Large Igneous Provinces,Richard E. Ernst,Cambridge University Press (2015), (653 pp., Hardback,price BP 85; US$ 130), ISBN: 978-0-521-87177-8     

《Ore Geology Reviews》2015

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淄博市西宝山耐火黏土矿地质特征及找矿方向     

孙聪聪 《山东国土资源》2020,36(3):20-25

西宝山耐火黏土矿为沉积型矿床,目前揭露1个耐火黏土矿矿层,赋存于石盒子群万山组底部“B”层黏土岩的下部,厚度较稳定,勘查开发潜力较大。通过对其地质特征、矿层特征、矿石结构构造及矿床成因分析,提出了找矿方向。认为该耐火黏土矿受沉积地层控制,呈层状分布,分布较稳定。依据该区地层产出情况,在青龙山断裂与禹王山断裂之间及两侧均具有良好的找矿前景,这为下一步找矿工作奠定了基础。  相似文献   

Tectonic evolution of the Qinling orogen and adjacent orogenic belts     

《Gondwana Research》2016

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The genesis of the ores and intrusions at the Yuhai Cu–Mo deposit in eastern Tianshan,NW China: Constraints from geology,geochronology, geochemistry,and Hf isotope systematics     

《Ore Geology Reviews》2016

The Yuhai porphyry Cu–Mo deposit is located in the eastern Tianshan orogenic belt of the southern Central Asian Orogen Belt, being an economically important porphyry Cu deposit in NW China. The deposit comprises sixteen buried orebodies that are predominantly associated with dioritic and granodioritic intrusions and are structurally controlled by roughly NE-trending faults. LA-ICP-MS zircon U–Pb dating yielded crystallization ages of 441.6 ± 2.5 Ma (MSWD = 0.03, n = 24) for diorite and 430.4 ± 2.9 Ma (MSWD = 0.04, n = 19) and 430.3 ± 2.6 Ma (MSWD = 0.09, n = 24) for granodiorite. In situ zircon Hf isotope data on a diorite sample show ε_Hf(t) values from + 8.7 to + 18.6, and two granodiorite samples exhibit similar ε_Hf(t) values from + 12.6 to + 19.6 and + 12.6 to + 18.9, respectively. The dioritic and granodioritic intrusions belong to a low-K tholeiite series and are relatively enriched in large ion lithophile elements (K, Ba, Pb, and Sr) and are depleted in high field strength elements (Th, Nb, Ta, and Ti). Moreover, these intrusions have high SiO₂, Al₂O₃ and MgO contents, low Na₂O, P₂O₅ and TiO₂ contents, low Nb/Ta ratios, and slightly positive Eu anomalies. Re–Os dating of molybdenite intergrowth with chalcopyrite yielded a well-constrained ¹⁸⁷Re–¹⁸⁷Os isochron age of 351.7 ± 2.9 Ma (MSWD = 1.5) with a weighted average age of 355.7 ± 2.4 Ma (MSWD = 0.69) Ma, indicating that the Yuhai Cu–Mo deposit is younger than the intrusion of the diorite and granodiorite. Combined with the regional geological history and above-mentioned data, we suggest that the Yuhai intrusions were most likely derived from the partial melting of mantle components that were previously metasomatized by slab melts formed by the northward subduction of the ancient Tianshan ocean plate beneath the Dananhu–Tousuquan island arc during the Silurian to Carboniferous. Under the subduction-related tectonic setting, the metasomatized mantle magma was emplaced into the shallow crust and induced the formation of the Early Carboniferous Yuhai Cu–Mo deposit, and the hydrothermal fluids of enriched sulfides probably played an important role in the Cu–Mo mineralization.  相似文献   

新疆东天山地区土屋和延东铜矿床斑岩叠加改造成矿作用   总被引：2，自引：0，他引：2  

王云峰  陈华勇  肖兵  韩金生  杨俊 《矿床地质》2016,35(1):51-68

土屋和延东铜矿床位于东天山大南湖-头苏泉岛弧带南部,是中亚成矿带的重要组成部分。文章根据脉次穿插关系、蚀变矿物组合及矿物共生关系,将土屋和延东铜矿床均划分为斑岩成矿期、叠加改造期和表生期3个期次。土屋铜矿床的铜矿化形成于斑岩成矿期和叠加改造期,而延东铜矿床的铜矿化主要形成于叠加改造期;土屋和延东铜矿床伴生的钼矿化主要形成于叠加改造期。因此,笔者认为前人获得的辉钼矿Re-Os年龄(326.2~322.7 Ma)代表叠加改造期的成矿年龄,该期矿化与石英钠长斑岩((323.6±2.5)Ma)的侵入相关,而斑岩成矿期的矿化与斜长花岗斑岩(339~332 Ma)相关,成矿年龄为341.2~333.9 Ma。叠加改造期的存在,使得斑岩成矿期的蚀变分带可能受到了叠加和破坏。  相似文献   

Geochemical Characteristics and Tectonic Significance of Early Carboniferous Volcanic Rocks of Kalamaili,Xinjiang     

Chen Wanfeng  Guo Gang  Miao Xiuquan  Wang Jinrong  Hu Wanlong  Zhao Binbin  Fan Lifei 《地球科学进展》2016,31(2):180-191

Shanlianglishi Formation strata volcanic rocks are widely distributed in western fault zone of Kalamaili. Studies show that the rocks are basalt, andesite and basaltic andesite, calc-alkaline series with SiO₂ content of samples ranging from 49.43% to 59.08%, TiO₂ (1.18%~2.49%), P₂O₅ (0.21%~0.92%) and MgO (3.81%~6.28%). Samples have relatively high HFSE content (Ti, Zr, Y) and also high La/Nb (2.98~1.96), Zr/Y (9.36~4.01) ratio. The primitive mantle normalized trace element spider shows samples enriched LILE (Rb, Ba, K, U) and Pb, but relatively depleted Nb, Ta and Ti. Rare earth element distribution of REE shows slightly enriched LREE, (La/Yb)_N=1.93~9.59, and that Eu is weakly negative anomaly (δEu=0.87~0.95). Combined with geochemical characteristics of WPB and VAB. Shanlianglishi Formation strata formed in the stretched after collision environmen. After partial melting of the enriched mantle that was previously metasomatized by the subduction fluid and with participation of the subduction sediment, magma experienced a certain degree of fractional crystallization and contamination by earth crust, and then erupted to form the Shanlianglishi Formation strata volcanic rocks. In eraly Late-Carboniferous, extensional movement was the most intense volcanic activity, which reached its peak in this area.  相似文献   

Distribution of PGE in Permo-Triassic basalts of the Siberian Large Igneous Province     

《Russian Geology and Geophysics》2016,57(5):809-821

We have revealed the spatio-temporal regularities of distribution of platinum group elements (PGE) in basaltoids related to the activity of the Siberian mantle plume. As objects of study, we chose rift and flood basalts from the Norilsk district (sampled from the SD-9 borehole), flood basalts from the central part of the Tunguska syneclise (Lower Tunguska), Kuznetsk Basin traps, and subalkalic basalt from the Semeitau volcanoplutonic structure in eastern Kazakhstan. Based on the PGE patterns of basaltoids related to the activity of the Permo-Triassic Siberian plume, we have shown that the rocks that formed in the central part of the Siberian Large Igneous Province (LIP) at the early rift stage have low contents of PGE, whereas picrites and tholeiitic flood basalts have high contents. The rift (Semeitau structure) and flood (Kuznetsk Basin traps) basalts from the peripheral regions are characterized by extremely low PGE contents. The high PGE contents in magmas of the plume head are responsible for the high productivity of ultramafic-mafic trap magmatism. The elevated K contents in magmas and the high PGE contents in the mantle plume head are probably due to the ascent of deep-seated material from the core-lower-mantle boundary, as follows from the thermochemical model of the Siberian plume.  相似文献   

From convergent plate margin to arc–continent collision: Formation of the Kenting Mélange,Southern Taiwan     

《Gondwana Research》2016

The Kenting Mélange on the Hengchun Peninsula, Taiwan, formed through tectonic shearing of subduction complex lithologies, probably within the plate boundary subduction channel between the Eurasian and Philippine Sea plates, with further deformation and exhumation in the Pliocene–Pleistocene during arc–continent collision. Field relations reveal a structural gradation from normal stratified turbidite sequence (Mutan Formation) through broken formation to highly sheared Kenting Mélange containing allochthonous polygenic blocks. This gradation is consistent with an increase of average vitrinite reflection values from ~ 0.72% in the Mutan Formation through ~ 0.93% in the broken formation to ~ 0.99% in the mélange, suggesting temperatures of at least 140 °C during formation of the Kenting Mélange. Zircons from gabbro in the Kenting Mélange are dated as 25.46 ± 0.18 Ma, which together with geochemical data constrains the source to South China Sea oceanic lithosphere. In combination with the field relationships, vitrinite reflectance values, microfossil stratigraphy, and offshore geophysical data from S and SE Taiwan, we propose that the Kenting Mélange initially formed at the subduction plate boundary from off-scraped trench deposits. Minor Plio–Pleistocene microfossils (< 5%) occur within the mélange in proximity to slope basin of equivalent age and were likely sheared into the mélange during out-of-sequence thrusting associated with active arc–continent collision, which in the Hengchun Peninsula commenced after 6.5 Ma.  相似文献   

Geochronology and geochemistry of igneous rocks in the Bailingshan area: Implications for the tectonic setting of late Paleozoic magmatism and iron skarn mineralization in the eastern Tianshan,NW China     

《Gondwana Research》2016

The late Paleozoic Bailingshan intrusions and volcanic rocks are located in the Aqishan–Yamansu arc belt in the southern part of the eastern Tianshan and are associated with an important group of iron skarn deposits. The exposed intrusive rocks are mainly granodiorite, monzonitic granite, and granite. Zircon U–Pb dating of the Tugutublak Formation tuffaceous dacitic lava yields an age of 324 Ma, whereas dates of the Bailingshan granodiorite, monzonitic granite, and granite yields ages of 317 Ma, 313 Ma, and 307 Ma, respectively. The results indicate that the Bailingshan granitoids were emplaced soon after the eruption of the Tugutublak dacite. All these rocks studied show calc-alkaline to high-K calc-alkaline and metaluminous affinities, with A/CNK values ranging 0.83–1.10. They are enriched in Rb, K, and Pb, depleted in Nb, Ta, Ti, and P, and contain low Sr/Y (4.16–23.7) and Sr (109.0–347.0 ppm) values, displaying typical arc geochemical affinities. The tuffaceous dacitic lava has low Nb/Ta (10.3–14.1) values, a wide range of Mg^# (6–64), positive zircon ε_Hf(t) (3.2–7.5) values, and elevated whole-rock ε_Nd(t) (2.03–4.41), but low I_Sr values (0.70427–0.70530), indicating that the source magma may have been derived from the juvenile lower crust with minor mantle input. The Bailingshan I-type intrusions also exhibit a mixed source signal, as constrained by Nb/Ta ratios, Mg^#, and isotopes characteristics. Because the granodiorite, monzonitic granite, and granite intrusions have higher zircon ε_Hf(t) (3.3–7.5, 11.8–13.5, and 10.2–14.4, respectively) and ε_Nd(t) (3.90, 5.78, and 5.94, respectively) values than those of the tuffaceous dacitic lava, it is suggested that mantle-derived materials may have played a more prominent role with their petrogenetic evolution. Integrating our new geological, age, geochemical and isotopic data we propose that the Aqishan–Yamansu iron skarn belt may have formed in a back-arc position or within an intra-arc basin generated by the southward subduction of the Kanggur oceanic plate beneath the Yili–Central Tianshan block during the late Paleozoic, with felsic-intermediate magmatism occurring during the basin inversion.  相似文献   

西藏谢通门地区中侏罗世花岗岩的地球化学特征及时代依据     

王贝  李鹏  刘智贤  程龙  闫磊  王卫军 《地质通报》2016,35(9):1479-1487

西藏谢通门县一带区域上属于冈底斯花岗岩带南亚带,侵入岩极其发育,目前填绘有白垩纪、古近纪和新近纪岩体。通过同位素年代学研究,获得12个锆石的U-Pb同位素年龄数据,在原划归白垩纪、古近纪和新近纪岩体中解体出侏罗纪侵入体,按其岩石类型特征,归并为早侏罗世东热村序列和中侏罗世东嘎乡序列。其中,在约拉嘎莫岩体中获得锆石U-Pb同位素年龄166.9±2.8Ma,时代为中侏罗世巴柔期。  相似文献