydrocarbon geochemistry; enrichment mechanisms; Xihu Sag

Online: 17 July 2023 (10:34:13 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202307.0468.v1

Fluid inclusion studies of barite disseminated in hydrothermal sediments of the Mohns Ridge

Marina D. Kravchishina, Vsevolod Yu. Prokofief, Olga M. Dara, Boris V. Baranov, Alexey A. Klyuvitkin, Karina S. Iakimova, Vladislav Yu. Kalgin, Alla Yu. Lein

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: barite; fluid inclusion; hydrothermal vent field; hydrothermal fluid; mineralization; volcanogenic massive sulfide deposits; ultraslow-spreading ridge; Mohns Ridge; Arctic Mid-Ocean Ridge.

Online: 7 July 2023 (10:09:20 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202307.0039.v1

Rapid Urbanization Change the Driving Factors of Groundwater Chemical Evolution in the World’s Largest Groundwater Depression Funnel Area, China

Wang Long, Zhang Qianqian, Wang Huiwei

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Urbanization; Groundwater chemistry; Water-rock interaction; Multivariate statistical techniques; Driving mechanisms

Online: 3 July 2023 (09:48:09 CEST)

Show abstract| Download PDF| Share

With the rapid development of urbanization, the chemical evolution of groundwater is significantly affected by human activities. However, the driving mechanisms of groundwater chemical evolution at different stages of urbanization remain unclear, severely impacting the implementation of groundwater protection. This study investigated the driving mechanisms of groundwater chemical evolution based on the long-term series (from 1985 to 2015) of hydrochemical data from 19 groundwater monitoring sites in rapidly urbanizing areas (Shijiazhuang, Hebei Province, China). The results show that the concentrations of various chemical components in groundwater gradually increase with the acceleration of urbanization process, especially NO3-, which has increased from 13.7 mg/L in the primary stage of urbanization (PSU) to 65.1mg/L in the advanced stage of urbanization (ASU), exceeding the WHO drinking water standard (50mg/L), indicating that the groundwater chemistry has been significantly affected by human activities. It is interesting to find that the main hydrochemical types have changed from HCO3•SO4-Ca•Mg type water in the PSU to SO4•HCO3-Ca•Mg type water in the ASU. It is worth noting that there were obvious differences in driving factors of groundwater chemical evolution at different urbanization stages. In the PSU, the driving factors of groundwater chemical evolution were carbonate and rock salt dissolution, cation exchange, and industrial activities. However, in the intermediate stage and advanced stage, the driving factors of groundwater chemical evolution were changed to carbonate and gypsum dissolution, groundwater over-exploitation, agricultural fertilization, and domestic sewage. Based on the above conclusions, it is suggested that future groundwater management should control the amount of agricultural fertilizers, apply scientific fertilization, and prohibit the discharge of various types of non-compliant sewage, while strengthening the supervision of groundwater extraction to reduce the impact of urbanization development on the groundwater chemical evolution process.

Preprint ARTICLE | doi:10.20944/preprints202306.1721.v1

Characteristics of Seismogenic Dust Particles from Mountain and Its Significance for Paleoseismic Records in Tufa Section: A Case Study of Jiuzhaigou, China

Shengwen Jing, Fudong Wang, Enrico Capezzuoli, Guoqing Huang, Junhao Li, Hanchao Jiang, Zijian Zhou, Xueqin Zhao, Faqin Dong, Andrea Brogi

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Jiuzhaigou; Tufa particulate matter; Sedimentation; Genetic analysis; Paleoearthquake

Online: 25 June 2023 (07:11:39 CEST)

Show abstract| Download PDF| Share

The sedimentary characteristics of the special interlayer contained in the section of the Sparking Lake dam revealed by the 8.8 Jiuzhaigou earthquake in 2017 are obviously different from the tufa in the dam body, and they are considered to be prehistoric flood relics. Based on the study of the particulate matter from the 8.8 Jiuzhaigou earthquake, this paper combines comparative petrographic, mineralogical, geochemical and chronological studies of the special interbedded sediments of the Sparking Lake dam with other genetic samples to obtain homology information and genetic links, as well as to explore the tufa depositional dynamics and earthquake disaster subsidence. The palaeoseismic benefit in the discontinuity layer is explored, and the palaeoseismic information embedded in the profiles is extracted, providing a new idea to reconstruct the palaeoseismic events in the tufa deposition sequence. According to X-ray diffraction, laser particle size analysis and scanning electron microscope experiments, the particulate matter in the Jiuzhaigou mountains has its own specific mineralogical characteristics. The mineral composition of the particulate matter is basically calcite. The particle size is large, and the single particle is mostly angular and subangular. The fracture morphology observed under the single particle microscope is uneven, showing the characteristics of dust caused by earthquake disasters. Geochemical analysis data show that the provenance of various types of particles in the same area is stable, indicating the homology of terrestrial carbonate sedimentation in the karst system. Combined with mineralogy and grain size morphology, the interbedded particles in the tufa depositional profile have the potential application of palaeoseismic archives to record extreme seismic events. The palaeoseismic date was inferred from the chronological data of special interlayered sediments in the tufa dam body. Therefore, the tufa bedding can be related to the palaeoearthquake, and the special interlayer of the tufa section can be used to reconstruct palaeoearthquakes.

Preprint ARTICLE | doi:10.20944/preprints202306.0971.v1

The Petrology & Geochemistry of REE-Enriched, Alkaline Vol-Canic Rocks of Ambitle Island, Feni Island Group, Papua New Guinea

Olive L. Ponyalou, Michael Petterson, Joseph Espi

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Ambitle; alkaline volcanics; TLTF; hornblende; feldspathoid; trachyandesite; phonotephrite

Online: 14 June 2023 (03:46:54 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202306.0870.v1

Paleoproterozoic U Mineralization in Huayangchuan Deposit, Xiaoqinling Area: Evidence From the U-Rich Granitic Pegmatite

Putao Li, Yongjun Li, Pingyang Gu, Shiping He, Yujun Zhuang, Ruiming Chen

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Southern Margin of North China Craton; Xiaoqinling; Huayangchuan; Uranium; Pegmatite; Paleoproterozoic; Mineralization age

Online: 13 June 2023 (03:31:13 CEST)

Show abstract| Download PDF| Share

The Huayangchuan uranium deposit, located in the west of the Xiaoqinling belt on the southern margin of the North China Craton, is a polymetallic deposit dominated by U, Nb, Pb, and rare earth elements. The Huayangchuan uranium deposit, discovered in the 1950s, has long been known as a carbonatite-type uranium deposit. Recently, new geological work has found uranium mineralisation in many granitic pegmatite veins in the Huayangchuan deposit and adjacent areas. Here, we report a systematic investigation of the petrography, whole-rock geochemistry, zircon U-Pb ages, and in situ Lu-Hf isotopic characteristics of newly discovered U-rich granitic pegmatite veins in the west of Huayangchuan deposit. The petrological results showed that the lithology of the samples is equivalent to that of granite. The U-Pb ages of zircon were 1826.3 ± 7.9 and 1829 ± 11 Ma. Microscopically, the symbiotic characteristics of zircon, betafite, and uraninite exist in the intergranular fissures of K-feldspar and quartz, reflecting metallogenic phenomena in the rock formation process. Almost all whole-rock samples were rich in SiO2 (64.37–70.69 wt.%), total alkalis (K2O+Na2O = 8.50–10.30 wt.%), and Al2O3 (12.20–14.41 wt.%), but poor in Ti2O (0.23–0.73 wt.%), MgO (0.38–0.90 wt.%), P2O5 (0.14–0.83 wt.%), MnO (0.04–0.57 wt.%). Additionally, they showed enrichment of LILEs (such as Rb, Ba, Th, U, and K), depletion of HFSEs (such as Ta, Nb, P, Ti, and Hf), no alkaline dark minerals, and the characteristics are typical of intraplate A1-type granite. The A1-type granite displayed low zircon εHf(t) values (-19.42– -15.02) with zircon two-stage Hf model aged 3.10–2.76 Ga, indicating that the U-rich granitic pegmatite was derived predominantly from partial melting of the ancient continental crust (such as the early Taihua group formed in Archean-Neoarchean). Combined with the above results and regional geological data, the U-rich granitic pegmatite discovered in the Huayangchuan deposit was related to granite magma activity that formed in a post-collisional regime after the Luliang movement in the late Palaeoproterozoic. This study suggests that future uranium prospecting work in this area should focus on late Palaeoproterozoic U-rich granitic pegmatites.

Preprint ARTICLE | doi:10.20944/preprints202305.1893.v1

Geochemistry and Geochronology (U-Pb and Lu-Hf) of the Soarinho Alkaline Massif (Brazil): Implications on mantle versus crustal signature of syenitic magma

Daniel Adelino Da Silva, Guilherme Loriato Potratz, Mauro Cesar Geraldes

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: syenitic magma sourece; alkali feldpsar syenite; quartz syenite; U-Pb dating; Lu-Hf isotopes

Online: 26 May 2023 (08:34:42 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202305.1644.v1

A New Method for Processing Geochemical Exploration Data: the Geological Connotation Method (GCM)

Shunli Zheng, Youye Zheng, Xin Chen, Zezhang Yu, Lie Chen

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: geochemical anomaly; anomaly extraction; anomaly evaluation; geological connotation meth-od(GCM)

Online: 23 May 2023 (10:40:15 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202305.1515.v1

Spatial Overlay Analysis of Geochemical Singularity Index α-Value of Porphyry Cu Deposit in Gangdese Metallogenic Belt, Tibet, Western China

Shunli Zheng, Xiaojia Jiang, Shunbao Gao

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Geochemical singularity index; Spatial Overlay Analysis; Gangdese metallogenic belt; porphyry Cu deposit

Online: 22 May 2023 (11:11:38 CEST)

Show abstract| Download PDF| Share

It is found in this paper that ILR-RPCA-back CLR has two problems when dealing with the closure effect of geochemical data. (1) After ilr transformation, RPCA is used for processing. It can be seen from the double-plot diagram that the first principal component and the second principal component transform with the element sequence transformation, and the unique principal component cannot be calculated; (2) the score and the load are transformed into the CLR space through the U matrix. According to the formula CLR=ALR·U, the score result can correspond to the original order of elements. However, the load result obtained by the use of this formula cannot correspond to the original order of elements, and the result can only be obtained through the formula” CLR=UT·ALR”. In order to obtain the best element assemblage of porphyry copper deposit, this paper adopted the mineral assemblage of discovered deposits in Gangdese metallogenic belt for statistical analysis, and obtained that the element assemblage of porphyry copper deposit was Cu, Mo, Au, Ag, W, Bi. Then, by analyzing the singularities of the composite elements, the spatial overlay of the combined element is carried out, and C-A fractal filtering is applied to identify the anomaly and background. In order to facilitate comparison, the different minerals and ore deposit types have been analyzed, the results show that (1) in view of the porphyry copper deposits, recognition effect of combination elements are better than which single element, (2) skarn type copper deposit that it has nothing to do with the porphyry had a high degree of difference, but skarn type copper deposit related to the porphyry had a low degree of difference, (3) This method has a certain advantage over the single element method in porphyry gold deposits, and it can reduce the level of anomalies. Such an advantage is that in the aspect of anomaly evaluation of porphyry copper deposits, the level is reduced at the initial stage of evaluation to reduce the investment in such anomalies, (4) This method has limited ability to distinguish porphyry copper deposit from porphyry molybdenum deposit.

Preprint ARTICLE | doi:10.20944/preprints202305.0763.v1

Late Ordovician High Ba-Sr intrusion in the Eastern North Qilian Orogen: Implications for Crust-Mantle Interaction and Proto-Tethys Ocean Evolution

Shaoqing Zhao, Lianfu Hai, Bin Liu, Huan Dong, Chao Mei, Qinghai Xu, Caixia Mu, Xiangcheng Wei

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: High Ba-Sr granitoids; Late Ordovician; Subduction; Proto-Tethys; North Qilian orogen

Online: 10 May 2023 (14:32:41 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202305.0754.v1

Peritectic Reaction of Olivine as Mechanism of Ultrabasic-Basic Evolution of the Diamond-Forming System Silicate-Carbonate-(C-O-H): Experiments at 6.0 GPa

Yuriy A. Litvin, Anastasiya V. Kuzyura, Anna Spivak

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: diamond-forming silicate-carbonate system; С-О-Н-fluid; peritectic reaction of olivine; ultrabasic-basic evolution; origin of diamond-bearing peridotites and eclogites; high pressure and temperature; experiment

Online: 10 May 2023 (13:29:40 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202305.0299.v1

Phosphate Petrochronology of the Belcina REE Mineralization (Ditrău Alkaline Massif, Romania)

Urs Klötzli, Jolanta Burda, Paul Tibuleac

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Phosphate petrochronology; Ditrău Alkaline Massif; Eastern Carpathians; REE mineralization; Metasomatism; Hydrothermal fluids

Online: 5 May 2023 (04:47:34 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202304.0934.v1

The Alteration Processes of the Weakly Magnetic Egyptian Black Sand Altered Ilmenite

Mohamed Ismail Moustafa

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: altered ilmenite; leached ilmenite; leucoxene; pseudorutile; leached pseudorutile; exsolved intergrowth; X ray diffraction.

Online: 26 April 2023 (03:12:34 CEST)

Show abstract| Download PDF| Share

One of the most extensively studied topics in dozens of studies is the alteration process of ilmenite, the formation of leucoxene and the presence of some impurity oxides; SiO2 and Al2O3. The altered Egyptian black sand ilmenite grains of relatively lower magnetic characters are studied using the binocular microscope and the Cameca SX-100 microprobe instrument. Both of individual brown and black altered grains separated at 0.5 and 1 ampere values are investigated. The detection of the Various alteration phases, the mechanism of formation, their molecular formulas & limits, and the role of SiO2&Al2O3 in alteration mechanisms are detected. The alteration phases includes: pseudorutile (psr) and leached pseudorutile (lpsr) of different phases in addition also to rutile. Few analyzed spots are detected to be leached ilmenite (lilm). Several Excel softwares are adopted to calculate the chemical formulas of each alteration phase. The contents of TiO2 and Fe2O3 of all the investigated psr-lpsr in the study range between 59.16-86.56%, and 37.3-6.68%, respectively. The Ti/(Ti+Fe) ratio for these formulas ranges between 0.60 and 0.88. The psr-lpsr chemical formulas of all the investigated grains range as follows: Fe2.01-0.50Ti3O8.97-4.50(OH)0.03-4.50 . The concluded lowest cationic iron content of the well defined accepted lpsr phase is 0.5 with a corresponding molecular formula of Fe0.50Ti3O4.5(OH)4.5. It was concluded that in the region of 68-70 TiO2%, the mechanism of ilmenite alteration may be changed where neither all the analyzed TiO2 of the spot nor all the calculated structural water are contained within the molecular formula of lpsr. There are other associated mineral phases containing for some TiO2 and also some structural water which most probably are removed from the lpsr phase. As the analyzed spots are located at highly fissured locations, as the alteration process is relatively faster and the lpsr phase can be broken into rutile and hematite. Also, as the analyzed TiO2 and structural and/or molecular water contents increase, as the darkness of the BSE image areas of the grain increases; this may reflect the existence of an individual TiO2 phase; most probably rutile, mixed in homogeneity with the existed lpsr component. As the content of TiO2 increases; within a definite TiO2 range (80-85%), as the associated contents of Al2O3&SiO2 increase. When the contents of the structural and/or molecular water contained within the lpsr phases decreases; the sum total oxides is more than 98%, the contents of Al2O3 are highly depleted. In the late alteration stages, the lpsr structure does not suddenly collapse but gradually producuing other associated mineral phases. The relatively enriched contents of SiO2 and/or Al2O3 in some secondary rutile grains can be explained as most of the SiO2% is associated with mol water or bearing for mol and/or str water necessary for the leachability of Fe3+ from the psr structure. The XRD patterns of the investigated grains before and after roasting at 1100 oC for one hour are detected and interpreted.

Preprint ARTICLE | doi:10.20944/preprints202304.0513.v2

A Transient Productivity Prediction Model for Horizontal Wells Coupled With Oil-Gas Two-Phase Seepage and Wellbore Flow

Wenqi Ke, Wei Luo, Shiyu Miao, Wen Chen, Yaodong Hou

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: horizontal well; capacity prediction; transient model; saturation pressure; two-phase seepage

Online: 19 April 2023 (10:26:05 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202304.0577.v1

The Generation Time and Accumulations of Lower Paleozoic Petroleum in Sichuan and Tarim Basin Determined by Re–Os Isotopic Dating

Jie Wang, Liangbang Ma, Cheng Tao, Wenhui Liu, Qingwei Dong

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Re–Os isotopic chronology; Pre–treatment means; Petroleum generation time; Lower Paleozoic petroleum; western part of China

Online: 19 April 2023 (08:51:30 CEST)

Show abstract| Download PDF| Share

With the targets of petroleum exploration transferred to the deep and ancient strata, abundant oil and gas resources have been found in the Lower Paleozoic and older strata in central and western China. Due to complex evolutionary processes including multiple episodes of hydrocarbon accumulation and ubiquitously accompanied by secondary alterations, significant uncertainties were remained for the generation time and accumulation processes of these revealed petroleum. In this paper, relative pure Re and Os elements existing in the asphaltene fractions of Lower Cambrian solid bitumen collected from the Guangyuan area, western Sichuan Basin, SW China and another Middle–Lower Ordovician heavy oils in the Aiding area of the Tahe oilfield in the Tarim Basin, NW China were successfully obtained by the sample pre-treatments, and Re–Os isotopic analysis was subsequently carried out for the dating of these two petroleum. The Re–Os isotopic composition indicates a generation time of Guangyuan bitumen to locate between 572 Ma and 559 Ma, corresponding to the late Sinian period of Neoproterozoic era. By the means of Re–Os isochron ages, initial 187Os/188Os ratios, and carbon isotopic compositions, the Lower Cambrian bitumen is supposed to be originated from source rocks of the Doushantuo Formation in the Sinian strata and subsequently migrated into the reservoirs of Dengying Formation. These previously reserved petroleum had been transformed to present bitumen by the destruction of reservoirs caused by tectonic uplift. The Re–Os dating results of Middle–Lower Ordovician heavy oil of Tarim Basin supposed that it was formed between 450 Ma to 436 Ma, corresponding to the Late Ordovician–Early Silurian system, and the generated petroleum is likely to migrate into the Middle–Lower Ordovician karst reservoirs to form early oil reservoirs. With tectonic uplift, these oil reservoirs were degraded and reformed to be present heavy oil reservoirs.

Preprint ARTICLE | doi:10.20944/preprints202304.0513.v1

A Transient Productivity Prediction Model for Horizontal Wells Coupled With Oil-Gas Two-Phase Seepage and Wellbore Flow

Wenqi Ke, Wei Luo, Shiyu Miao, Wen Chen, Yaodong Hou

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: horizontal well; capacity prediction; transient model; saturation pressure; two-phase seepage

Online: 18 April 2023 (10:26:46 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202304.0434.v1

Nyrdvomenshor Gem Stones Deposit, Polar Urals, Russia

Evgeniy V. Kislov, Mikhail P. Popov, Firat M. Nurmukhametov, Viktor F. Posokhov, Vladislav V. Vanteev

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: nephrite; diopsidite; rodingite Nyrdvomenshor; uvarovite; chromite; metamorphism; metasomatism

Online: 17 April 2023 (09:48:19 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202304.0035.v1

Effect of Cation Chloride Concentration on the Dissolution Rates of Basaltic Glass and Labradorite at pH 3.6 and 25°C and Applica-Tion to Subsurface Carbon Storage

Kiflom G MESFIN, Domeick WOLFF-BOENISCH, Sigurdur R GISLASON, Eric H OELKERS

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Labradorite; basaltic glass; mineral carbonation; dissolution rates

Online: 4 April 2023 (03:06:05 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202303.0462.v1

Acoustic Emissions in Rock Deformation and Failure: New Insights from Q-Statistical Analysis

Sergio Vinciguerra, Annalisa Greco, Alessandro Pluchino, Andrea Rapisarda, Constantino Tsallis

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Acoustic emissions; q-statistics; rocks fractures

Online: 27 March 2023 (13:30:55 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202303.0312.v1

Ultrahigh-Pressure Mineral Inclusions in a Crustal Granite: Evidence for a Novel Transcrustal Transport Mechanism

Rainer Thomas, Paul Davidson, Adolf Rericha, Ulrich Recknagel

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Stishovit; coesite; diamond; lonsdaleite; supercritical fluid; granite; transcrustal transport

Online: 17 March 2023 (02:04:53 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202302.0204.v1

Interaction of Lherzolite Xenoliths with Basanite is not Isochemical: Evidence from Tumusun Volcano, Baikal Rift Zone

Marina A. Gornova, Vasiliy A. Belyaev, Anas A. Karimov, Alexander B. Perepelov, Sergei I. Dril

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: mantle xenolith; lherzolite; clinopyroxene; basanite; reaction rim; melt-peridotite interaction; trace elements

Online: 13 February 2023 (07:51:23 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202212.0134.v1

Unique Amphibole Bearing Mantle Column Beneath the Lenin-Grad Kimberlite Pipe, West Ukukit field, NE Yakutia.

Igor Victorovich Ashchepkov, Svetlana Anatolievna Babushkina, Nikolai Sergeevich Mevedev, Oleg Borisovich Oleinikov, Denis Sergevich Yudin, Nikolai Semenovich Karmanov

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: kimberlite; garnet; amphibole; monomineral thermobarometry; trace elements; lithospheric mantle

Online: 7 December 2022 (14:24:08 CET)

Show abstract| Download PDF| Supplementary Files| Share

In the subcratonic lithospheric mantle (SCLM) beneath Leningrad pipe (West Ukukit field), Yakutia garnet thermobarometry allows us to identify seven horizons (paleo subduction slab). Microprobe data for Cr-bearing amphiboles >500 grains from mantle xenoliths and concentrates reveal a broad range of compositions changing from Cr- pargasitic hornblendes to pargasites, edinites, kataforites, К-richterites with increasing pressure determined with new amphibole ther-mobarometer constructed by the first author The low pressure (LP) Cr-hornblendes and pargasites compiles the high-temperature branch (90-60 mw/m2) from 3.5 GPa to Moho traced by basaltic cumulates. In the middle part of SCLM edinites mark 35 to 40 mw/m2 geotherms. At high pres-sures kataforites also vary in thermal conditions. Richterites near the lithosphere base trace both low –and high temperature convective branches. The amphiboles reveal divisions into 9 chemical groups. The melts coexistion with amphiboles have concave patters typical for subduction related melts. LP varieties reveal Eu inflection U, Rb, Ba, Sr peaks and deep troughs in HFSE (except Zr), Pb. The pargasites show high U peaks and relativle less HFSE depressions. Encreasing in pressure for edinites, kataforites and richterise are accompanied byrise in U and Zr peak gentling of depressions in Th, Sr, Nb and Hf and less in Nb,Ta, Hf and peak in Zr and also decrease in LREE and REE. Clinopyroxenes and garnets show variable trace element patterns and divisions in groups with the plume and subduction signatures. The contrasting behaviour of Ta and Nb is regulated by the rutile partition coefficients likely for primary eclogites. Subduction and Na and K (siliceous) types of fluids percolated through the mantle with abundant eclogites possibly was accompanied by amphibolization at the different levels through all the mantle column. The plume melts produced hybridism with the mantle metasomatic assembleges which created more smooth trace element patterns in reacted minerals, clinopyroxene. The new version of monomineral amphibole thermobarometry is suggested

Preprint ARTICLE | doi:10.20944/preprints202210.0090.v1

Transformational Geothermal Fluids in the Upper Jurassic Carbonate Reservoir of the South German Molasse Basin

Jochen Schneider, Florian Heine, Michael Heidinger, Martin Rosner

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Environmental isotope analyses; Strontium isotopes; Boron isotopes; Upper Jurassic carbonate aquifer; South German Molasse Basin; Tansformational Fluid Flow; Geothermal

Online: 8 October 2022 (03:17:44 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202209.0149.v1

Comparison of geogases in Cenozoic sedimentary environments

Gabriele M. Berberich, Martin B. Berberich

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: soil gas anomalies; Helium, Radon, CO2; Lower Rhine Embayment (LRE); Meinweg; Roer Valley Rift System (RVRS); Molasse Basin; Bodanrück; Freiburg–Bonndorf–Bodensee Fault Zone (FBBFZ); GeoBio-Interactions

Online: 12 September 2022 (12:47:53 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202209.0074.v1

Metamorphic Ages of the Jurassic Accretionary Complexes in the Kanto Mountains, Central Japan, Determined by K–Ar Dating of Illite: Implications for the Tectonic Relationship Between the Chichibu and Sanbagawa Belts

Lu Zhiqiang, Ichiko Shimizu, Tetsumaru Itaya

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: K–Ar dating; illite crystallinity; Northern Chichibu Belt; Mikabu Greenstones; Sanbagawa (Sambagawa) metamorphism; accretionary complex

Online: 6 September 2022 (02:50:39 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202208.0477.v1

LiDAR and UAV SfM-MVS of Merapi Volcanic Dome And Crater Rim Change from 2012 to 2014

Christopher Gomez, Franck Lavigne, Noviyanti Listyaningrum, Sandy Budi Wibowo, Danang Sri Hadmoko, Wiwit Suryanto, Herlan Darmawan, Balazs Bradak, Rikuto Daikai, Sunardi Sunardi, Yudo Prasetyo, Annisa Joviani Astari, Lukman Lukman, Idea Wening Nurani, Moh. Dede, Indranova Suhendro

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Merapi Volcano; Indonesia; Natural Hazards; Disaster Risk and Point-cloud technology

Online: 29 August 2022 (08:34:39 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202207.0163.v1

A Step-Wise Modelling Approach to Identifying Structural Features That Control Groundwater Flow in a Folded Carbonate Aquifer System

Elisabetta Preziosi, Nicolas Guyennon, Anna Bruna Petrangeli, Emanuele Romano, Cristina Di Salvo

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Carbonate aquifer; groundwater modelling; multilayer aquifer; MODFLOW-NWT formulation; Central Italy

Online: 11 July 2022 (14:19:53 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202206.0273.v1

The Heavy Mineral Map of Australia: Vision and Pilot Project

Patrice De Caritat, Brent I.A. McInnes, Alexander T. Walker, Evgeniy Bastrakov, Stephen M. Rowins, Alexander M. Prent

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: heavy minerals atlas; heavy mineral maps; National Geochemical Survey of Australia; mineral network analysis; geological setting; mineral system; mineral prospectivity; critical minerals; critical elements

Online: 20 June 2022 (11:16:22 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202206.0184.v1

Effect of Methane Cracking on Carbon Isotope Reversal and the Production of Over Mature Shale Gas

Jingkui Mi, Wei Wu, Di Zhu, Ziqi Feng

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Over mature shale gas; Magnitude of isotope reversal; CH4 polymerization; CH4 cracking; Mud gas

Online: 13 June 2022 (10:41:14 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202203.0045.v1

Morphotectonic and Petrological Characteristics of Permo-Triassic Traps of Siberia

Victor Sharapov, Yury Perepechko, Anna Mikheeva, Igor Ashchepkov, Viktoria Lyamina, Anatoly Boguslavsky

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Siberian traps; petrology; morphotectonics; GIS technologies

Online: 2 March 2022 (10:58:52 CET)

Show abstract| Download PDF| Share

Preprint REVIEW | doi:10.20944/preprints202202.0272.v1

Indicator Minerals, Pathfinder Elements, and Portable Analytical Instruments in Mineral Exploration Studies

Balaram V., Sawant S. S.

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Portable instruments; indicator minerals; pathfinder elements; core scanners; pXRF; pXRD; pNIR-SWIR spectrometer; μRaman spectrometer; LIBS; mineral exploration; on-site analysis

Online: 22 February 2022 (11:24:35 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202112.0155.v2

Serpentinization and Weathering of Peridotite: A Study on the Mineralogical and Geochemical Evolution of the Sta. Cruz Nickel Laterite Deposit, Zambales, Philippines

Karmina Aquino, Carlo Arcilla, Christian Schardt, Carmela Tupaz

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Nickel laterites; laterization; serpentinization; weathering; goethite ageing

Online: 27 January 2022 (12:43:44 CET)

Show abstract| Download PDF| Share

While there are extensive studies on the mineralogy and geochemistry of laterites worldwide, the temporal and spatial mineralogical development of a typical nickel laterite profile is still poorly constrained. In this study, we present a detailed mineralogical and geochemical characterization of samples systematically collected from a nickel laterite profile at the Sta. Cruz nickel laterite deposit, Zambales, Philippines, to describe the temporal and spatial development of the laterite profile. Wavelength-dispersive X-ray fluorescence spectroscopy (WDSXRF), mass balance-element mobility calculations, transmitted and reflected light microscopy, and previously reported results from coupled X-ray diffraction (XRD) and Rietveld refinement analyses, reveal that the laterite profile investigated is composed of two main horizons: the limonite and saprolite zones, separated by a thin transitional zone. The main zones are further subdivided into subzones based primarily on the mineral assemblage and major element chemistry: upper limonite, lower limonite, transitional zone, upper saprolite, and lower saprolite. Late-stage Ni-rich serpentine veins were observed cutting the upper and lower saprolite subzones. Investigation of the structure of goethite within the limonite zone via Rietveld refinement show that the crystallinity of goethite decreases with increasing Ni content and increasing crystallite size. This suggests that upwards through the limonite zone, as goethite ages, its crystallinity increases which possibly results in the removal of Ni from its crystal structure and eventual remobilization to the lower laterite zones. We propose a genetic model of the formation of the Sta. Cruz laterite consisting of four stages: (1) early-stage alteration, (2) continued serpentinization and volume expansion, (3) late stage serpentinization, dissolution, and incipient oxide formation, and (4) goethite ageing and Ni-rich serpentine vein formation. Overall, our results suggest that serpentinization is an important aspect of Ni laterite formation, both before and after the emplacement of the peridotite protolith.

Preprint ARTICLE | doi:10.20944/preprints202201.0331.v1

Geochemical Association Rules of Elements Mined using Clustered Events of Spatial Auto-correlation: A Case Study in the Chahanwusu River Area, Qinghai Province, China

Baoyi Zhang, Zhengwen Jiang, Yiru Chen, Nanwei Cheng, Umair Khan, Jiqiu Deng

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Concentration field; Spatial auto-correlation; Association rules; Apriori algorithm; Element co-occurrence

Online: 21 January 2022 (13:42:44 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202201.0125.v1

Precipitation of Minerals from Water-Rich Fumarolic Gas Using a Flow-through Benchtop Installation

Michael Zelenski, Yuri Taran, Alina Korneeva, Fedor Sandalov, Nikolai Nekrylov

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: benchtop fumarole; flow-through reactor; sublimates; volatile metal species; simulation

Online: 10 January 2022 (15:19:35 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202201.0059.v1

Multimodal Carbonates: Distribution of Oil Saturation in the Microporous Rock Regions

Tadeusz Patzek, Ahmed Saad, Ahmed Hassan

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: microporous carbonates; multimodal porosity; primary drainage; capillary invasion; mixed wettability

Online: 6 January 2022 (10:03:11 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202112.0444.v1

Unique Amphibole Bearing Mantle Column Beneath the Leningrad Kimberlite Pipe, West Ukukit Field, NE Yakutia

Igor Victorovich Ashchepkov, Svetlana Anatolievna Babushkina, Nikolai Sergeevich Mevedev, Oleg Borisovich Oleinikov

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: kimberlite; garnet; amphibole; monomineral thermobarometry; trace elements; lithospheric mantle

Online: 28 December 2021 (10:55:15 CET)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202112.0184.v2

Quantitative Geochemical Prediction from Spectral Measurements and its Application to Spatially Dispersed Spectral Data

Andrew Rodger, Carsten Laukamp

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Spectral; Geochemistry; Random Forest; Regression; Whole Rock; MIR; SWIR; VNIR; NMF

Online: 21 December 2021 (12:35:45 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202112.0184.v1

Quantitative Geochemical Prediction from Spectral Measurements and its Application to Spatially Dispersed Spectral Data

Andrew Rodger, Carsten Laukamp

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Spectral; Geochemistry; Random Forest, Regression, Whole Rock, MIR, SWIR, VNIR, NMF

Online: 10 December 2021 (13:28:12 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202112.0155.v1

Linking Serpentinization and Weathering of Peridotite: A Study on the Mineralogical and Geochemical Evolution of the Sta. Cruz Nickel Laterite Deposit, Zambales, Philippines

Karmina Aquino, Carlo Arcilla, Christian Schardt, Carmela Tupaz

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Nickel laterites; laterization; serpentinization; weathering; goethite ageing

Online: 9 December 2021 (14:40:08 CET)

Show abstract| Download PDF| Share

Working Paper ARTICLE

U-Pb Age and Hf Isotope Systematics of Zircon from Eclogite Xenoliths in Devonian Kimberlites: The Neoarchaean Roots of the Central Belarus Suture Zone

Leonid Shumlyanskyy, Stepan Tsymbal, Monika A. Kusiak, Simon A. Wilde, Alexander A. Nemchin, Iryna Tarasko, Liudmyla Shumlianska, Mandy Hofmann

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Eclogite xenolith; kimberlite; zircon; U-Pb age; Hf isotopes; Ukrainian Shield; Devonian; East European Platform.

Online: 5 October 2021 (15:43:55 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202110.0008.v1

Low Calcium Cave Dripwaters in a High CO₂ Environment: Formation and Development of Corrosion Cups in Postojna Cave, Slovenia

Lovel Kukuljan, Franci Gabrovšek, Vanessa E. Johnston

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: speleothem corrosion; undersaturated drip spots; carbon dioxide; cave microclimate; karst water geochemistry

Online: 1 October 2021 (11:35:01 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202108.0231.v1

Thermobarometry of Diamond Inclusions: Evidence Mantle Evolution beneath Siberian Craton and Archean Cratons Worldwide.

Igor Ashchepkov, Alla Logvinova, Zdislav Spetsius, Hilary Downes

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: diamond inclusions; thermobarometry; pyrope; clinopyroxenes; chromite; eclogites; peridotites

Online: 10 August 2021 (12:19:55 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Thermobarometric calculations for mineral inclusions in diamonds provide a systematic comparison of PTXFO2 conditions for different cratons worldwide, using a database of 4440 mineral EPMA analyses. Beneath all cratons, the cold branch of the mantle geotherm (35-32 mWm−2) relates to the sub-Ca garnets and rarely omphacitic diamond inclusions, referring to major continental growth events in Archean. High-temperature plume-related geotherms are common in Proterozoic kimberlites such as Premier, Mesozoic – Roberts Victor etc. and are common in Slave and Siberian cratons. In mobile belts: Limpopo, Magondi, Ural Ural, Khapchan belts and in the marginal parts of cratons like Kimberly Australia pyroxenitic and eclogitic pyroxenes and garnets prevail. The pyropes in the mobile belts are more Fe- and Ca-rich, in central parts of cratons, the peridotitic associations with sub- Ca pyropes prevail. The accretionary complexes like Khapchan and Magondi belts a thick eclogite-pyroxenite lens is highly diamondiferous. Comparison by minerals shows that the PT estimates for clinopyroxenes and orthopyroxene from peridotites and eclogites are representing mainly the middle part of the sub-lithospheric mantle while garnets gives more high-pressure estimates. refer to eclogites and reflect the processes of the differentiation during migration of partial melts. This produces the trends of joint decreasing Mg’ and pressures. The PT for the chromites reflect conditions just above the lithosphere-asthenosphere boundary and mainly were formed due to interaction with the hydrous plume protokimberlite melts. Archean diamond inclusions from Wawa province Canada are represented by Ca-enrich pyropes giving low-temperature conditions. Inclusions from younger kimberlites in Superior and Slave (and Siberian and East European ) cratons show complex high-temperature geotherms due to plumes influence. Peridotite garnets beneath the Amazonian craton indicate complex layering in the lithosphere base and a pyroxene layer in the middle part of SCLM. Diamond inclusions from the Kimberley craton of Australia show the greatest variations in the temperatures and composition.

Working Paper ARTICLE

Characteristics and Control Mechanism of Low Resistivity Contrast Oil Pays in Chang 8 Tight Sandstone Reservoir of Longdong West Area, Ordos Basin

Ze Bai, Maojin Tan, Yujiang Shi, Gaoren Li, Simon Clark

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Tight sandstone; Low resistivity contrast oil pay; Reservoir Characteristic; Control mechanism; Longdong West area.

Online: 15 January 2021 (13:02:42 CET)

Show abstract| Download PDF| Share

The log interpretation and evaluation of Chang 8 tight sandstone reservoir in Longdong West area, Ordos Basin, is facing great challenges due to the existence of low resistivity contrast oil pays. To better guide the exploration of oil resources in this area, the characteristics and control mechanism of low resistivity contrast oil pays were studied in this research. Firstly, according to the relative value of apparent resistivity increase rate of the target formation, the reservoir was divided into two types: low resistivity contrast oil pay (LRCP) and high resistivity oil pay (HRP). Then, the reservoir characteristics were studied by comparing and analyzing the experimental data, formation water data and logging data collected from the two reservoir types. On this basis, the control mechanism of LRCP was studied and summarized into reservoir micro factors and regional macro factors, respectively. It is found that the reservoir rock composition between LRCP and HRP is basically the same. Compared with HRP reservoir, the average porosity and permeability of LRCP reservoir are relatively better, but the pore structure is relatively poorer because of the high content of micro pores. When the filling pressure of crude oil is sufficient enough, the high oil saturation can be formed in LRCP reservoir. The high irreducible water saturation and high formation water salinity are the main micro factors reduced the reservoir resistivity. Besides, the difference of hydrocarbon expulsion capacity of source rock and the regional difference of formation water salinity are the macro factors influenced the distribution of LRCP and HRP from vertical and horizontal of the region. The formation of LRCP is controlled by the comprehensive influence of reservoir micro factors and regional macro factors. And the comprehensive consideration of the influence of micro factors and macro factors on LRCP is suggested during the log interpretation and evaluation.

Preprint ARTICLE | doi:10.20944/preprints202101.0154.v1

Thermal Annealing and Phase Transformation of Serpentine-like Garnierite

Arun Kumar, Michele Cassetta, Marco Giarola, Marco Zanatta, Monique Le Guen, Gian Domenico Sorarù, Gino Mariotto

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Garnierite, Phase transformation, TGA/DSC, XRD, micro Raman spectroscopy

Online: 8 January 2021 (12:59:34 CET)

Show abstract| Download PDF| Share

Preprint REVIEW | doi:10.20944/preprints202009.0598.v1

Geology, Geochemistry and Geochronology of the Gold Mineralization Hosting Syenite, Tulu Kapi, Western Ethiopia: A Review

Temesgen Oljira, Geleta Warkisa

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Geology; Geochemistry; Geochronology; Gold mineralization; Syenite; Tulu Kapi

Online: 25 September 2020 (08:28:22 CEST)

Show abstract| Download PDF| Share

The Neoproterozoic (900-600 Ma) Arabian Nubian Shield is an example of Precambrian plate tectonics and arc accretion. The Western Ethiopian Shield (the southern extension of ANS) is geo-tectonically a characteristic of lower grades of Metavolcano-sedimentary sequences of ANS intruded by associated felsic granitoid and mafic bodies and at the same time it is contained of gneisses rocks of the MB. The Gold mineralization and alterations initiating throughout the Tulu Kapi syenite are in the form of in enechelon vein arrays and related structures, which are controlled by conjugate shear zones in the syenite and steep N-S striking structures. The earliest recorded deformation and alterations revealed the syenite albitization which is the one hosting for gold mineralization and it has been widely overprinted by multistage hydrothermal system that appears to have been controlled mainly by veins, crackle zones, fractures and minor breccia zones. Primary gold mineralization displays spatial and temporal relationship with Tulu Kapi syenite and the Kapi gabbro, both of which host gold mineralization, are 738.3±2.6 Ma and 699.5±2.7 Ma period, respectively, in a volcanic arc subduction syn-collisional tectonic setting by the fractionation of underplated, LREE-enriched basaltic magma with substantial crustal input to possible crustal melting. The underplated basaltic magma had been sourced from LREE-enriched mantle by subduction of sediment laden crustal slabs at a subduction zone. Fractional crystallization involved formation of Ca-rich plagioclase, which continually reacted with hydrothermal fluids to more fractionated Na-rich plagioclase, forming the gold mineralization hosting altered (albitized) syenites. The Pan-African orogeny, and associated regional metamorphism and magmatism, generated large-scale movements of gold and base metal-bearing fluids in the crust, channelized along complex fractures into regional NE-SW foliation in Ethiopia (e.g., western Ethiopia). However, these gold-rich alkalic magmas are so modified by crustal processes that evidence of their genetic relationship with gold become obscured. The primary ore mineral assemblage of quartz veins and veinlets, and associated mineralised syenite within Tulu Kapi area consists of pyrite, galena, chalcopyrite, hematite, and gold. The major and trace element composition of ore- forming fluids from the mineralised vein, barren and granitic intrusion is still largely unknown, yet could provide important and more direct evidence for the fluid source(s). This is vital in establishing a direct genetic link between syenite and other granitoid intrusion, and gold mineralization.

Preprint ARTICLE | doi:10.20944/preprints202009.0135.v1

Localisation of Ancient Migration Pathways inside a Fractured Metamorphic Hydrocarbon Reservoir in South-East Hungary

Tivadar M. Tóth, László Molnár, Sándor Körmös, Nóra Czirbus, Félix Schubert

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Pannonian Basin; fractured reservoir; well-log; DFN modelling; fluid inclusion chemostratigraphy

Online: 5 September 2020 (09:31:16 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202008.0314.v2

The Early Silurian Gabbro in the Eastern Kunlun Orogenic Belt, Northeast Tibet: Constraints on the Proto-Tethyan Ocean Closure

Wenxiao Zhou, Haiquan Li, Feng Chang, Xinbiao Lv

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: northeast Tibet; Proto-Tethyan Ocean; early Silurian; eastern Kunlun Orogenic Belt; gabbro; zircon U–Pb dating

Online: 31 August 2020 (09:57:20 CEST)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202008.0314.v1

The Early Silurian Gabbro in the Eastern Kunlun Orogenic Belt, Northeast Tibet: Constraints on the Proto-Tethyan Ocean Closure

Wenxiao Zhou, Haiquan Li, Feng Chang, Xinbiao Lv

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: northeast Tibet; Proto-Tethyan ocean; early silurian; eastern Kunlun orogenic belt; gabbro; zircons U-Pb age

Online: 14 August 2020 (09:02:26 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202007.0442.v1

Genesis of Two Types of Carbonaceous Material and Associated with Gold Mineralization in the Bumo Deposit, Hainan Province, South China

Zhengpeng Ding, Teng Deng, Deru Xu, Zenghua Li, Shaohao Zou, Lirong Li, Ke Xu, Yan Hai

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Carbonaceous material; Raman spectra; gold deposit; Hainan; Organic matter

Online: 19 July 2020 (20:52:43 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Carbonaceous material (CM) is common in meta-sediments and is generally interpreted to be intimately associated with gold mineralization. For the Bumo deposit in Hainan Province, South China, CM is mainly hosted by greenschist facies- to amphibolite-facies metamophic rocks of the Paleo- to Mesoproterozoic Baoban Group and by auriferous veins and is used as an important gold prospecting indicator. However, the genesis of CM and the relationship with gold mineralization are still not clear. Field work and thin section observation indicates that two types of CM occur, i.e., layered and veinlet. Layered CM, up to meters thick, prevails in the deposit. More importantly, Au-bearing sulfides are commonly distributed along the boundary between the quartz veins and layered CM. In contrast, veinlet CM, co-precipitated with gold and sulfides, has the thickness of micro- to centi- meters, and these thin veins occur in quartz veins and hydrothermally altered rocks. Scanning Electron Microscope (SEM) analysis indicates that layered CM has a stringy shape and laminate structure, while veinlet CM occurs as isometric particles. Raman carbonaceous material geothermometer indicates that layered CM with high maturity is formed at elevated temperatures of 400 – 550°C, consistent with X-ray diffraction (XRD) analysis. In contrast, veinlet CM with low maturity is formed at 200 – 350°C, generally consistent with gold mineralization. In addition, layered CM has δ13C values ranging from -30 to -20%, demonstrating a biogenic origin. Consequently, it is interpreted that layered CM is formed by a pre-ore metamorphic event during Caledonian, and its reducing nature promotes gold precipitation via destabilization of aqueous Au bisulfide complexes or facilitating sulfidation. Veinlet CM is hydrothermal origin, and its precipitation modified the chemical conditions of ore fluids, leading to the destabilization of Au complexes and thus favorable for mineralization.

Preprint ARTICLE | doi:10.20944/preprints202007.0348.v1

Mantle-derived Corundum-bearing Felsic Dykes May Survive Only within the Lower (refractory/inert) Crust: Evidence from Zircon Geochemistry and Geochronology (Ivrea-Verbano Zone, Southern Alps, Italy)

Mattia Bonazzi, Antonio Langone, Simone Tumiati, Edoardo Dellarole, Maurizio Mazzucchelli, Tommaso Giovanardi, Alberto Zanetti

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: LA-ICP-MS dating; zircon; felsic dykes; corundum megacryst; magmatic differentiation

Online: 16 July 2020 (12:49:25 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Working Paper ARTICLE

Abiotic Hydrocarbons Discharge from A Felsic Rock-Hosted Hydrothermal System

Xue-Gang Chen, Mark Schmidt, Shuhei Ono, Chen-Tung Arthur Chen, Ying Ye

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: abiotic; hydrothermal; methane; clumped isotope

Online: 27 April 2020 (03:44:32 CEST)

Show abstract| Download PDF| Supplementary Files| Share

Preprint ARTICLE | doi:10.20944/preprints202002.0414.v1

Sources of Salinization of Groundwater in the Lower Yarmouk Gorge, East of the River Jordan

Peter Möller, Marco De Lucia, Eliahu Rosenthal, Nimrod Inbar, Elias Salameh, Fabien Magri, Christian Siebert

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Hauran Plateau; Golan Heights; Ajloun Dome; Yarmouk Basin; Salinization; Mixing of water types; Statistical Modelling

Online: 28 February 2020 (01:49:06 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints202001.0111.v1

Mineralogical Characterization of Slags from Oiola Site (Biscay) to Assess the Development in Bloomery Iron Smelting Technology from the Roman Period to the Early Middle Ages

Haizea Portillo-Blanco, Maria Cruz Zuluaga, Luis Angel Ortega, Ainhoa Alonso-Olazabal, Juanjo Cepeda-Ocampo, Ana Martínez Salcedo

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: smelting slags; multianalytical study; furnace operating conditions; Roman Period; Early Middle Age; North Spain

Online: 11 January 2020 (14:24:35 CET)

Show abstract| Download PDF| Share

Preprint ARTICLE | doi:10.20944/preprints201912.0334.v1

Physical Scaling Predicts Oil Production Rates and Ultimate Recovery from All Horizontal Wells in the Bakken Shale

Wardana Saputra, Wissem Kirati, Tadeusz Patzek

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: scaling EUR; unconventional; refracturing; USGS; EIA

Online: 25 December 2019 (03:41:27 CET)

Show abstract| Download PDF| Share

A recent study by the Wall Street Journal reveals that the hydrofractured horizontal wells in shales have been producing less than forecasted by the industry with the empirical hyperbolic decline curve analysis (DCA). As an alternative to DCA, we introduce a simple, fast and accurate method of estimating ultimate recovery (EUR) in oil shales. We adopt a physics-based scaling approach to analyze oil rates and ultimate recovery from 14,888 active horizontal oil wells in the Bakken shale. To predict EUR, we collapse production records from individual horizontal shale oil wells onto two segments of a master curve: (1) We find that cumulative oil production from 4,845 wells is still growing linearly with the square root of time; and (2) 6,401 wells are already in exponential decline after approximately seven years on production. In addition, 2,363 wells have discontinuous production records, because of refracturing or changes in downhole flowing pressure, and are matched with a linear combination of scaling curves superposed in time. The remaining 1,279 new wells with less than 12 months on production have too few production records to allow for robust matches. These wells are scaled with the slopes of other comparable wells in the square-root-of-time flow regime. In the end, we predict that total ultimate recovery from all existing horizontal wells in Bakken will be some 4.5 billion barrels of oil. We also find that wells completed in the Middle Bakken formation, in general, produce more oil than those completed in the Upper Three Forks formation. The newly completed longer wells with larger hydrofractures have higher initial production rates, but they decline faster and have EURs similar to the cheaper old wells. There is little correlation among EUR, lateral length, and the number and size of hydrofractures. Therefore, technology may not help much in boosting production of new wells completed in the poor immature areas along the edges of the Williston Basin. Operators and policy-makers may use our findings to optimize the possible futures of the Bakken shale and other plays. More importantly, petroleum industry may adopt our physics-based method as an alternative to the overly-optimistic hyperbolic DCA that yields an "illusory picture" of shale oil resources.

Preprint ARTICLE | doi:10.20944/preprints201910.0298.v1

Artisanal and Small-Scale Gold Mining in Syanyonja, Busia Gold District, South Eastern Uganda: Impacts on the Mining Population and the Environment

Timothy Omara, Shakilah Karungi, Stephen Ssebulime, Kibet Mohamed Kiplagat, Ocident Bongomin, Remish Ogwang, Solomon Akaganyira

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: artisanal gold mining; Busia; environmental impacts; mercury pollution; Namukombe stream; panning; Syanyonja; Uganda

Online: 27 October 2019 (10:09:44 CET)

Show abstract| Download PDF| Share

Syanyonja village in the gold district of Busia, South East of the Republic of Uganda contain geologically epigenetic gold quartz vein deposits in carbonate-altered mafic metavolcanic rocks, deposited as quartz reefs in mineralized shear zones. In supracrustal rocks, alluvial gold is obtained from weathered auriferous quartz veins, which are of late orogenic granitic activity. The Syanyonja gold deposits have long been subjected to artisanal and small-scale gold mining (ASGM) by the locals for livelihood. This study determined the amount of mercury discharged with tailings into Namukombe stream, a major water body in Syanyonja village and investigated the impacts of ASGM on the mining population and the environment. Quantitation of mercury discharged with tailings was done by mass balance method. Field survey at the mining sites was done followed by administration of questionnaires to 50 stampeders in the village. The study indicates that about 8% of mercury mixed with auriferous materials are lost in tailings, accounting for an annual mercury release of about 1.757 kg into the environment. Socio-demographic results indicate that the majority of the mining population (64%) are male and ASGM have left health and environmental footprints, which directly or indirectly affects the population. The most common health problems among miners are malaria (36%) and abdominal pain (20%). The standard of living of the miners are evidently low, and most mines are characterized by school dropouts, prostitutes and thieves. Mining sites have deplorably poor hygiene, with evident burning of amalgams to recover gold. ASGM have been accompanied by wanton mowing down of vegetation, land degradation as well as mercuric pollution of water, air, land and aquatic ecosystems. It is suggested that the Ugandan government should re-enforce committees to follow up on ASGM activities, train artisans on sustainable gold mining using borax, magnets, sluice boxes as well as take up farming actively as an alternative.

Preprint ARTICLE | doi:10.20944/preprints201910.0237.v1

Geochemical Anomaly Separation by Statistical and Fractal Methods in the Sehezar Valley of Tonekabon – Northern Iran

Meysam Yazdani, Firouz Alinia

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Sehezar; geochemical anomaly separation; threshold; factor analysis; cluster analysis; concentration - area fractal

Online: 20 October 2019 (16:53:36 CEST)

Show abstract| Download PDF| Share

Sehezar area is located in southern Tonokabon in Mazandaran province, north of Iran, near the Tarom – Hashdtjin belt. The existence of granitoid masses in the region can be important in terms of the potential of mineralization. Geochemical anomaly separation from the background is one of the important steps in mineral exploration. In the past decades, geochemical anomalies have been identified by means of various methods. Some of these separation methods include: statistical analysis methods (like univariate, bivariate, multivariate statistics), spatial statistical methods and fractal and multi-fractal methods. To identify the anomalous area, 71 stream sediment samples were collected from the area and analyzed by the ICP-MS method, and then interpreted. Initially, data were normalized and afterwards, univariate analysis (threshold limit and screening (P.N) methods) was used, in which results of the probable and definite anomaly of the threshold method were confirmed by the P.N screening method. Finally, the maps of the anomal zones were drawn. Then, bivariate analysis (Pearson correlation coefficients) and multivariate analysis on normal data were performed on SPSS software, in which factor analysis and cluster analysis were used for multivariate analysis. As a result of using the factor analysis method, six factors were identified and factor maps were drawn by the Surfer software. Also, by using cluster analysis, the variables were divided into two groups. In order for a better separation of the geochemical anomaly from the background, in addition to the threshold method, the Concentration - Area fractal method was used. Here, the fractal geometry using full-logarithmic graphs of the Concentration - Area obtained is capable of separating the stairs of different sections (background, threshold, and anomaly) with respect to the angle coefficient of the Concentration - Area plot. Then, in conclusion, results of these methods were compared and investigated, and finally, the anomalies area maps of the Au, Ag, Cu, Fe, W elements were drawn by Concentration - Area fractal and threshold methods and anomalous zones were introduced.

Preprint ARTICLE | doi:10.20944/preprints201910.0079.v1

Sol Hamed Ophiolitic Complex, Southern Eastern Desert, Egypt: Petrological, Economic Potentiality and Structural Implications

Tarek Sedki, Shehata Ali, Haroun A. Mohamed, Rafat Zaki

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Sol Hamed; supra-subduction zone; serpentinites; magnesite mineralization; gold deposits

Online: 8 October 2019 (06:33:39 CEST)

Show abstract| Download PDF| Share

The Sol Hamed (SH) area is a part of the Arabian-Nubian Shield (ANS) ophiolites occurred within Onib-Sol Hamed suture zone in the southern Eastern Desert of Egypt. The ophiolitic assemblages in this area are represented by serpentinite, metagabbro and arc assemblages represented by metavolcanics. They later intruded by gabbroes and granites. Geochemically, the compatible trace elements (Cr=2426–2709 ppm, Ni=1657–2377 ppm and Co=117–167 ppm) enrichment in SH serpentinites indicate derivation from a depleted mantle peridotite source. They show affinity to the typical metamorphic peridotites. The normative compositions reflect harzburgitic mantle source. Their Al2O3 contents (0.05–1.02 wt. %) are akin to oceanic and active margin peridotites and Pan-African serpentinites. The Cr and TiO2 contents indicate supra-subduction zone (SSZ) environment. Their Al2O3/SiO2 and MgO/SiO2 ratios support the SSZ affinity and are similar to ANS peridotites with fore-arc setting. Moreover, their Al2O3 and CaO depletion is typical of fore-arc peridotites. Structurally, the area represents four deformational events can be well-known in the Neoproterozoic rocks (D1, D2, D3 and D4); D1: E–W thrust faults and related E–W (F1) folds; D2: NW–SE thrust faults and related NW–SE (F2) folds were formed; D3: conjugate NNW-trending sinistral and NNE-trending dextral transpression, as well as N–trending tight folds (F3) and D4: is E–W dextral strike-slip and dip-slip normal faults striking NNW–SSE to N–S and E–W may be related to Red Sea rifting. There are major three fault sets affected the area. The first set trend mainly NE-SW and is manifested in the volcanic-sedimentary assemblage and Gabal SH and have important role in mineralization. The second set trend E-W affecting all the basement rocks and disturbs the first fault set. The third set trend N-S affected all the rock units. Magnesite mineralization in SH serpentinites is cryptocrystalline formed due to hydrothermal alteration of the serpentinite host rocks. It is occur as snow-white veins and stock-works. These characteristics are typical of Kraubath type magnesite deposits. Gold mineralization is confined to malachite-bearing quartz veins, smoky quartz veins and alteration zones. Malachite-bearing quartz veins trending NW-SE cut through gabbroic rocks and exhibit mylonitic structure. They are fractured containing malachite and disseminated sulfide minerals. Smoky quartz veins trending NE-SW with SE steeply dipping intrude the meta-andesite. They are intensively sheared containing iron oxides in the fissures. The gold grades increase with arsenopyrite occurrences. On the other hand, the barren quartz veins are nearly vertical with E-W directions. Alteration zones with NW-SE trend and nearly vertical dip intrude metagabbros and metavolcanics. Hematite, limonite, goethite and fresh pyrite characterize these zones. They occur mainly neighboring the auriferous quartz veins.

Preprint ARTICLE | doi:10.20944/preprints201907.0327.v2

Implications of Hf Isotopes for the Evolution of the Mantle Source of Magmas Associated with the Giant El Teniente Cu-Mo Megabreccia Deposit, Central Chile

Charles R. Stern, Kwan-Nang Pang, Hao-Yang Lee, M. Alexandra Skewes, Alejandra Arévalo

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: El Teniente Cu-Mo deposit; Andean magmatism; subduction erosion; mantle source region contamination; hafnium isotopes

Online: 8 September 2019 (17:22:48 CEST)

Show abstract| Download PDF| Share

Environmental and Earth Sciences