Pub Date : 2024-02-08DOI: 10.1134/s107570152308007x
T. A. Gornostaeva, A. V. Mokhov, P. M. Kartashov, K. V. Lobanov
Abstract
Native cobalt was found in amphibolite of the Kola superdeep borehole (SG-3) from a depth of 9630 m by a complex of local analytical methods (analytical scanning electron microscopy, electron backscatter diffraction). The studied amphibolite is a fine-grained melanocratic rock composed mainly of magnesioferri- hornblende and containing accessory native metal, telluride, sulphotelluride, and sulphide (Au, Ag, Pd, Bi, Cu, Pb, Zn, Sb, and Fe) mineralization.It also includes the clinopyroxene xenoclast carrying a fundamentally different set of accessories—poor in sulphides and including native cobalt. The absence of significant impurities, including iron, in native cobalt and its belonging to the hexagonal α-modification was determined. It is shown, that the metallic cobalt particles exposed during ion polishing of a compact pyroxene matrix cannot be a contaminant, introduced into the sample during drilling and sample preparation. Cobalt, obviously, was formed not only before the stage of retrograde metamorphism and subsequent hydrothermal processing of the amphibolite containing it, but probably long before the formation of the sedimentary protolith of this rock. That is, native cobalt belongs to the early high-temperature mineral phases inherited from the older Proterozoic—Archean main volcanism, while the time of formation of this layer of amphibolites dates back to the age of 2.4 billion years—the Early Karelian era of the Proterozoic.
{"title":"Native Cobalt in Deep Levels of the Kola Superdeep Borehole","authors":"T. A. Gornostaeva, A. V. Mokhov, P. M. Kartashov, K. V. Lobanov","doi":"10.1134/s107570152308007x","DOIUrl":"https://doi.org/10.1134/s107570152308007x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Native cobalt was found in amphibolite of the Kola superdeep borehole (SG-3) from a depth of 9630 m by a complex of local analytical methods (analytical scanning electron microscopy, electron backscatter diffraction). The studied amphibolite is a fine-grained melanocratic rock composed mainly of magnesioferri- hornblende and containing accessory native metal, telluride, sulphotelluride, and sulphide (Au, Ag, Pd, Bi, Cu, Pb, Zn, Sb, and Fe) mineralization.It also includes the clinopyroxene xenoclast carrying a fundamentally different set of accessories—poor in sulphides and including native cobalt. The absence of significant impurities, including iron, in native cobalt and its belonging to the hexagonal α-modification was determined. It is shown, that the metallic cobalt particles exposed during ion polishing of a compact pyroxene matrix cannot be a contaminant, introduced into the sample during drilling and sample preparation. Cobalt, obviously, was formed not only before the stage of retrograde metamorphism and subsequent hydrothermal processing of the amphibolite containing it, but probably long before the formation of the sedimentary protolith of this rock. That is, native cobalt belongs to the early high-temperature mineral phases inherited from the older Proterozoic—Archean main volcanism, while the time of formation of this layer of amphibolites dates back to the age of 2.4 billion years—the Early Karelian era of the Proterozoic.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"17 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1134/s1075701523080081
N. I. Ponomareva, V. V. Gordienko, N. O. Melyantsov
Abstract
Study data on dark-colored, bright, and pale pink tourmalines of rare-metal pegmatites from Mt. Okhmylk in the Voron’ya Tundra region are reported. Chemical compositions and parameters of elementary cells are determined for tourmalines. Dark-colored tourmaline I is schörl–olenite, and pink tourmaline corresponds to elbaite–olenite. Studied tourmalines and tourmalines from spodumene pegmatites of other regions are compared. Based on the rare-earth element distribution in tourmalines, they are suggested to have been formed with involvement of high-temperature postmagmatic solutions. Mineral inclusions in schörl–olenite are represented by biotite and magnetite. Mineral inclusions in elbaite–olenite are cassiterite, pollucite, apatite, and tantalite. Tantalite is characterized by higher tantalum and low niobium. In addition, pure manganotantalite is often present in elbaite–olenite, and simpsonite is always observed at contacts between tantalite inclusions and tourmaline. All these data are indicative that albite–spodumene pegmatites of this region were formed with an active role of metasomatic processes.
摘要报告了沃龙亚苔原地区奥赫米尔克山稀有金属伟晶岩中深色、明亮和淡粉色电气石的研究数据。报告确定了碧玺的化学成分和基本单元参数。深色電氣石 I 是雪橄橄欖石，而粉紅色電氣石則是埃爾白橄欖石。研究中的电气石和来自其他地区磷灰石伟晶岩的电气石进行了比较。根据电气石中稀土元素的分布，认为它们是在高温后熔岩溶液的参与下形成的。辉绿岩中的矿物包裹体以生物铁和磁铁矿为代表。埃尔白橄榄石中的矿物包裹体有锡石、辉石、磷灰石和钽铁矿。钽铁矿的特点是钽含量较高而铌含量较低。此外，在埃尔白橄榄石中经常出现纯锰钽铁矿，在钽铁矿包裹体与电气石的接触处总是能观察到矽卡岩。所有这些数据都表明，该地区的白云石-黝帘石伟晶岩是在元成岩过程中形成的。
{"title":"Tourmaline Supergroup Minerals from Rare-Metal Pegmatites of the Voron’ya Tundra (Kola Peninsula, Russia)","authors":"N. I. Ponomareva, V. V. Gordienko, N. O. Melyantsov","doi":"10.1134/s1075701523080081","DOIUrl":"https://doi.org/10.1134/s1075701523080081","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Study data on dark-colored, bright, and pale pink tourmalines of rare-metal pegmatites from Mt. Okhmylk in the Voron’ya Tundra region are reported. Chemical compositions and parameters of elementary cells are determined for tourmalines. Dark-colored tourmaline I is schörl–olenite, and pink tourmaline corresponds to elbaite–olenite. Studied tourmalines and tourmalines from spodumene pegmatites of other regions are compared. Based on the rare-earth element distribution in tourmalines, they are suggested to have been formed with involvement of high-temperature postmagmatic solutions. Mineral inclusions in schörl–olenite are represented by biotite and magnetite. Mineral inclusions in elbaite–olenite are cassiterite, pollucite, apatite, and tantalite. Tantalite is characterized by higher tantalum and low niobium. In addition, pure manganotantalite is often present in elbaite–olenite, and simpsonite is always observed at contacts between tantalite inclusions and tourmaline. All these data are indicative that albite–spodumene pegmatites of this region were formed with an active role of metasomatic processes.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"87 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139762988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1134/s107570152308010x
A. B. Vrevsky
Abstract
This paper presents the data on the structure and composition of a concentric-zonal komatiite pillow from the Ruvinvaar Formation of the Neo-Archean Kostomuksha greenstone structure of the Fennoscandian Shield. The features of the zonal pillow structure include a narrow range of variations in concentrations of rare-earth elements (REEs), similar REE patterns of dacite and andesite from the pillow core and komatiite and komatiitic basalt from the outer part, and higher REE contents of andesite relative to dacite. These features of REE distribution indicate liquation differentiation of basic melts. According to the Sm–Nd isotopic systematics of rocks of the komatiite matrix and dacite, their isochron age is 2874 ± 35 Ma (εNd = +1.5). Our data indicate an older (than was previously considered) age of the Kontok Group of the Kostomuksha greenschist structure.
{"title":"Liquation Differentiation of Komatiites: Features of Isotopic–Geochemical Composition of Rocks, Age, and Petrological–Geodynamic Implications (Using the Example of the Kostomuksha Greenstone Structure, Fennoscandian Shield)","authors":"A. B. Vrevsky","doi":"10.1134/s107570152308010x","DOIUrl":"https://doi.org/10.1134/s107570152308010x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper presents the data on the structure and composition of a concentric-zonal komatiite pillow from the Ruvinvaar Formation of the Neo-Archean Kostomuksha greenstone structure of the Fennoscandian Shield. The features of the zonal pillow structure include a narrow range of variations in concentrations of rare-earth elements (REEs), similar REE patterns of dacite and andesite from the pillow core and komatiite and komatiitic basalt from the outer part, and higher REE contents of andesite relative to dacite. These features of REE distribution indicate liquation differentiation of basic melts. According to the Sm–Nd isotopic systematics of rocks of the komatiite matrix and dacite, their isochron age is 2874 ± 35 Ma (εNd = +1.5). Our data indicate an older (than was previously considered) age of the Kontok Group of the Kostomuksha greenschist structure.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"10 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1134/s1075701523080093
N. V. Sidorova, N. N. Korotaeva, E. M. Spiridonov, D. A. Khanin
Abstract
New data are reported on composition and morphology of wulfenite—stolzite-range minerals in oxidized ores at the Novoburannoe (Gumbeyskoe) scheelite deposit in the Southern Urals (Russia). Supergene stolzite and W-bearing wulfenite occur as veinletlike complex-zoned aggregates along the cracks in Mo-bearing scheelite at the point of contact with calcite, dolomite, chalcopyrite, and tennantite. The mineral composition varies from Mo-bearing stolzite (Pb0.98Ca0.02)(W0.78Mo0.22)О4 and W-rich wulfenite (Pb0.93Sr0.05Ca0.02)(Mo0.59W0.41)О4 to pure wulfenite. W-bearing wulfenite is predominant in the studied samples. W-free wulfenite forms pseudomorphs after molybdenite inclusions in galena.
摘要 报告了关于俄罗斯南乌拉尔地区Novoburannoe (Gumbeyskoe)白钨矿氧化矿石中的乌芬石-匍匐石系列矿物的成分和形态的新数据。在与方解石、白云石、黄铜矿和天南星石接触的地方，超生钨矿和含W的硫铁矿沿着含钼白钨矿的裂缝以细脉状复合带状聚集体的形式出现。矿物成分从含钼的 stolzite（Pb0.98Ca0.02）(W0.78Mo0.22)О4 和富含 W 的 wulfenite（Pb0.93Sr0.05Ca0.02）(Mo0.59W0.41)О4 到纯粹的 wulfenite 不一而足。在所研究的样品中，含 W 的硫铁矿占主导地位。不含W的硫铁矿在方铅矿中的辉钼矿包裹体后形成假象。
{"title":"Stolzite and Wulfenite in the Oxidation Zone of the Novoburannoe (Gumbeyskoe) Deposit (Southern Urals)","authors":"N. V. Sidorova, N. N. Korotaeva, E. M. Spiridonov, D. A. Khanin","doi":"10.1134/s1075701523080093","DOIUrl":"https://doi.org/10.1134/s1075701523080093","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>New data are reported on composition and morphology of wulfenite—stolzite-range minerals in oxidized ores at the Novoburannoe (Gumbeyskoe) scheelite deposit in the Southern Urals (Russia). Supergene stolzite and W-bearing wulfenite occur as veinletlike complex-zoned aggregates along the cracks in Mo-bearing scheelite at the point of contact with calcite, dolomite, chalcopyrite, and tennantite. The mineral composition varies from Mo-bearing stolzite (Pb<sub>0.98</sub>Ca<sub>0.02</sub>)(W<sub>0.78</sub>Mo<sub>0.22</sub>)О<sub>4</sub> and W-rich wulfenite (Pb<sub>0.93</sub>Sr<sub>0.05</sub>Ca<sub>0.02</sub>)(Mo<sub>0.59</sub>W<sub>0.41</sub>)О<sub>4</sub> to pure wulfenite. W-bearing wulfenite is predominant in the studied samples. W-free wulfenite forms pseudomorphs after molybdenite inclusions in galena.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"17 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1134/s1075701523080111
E. S. Zhitova, A. A. Nuzhdaev, A. V. Sergeeva, V. V. Shilovskikh
Abstract
This work considers the occurrence of Hg in a clay strata and pore fluids and conditions of Hg incorporation in sulfides and clay minerals abundant in thermal fields of the Koshelev, Kambalny, and Pauzhetka hydrothermal systems. It is shown that, under physicochemical conditions typical of the studied thermal fields, Hg is mostly incorporated in sulfides (pyrite, marcasite, cinnabar) and clay minerals (kaolinite and montmorillonite) as a result of sorption. Under the conditions of a thermal field, cinnabar is the most stable Hg form, because Fe sulfides are unstable during oxidation. The optimal pH value for Hg sorption by clay minerals (in the absence of chlorides and sulfites) is 3.15. In the presence of Hg-bonding chlorides, sulfites, and other anions, the optimal Hg sorption on layered silicates starts from a pH value of >5. The Hg sorption by clay minerals strongly depends on the local highly dynamic geochemical conditions.
{"title":"Hg Mineral Forms in Argillisites of the South Kamchatka Thermal Fields, Russia","authors":"E. S. Zhitova, A. A. Nuzhdaev, A. V. Sergeeva, V. V. Shilovskikh","doi":"10.1134/s1075701523080111","DOIUrl":"https://doi.org/10.1134/s1075701523080111","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This work considers the occurrence of Hg in a clay strata and pore fluids and conditions of Hg incorporation in sulfides and clay minerals abundant in thermal fields of the Koshelev, Kambalny, and Pauzhetka hydrothermal systems. It is shown that, under physicochemical conditions typical of the studied thermal fields, Hg is mostly incorporated in sulfides (pyrite, marcasite, cinnabar) and clay minerals (kaolinite and montmorillonite) as a result of sorption. Under the conditions of a thermal field, cinnabar is the most stable Hg form, because Fe sulfides are unstable during oxidation. The optimal pH value for Hg sorption by clay minerals (in the absence of chlorides and sulfites) is 3.15. In the presence of Hg-bonding chlorides, sulfites, and other anions, the optimal Hg sorption on layered silicates starts from a pH value of >5. The Hg sorption by clay minerals strongly depends on the local highly dynamic geochemical conditions.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1134/s1075701523080068
V. E. Glushkova, I. S. Peretyazhko, E. A. Savina, E. A. Khromova
Abstract
This paper reports the olivine-group minerals from melilite–nepheline paralavas of two combustion metamorphic (CM) complexes of Mongolia. The paralavas formed by thermal alterations of sedimentary rocks due to multistage modern and ancient (since the Quaternary) wild coal fires. The decomposition products of the olivine solid solution into Ca-bearing fayalite and kirschsteinite have been found in paralavas of the Khamaryn–Khural–Khiid CM complex. Apart from these minerals, members of isomorphic series forsterite–fayalite, and monticellite–kirschsteinite, and simplectite-like intergrowths of kirschsteinite with nepheline were identified in the paralavas of the Nyalga CM complex. The studied minerals differ in structural features, Mg# value, and crystallization temperature as a consequence of local variations in formation conditions and composition of silica-undersaturated Ca-rich mafic melts initial for melilite–nepheline paralavas. The olivines of the monticellite–kirschsteinite series reaching 86 mol % of kirschsteinite end-member occur only in paralavas bearing xenoliths of thermally modified carbonate-silicate sedimentary rocks. The crystallization of these olivines together with gehlenitic melilite took place through interaction between mafic paralava melts and xenoliths of marly limestones with large variations in content of silicate (clay–feldspar) admixture.
摘要 本文报告了蒙古两个燃烧变质岩群（CM）熔融-涅盘状副岩体中的橄榄石族矿物。这些副岩是由现代和远古（自第四纪以来）多级野煤火引起的沉积岩热变形成的。在 Khamaryn-Khural-Khiid CM 复合体的副岩中发现了橄榄石固溶体的分解产物，即含 Ca 的法叶腊石和基氏石。除这些矿物外，在聂雅嘎 CM 矿群的副岩体中还发现了同构系列的芒硝-法安石、芒硝-钾长石，以及钾长石与霞石的类单斜辉石互生。所研究的矿物在结构特征、Mg#值和结晶温度方面存在差异，这是因为形成条件和富含二氧化硅-过饱和钙的黑云母熔体成分的局部变化导致了黑云母-霞石副熔岩的形成。只有在热改造碳酸盐-硅酸盐沉积岩的副岩中才会出现蒙脱石-柯氏橄榄石系列橄榄石，其中柯氏橄榄石的终成体含量高达 86 摩尔%。这些橄榄石与gehlenitic melilite的结晶是在黑云母副熔岩熔体与硅酸盐（粘土长石）掺杂物含量变化较大的泥质灰岩侧晶之间的相互作用下形成的。
{"title":"Olivine-Group Minerals from Melilite–Nepheline Paralavas of Combustion Metamorphic Complexes of Mongolia","authors":"V. E. Glushkova, I. S. Peretyazhko, E. A. Savina, E. A. Khromova","doi":"10.1134/s1075701523080068","DOIUrl":"https://doi.org/10.1134/s1075701523080068","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper reports the olivine-group minerals from melilite–nepheline paralavas of two combustion metamorphic (CM) complexes of Mongolia. The paralavas formed by thermal alterations of sedimentary rocks due to multistage modern and ancient (since the Quaternary) wild coal fires. The decomposition products of the olivine solid solution into Ca-bearing fayalite and kirschsteinite have been found in paralavas of the Khamaryn–Khural–Khiid CM complex. Apart from these minerals, members of isomorphic series forsterite–fayalite, and monticellite–kirschsteinite, and simplectite-like intergrowths of kirschsteinite with nepheline were identified in the paralavas of the Nyalga CM complex. The studied minerals differ in structural features, Mg# value, and crystallization temperature as a consequence of local variations in formation conditions and composition of silica-undersaturated Ca-rich mafic melts initial for melilite–nepheline paralavas. The olivines of the monticellite–kirschsteinite series reaching 86 mol % of kirschsteinite end-member occur only in paralavas bearing xenoliths of thermally modified carbonate-silicate sedimentary rocks. The crystallization of these olivines together with gehlenitic melilite took place through interaction between mafic paralava melts and xenoliths of marly limestones with large variations in content of silicate (clay–feldspar) admixture.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"17 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-08DOI: 10.1134/s1075701523080056
B. B. Gerasimov
Abstract
Typomorphic features of placer gold are carriers of important information necessary for reconstruction of the formation history of gold placers and can be used as mineralogical criteria to search primary sources. The internal structure of grains of native gold is one of the most informative features. Internal structures of gold grains from modern placers and Early Permian conglomerates in the northeast of the Siberian Platform are studied. Structural etching of native gold was performed using the reagent (HCl + HNO3 + FeCl3⋅6H2O + CrO3 + thiurea + water). It was found that the well-rounded high-grade gold grains from modern placers experienced repeated redeposition through intermediate reservoirs. The discovery of slightly rounded gold grains, the internal structure of which bear no signs of exogenous transformation indicates that they were supplied to the modern alluvium from a nearby primary source. Apo-carbonate hydrothermal–metasomatic formations with the disseminated gold-sulfide mineralization were identified in the course of gold-ore exploration.
{"title":"Internal Structures of Placer Gold Grains As Prospecting Indicators of Primary Gold Sources in the Northeast of the Siberian Platform","authors":"B. B. Gerasimov","doi":"10.1134/s1075701523080056","DOIUrl":"https://doi.org/10.1134/s1075701523080056","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Typomorphic features of placer gold are carriers of important information necessary for reconstruction of the formation history of gold placers and can be used as mineralogical criteria to search primary sources. The internal structure of grains of native gold is one of the most informative features. Internal structures of gold grains from modern placers and Early Permian conglomerates in the northeast of the Siberian Platform are studied. Structural etching of native gold was performed using the reagent (HCl + HNO<sub>3</sub> + FeCl<sub>3</sub>⋅6H<sub>2</sub>O + CrO<sub>3</sub> + thiurea + water). It was found that the well-rounded high-grade gold grains from modern placers experienced repeated redeposition through intermediate reservoirs. The discovery of slightly rounded gold grains, the internal structure of which bear no signs of exogenous transformation indicates that they were supplied to the modern alluvium from a nearby primary source. Apo-carbonate hydrothermal–metasomatic formations with the disseminated gold-sulfide mineralization were identified in the course of gold-ore exploration.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"11 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140881554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.1134/s107570152307005x
V. G. Krivovichev, K. A. Kuksa, P. B. Sokolov, O. Yu. Marakhovskaya, M. E. Klimacheva
Abstract
A comparative study of the mineral-species distribution by various systems in evaporites from the Inder deposit (Kazakhstan) and in marbles of the Luc Yen deposit in North Vietnam, as well as a comparison of these locations in the distribution of species-defining elements, has been conducted. The obtained data show that both locations are almost identical in the set of species-defining elements (O, H, Si, Ca, S, Al, Na, Mg, K, C, F, Cl, and B), but slightly differ only in the Luc Yen marble enrichment in Al, Si, C, and F. The differences in the mineral abundance between evaporites and metamorphic rocks are due to landscape environments and physicochemical conditions of their formation. A comprehensive analysis of the evaporite and marble mineralogy with the identification of species-defining elements (mineral systems) may provide an objective basis for the assumption that evaporites with minor terrigenous material rocks were involved into the formation of ruby and gem spinel deposits.
摘要 对 Inder 矿床（哈萨克斯坦）蒸发岩和越南北部 Luc Yen 矿床大理石中各种系统的矿物物种分布进行了比较研究，并对这些地点的物种定义元素分布进行了比较。获得的数据表明，两地的物种定义元素（O、H、Si、Ca、S、Al、Na、Mg、K、C、F、Cl 和 B）几乎完全相同，仅在 Luc Yen 大理石中 Al、Si、C 和 F 的富集程度略有不同。蒸发岩和大理岩矿物学的综合分析，以及物种定义元素（矿物系统）的鉴定，可为红宝石和宝石尖晶石矿床形成过程中涉及蒸发岩和少量原生物质岩石的假设提供客观依据。
{"title":"Marble-Hosted Gem Spinel Deposits from Luc Yen District, North Vietnam: Mineral Systems and Some Aspects of Genesis","authors":"V. G. Krivovichev, K. A. Kuksa, P. B. Sokolov, O. Yu. Marakhovskaya, M. E. Klimacheva","doi":"10.1134/s107570152307005x","DOIUrl":"https://doi.org/10.1134/s107570152307005x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A comparative study of the mineral-species distribution by various systems in evaporites from the Inder deposit (Kazakhstan) and in marbles of the Luc Yen deposit in North Vietnam, as well as a comparison of these locations in the distribution of species-defining elements, has been conducted. The obtained data show that both locations are almost identical in the set of species-defining elements (O, H, Si, Ca, S, Al, Na, Mg, K, C, F, Cl, and B), but slightly differ only in the Luc Yen marble enrichment in Al, Si, C, and F. The differences in the mineral abundance between evaporites and metamorphic rocks are due to landscape environments and physicochemical conditions of their formation. A comprehensive analysis of the evaporite and marble mineralogy with the identification of species-defining elements (mineral systems) may provide an objective basis for the assumption that evaporites with minor terrigenous material rocks were involved into the formation of ruby and gem spinel deposits.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"7 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139755588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.1134/s1075701523070152
N. V. Zubkova, N. V. Chukanov, D. A. Varlamov, M. F. Vigasina, I. V. Pekov, D. A. Ksenofontov, D. Yu. Pushcharovsky
Abstract
The crystal structure of a mineral of the cancrinite group with an aluminosilicate framework of the marinellite type and a dominant sulfite group ({text{SO}}_{3}^{{2 - }}) in one of the extraframework sites in the liottite cavity is studied. The studied mineral is derived from a paleovolcano near Magliano (Lazio, Italy) and is one of the major rock-forming phases of the leucite–nepheline syenite. The divergence factor was R = 5.71% for 6819 independent reflections with I > 2σ(I). The studied mineral is trigonal, space group is P31c, and the unit cell parameters are a = 12.87267(18), c = 31.7393(5) Å, V = 4554.75(15) Å3. The crystal chemical formula Na29.78K11.82Ca6.40(Si36Al36O144)(SO4)6(SO3)2Cl2(OH)0.40⋅3.98H2O (Z = 1), which is based on the results of XRD structure analysis, is consistent with electron-microprobe data. The presence of the ({text{SO}}_{3}^{{2 - }}) anion was confirmed by the Raman spectrum.
{"title":"A Sulfite-Bearing Analog of Marinellite","authors":"N. V. Zubkova, N. V. Chukanov, D. A. Varlamov, M. F. Vigasina, I. V. Pekov, D. A. Ksenofontov, D. Yu. Pushcharovsky","doi":"10.1134/s1075701523070152","DOIUrl":"https://doi.org/10.1134/s1075701523070152","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The crystal structure of a mineral of the cancrinite group with an aluminosilicate framework of the marinellite type and a dominant sulfite group <span>({text{SO}}_{3}^{{2 - }})</span> in one of the extraframework sites in the liottite cavity is studied. The studied mineral is derived from a paleovolcano near Magliano (Lazio, Italy) and is one of the major rock-forming phases of the leucite–nepheline syenite. The divergence factor was <i>R</i> = 5.71% for 6819 independent reflections with <i>I</i> > 2σ(<i>I</i>). The studied mineral is trigonal, space group is <i>P</i>31<i>c</i>, and the unit cell parameters are <i>a</i> = 12.87267(18), <i>c</i> = 31.7393(5) Å, <i>V</i> = 4554.75(15) Å<sup>3</sup>. The crystal chemical formula Na<sub>29.78</sub>K<sub>11.82</sub>Ca<sub>6.40</sub>(Si<sub>36</sub>Al<sub>36</sub>O<sub>144</sub>)(SO<sub>4</sub>)<sub>6</sub>(SO<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>(OH)<sub>0.40</sub>⋅3.98H<sub>2</sub>O (<i>Z</i> = 1), which is based on the results of XRD structure analysis, is consistent with electron-microprobe data. The presence of the <span>({text{SO}}_{3}^{{2 - }})</span> anion was confirmed by the Raman spectrum.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"4 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139755658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-02-07DOI: 10.1134/s1075701523070061
S. V. Krivovichev
Abstract
Density functional theory (DFT) has been used with CRYSTAL14 program to optimize hydrogen atom positions in the crystal structure of parascorodite Fe(AsO4)⋅2H2O. It has been shown that taking into account hydrogen bonding, the structure forms six-membered asymmetrical cycles –Fe1–O1–H1…O3–As–O2– and eight-membered cycles –Fe1–O1–H2…O2–Fe1–O2…H2–O1– with lateral topological symmetry. Calculation of the structural complexity parameters for scorodite and parascorodite and their comparison with thermodynamic characteristics shows that the Fe(AsO4)⋅2H2O polymorph modifications correspond well to Goldsmith’s rule that states that metastable transitional polymorphs are structurally simpler than thermodynamically stable phases. Scorodite is a stable phase, whereas parascorodite is metastable, which agrees well with the conclusions made in the previous works. Crystallization of parascorodite under natural conditions of oxidation zones of ore-mineral deposits may occur due to the high speed of its nucleation as a metastable phase, i.e., due to the kinetic stabilization of its structure.
{"title":"Hydrogen Bonding in Parascorodite and Relative Stability of Fe(AsO4)⋅2H2O Polymorphs","authors":"S. V. Krivovichev","doi":"10.1134/s1075701523070061","DOIUrl":"https://doi.org/10.1134/s1075701523070061","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Density functional theory (DFT) has been used with CRYSTAL14 program to optimize hydrogen atom positions in the crystal structure of parascorodite Fe(AsO<sub>4</sub>)⋅2H<sub>2</sub>O. It has been shown that taking into account hydrogen bonding, the structure forms six-membered asymmetrical cycles –Fe1–O1–H1<sup>…</sup>O3–As–O2– and eight-membered cycles –Fe1–O1–H2<sup>…</sup>O2–Fe1–O2<sup>…</sup>H2–O1– with lateral topological symmetry. Calculation of the structural complexity parameters for scorodite and parascorodite and their comparison with thermodynamic characteristics shows that the Fe(AsO<sub>4</sub>)⋅2H<sub>2</sub>O polymorph modifications correspond well to Goldsmith’s rule that states that metastable transitional polymorphs are structurally simpler than thermodynamically stable phases. Scorodite is a stable phase, whereas parascorodite is metastable, which agrees well with the conclusions made in the previous works. Crystallization of parascorodite under natural conditions of oxidation zones of ore-mineral deposits may occur due to the high speed of its nucleation as a metastable phase, i.e., due to the kinetic stabilization of its structure.</p>","PeriodicalId":12719,"journal":{"name":"Geology of Ore Deposits","volume":"17 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2024-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139763049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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