Ping Zheng, Ke Chen, Jun-Ke Zhang, Zhong-Fa Liu, Yong-Shun Li, Ming-Peng He
Baoshan is a world-class skarn Cu-polymetallic deposit located at the junction of the Nanling and Qin-Hang metallogenic belts in China. While there has been extensive research on the mineralogy and geochemistry of skarn deposits, studies on the fluid characteristics and evolutionary history from the early to late skarn stages in such deposits are still limited. In this study, we analyzed garnet and pyroxene from the early skarn stage and scheelite from the late skarn stage of the Baoshan deposit. We distinguished two generations of garnet (Grt1 and Grt2), one generation of pyroxene, and three generations of scheelite (Sch I, Sch II, and Sch III) on the basis of mineral assemblages and microscopic characteristics. Grt1 appears coarse-grained, and Grt2 cuts through Grt1 as veinlets. In Grt1, the andradite end-member increases from the core to the rim, while the grossular portion decreases (Ad35–36Gr59–61Sp3–4 to Ad59–61Gr36–37Sp2–3), and in Grt2, the andradite end-member significantly increases (Ad41–73Gr25–55Sp2–3). Grt1 and Grt2 have similar trace element compositions, with enrichment in Zr and depletion in Nb and Hf, depletion in LREE, enrichment in HREE, and weak negative Eu anomalies. Pyroxene coexists with Grt1 and is similarly cut by Grt2, with its composition mainly being diopside (Di82–99Hd0.6–15Jo0–3.2). Sch I and Sch II appear as anhedral to subhedral grains, while Sch III is predominantly found in veinlets. In Sch I and Sch II, most REEs enter the scheelite lattice via the Na-REE coupled substitution mechanism, with a smaller portion substituting Ca vacancies. In Sch III, the substitution mechanism involving Ca site vacancies may dominate. During the early skarn stage, the oxygen fugacity of the fluid gradually decreased from Grt1 and pyroxene to Grt2. In the late skarn stage, fluid oxygen fugacity remains stable from Sch I and Sch II to Sch III in shallow parts but significantly decreases in deeper parts. The garnet and pyroxene from the Baoshan deposit align with typical skarn Cu deposit compositions, while scheelite in the late skarn stage shows Sch I, Sch II, and shallow Sch III as skarn-type and deep Sch III as vein-type scheelite. Early skarn stage fluids were weakly acidic. Sch I, Sch II, and Sch III originated from fluids related to the Baoshan granite porphyry, with Sch III also showing evidence of water–rock interaction. This study reconstructed the fluid evolution history from the early to late skarn stages at the Baoshan deposit, providing insights into the ore-forming processes of other skarn deposits.
宝山是一个世界级的矽卡岩铜多金属矿床，位于中国南岭成矿带和秦杭成矿带的交界处。虽然人们对矽卡岩矿床的矿物学和地球化学进行了大量研究，但对此类矿床从早期矽卡岩阶段到晚期矽卡岩阶段的流体特征和演化历史的研究仍然有限。在这项研究中，我们分析了宝山矿床早期矽卡岩阶段的石榴石和辉石，以及晚期矽卡岩阶段的白钨矿。根据矿物组合和显微特征，我们区分了两代石榴石（Grt1 和 Grt2）、一代辉石和三代白钨矿（Sch I、Sch II 和 Sch III）。Grt1 看起来颗粒较粗，而 Grt2 则以细脉形式穿过 Grt1。在 Grt1 中，从岩心到岩缘，安长石端粒增加，而毛玻璃部分减少（Ad35-36Gr59-61Sp3-4 至 Ad59-61Gr36-37Sp2-3），而在 Grt2 中，安长石端粒显著增加（Ad41-73Gr25-55Sp2-3）。Grt1和Grt2的微量元素组成相似，Zr富集，Nb和Hf贫化，LREE贫化，HREE富集，Eu呈弱负异常。辉石与 Grt1 共存，并同样被 Grt2 切割，其成分主要为透辉石（Di82-99Hd0.6-15Jo0-3.2）。SchⅠ和SchⅡ呈正方体至次正方体晶粒，而SchⅢ则主要呈细脉状。在 Sch I 和 Sch II 中，大部分 REEs 通过 Na-REE 耦合取代机制进入白钨矿晶格，小部分取代 Ca 空位。在 Sch III 中，涉及 Ca 位点空位的置换机制可能占主导地位。在早期矽卡岩阶段，流体的氧富集度从 Grt1 和辉石逐渐下降到 Grt2。在矽卡岩晚期，流体氧富集度在浅部从 Sch I 和 Sch II 到 Sch III 保持稳定，但在深部明显下降。宝山矿床的石榴石和辉石符合典型的矽卡岩铜矿床成分，而矽卡岩晚期的白钨矿则表现为矽卡岩型的SchⅠ、SchⅡ和浅SchⅢ，以及脉石型的深SchⅢ。早期矽卡岩阶段的流体呈弱酸性。SchⅠ、SchⅡ和SchⅢ源于与宝山花岗斑岩有关的流体，其中SchⅢ还显示出水岩相互作用的迹象。这项研究重建了宝山矽卡岩矿床从早期到晚期的流体演化史，为其他矽卡岩矿床的成矿过程提供了启示。
{"title":"The Fluid Evolution in the Skarn Stages of the Baoshan Skarn Cu-Polymetallic Deposit, South China","authors":"Ping Zheng, Ke Chen, Jun-Ke Zhang, Zhong-Fa Liu, Yong-Shun Li, Ming-Peng He","doi":"10.3390/min14090907","DOIUrl":"https://doi.org/10.3390/min14090907","url":null,"abstract":"Baoshan is a world-class skarn Cu-polymetallic deposit located at the junction of the Nanling and Qin-Hang metallogenic belts in China. While there has been extensive research on the mineralogy and geochemistry of skarn deposits, studies on the fluid characteristics and evolutionary history from the early to late skarn stages in such deposits are still limited. In this study, we analyzed garnet and pyroxene from the early skarn stage and scheelite from the late skarn stage of the Baoshan deposit. We distinguished two generations of garnet (Grt1 and Grt2), one generation of pyroxene, and three generations of scheelite (Sch I, Sch II, and Sch III) on the basis of mineral assemblages and microscopic characteristics. Grt1 appears coarse-grained, and Grt2 cuts through Grt1 as veinlets. In Grt1, the andradite end-member increases from the core to the rim, while the grossular portion decreases (Ad35–36Gr59–61Sp3–4 to Ad59–61Gr36–37Sp2–3), and in Grt2, the andradite end-member significantly increases (Ad41–73Gr25–55Sp2–3). Grt1 and Grt2 have similar trace element compositions, with enrichment in Zr and depletion in Nb and Hf, depletion in LREE, enrichment in HREE, and weak negative Eu anomalies. Pyroxene coexists with Grt1 and is similarly cut by Grt2, with its composition mainly being diopside (Di82–99Hd0.6–15Jo0–3.2). Sch I and Sch II appear as anhedral to subhedral grains, while Sch III is predominantly found in veinlets. In Sch I and Sch II, most REEs enter the scheelite lattice via the Na-REE coupled substitution mechanism, with a smaller portion substituting Ca vacancies. In Sch III, the substitution mechanism involving Ca site vacancies may dominate. During the early skarn stage, the oxygen fugacity of the fluid gradually decreased from Grt1 and pyroxene to Grt2. In the late skarn stage, fluid oxygen fugacity remains stable from Sch I and Sch II to Sch III in shallow parts but significantly decreases in deeper parts. The garnet and pyroxene from the Baoshan deposit align with typical skarn Cu deposit compositions, while scheelite in the late skarn stage shows Sch I, Sch II, and shallow Sch III as skarn-type and deep Sch III as vein-type scheelite. Early skarn stage fluids were weakly acidic. Sch I, Sch II, and Sch III originated from fluids related to the Baoshan granite porphyry, with Sch III also showing evidence of water–rock interaction. This study reconstructed the fluid evolution history from the early to late skarn stages at the Baoshan deposit, providing insights into the ore-forming processes of other skarn deposits.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215235","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}
Geochemical measurements of stream sediments are practical for small-scale mineral exploration. However, traditional grid interpolation methods cause element concentrations to diffuse and smooth out anomalies, particularly in complex terrains, making it challenging to reflect the actual distribution of elements accurately. We applied the Dynamic Enhanced Weighted Drainage Catchment Basin (DE-WDCB) method to enhance the retention and identification of local anomalies by limiting the scope of analysis to specific drainage units. This method reduces interference from varying background values across different watersheds, effectively enhancing geochemical element anomalies and aligning better with geomorphic conditions. The DE-WDCB method was tested in the Duobaoshan–Heihe area, a significant copper polymetallic mineral district in northeastern China. Compared with traditional grid interpolation methods, the DE-WDCB method retained and strengthened low and weak abnormal information of favorable mineralization elements, particularly in the Luotuowaizi area. The method demonstrated a higher spatial coverage rate with mineral points and a more vital ore-indicating ability. Specifically, the DE-WDCB method identified anomalies with a mean accuracy of 63.57% (p < 0.05, 95% CI: 47.64-79.50%), compared to 50.53% for traditional methods. In conclusion, in regions with a complex topography and watershed differences, the DE-WDCB method effectively reduces local geochemical background interference, accurately identifies low and weak geochemical anomalies, and better reflects the actual distribution of elements. This makes it a significantly advantageous method for geochemical anomaly extraction, delineating higher-confidence exploration targets in the Sandaowan–Luotuowaizi area in the east and the triangular area between Duobaoshan, Yubaoshan, Sankuanggou, and the midstream highlands of the Guanbird River in the west.
{"title":"Dynamic Enhanced Weighted Drainage Catchment Basin Method for Extracting Geochemical Anomalies","authors":"Zijia Cui, Jianping Chen, Renwei Zhu, Quanping Zhang, Guanyun Zhou, Zhen Jia, Chang Liu","doi":"10.3390/min14090912","DOIUrl":"https://doi.org/10.3390/min14090912","url":null,"abstract":"Geochemical measurements of stream sediments are practical for small-scale mineral exploration. However, traditional grid interpolation methods cause element concentrations to diffuse and smooth out anomalies, particularly in complex terrains, making it challenging to reflect the actual distribution of elements accurately. We applied the Dynamic Enhanced Weighted Drainage Catchment Basin (DE-WDCB) method to enhance the retention and identification of local anomalies by limiting the scope of analysis to specific drainage units. This method reduces interference from varying background values across different watersheds, effectively enhancing geochemical element anomalies and aligning better with geomorphic conditions. The DE-WDCB method was tested in the Duobaoshan–Heihe area, a significant copper polymetallic mineral district in northeastern China. Compared with traditional grid interpolation methods, the DE-WDCB method retained and strengthened low and weak abnormal information of favorable mineralization elements, particularly in the Luotuowaizi area. The method demonstrated a higher spatial coverage rate with mineral points and a more vital ore-indicating ability. Specifically, the DE-WDCB method identified anomalies with a mean accuracy of 63.57% (p < 0.05, 95% CI: 47.64-79.50%), compared to 50.53% for traditional methods. In conclusion, in regions with a complex topography and watershed differences, the DE-WDCB method effectively reduces local geochemical background interference, accurately identifies low and weak geochemical anomalies, and better reflects the actual distribution of elements. This makes it a significantly advantageous method for geochemical anomaly extraction, delineating higher-confidence exploration targets in the Sandaowan–Luotuowaizi area in the east and the triangular area between Duobaoshan, Yubaoshan, Sankuanggou, and the midstream highlands of the Guanbird River in the west.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215237","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}
The Songpan–Ganzi Orogenic Belt (SGOB) is bounded by the South China, North China, and Qiangtang blocks and forms the eastern margin of the Tibetan Plateau. The Tiechanghe Granite is located at the junction of the southeast margin of the SGOB and the western margin of the Yangtze Block. To elucidate the genetic relationship between the Tiechanghe Granite and the surrounding molybdenum deposits in Western Sichuan, in this study, we conducted zircon U-Pb and molybdenite Re-Os isotopic dating. The results indicate that the Tiechanghe Granite predominantly consists of monzogranite, with minor occurrences of syenogranite, while the molybdenum deposits are mainly found in skarn and quartz veins. The laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb ages of the Tiechanghe Granite range from 162.9 ± 0.7 Ma (MSWD = 0.31, n = 25) to 163.4 ± 0.6 Ma (MSWD = 0.85, n = 26), and the LA-ICP-MS zircon U-Pb age of the pegmatite veins is 164.1 ± 0.9 Ma (MSWD = 1.3, n = 19). These ages are consistent with the weighted average Re-Os age of the Ziershi molybdenite (160.3 ± 1.6 Ma, n = 2) within the error margins. These findings and previously obtained magmatic and metallogenic ages for the region suggest that a magmatic and mineralization event involving granite, molybdenum, tungsten, and copper occurred at around 162–164 Ma in the study area. This discovery broadens the exploration perspective for mineral resources in the Jiulong area of Western Sichuan and the entirety of Western Sichuan.
{"title":"Metallogenic Chronology and Prospecting Indication of Tiechanghe Granite and Polymetallic Molybdenum Mineralization Types in Jiulong Area, Western Sichuan, China","authors":"Shuang Yang, Hongqi Tan, Zhongquan Li, Junliang Hu, Xinyan Wang, Daming Liu","doi":"10.3390/min14090909","DOIUrl":"https://doi.org/10.3390/min14090909","url":null,"abstract":"The Songpan–Ganzi Orogenic Belt (SGOB) is bounded by the South China, North China, and Qiangtang blocks and forms the eastern margin of the Tibetan Plateau. The Tiechanghe Granite is located at the junction of the southeast margin of the SGOB and the western margin of the Yangtze Block. To elucidate the genetic relationship between the Tiechanghe Granite and the surrounding molybdenum deposits in Western Sichuan, in this study, we conducted zircon U-Pb and molybdenite Re-Os isotopic dating. The results indicate that the Tiechanghe Granite predominantly consists of monzogranite, with minor occurrences of syenogranite, while the molybdenum deposits are mainly found in skarn and quartz veins. The laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb ages of the Tiechanghe Granite range from 162.9 ± 0.7 Ma (MSWD = 0.31, n = 25) to 163.4 ± 0.6 Ma (MSWD = 0.85, n = 26), and the LA-ICP-MS zircon U-Pb age of the pegmatite veins is 164.1 ± 0.9 Ma (MSWD = 1.3, n = 19). These ages are consistent with the weighted average Re-Os age of the Ziershi molybdenite (160.3 ± 1.6 Ma, n = 2) within the error margins. These findings and previously obtained magmatic and metallogenic ages for the region suggest that a magmatic and mineralization event involving granite, molybdenum, tungsten, and copper occurred at around 162–164 Ma in the study area. This discovery broadens the exploration perspective for mineral resources in the Jiulong area of Western Sichuan and the entirety of Western Sichuan.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215234","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}
Ruilin Hao, Liyin Pan, Nana Mu, Xi Li, Xiaodong Fu, Shaoyun Xiong, Siqi Liu, Jianfeng Zheng, Min She, Axel Munnecke
The age and dolomitization processes in the Paleo-oil reservoir zone, which is composed of massive dolostones found in the Qiangtang Basin (SW China), are still debated. In this research, the Long’eni-Geluguanna Area was selected. Macroscopic information, thin sections, and geochemical methods were used to investigate the dolomitization characteristics and the processes that controlled dolomitization. Five types of replacive dolomites and two types of dolomite cement were observed. Some of the dolomites displayed ghosts of primary sedimentary structures. Saddle dolomites were prevalent, occurring in the interparticle and moldic pores of the limestone which should have been filled at an early diagenetic stage. Ten microfacies types were identified. The foraminifera assemblage provides evidence that the studied interval is of Early Jurassic age. The δ13C values are similar to the contemporaneous seawater signature. The REE+Y patterns of limestones and dolostones exhibit similarities to that of seawater. The mean Na and Sr values are comparable to those of other near-normal seawater dolomites. The δ18O values of all lithologies are markedly depleted. The dolomitization started penecontemporaneously, with deposition. A general sand shoal setting with patch reefs developed. The dolomitizing fluids, near-normal seawater, was probably formed by slight evaporation on top of the shoal. Saddle dolomites in the interparticle and moldic pores might indicate hydrothermal activity, which also caused the recrystallization of some pre-existing dolomites. The recrystallization might have slightly increased the crystal size, demolished the ghost structures, formed saddle dolomites, and altered the REE+Y patterns. The recrystallization extent diminished with increasing distance from the fluids-providing fracture. Furthermore, the existence of protected areas within the sand shoal settings could enhance the vertical and horizontal heterogeneity of dolostone reservoirs.
羌塘盆地（中国西南部）由块状白云岩组成的古油藏带的年龄和白云岩化过程仍存在争议。本研究选取了隆恩-格鲁盖纳地区。利用宏观信息、薄片和地球化学方法研究了白云岩化特征和控制白云岩化的过程。观察到了五种替代白云石和两种白云石胶结物。一些白云岩显示出原始沉积结构的幽灵。鞍状白云岩很普遍，出现在石灰岩的颗粒间隙和模孔中，这些孔隙应该在成岩早期就被填满了。确定了十种微地层类型。有孔虫的组合证明了所研究的区间属于早侏罗世。δ13C值与同期海水特征相似。石灰岩和白云石的 REE+Y 模式与海水相似。Na 和 Sr 的平均值与其他接近正常海水的白云岩相当。所有岩性的 δ18O 值都明显偏低。白云岩化与沉积同时开始。形成了带有片状礁石的总体沙滩环境。白云石化的流体是近乎正常的海水，可能是由浅滩顶部的轻微蒸发形成的。颗粒间和模孔中的鞍状白云石可能表明存在热液活动，这也导致了一些原有白云石的重结晶。重结晶可能使晶体尺寸略有增大，破坏了幽灵结构，形成了鞍状白云岩，并改变了 REE+Y 模式。再结晶的范围随着与提供流体的断裂距离的增加而减小。此外，沙洲环境中存在的保护区可能会增强白云岩储层的垂直和水平异质性。
{"title":"Multi-Phase Dolomitization in the Jurassic Paleo-Oil Reservoir Zone, Qiangtang Basin (SW China): Implications for Reservoir Development","authors":"Ruilin Hao, Liyin Pan, Nana Mu, Xi Li, Xiaodong Fu, Shaoyun Xiong, Siqi Liu, Jianfeng Zheng, Min She, Axel Munnecke","doi":"10.3390/min14090908","DOIUrl":"https://doi.org/10.3390/min14090908","url":null,"abstract":"The age and dolomitization processes in the Paleo-oil reservoir zone, which is composed of massive dolostones found in the Qiangtang Basin (SW China), are still debated. In this research, the Long’eni-Geluguanna Area was selected. Macroscopic information, thin sections, and geochemical methods were used to investigate the dolomitization characteristics and the processes that controlled dolomitization. Five types of replacive dolomites and two types of dolomite cement were observed. Some of the dolomites displayed ghosts of primary sedimentary structures. Saddle dolomites were prevalent, occurring in the interparticle and moldic pores of the limestone which should have been filled at an early diagenetic stage. Ten microfacies types were identified. The foraminifera assemblage provides evidence that the studied interval is of Early Jurassic age. The δ13C values are similar to the contemporaneous seawater signature. The REE+Y patterns of limestones and dolostones exhibit similarities to that of seawater. The mean Na and Sr values are comparable to those of other near-normal seawater dolomites. The δ18O values of all lithologies are markedly depleted. The dolomitization started penecontemporaneously, with deposition. A general sand shoal setting with patch reefs developed. The dolomitizing fluids, near-normal seawater, was probably formed by slight evaporation on top of the shoal. Saddle dolomites in the interparticle and moldic pores might indicate hydrothermal activity, which also caused the recrystallization of some pre-existing dolomites. The recrystallization might have slightly increased the crystal size, demolished the ghost structures, formed saddle dolomites, and altered the REE+Y patterns. The recrystallization extent diminished with increasing distance from the fluids-providing fracture. Furthermore, the existence of protected areas within the sand shoal settings could enhance the vertical and horizontal heterogeneity of dolostone reservoirs.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215241","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}
Hao Lin, Zuochen Li, Xianzhi Pei, Ruibao Li, Hai Zhou, Meng Wang, Shaowei Zhao, Li Qin, Mao Wang
The main ocean–continent transformation stage of the Qinling and Qilian conjunction zone happened in the Early Paleozoic with the occurrence of a lot of subduction–collision–related magmatic rocks. However, there is still considerable controversy over the duration of the subduction–collision orogeny process of the Proto-Tethys Ocean, here termed as the Wushan–Shangdan Ocean. We provide geochronological, geochemical, and Lu-Hf isotopic data for typical Early Devonian igneous rocks there, named Tailu pluton. The Tailu pluton at 410 Ma comprised K-rich, calc-alkaline, metaluminous A-type granite with low Y/Nb ratios (0.85 to 1.35) and A/CNK values (0.90 to 1.01); with high SiO2 contents (65.44 to 74.46 wt%), Mg# values (39.2 to 50.7), and zircon saturation temperatures (745 to 846 °C); and with negative εHf (t) values (−8.0 to −1.9); therefore, they resulted from the partial melting of the ancient felsic lower crust accompanied by the incorporation of mantle-derived material during the intraplate magmatism process. Research on Tailu pluton has provided more sufficient evidence for the evolution process of the Qinling–Qilian conjunction zone in the Early Paleozoic, associated with evolution of the Wushan–Shangdan Ocean, the northern part of the Proto-Tethys Ocean.
{"title":"Investigating the Orogenic Evolution of the Wushan–Shangdan Ocean in the Qinling–Qilian Conjunction Zone: Insights from the Early Devonian Tailu Pluton","authors":"Hao Lin, Zuochen Li, Xianzhi Pei, Ruibao Li, Hai Zhou, Meng Wang, Shaowei Zhao, Li Qin, Mao Wang","doi":"10.3390/min14090910","DOIUrl":"https://doi.org/10.3390/min14090910","url":null,"abstract":"The main ocean–continent transformation stage of the Qinling and Qilian conjunction zone happened in the Early Paleozoic with the occurrence of a lot of subduction–collision–related magmatic rocks. However, there is still considerable controversy over the duration of the subduction–collision orogeny process of the Proto-Tethys Ocean, here termed as the Wushan–Shangdan Ocean. We provide geochronological, geochemical, and Lu-Hf isotopic data for typical Early Devonian igneous rocks there, named Tailu pluton. The Tailu pluton at 410 Ma comprised K-rich, calc-alkaline, metaluminous A-type granite with low Y/Nb ratios (0.85 to 1.35) and A/CNK values (0.90 to 1.01); with high SiO2 contents (65.44 to 74.46 wt%), Mg# values (39.2 to 50.7), and zircon saturation temperatures (745 to 846 °C); and with negative εHf (t) values (−8.0 to −1.9); therefore, they resulted from the partial melting of the ancient felsic lower crust accompanied by the incorporation of mantle-derived material during the intraplate magmatism process. Research on Tailu pluton has provided more sufficient evidence for the evolution process of the Qinling–Qilian conjunction zone in the Early Paleozoic, associated with evolution of the Wushan–Shangdan Ocean, the northern part of the Proto-Tethys Ocean.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215236","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}
Laboratory flotation tests carried out using an ore sample containing Rare Earth Elements (REEs) present as monazite and bastnaesite show that the flotation of monazite is slower and yielded lower recovery than that of bastnaesite. Results show that when studying the performances of a concentration process for an REE ore, it is essential to not look only at the behavior of the individual REEs but to convert elemental assays into mineral assays to obtain the mineral’s actual response to the concentration process. The results of the laboratory flotation tests are used to calibrate a flotation simulator applied to study different circuit configurations for the concentration of the REE minerals. Indeed, it is shown that for the studied ore, two cleaning stages of a rougher concentrate are sufficient to produce a concentrate with a Total Rare Earth Oxide (TREO) grade above 40%, which is acceptable for the subsequent hydrometallurgical process. The simulation also shows that it may be feasible, if required for the hydrometallurgy step, to separate bastnaesite and monazite by taking advantage of the different flotation kinetics of the two minerals.
{"title":"Investigation of the Flotation of an Ore Containing Bastnaesite and Monazite: Kinetic Study and Process Flowsheet Simulation","authors":"Claude Bazin, Jean-François Boulanger","doi":"10.3390/min14090906","DOIUrl":"https://doi.org/10.3390/min14090906","url":null,"abstract":"Laboratory flotation tests carried out using an ore sample containing Rare Earth Elements (REEs) present as monazite and bastnaesite show that the flotation of monazite is slower and yielded lower recovery than that of bastnaesite. Results show that when studying the performances of a concentration process for an REE ore, it is essential to not look only at the behavior of the individual REEs but to convert elemental assays into mineral assays to obtain the mineral’s actual response to the concentration process. The results of the laboratory flotation tests are used to calibrate a flotation simulator applied to study different circuit configurations for the concentration of the REE minerals. Indeed, it is shown that for the studied ore, two cleaning stages of a rougher concentrate are sufficient to produce a concentrate with a Total Rare Earth Oxide (TREO) grade above 40%, which is acceptable for the subsequent hydrometallurgical process. The simulation also shows that it may be feasible, if required for the hydrometallurgy step, to separate bastnaesite and monazite by taking advantage of the different flotation kinetics of the two minerals.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215238","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}
Bo Hui, Daxing Gong, Lu Xu, Yang Lai, Jianhua Qin, Ying Xu, Wei Yang, Haitao Lin
The Xuanwei Formation’s claystones in the Dian-Qian District of Southwest China are rich in rare-earth elements (REEs), suggesting their potential as a source of medium and heavy rare earths. However, the REE content in these rocks is lower than other types of rare-earth deposits, and the interrelationship among clay minerals is intricate. There is no direct evidence indicating the mineralization of REEs, limiting their beneficiation and extraction. The objective of this study is the characterization of REE distribution in the Dian-Qian District. The sedimentary rocks in this district are mainly composed of kaolinite, boehmite, quartz, rutile, and pyrite. The results of continuous chemical extraction of REE-rich claystone and transmission electron microscope (TEM) observations have confirmed that REEs occurred as florencite in the rocks, and that the ion-absorption state makes only a negligible contribution to the REE content. A close relationship between florencite and kaolinite makes traditional mineral processing operations very difficult. Combined with the properties of kaolinite, roasting-acid leaching was the efficacious approach for rare-earth resources extracted from the rare earth-rich clay rocks of the Xuanwei Formation.
{"title":"Sediment-Hosted Rare-Earth Elements Mineralization from the Dian-Qian District, Southwest China: Mineralogy and Mode of Occurrence","authors":"Bo Hui, Daxing Gong, Lu Xu, Yang Lai, Jianhua Qin, Ying Xu, Wei Yang, Haitao Lin","doi":"10.3390/min14090903","DOIUrl":"https://doi.org/10.3390/min14090903","url":null,"abstract":"The Xuanwei Formation’s claystones in the Dian-Qian District of Southwest China are rich in rare-earth elements (REEs), suggesting their potential as a source of medium and heavy rare earths. However, the REE content in these rocks is lower than other types of rare-earth deposits, and the interrelationship among clay minerals is intricate. There is no direct evidence indicating the mineralization of REEs, limiting their beneficiation and extraction. The objective of this study is the characterization of REE distribution in the Dian-Qian District. The sedimentary rocks in this district are mainly composed of kaolinite, boehmite, quartz, rutile, and pyrite. The results of continuous chemical extraction of REE-rich claystone and transmission electron microscope (TEM) observations have confirmed that REEs occurred as florencite in the rocks, and that the ion-absorption state makes only a negligible contribution to the REE content. A close relationship between florencite and kaolinite makes traditional mineral processing operations very difficult. Combined with the properties of kaolinite, roasting-acid leaching was the efficacious approach for rare-earth resources extracted from the rare earth-rich clay rocks of the Xuanwei Formation.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215239","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}
Yu Song, Paerzhana Paerhati, Shilin Xu, Bo Gao, Shu Jiang, Shuifu Li, Yuchen Wang, Hecun Lv
Although boron (B) is widely applied as a paleosalinity indicator for ancient lakes, the occurrence and geological controls of B enrichment in salinized lacustrine organic-rich shale (SLORS) are poorly understood. This study addresses this issue by comparing the mineral and element compositions of high-boron shale (HBS) and low-boron shale (LBS) from the Paleogene Biyang Depression, using integrated XRD, XRF, and ICP-MS analyses. The mineral composition of HBS is dominated by illite, whereas LBS primarily consists of albite; both are of detrital origin. Compared to the element composition of UCC, HBS is extremely enriched in Mo and W, whereas LBS is extremely enriched in W and U. Boron is positively correlated with Al2O3 and negatively correlated with Na2O, suggesting that B primarily occurs in illite. An enhanced extent of chemical weathering prevailed during the deposition of HBS, providing a greater supply of illite to the basin. Higher pH levels and greater reduction during HBS deposition encouraged illite absorption of B, ultimately leading to B enrichment in shale. Our findings suggest that pH and redox conditions, as well as the mineral compositions of shale, should be fully considered during the application of B and related ratios as paleosalinity indicators.
{"title":"Boron Enrichment in Salinized Lacustrine Organic-Rich Shale of the Paleogene Biyang Depression, East China: Occurrence and Geological Controlling Factors","authors":"Yu Song, Paerzhana Paerhati, Shilin Xu, Bo Gao, Shu Jiang, Shuifu Li, Yuchen Wang, Hecun Lv","doi":"10.3390/min14090904","DOIUrl":"https://doi.org/10.3390/min14090904","url":null,"abstract":"Although boron (B) is widely applied as a paleosalinity indicator for ancient lakes, the occurrence and geological controls of B enrichment in salinized lacustrine organic-rich shale (SLORS) are poorly understood. This study addresses this issue by comparing the mineral and element compositions of high-boron shale (HBS) and low-boron shale (LBS) from the Paleogene Biyang Depression, using integrated XRD, XRF, and ICP-MS analyses. The mineral composition of HBS is dominated by illite, whereas LBS primarily consists of albite; both are of detrital origin. Compared to the element composition of UCC, HBS is extremely enriched in Mo and W, whereas LBS is extremely enriched in W and U. Boron is positively correlated with Al2O3 and negatively correlated with Na2O, suggesting that B primarily occurs in illite. An enhanced extent of chemical weathering prevailed during the deposition of HBS, providing a greater supply of illite to the basin. Higher pH levels and greater reduction during HBS deposition encouraged illite absorption of B, ultimately leading to B enrichment in shale. Our findings suggest that pH and redox conditions, as well as the mineral compositions of shale, should be fully considered during the application of B and related ratios as paleosalinity indicators.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215240","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}
The increased exploitation of ores leads to the generation of mining waste, which has a negative impact on the environment and human health. For this reason, it is necessary to take care of it in an adequate way by applying some of the possible treatments. In addition to protecting the environment by applying appropriate treatment, there is also the possibility of making a profit by valorizing useful elements from mining waste. In order to choose the most adequate treatment, it is necessary to perform the characterization of mining waste. This paper contains a detailed characterization of the flotation tailings deposited at the Old Flotation Tailings in eastern Serbia, originating from copper ore processing. Characterization includes physico-chemical analysis, polarizing microscope analysis, X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) analysis analysis. The obtained results indicate that the investigated flotation tailings can be used as a secondary raw material for metal recovery, in this case primarily copper (whose content is about 0.24%), gold (with a content of about 0.43 ppm) and silver (with a content of about 1.7 ppm). Considering that the content of valuable elements is quite low, it is suggested to apply hydrometallurgical treatment for their recovery.
{"title":"Flotation Tailings from Cu-Au Mining (Bor, Serbia) as a Potential Secondary Raw Material for Valuable Metals Recovery","authors":"Vanja Trifunović, Ljiljana Avramović, Dragana Božić, Marija Jonović, Dragan Šabaz, Dejan Bugarin","doi":"10.3390/min14090905","DOIUrl":"https://doi.org/10.3390/min14090905","url":null,"abstract":"The increased exploitation of ores leads to the generation of mining waste, which has a negative impact on the environment and human health. For this reason, it is necessary to take care of it in an adequate way by applying some of the possible treatments. In addition to protecting the environment by applying appropriate treatment, there is also the possibility of making a profit by valorizing useful elements from mining waste. In order to choose the most adequate treatment, it is necessary to perform the characterization of mining waste. This paper contains a detailed characterization of the flotation tailings deposited at the Old Flotation Tailings in eastern Serbia, originating from copper ore processing. Characterization includes physico-chemical analysis, polarizing microscope analysis, X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) analysis analysis. The obtained results indicate that the investigated flotation tailings can be used as a secondary raw material for metal recovery, in this case primarily copper (whose content is about 0.24%), gold (with a content of about 0.43 ppm) and silver (with a content of about 1.7 ppm). Considering that the content of valuable elements is quite low, it is suggested to apply hydrometallurgical treatment for their recovery.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215149","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}
Igor V. Pekov, Natalia V. Zubkova, Vladimir N. Apollonov, Vasiliy O. Yapaskupt, Sergey N. Britvin, Dmitry Yu. Pushcharovsky
The new mineral calcioveatchite, ideally SrCaB11O16(OH)5·H2O, is a Ca-Sr-ordered analogue of veatchite. It was found at the Nepskoe potassium salt deposit, Irkutsk Oblast, Siberia, Russia in halite-sylvite and sylvite-carnallite rocks, with boracite, hilgardite, kurgantaite, hydroboracite, volkovskite, veatchite, anhydrite, magnesite, and quartz. Calcioveatchite forms prismatic or tabular crystals up to 1 × 1.5 × 3 mm3 and crystal clusters up to 3 mm across. It is transparent and colourless with vitreous lustre. Calcioveatchite is brittle, cleavage is perfect on {010}, the Mohs’ hardness is ca 2, Dmeas is 2.58(1), and Dcalc is 2.567 g cm−3. Calcioveatchite is optically biaxial (+), α = 1.543(2), β = 1.550(5), γ = 1.626(2), 2Vmeas = 30(10)°, and 2Vcalc = 35°. The average chemical composition (wt.%, electron microprobe, H2O calculated by stoichiometry) is: CaO 7.05, SrO 20.70, B2O3 61.96, H2O 10.22, and total 99.93. The empirical formula, calculated based on 22 O apfu = O16(OH)5(H2O) pfu, is Sr1.23Ca0.78B10.99O16(OH)5·H2O. Calcioveatchite is monoclinic, space group P21, a = 6.7030(3), b = 20.6438(9), c = 6.6056(3) Å, β = 119.153(7)°, V = 798.26(8) Å3, and Z = 2. Polytype: 1M. The strongest reflections of the powder XRD pattern [d,Å(I,%)(hkl)] are: 10.35(100)(020), 5.633(12)(110), 5.092(10)(120), 3.447(14)(060), 3.362(13)(101, 051), 3.309(38)(–102), 2.862(10)(012), and 2.585(19)(080). The crystal structure was solved based on single-crystal XRD data, R1 = 0.0420. Calcioveatchite (calcioveatchite-1M) is an isostructural analogue of veatchite-1M with the 11-fold cation polyhedron occupied mainly by Sr [Sr0.902(8)Ca0.098(8)] whereas the 10-fold polyhedron is Ca dominant [Ca0.686(7)Sr0.314(7)]. The chemical composition of veatchite from five localities in Russia (Nepskoe), Kazakhstan (Shoktybay and Chelkar in the North Caspian Region), and the USA (Tick Canyon and Billie Mine in California) was studied, and it is shown to exist in nature as a continuous, almost complete isomorphous series which extends from Ca-free veatchite, Sr2B11O16(OH)5·H2O, to calcioveatchite with the composition Sr1.14Ca0.87B10.99O16(OH)5·H2O.
{"title":"A New Mineral Calcioveatchite, SrCaB11O16(OH)5·H2O, and the Veatchite–Calcioveatchite Isomorphous Series","authors":"Igor V. Pekov, Natalia V. Zubkova, Vladimir N. Apollonov, Vasiliy O. Yapaskupt, Sergey N. Britvin, Dmitry Yu. Pushcharovsky","doi":"10.3390/min14090901","DOIUrl":"https://doi.org/10.3390/min14090901","url":null,"abstract":"The new mineral calcioveatchite, ideally SrCaB11O16(OH)5·H2O, is a Ca-Sr-ordered analogue of veatchite. It was found at the Nepskoe potassium salt deposit, Irkutsk Oblast, Siberia, Russia in halite-sylvite and sylvite-carnallite rocks, with boracite, hilgardite, kurgantaite, hydroboracite, volkovskite, veatchite, anhydrite, magnesite, and quartz. Calcioveatchite forms prismatic or tabular crystals up to 1 × 1.5 × 3 mm3 and crystal clusters up to 3 mm across. It is transparent and colourless with vitreous lustre. Calcioveatchite is brittle, cleavage is perfect on {010}, the Mohs’ hardness is ca 2, Dmeas is 2.58(1), and Dcalc is 2.567 g cm−3. Calcioveatchite is optically biaxial (+), α = 1.543(2), β = 1.550(5), γ = 1.626(2), 2Vmeas = 30(10)°, and 2Vcalc = 35°. The average chemical composition (wt.%, electron microprobe, H2O calculated by stoichiometry) is: CaO 7.05, SrO 20.70, B2O3 61.96, H2O 10.22, and total 99.93. The empirical formula, calculated based on 22 O apfu = O16(OH)5(H2O) pfu, is Sr1.23Ca0.78B10.99O16(OH)5·H2O. Calcioveatchite is monoclinic, space group P21, a = 6.7030(3), b = 20.6438(9), c = 6.6056(3) Å, β = 119.153(7)°, V = 798.26(8) Å3, and Z = 2. Polytype: 1M. The strongest reflections of the powder XRD pattern [d,Å(I,%)(hkl)] are: 10.35(100)(020), 5.633(12)(110), 5.092(10)(120), 3.447(14)(060), 3.362(13)(101, 051), 3.309(38)(–102), 2.862(10)(012), and 2.585(19)(080). The crystal structure was solved based on single-crystal XRD data, R1 = 0.0420. Calcioveatchite (calcioveatchite-1M) is an isostructural analogue of veatchite-1M with the 11-fold cation polyhedron occupied mainly by Sr [Sr0.902(8)Ca0.098(8)] whereas the 10-fold polyhedron is Ca dominant [Ca0.686(7)Sr0.314(7)]. The chemical composition of veatchite from five localities in Russia (Nepskoe), Kazakhstan (Shoktybay and Chelkar in the North Caspian Region), and the USA (Tick Canyon and Billie Mine in California) was studied, and it is shown to exist in nature as a continuous, almost complete isomorphous series which extends from Ca-free veatchite, Sr2B11O16(OH)5·H2O, to calcioveatchite with the composition Sr1.14Ca0.87B10.99O16(OH)5·H2O.","PeriodicalId":18601,"journal":{"name":"Minerals","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142215150","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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