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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

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Geoscience Frontiers 2015年第2期6卷 191-209页

作者： mark scheltens Lifei Zhang Wenjiao Xiao Jinjiang Zhang School of Earth and Space Sciences Peking University State Key Laboratory of Lithosphere Evolution Institute of Geology and Geophysics Chinese Academy of Sciences

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 cloclkwise 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.

关键词： Structural geology Tianshan Subduction polarity HP/UHP belt

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Mineral Chemistry and Crystallization Conditions of the Late Cretaceous Mamba Pluton from the Eastern Gangdese, Southern Tibetan Plateau

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Journal of Earth Science 2016年第4期27卷 545-570页

作者： Xiaowei Li Xuanxue Mo mark scheltens Qi Guan State Key Laboratory of Geological Processes and Mineral Resources School of Earth Sciences and ResourcesChina University of Geosciences School of Earth and Space Sciences Peking University College of Resources Hebei GEO University

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.

关键词： Mamba pluton Gangdese terrane MMEs K-feldspar megacrysts magma mixing P-Tconditions oxygen fugacity in-situ trace element.

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The Neoarchean ultramafic–mafic complex in the Yinshan Block,North China Craton:Magmatic monitor of development of Archean lithospheric mantle

The Neoarchean ultramafic–mafic complex in the Yinshan Bloc...

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中国科学院地质与地球物理研究所2015年度（第15届）学术年会

作者： Dan Wang Jinghui Guo Guangyu Huang mark scheltens State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking University

Neoarchean ultramafic–mafic complexes are critical for characterizing the embryonic continental lithosphere and hence for arbitrating the extrapolation of plate tectonics into the Archean *** geochronological and geochemical study documents the newly identified amphibolite-to granulite-facies Xiwulanbulang(XWLBL)ultramafic–mafic complex in the Yinshan Block,North China Craton(NCC).It is composed mainly of meta-gabbro,hornblendite and *** U–Pb zircon dating on the later granite constrains a minimum formation age of～2581 Ma for the complex,whereas the metamorphic zircons from the hornblendite and coexisting kyanite-garnet gneiss yield a metamorphic age of～2.50 *** dominant meta-gabbros in the complex show an"MORB"composition,and characterized by an LREE-depleted to flat REE pattern,yet possessing prominent Nb,Zr and Ti depletions,which suggest dual geochemical *** with their depletedεNd(t)isotope compositions(+1.77 to+2.23)and regional high temperature high Mg#basaltic magmatism,we suggest that they may have been produced by interaction of the upwelling asthenosphere with the metasomatized lithospheric *** hornblendites/pyroxenites that occurred in the complex display high Mg O(13.6–20.2 wt.%),Ca O(7.5–13.8 wt.%),Cr(475–2049 ppm)and Ni(154–859 ppm)contents,reflecting they have originated either as a crystal mush magma or high-degree partial melts of a mantle *** show moderately fractionated REE patterns((La/Yb)N=2.9–10.7)but depletedεNd(t)(+1.48 to+3.53)and zirconεHf(t)(up to+7.3)*** their negative anomalies for Nb,Zr and Ti relative to neighboring REE,we suggest that the mantle source of the hornblendites was refractory depleted peridotite that experienced prior basaltic magma extraction followed by metasomatism of subduction-related *** variations trend in both major and trace elements between the hornblendites and the associated serpentinites support their genetic *** Ca

关键词： Neoarchean Hornblendites Mafic-ultramafic rocks Yinshan Block North China Craton

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Regulated upon activation,normal T cell expressed and secreted(RANTES)levels in the peripheral blood of patients with Alzheimer’s disease

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Neural Regeneration Research 2021年第4期16卷 775-779页

作者： Gabriela Vacínová Daniela Vejražkova Robert Rusina Iva Holmerová Hana Vaňková Eva Jarolímová Josef Včelák Běla Bendlová markéta Vaňková Department of Molecular Endocrinology Institute of EndocrinologyPragueCzech Republic Department of Anthropology and Human Genetics Faculty of ScienceCharles UniversityPragueCzech Republic Department of Neurology Third Faculty of Medicine of Charles University and Thomayer Hospital PragueCzech Republic II.Internal Medicine Clinic Third Faculty of MedicineCharles UniversityPragueCzech Republic Faculty of Humanitites Charles University PragueCzech Republic

Alzheimer’s disease(AD)is the most common type of dementia,but it is very difficult to diagnose with certainty,so many AD studies have attempted to find early and relevant diagnostic *** upon activation,normal T cell expressed and secreted(RANTES,also known as C-C chemokine ligand)is a chemokine involved in the migration of T cells and other lymphoid *** in RANTES levels and its expression in blood or in cerebrospinal fluid have been reported in some neurodegenerative diseases,such as Parkinson’s disease and multiple sclerosis,but also in metabolic diseases in which inflammation plays a *** aim of this observational study was to assess RANTES levels in peripheral blood as clinical indicators of *** levels of RANTES were investigated in 85 AD patients in a relatively early phase of AD(median 8.5 months after diagnosis;39 men and 46 women;average age 75.7 years),and in 78 control subjects(24 men and 54 women;average age 66 years).We found much higher plasma levels of RANTES in AD patients compared to controls.A negative correlation of RANTES levels with age,disease duration,Fazekas scale score,and the medial temporal lobe atrophy(MTA)score(scheltens’s scale)was found in AD patients,i.e.,the higher levels corresponded to earlier stages of the *** RANTES levels were not correlated with cognitive *** AD patients,RANTES levels were positively correlated with the levels of pro-inflammatory cytokines interleukin-6 and tumor necrosis factor-α,which is consistent with the wellknown fact that AD is associated with inflammatory *** levels were also positively correlated with insulin levels in AD patients,with insulin resistance(HOMA-R)and pancreatic beta cell function(HOMA-F).This study evaluated several clinical and metabolic factors that may affect plasma levels of RANTES,but these factors could not explain the increases in RANTES levels observed in AD *** levels of RANTES appear to be an interesting

关键词： Alzheimer’s disease biomarker central nervous system cognitive impairment inflammation RANTES

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