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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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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)

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Preprint ARTICLE | doi:10.20944/preprints201907.0327.v1

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: 29 July 2019 (04:20:12 CEST)

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Working Paper ARTICLE

Pyrochlore-Group Minerals in the Granite-Hosted Katugin Rare-Metal Deposit, Transbaikalia, Russia

Anastasiya E. Starikova, Ekaterina P. Bazarova, Valentina B. Savelieva, Eugene V. Sklyarov, Elena A. Khromova, Sergei V. Kanakin

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: pyrochlore-group minerals; fluornatropyrochlore; alkaline granites; Katugin rare-metal deposit; East Transbaikalia

Online: 30 June 2019 (11:53:45 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201906.0170.v1

Development of Geopolymers Formulations Based on Low-Grade Kaolins as a Potential Construction Material

Cristiana Costa, Sara Fernandes, Ana Velosa, Fernando Rocha

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: geopolymers; kaolins; diatomite; applications

Online: 18 June 2019 (08:27:14 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201906.0020.v1

Using rare earth elements (REE) to study the origin of ore-fluids associated with granite intrusions

Xue-Ming Yang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: REE distribution pattern; REE fluid-melt partition coefficient; granite; intrusion-related gold system; porphyry copper (gold) system

Online: 3 June 2019 (12:16:38 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201906.0011.v1

Influence of the Rift Molango over the mineralization of platinum group elements and light rare earths into a sedimentary exhalative ore deposit

Edgar A. Cardenas-Reyes, Eleazar Salinas-Rodríguez, Juan Hernández-Ávila, Ventura Rodríguez-Lugo, Ma. Pilar Gutierrez-Amador, Edmundo Roldan-Contreras, Eduardo Cerecedo-Sáenz

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Platinum; Light Rare Earths Elements; Sedimentary ore deposit: SEDEX

Online: 3 June 2019 (09:12:09 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201903.0078.v1

Microbial Simulation Experiment on Enhancing Coalbed Methane Production

Chen Hao, Qin Yong, Zhou Shangwen, Wang Hongyan, Chen Zhenhong, LI Guizhong, Deng Ze, Cheng Lei

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Coalbed Methane(CBM); Methanogens; Biogenic Gas; CBM Production Enhancement

Online: 6 March 2019 (11:40:20 CET)

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Preprint ARTICLE | doi:10.20944/preprints201902.0202.v1

Precipitation of CaCO3 Polymorphs from Aqueous Solutions: The Role of pH and Sulphate Groups

Iris Cuesta Mayorga, José Manuel Astilleros, Lurdes Fernández-Díaz

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: CaCO3 polymorphs; sulphate; ageing process; aragonite; gypsum

Online: 21 February 2019 (10:45:12 CET)

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Preprint ARTICLE | doi:10.20944/preprints201901.0027.v1

Chemostratigraphy of the Upper Jurassic (Oxfordian) Smackover Formation for Little Cedar Creek and Brooklyn Fields, Alabama

Rian Engle, Lance D. Yarbrough, Greg Easson

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: x-ray fluorescence, paleo-depositional environments; porosity correlation

Online: 3 January 2019 (13:54:22 CET)

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Preprint ARTICLE | doi:10.20944/preprints201812.0038.v1

Speleothem Stable Isotope Records from Eastern Europe & Turkey

Zoltán Kern, Attila Demény, István Gábor Hatvani

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Carpathians; Balkan peninsula; holocene; hydroclimate; cryogenic cave carbonate; carbon; oxygen

Online: 4 December 2018 (02:46:38 CET)

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Preprint ARTICLE | doi:10.20944/preprints201811.0192.v1

A Combined Geochemical and Fluid Inclusion Study of the Hongyan Cu-Polymetallic Deposit in the Eastern Hegenshan-Heihe Suture Zone, NE China: Implications for Petrogenesis, Tectonic Setting and Mineralization

Chen Mao, Xinbiao Lü, Chen Chao

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Hegenshan-Heihe suture zone; Permian A-type granite; granite petrogenesis; Hongyan Cu-polymetallic deposit; ore-forming fluids; post-collisional slab break-off

Online: 8 November 2018 (09:45:45 CET)

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Preprint ARTICLE | doi:10.20944/preprints201810.0648.v1

Zircon Xenocrysts from Cenozoic Alkaline Basalts of the Ratanakiri Volcanic Province (Cambodia), Southeast Asia—Trace Element Geochemistry, O-Hf Isotopic Composition, U-Pb and (U-Th)/He Geochronology—Revelations into the Underlying Lithospheric Mantle

Paula C. Piilonen, F. Lin Sutherland, Martin Danišík, Glenn Poirier, John W. Valley, Ralph Ralph

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: zircon; xenocryst; alkali basalt; Ratanakiri Volcanic Province; trace elements; O- and Hf-isotopes; U-Pb; (U-Th)/He

Online: 29 October 2018 (04:17:53 CET)

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Preprint ARTICLE | doi:10.3390/sci1010002

Correlation between the Fluctuations in Worldwide Seismicity and Atmospheric Carbon Pollution

Alberto Carpinteri, Gianni Niccolini

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: atmospheric evolution; seismicity; low-energy nuclear reactions; carbon pollution; time series analysis

Online: 28 September 2018 (00:00:00 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201809.0551.v1

Mineralogical and Geochemical Constraints on the Origin and Late-Stage Crystallization History of the Breivikbotn Silicocarbonatite, Seiland Igneous Province in Northern Norway: Prerequisites for Zeolite Deposits in Carbonatite Complexes

Dmitry Zozulya, Kåre Kullerud, Erling Ravna, Yevgeny Savchenko, Ekaterina Selivanova, Marina Timofeeva

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: : silicocarbonatite; melteigite; calcite; nepheline; zeolite group minerals; garnet; crystal fractionation; Breivikbotn; Northern Norway

Online: 27 September 2018 (17:37:30 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201809.0510.v1

Vanadium mineralization in the Kola region, Fennoscandian Shield

Alena Kompanchenko, Anatoly Voloshin, Victor Balagansky

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: vanadium mineralization, mineralogy, Paleoproterozoic, Kola region, Arctic zone, Fennoscandian Shield

Online: 26 September 2018 (13:29:00 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201809.0190.v1

A Further Investigation of NH₄⁺ Removal Mechanisms by Using Natural and Synthetic Zeolites in Different Concentrations and Temperatures

Huei-Fen Chen, Yi-Jun Lin, Bo-Hong Chen, Iizuka Yoshiyuki, Sofia Ya-Hsuan Liou, Rong-Tan Huang

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: zeolite; ion-exchange; adsorption; ammonium; Si/Al; temperature

Online: 11 September 2018 (08:50:29 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201809.0151.v1

Precious Metal Enrichment at the Myra Falls VMS Deposit, British Columbia, Canada

Daniel Marshall, Carol-Anne Nicol, Robert Greene, Rick Sawyer, Armond Stansell, Ross Easterbrook

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: VMS deposits; gold; fluid inclusions

Online: 10 September 2018 (05:53:04 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201808.0316.v1

Prediction of Holocene Mercury Accumulation Trends by Combining Palynological and Geochemical Records of Lake Sediments (Black Forest, Germany)

Martin Schütze, Gegeensuvd Tserendorj, Marta Pérez-Rodríguez, Manfred Rösch, Harald Biester

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Mercury accumulation, Lake sediment, Holocene, Landscape development

Online: 17 August 2018 (16:04:26 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201808.0310.v1

New Data on Copper and Silver Ore-Occurrence Sigurd in West-Spitsbergen Island, Svalbard archipelago

Alexandr Evdokimov, Alexandr Sirotkin, Gusel Korobova

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Svalbard, Sigurd, copper, silver, gold, geochemistry

Online: 17 August 2018 (13:05:11 CEST)

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Preprint COMMUNICATION | doi:10.20944/preprints201806.0441.v2

A Simple Unified Equation for Accurate and Rapid Quantification of Fe³⁺/∑FeObtained from Room Temperature Mössbauer Spectroscopic Measurements

Jacob Adetunji

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: Mössbauer spectroscopy; recoilless fractions; corrected Fe3+/∑Fe ratios; room temperature measurements

Online: 11 July 2018 (12:17:20 CEST)

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The accurate quantification of

\frac{F e^{3 +}}{Σ F e}

ratios for Mössbauer spectroscopic room temperature measurements involves many steps and, when shown in a composite Mössbaur data table, does not allow enough space for more Mössbauer parameters to be presented in the composite table. So a simple formula is derived, (presented as a short communication) which users will find helpful when they have to determine corrected

\frac{F e^{3 +}}{Σ F e}

ratios in their room temperature Mössbauer experiments.

Preprint ARTICLE | doi:10.20944/preprints201806.0344.v1

Petrogenesis and Tectonic Setting of a Granitic Pluton in the Northern Ya-Gan fault Zone, North Alxa, China: Constraints from Whole-Rock Geochemistry, Zircon U–Pb Ages, and Sr–Nd–Hf Isotope Compositions

Fenquan Xie, Qianhong Wu, Lidong Wang, Zhaoxia Shi, Wenzhou Xiao, Jingya Cao, Biao Liu, Jiangbo Jiang, Jiajia Song

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: hetaoergai pluton; Yagan Belt; I-type granites; geochemistry; zircon U–Pb dating; Sr–Nd–Hf isotopes

Online: 22 June 2018 (05:04:29 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201805.0067.v1

Tsygankoite, Mn8Tl8Hg2(Sb21Pb2Tl)Σ24S48, a New Sulfosalt from the Vorontsovskoe Gold Deposit, Northern Urals, Russia

Anatoly V. Kasatkin, Emil Makovicky, Jakub Plášil, Radek Škoda, Atali A. Agakhanov, Vladimir Y. Karpenko, Fabrizio Nestola

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: tsygankoite; new sulfosalt; thallium; crystal structure; Vorontsovskoe gold deposit

Online: 3 May 2018 (11:20:28 CEST)

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Tsygankoite, ideally Mn8Tl8Hg2(Sb21Pb2Tl)Σ24S48, is a new sulfosalt discovered at the Vorontsovskoe gold deposit, Northern Urals, Russia. It occurs as lath-like elongated crystals up to 0.2 mm embedded in calcite-dolomite-clinochlore matrix. The associating minerals also include aktashite, alabandite, arsenopyrite, barite, cinnabar, fluorapatite, orpiment, pyrite, realgar, routhierite, sphalerite, tilasite, titanite, etc. The new mineral is non-fluorescent, black, opaque with a metallic lustre and black streak. It is brittle with an uneven fracture and no obvious parting and cleavage. Its Vickers hardness (VHN10) is 144 kg/mm2 (range 131–167) and its calculated density is 5.450 g cm-3. In reflected light tsygankoite is white; between crossed polars it is dark-grey to black. It is strongly anisotropic: rotation tints vary from light-grey to dark-grey to black. Pleochroism and internal reflections are not observed. The chemical composition of tsygankoite (wt.%, electron-microprobe data) is: Mn 6.29, Fe 0.02, Cu 0.02, Ag 0.01, Hg 5.42, Tl 26.05, Pb 5.84, As 3.39, Sb 30.89, S 21.87, Se 0.01, total 99.81. The empirical formula, calculated on the basis of 90 atoms pfu, is: Mn8.06Tl8.00(Hg1.90Fe0.03Cu0.02Ag0.01)Σ1.96(Sb17.85As3.18Pb1.98Tl0.97)Σ23.98(S48.00Se0.01)Σ48.01. Tsygankoite is monoclinic, space group C2/m, a = 21.362(4) Å, b = 3.8579(10) Å, c = 27.135(4) Å, β= 106.944(14)°, V = 2139.19(17) Å3 and Z = 1. The five strongest diffraction peaks from X-ray powder pattern [listed as (d,Å(I)(hkl)] are: 3.587(100)(112), 3.353(70)(-114), 3.204(88)(405), 2.841(72)(-513) and 2.786(99)(-514). The crystal structure of tsygankoite was refined from single-crystal X-ray diffraction data to R = 0.0607 and consists of an alternation of two thick layer-like arrays, one based on PbS-archetype and second – on SnS-archetype. Tsygankoite has been approved by the IMA-CNMNC under the number 2017-088. It is named for Mikhail V. Tsyganko, mineral collector from Northern Urals, who collected the samples where the new mineral was discovered.

Preprint ARTICLE | doi:10.20944/preprints201804.0277.v1

Si-Disordering in MgAl₂O₄-Spinel at High P-T Conditions, with Implication to Si-Mg Disorder in Mg₂SiO₄-Ringwoodite

Liping Liu, Xi Liu, Xinjian Bao, Qiang He, Wei Yan, Yunlu Ma, Mingyue He, Renbiao Tao, Ruqiang Zou

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: 4-coordinated Si; 6-coordinated Si; MgAl2O4-spinel; Mg2SiO4-ringwoodite; Raman spectroscopy; Si-disordering

Online: 23 April 2018 (08:37:36 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201804.0244.v1

Oyonite, Ag₃Mn₂Pb₄Sb₇As₄S₂₄, a New Member of the Lillianite Homologous Series from the Uchucchacua Polymetallic Deposit, Oyon District, Peru

Luca Bindi, Cristian Biagioni, Frank Keutsch

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: oyonite; lillianite homologous series; sulfosalt; copper; antimony; arsenic; Oyon district; Lima department; Peru

Online: 18 April 2018 (16:09:50 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201804.0117.v1

REE and Y Mineralogy of the Krudum Granite Body (Saxothuringian Zone)

Miloš René

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: monazite; xenotime; zircon; granite; Bohemian Massif; Horní Slavkov; Karlovy Vary

Online: 10 April 2018 (08:20:50 CEST)

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The Krudum granite body comprises highly fractionated granitic rocks ranging from medium-F biotite granites to high-F, high-P₂O₅ Li-mica granites. This unique assemblage is an ideal site to continue recent efforts in petrology to characterize the role of zircon, monazite and xenotime as hosts to REEs. The granitic rocks of the Krudum body analysed in this study were found to contain variable concentrations of monazite and zircon, while xenotime was only found in the high-F, high-P₂O₅ Li-mica granites and in the alkali-feldspar syenites of the Vysoký Kámen stock. For analysed monazites of all magmatic suites cheralite substitution was significant. The highest concentration of cheralite was found in monazites from the high-F, Li-mica granites and from the alkali-feldspar syenites. The proportion of YPO₄ in all analysed xenotimes ranges from 71 to 84 mol. %. Some xenotimes were found to be hydrated and the observed water content estimated from analytical data ranged from 5 to 11 wt. % H₂O. Analysed xenotimes were commonly enriched in HREEs (9.3– 19.5 wt. % HREE₂O₃) and thorite-coffinite and cheralite exchange was observed. Analysed zircons from granite suites of the Krudum granite body contained moderate Hf concentrations (1.0–4.7 wt. % HfO₂; 0.010–0.047 apfu Hf). The highest concentrations of HfO₂ were found in zircons from the high-F, high P₂O₅ Li-mica granites (1.2–4.7 wt. % HfO₂) and from the alkali-feldspar syenites (1.3–4.1 wt. % HfO₂). Zircons from the high-F, high-P₂O₅ Li-mica granites were often hydrated and fluorised. The concentrations of F in zircon from partly greisenised high-F, high-P₂O₅ Li-mica granites reached up to 1.2 wt. % (0.26 apfu F). In zircons from the alkali-feldspar syenites enrichment in P, which is not associated with a simultaneous enrichment in Y + REE, was also observed. Analysed zircons from the high-F, high P₂O₅ Li-mica granites were enriched in Y (up to 5.5 wt. % Y₂O₃; 0.10 apfu Y) and Sc (up to 1.17 wt. % Sc₂O₃; 0.03 apfu Sc).

Preprint ARTICLE | doi:10.20944/preprints201803.0188.v1

Characterization and Possible Uses of Recycled Aggregates from Construcction and Demolition Waste from Mexico City

Emiliano Moreno-Pérez, Juan Hernández-Ávila, Yamile Rangel- Martínez, Eduardo Cerecedo-Sáenz, Alberto Arenas-Flores, Ma. Isabel Reyes-Valderrama, Eleazar Salinas-Rodríguez

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: recycled aggregates; cement paste; carbonation; calcite; pH

Online: 21 March 2018 (07:52:05 CET)

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Preprint ARTICLE | doi:10.20944/preprints201801.0256.v1

C₁₄-₂₂ n-alkanes in Soil from the Freetown Layered Intrusion, Sierra Leone: Products of Pt Catalytic Breakdown of Natural Longer Chain n-alkanes?

John Bowles, Jessica Bowles, Andrew Giże.

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: n-alkanes, platinum, catalyst, soil, humic acid, Freetown Intrusion, Sierra Leone

Online: 26 January 2018 (16:11:36 CET)

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Preprint ARTICLE | doi:10.20944/preprints201801.0176.v1

Towards Zn-dominant Tourmaline: a Case of Zn-rich Fluor-Elbaite and Elbaite from the Julianna System at Piława Górna, Lower Silesia, SW Poland

Adam Pieczka, Bożena Gołębiowska, Piotr Jeleń, Adam Włodek, Eligiusz Szełęg, Adam Szuszkiewicz

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: tourmaline, fluor-elbaite, elbaite, Zn-enrichment, electron microprobe, Raman spectroscopy, granitic pegmatites, Piława Górna, Sudetes

Online: 18 January 2018 (17:00:38 CET)

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Preprint ARTICLE | doi:10.20944/preprints201801.0084.v1

Dissolved Silica Effects on Adsorption and Co-Precipitation of Sb(III) and Sb(V) with Ferrihydrite

Shuang Zhou, Tsutomu Sato, Tsubasa Otake

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: antimony; ferrihydrite; silica; adsorption; co-precipitation

Online: 10 January 2018 (07:02:42 CET)

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Preprint COMMUNICATION | doi:10.20944/preprints201709.0096.v1

The Carbon and Nitrogen Isotope Characteristics of Type Ib-IaA Cuboid Diamonds from Alluvial Placers in the Northeastern Siberian Platform

Dmitry Zedgenizov, Vadim Reutsky, Michael Wiedenbeck

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: cuboid diamond; carbon; nitrogen; SIMS

Online: 20 September 2017 (10:55:56 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201708.0047.v2

Cancer and Non-Cancer Risk of Santiago Island (Cape Verde) Population due to Potential Toxic Elements Exposure from Soils

Marina M.S. Cabral Pinto, Maria M. V. Silva, Eduardo. A. Ferreira Da Silva, Amelia Paula Reis

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: cancer risk; risk assessment; volcanic soils; Santiago Island

Online: 14 August 2017 (09:11:20 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201708.0047.v1

Cancer and Non-Cancer Risk of Santiago Island (Cape Verde) Population due to Potential Toxic Elements Exposure from Soils

Marina Cabral Pinto, Maria Manuela Silva, Eduardo Ferreira da Silva, A. Paula Marinho-Reis

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: cancer risk, risk assessment, volcanic soils, Santiago Island

Online: 12 August 2017 (21:10:19 CEST)

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Preprint REVIEW | doi:10.20944/preprints201707.0076.v1

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

Andrew J.S. Mcgonigle, Tom D. Pering, Thomas C. Wilkes, Giancarlo Tamburello, Roberto D’Aleo, Marcello Bitetto, Alessandro Aiuppa

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: ultraviolet cameras; volcanic plumes; interdisciplinary volcanology

Online: 26 July 2017 (08:57:24 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201703.0043.v2

Biomineralization of Carbonate Minerals Induced by the Halophilic Chromohalobacter israelensis under High Salt Concentrations: Implications for Natural Environments

Zuozhen Han, Dan Li, Hui Zhao, Huaxiao Yan, Peiyuan Li

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: biomineralization; halophilic bacteria; precipitation; carbonate minerals; Mg/Ca ratios; nucleation sites

Online: 26 April 2017 (12:15:58 CEST)

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The mechanism underlying microbiologically induced carbonate precipitation have not been thoroughly characterized, although numerous scholars and experts have specifically investigated questions regarding minerals induced by bacteria. The study of the precipitation of carbonate minerals induced by halophilic bacteria has aroused wide concern. The present study aimed to investigate the characterization and process of biomineralization in high salt systems by a halophilic bacterium, Chromohalobacter israelensis strain LD532 (GenBank: KX766026), which was isolated from the Yinjiashan Saltern in China. Carbonate minerals induced by LD532 were investigated in several sets of comparative experiments that employed magnesium sulfate and magnesium chloride as Mg resources. Magnesium calcite and aragonite were induced by LD532 bacteria, whereas these minerals did not appear in the control group. The mineral phases, micromorphologies, and crystal structures were analysed using X-ray powder diffraction, scanning electron microscopy, and energy dispersive X-ray detection. The carbonic anhydrase and urease secreted by strain LD532 through metabolism increased the pH value of the liquid medium and promoted the process of carbonate precipitation. Further study using high resolution transmission electron microscopy, energy dispersive X-ray detection and analysis of ultrathin slices showed that the nucleation sites of carbonate minerals were located on extracellular polymeric substances and the membranes of intracellular vesicles of LD532 bacteria, which provided favourable conditions for the growth of carbonate mineral crystals. The morphologies and compositions of minerals formed in solutions of MgSO₄ and MgCl₂ display significant differences, indicating that different sources of Mg²⁺ may also affect the physiological and biochemical activities of microorganisms and thus mineral deposition. This study will be of some interest for the interpretation of carbonate biomineralization in natural salt environments and has some value as a reference in understanding sedimentary carbonates in ancient marine environments, such as tidal flats.

Preprint ARTICLE | doi:10.20944/preprints201704.0168.v1

Silicate-Promoted Phosphorylation of Glycerol in Non-Aqueous Solvents: A Prebiotically Plausible Route to Organophosphates

Maheen Gull, Brian J. Cafferty, Nicholas V. Hud, Matthew A. Pasek

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: prebiotic synthesis; phosphorylation; origin of life; deep eutectic solvents; formamide; mineral catalysis

Online: 26 April 2017 (06:30:50 CEST)

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Preprint ARTICLE | doi:10.20944/preprints201703.0043.v1

Biomineralization of Carbonate Minerals Induced by Halophilic Chromohalobacter israelensis in High Salt Concentration: Implications for Natural Environments

Zuozhen Han, Dan Li, Huaxiao Yan, Peiyuan Li

Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: biomineralization; halophilic bacteria; precipitation; carbonate minerals; Mg/Ca ratios; nucleation sites

Online: 8 March 2017 (05:00:01 CET)

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High salt environment was widespread in modern and geological record, and sedimentation induced by microbes in these systems was an important part of sedimentary minerals and rocks. The mechanism of microbiologically induced carbonate precipitation has not been solved thoroughly although numerous scholars and experts have made specifically research of the problems with respect to minerals induced by bacteria. The study of carbonate minerals induced by Halophilic bacteria has aroused wide concern. The present study was aim to investigate the characterization and process of biomineralization in the high salt system, a Halophilic bacterium, Chromohalobacter israelensis LD532 strain (Genbank: KX766026), which isolated from Yinjiashan Saltern of China, was selected as an object to induce carbonate minerals. Carbonate minerals induced by LD532 were investigated in several comparative experimental sets with Mg resources of magnesium sulfate and magnesium chloride. Magnesium calcite and aragonite were induced by LD532 bacteria while these minerals were not in the control group. The mineral phases, micromorphologies, and crystal structures were analyzed using X-ray powder diffraction, scanning electron microscope, and energy dispersive X-ray detector. Carbonic anhydrase and urease secreted by strain LD532 through metabolism promoted the pH values of the liquid medium and the process of carbonate precipitation. Further study proved that the nucleation sites of partial carbonate nucleus were located on the extracellular polymeric substance and the membrane of intracellular vesicles of LD532 bacteria by high resolution transmission electron microscopy, energy dispersive X-ray detector and ultrathin slices analysis, which provided favorable conditions for the growth of carbonate mineral crystals. The morphology and composition of minerals formed in MgSO4 and MgCl2 solution have significant differences, indicating that different sources of Mg2+ could also affect the physiological and biochemical activities of microorganisms and then affect the mineral deposition. The accomplished study is of certain interest for interpretation of the carbonates biomineraliazation in natural salt environment, and has a certain reference value in understand of the sedimentary carbonates in ancient marine environment like evaporated tidal flat.

Environmental and Earth Sciences