Oxidation state inherited from the magma source and implications for mineralization: Late Jurassic to Early Cretaceous granitoids, Central Lhasa subterrane, Tibet
Oxidation state inherited from the magma source and implications for mineralization: Late Jurassic to Early Cretaceous granitoids, Central Lhasa subterrane, Tibet
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岩浆源继承的氧化态及其对成矿的影响：西藏拉萨中部地下晚侏罗世至早白垩世花岗岩类
DOI：
10.1007/s00126-017-0739-3
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发表时间：
2018-03
影响因子：
4.8
通讯作者：
Junxing Zhao
中科院分区：
文献类型：
--
作者：
Mingjian Cao;Kezhang Qin;Guangming Li;Noreen J. Evans;Brent I.A. McInnes;Jinxiang Li;Junxing Zhao
Arc magmas are more oxidized than mid-ocean ridge basalts; however, there is continuing debate as to whether this higher oxidation state is inherited from the source magma or developed during late-stage magmatic differentiation processes. Well-constrained Late Jurassic to Early Cretaceous arc-related intermediate to felsic rocks derived from distinct magma sources provide us with a good opportunity to resolve this enigma. A series of granitoids from the western Central Lhasa subterrane were analyzed for whole-rock magnetic susceptibility, Fe2O3/FeO ratios, and trace elements in zircon. Compared to Late Jurassic samples (1.8 ± 2.0 × 10−4emu g−1oe−1, Fe3+/Fetotal= 0.32 ± 0.07, zircon Ce4+/Ce3+* = 15.0 ± 13.4), Early Cretaceous rocks show higher whole-rock magnetic susceptibility (5.8 ± 2.5 × 10−4emu g−1oe−1), Fe3+/Fetotalratios (0.43 ± 0.04), and zircon Ce4+/Ce3+* values (23.9 ± 22.3). In addition, positive correlations among whole-rock magnetic susceptibility, Fe3+/Fetotalratios, and zircon Ce4+/Ce3+* reveal a slight increase in oxidation state fromfO2= QFM to NNO in the Late Jurassic tofO2= ∼NNO in the Early Cretaceous. Obvious linear correlation between oxidation indices (whole-rock magnetic susceptibility, zircon Ce4+/Ce3+*) and source signatures (zircon εHf(t), TDMCages) indicates that the oxidation state was predominantly inherited from the source with only a minor contribution from magmatic differentiation. Thus, the sources for both the Late Jurassic and Early Cretaceous rocks were probably influenced by mantle wedge-derived magma, contributing to the increasedfO2. Compared to ore-forming rocks at giant porphyry Cu deposits, the relatively low oxidation state (QFM to NNO) and negative εHf(t) (−16 to 0) of the studied granitoids implies relative infertility. However, this study demonstrates two potential fast and effective indices (fO2and εHf(t)) to evaluate the fertility of granitoids for porphyry-style mineralization. In an exploration context for the west Central Lhasa subterrane, features indicative of potential fertility might include more oxidized, positive εHf(t), young rocks (<130 Ma).
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影响因子：
3.5
作者：
S. Eggins
通讯作者：
S. Eggins
影响因子：
2.9
作者：
Mingjian Cao;Guangming Li;K. Qin;N. Evans;E. Seitmuratova
通讯作者：
Mingjian Cao;Guangming Li;K. Qin;N. Evans;E. Seitmuratova
包古图还原斑岩铜矿床（中国西北准噶尔）钛铁矿系列 I 型花岗岩的结晶条件和岩石成因的矿物学证据：穆斯堡尔谱、EPM 和 LA-(MC)-ICPMS 分析
影响因子：
3.3
作者：
Mingjian Cao;Kezhang Qin;Guangming Li;Noreen J. Evans;Pete Hollings;Markus Maisch;Andreas Kappler
通讯作者：
Andreas Kappler
影响因子：
3.5
作者：
Sophie Demouy;J. Paquette;M. Blanquat;M. Benoit;E. Belousova;S. O’Reilly;F. García;L. C. Tejada;Ricardo Gallegos;T. Sempéré
通讯作者：
Sophie Demouy;J. Paquette;M. Blanquat;M. Benoit;E. Belousova;S. O’Reilly;F. García;L. C. Tejada;Ricardo Gallegos;T. Sempéré
影响因子：
3.5
作者：
Jinxiang Li;K. Qin;Guangming Li;J. Richards;Junxing Zhao;Mingjian Cao
通讯作者：
Jinxiang Li;K. Qin;Guangming Li;J. Richards;Junxing Zhao;Mingjian Cao