The gold deposits of the eastern region of Cuba are genetically related to the lithological formations of the island arc and the ophiolitic complex, which have been studied and exploited since the time of the Spanish colonization in the mid-sixteenth century. These deposits are part of the so-called Aguas Claras-Guajabales mineral field, in the Holguín Province (Cuba) and lie in an extensive elongated strip of approximately 15 km in length. The object of this work is to make an orderly, detailed, and chronological review of the geological and mining work carried out in this region as well as to highlight the degree of study achieved in each of the stages of research. To facilitate this work, an extensive bibliographic review of all available materials was planned and carried out, such as reports, manuals, monographs, and articles. The results obtained from this study highlight that gold mineralization is closely linked to metasomatic processes produced by the circulation of hydrothermal fluids that affected different lithologies of both the volcanic island arc and the ophiolitic complex, it is noteworthy that the highest gold contents are mainly where the lithologies contact each other. This highlights the fact that the presence of alterations such as serpentinization, listvenitization, rodingitization and propylitization have played a primary role in the deposition of gold during mineralization processes. This work could be a very useful guide for future research in this region, as it is an orderly, concrete, and practical compilation of the characteristics of the mineralization and alterations, as well as a precise indication of the spatial position, thicknesses, and contents of the gold horizons.

This paper presents petrography, EDS, LA-ICP-MS, and Raman spectroscopy data characterizing mineral associations and composition of apatite group minerals from anorthosites of the Kievey deposit, North PGE Reef, Fedorova-Pana Complex, Russia. The mineralized coarse-grained anorthosite belongs to the most common rock type of the main ore body and hosts irregular interstitial sulfide dissemination of 5–7 vol. %. Apatite in the anorthosite forms a) euhedral grains included in the marginal parts of cumulus plagioclase laths, and b) xenomorphic grains associated with intercumulus minerals. The composition of apatite evolves along a narrow trend from fluorapatite to hydroxylapatite. The F content in apatite reaches 2.21 wt. %; the maximum Sr and REE concentration is 257 and 5623 ppm respectively, while the average ratio of La/YbN=11.78, Sr/Sr*=0.01, and Eu/Eu*=0.06. Compared to classic PGE reefs in layered intrusions such as Bushveld in South Africa and Stillwater in the United States, the mineralized anorthosite is distinguished by apatite with an unusual low chlorine concentration of only 0.46 wt. %. One of suggested reason of this difference is percolating nature of sulfide liquid which has not been enriched in PGE in situ.

The reaction of mercaptoacetic acid esters with pentachloro-2-nitro-1,3-butadiene provides appropriate precursors for the synthesis of 2,3,4-trisubstituted benzo[h]quinolines. These heterocycles are easily accessible via a single-step reaction with 1-naphthyl- or 1-anthracenylamine, respectively. Due to steric bulk and high electron density ring closure to benzo[h]quinolines takes place, exclusively. Such highly substituted annelated pyridine systems can be modified in subsequent, selective reactions to build up new N-heterocycles with promising microbiological properties. Antibacterial and antiproliferative assays against four cell mammalian cell lines demonstrate that some of the sulfur-substituted benzo[h]quinolines analogs display potent phenotypic bioactivities in the single-digit micromolar range.

The ultramafic-hosted Kairei vent field, located at 25°19′S, 70°02′E towards the northern end of the segment 1 of the Central Indian Ridge (CIR-S1) in a water depth of ~2450 m. This study aims to investigate the distribution of trace elements among sulfides of differing textures, and discuss the possible factors controlling the trace element distribution in those minerals by using LA-ICP-MS spot analyses as well as line scans. Our results show that there are distinct systematic trace element distributions throughout the different minerals：(1) Pyrite is divided into three types at the Kairei, including early-stage euhedral pyrites (py-I), sub-euhedral pyrites (py-II), and colloform pyrites (py-III). Pyrite is generally enriched in Mo, Au, As, Tl, Mn, and U. py-I have higher contents of Se, Te, Bi, and Ni, py-II are enriched in Au relative to py-I and py-III, but poor in Ni, py-III are enriched in Mo, Pb, and U but are poor in Se, Te, Bi, and Au. Variations in the concentrations of Se, Te, and Bi in pyrite are likely governed by the strong temperature gradient. Ni is generally lower than Co in pyrites, indicates that our samples precipitated at a high-temperature condition, whereas the extreme Co enrichment is likely from a magmatic heat source combined serpentinization reactions underlie the deposits. (2) Chalcopyrite is characterized by high concentrations of Co, Se, Te. The abundant of Se and Te in chalcopyrite cause by the high solubilities of Se and Te incorporated into chalcopyrite lattice at high temperature fluids. The concentration of Sb, As and Au is relatively low in chalcopyrite from the Kairei vent field. (3) Sphalerite from both the Zn-rich chimney is characterized by high concentrations of Sn, Co, Ga, Ge, Ag, Pb, Sb, As, and Cd, but depleted in Se, Te, Bi, Mo, Au, Ni, Tl, Mn, Ba, V, and U in comparison with the other minerals. The high concentration of Cd and Co is likely caused by the substitution of Cd2+ and Co2+ for Zn2+ in sphalerite. A high concentration of Pb accompanied by high Ag concentration in sphalerite indicating the Ag occurs in the microinclusions of Pb-bearing minerals such as galena. Au is generally low in sphalerite and strong correlate with Pb suggesting its presence in the microinclusions of galena. The strong correlation of As with Ge in sphalerite from Kairei suggests that they might precipitate under medium- to low-temperature with moderately reduced conditions. (4) Bornite-digenite is very low in most trace elements, except for Co, Se, and Bi. The high concentration of Se and Bi in all the sulfide minerals was observed in bornite-digenite can be explained by abundant Bi-selenide inclusions. Serpentinization in ultramafic-hosted hydrothermal systems might play an important role on Au enrichment in pyrite with low As contents. Compared with felsic-hosted seafloor massive sulfide (SMS) deposits, sulfide minerals from the ultramafic-hosted deposits show higher concentrations of Se and Te, but lower As, Sb, and Au concentrations attributed to the contribution of magmatic volatile input. Significant Se enrichment in chalcopyrite has been found from mafic-hosted SMSs indicate that the primary factor that controls the Se enrichment is its temperature-controlled mobility in fluids.