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您的检索式：作者名="Mark Scheltens"
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| 1 | Mineral Chemistry and Crystallization Conditions of the Late Cretaceous Mamba Pluton from the Eastern Gangdese, Southern Tibetan Plateau显示文摘The Late Cretaceous Mamba granodiorite belongs to a part of the Mesozoic Gangdese continental magmatic belt. No quantitative mineralogical study has been made hitherto, and hence the depth at which it formed is poorly constrained. Here we present mineralogical data for the Mamba pluton, including host rocks and their mafic microgranular enclaves(MMEs), to provide insights into their overall crystallization conditions and information about magma mixing. All amphiboles in the Mamba pluton are calcic, with ~B(Ca+Na)>1.5, and Si=6.81–7.42 apfu for the host rocks and Si=6.77–7.35 apfu for the MMEs. The paramount cation substitutions in amphibole include edenite type and tschermakite type. Biotites both in the host rocks and the MMEs collectively have high Mg O(13.19 wt.%–13.03 wt.%) contents, but define a narrow range of Al apfu(atoms per formula unit) variations(2.44–2.57). The oxygen fugacity estimates are based on the biotite compositions cluster around the NNO buffer. The calculated pressure ranges from 1.2 to 2.1 kbar according to the aluminum-in-hornblende barometer. The computed pressure varies from 0.9 to 1.3 kbar based on the aluminum-in-biotite barometer which corresponds to an average depth of ca. 3.9 km. Besides, the estimates of crystallization pressures vary from 0.8 to 1.4 kbar based on the amphibole barometer proposed by Ridolfi et al.(2010), which can be equivalent to the depths ranging from 3.1 to 5.2 km. The MMEs have plagioclase oscillatory zonings and quartz aggregates, probably indicating the presence of magma mixing. Besides, core-to-rim element variations(Rb, Sr, Ba, and P) for the K-feldspar megacrysts serve as robust evidence to support magma mixing and crystal fractionation. This indicates the significance of the magma mixing that contributes to the formation of K-feldspar megacryst zonings in the Mamba pluton. | Xiaowei Li Xuanxue Mo Mark Scheltens Qi Guan | 2016 | Journal of Earth Science2016，27，4： | 11 |
| 2 | Northward subduction-related orogenesis of the southern Altaids:Constraints from structural and metamorphic analysis of the HP/UHP accretionary complex in Chinese southwestern Tianshan,NW China显示文摘The Chinese Tianshan belt of the southern Altaids has undergone a complicated geological evolution.Different theories have been proposed to explain its evolution and these are still hotly debated.The major subduction polarity and the way of accretion are the main problems.Southward,northward subduction and multiple subduction models have been proposed.This study focuses on the structural geology of two of the main faults in the region,the South Tianshan Fault and the Nikolaev Line.The dip direction in the Muzhaerte valley is southward and lineations all point towards the NW.Two shear sense motions have been observed within both of these fault zones,a sinistral one,and a dextral one,the latter with an age of 236-251 Ma.Structural analyses on the fault zones show that subduction has been northward rather than southward.The two shear sense directions indicate that the Yili block was first dragged along towards the east due to the clockwise rotation of the Tarim block.After the Tarim block stopped rotating,the Yili block still kept going eastward,inducing the dextral shear senses within the fault zones. | Mark Scheltens Lifei Zhang Wenjiao Xiao Jinjiang Zhang | 2015 | Geoscience Frontiers2015，6，2： | 5 |
| 3 | How Useful Is the IQCODE for Discriminating between Alzheimer’s Disease, Mild Cognitive Impairment and Subjective Memory Complaints?显示文摘 | Sikkes Sietske A M Van Den Berg Mark T Knol Dirk L De Lange-de Klerk Elly S M Scheltens Philip Uitdehaag Bernard M J Klein Martin Pijnenburg Yolande A L | 2010 | Dementia and Geriatric Cognitive Disorders2010，，： | 1 |
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