Geochemical Characteristics and Genesis of the Niobium-rich Carbonatite in the Dagele Area, East Kunlun

被引：0

作者：

Wang T. ^{[1
,2
,3
]}

Li W. ^{[1
]}

Wang B. ^{[1
]}

Wang T. ^{[1
,2
,3
]}

Li J. ^{[1
]}

Xue W. ^{[1
]}

Li Y. ^{[1
]}

Lin Y. ^{[1
]}

Wang C. ^{[1
]}

Zhang X. ^{[1
]}

Cao J. ^{[1
]}

Yuan B. ^{[1
]}

Zheng Y. ^{[1
]}

Li Q. ^{[1
]}

Zhang X. ^{[1
]}

Zhao Z. ^{[1
]}

Jin T. ^{[1
]}

Ma L. ^{[1
]}

Han X. ^{[1
]}

机构：

[1] Qinghai Geological Survey Institute, Qinghai, Xining

[2] Key Laboratory of the Northern Qinghai-Tibet Plateau Geological Processes and Mineral Resources, Qinghai, Xining

[3] Engineering and Technology Center of Remote Sensing Big Data in Qinghai Province, Qinghai, Xining

来源：

Geotectonica et Metallogenia | 2024年 / 48卷 / 01期

关键词：

C-O isotope; carbonatite; Dagele; geochemical; mantle source; Sr-Nd isotope;

D O I：

10.16539/j.ddgzyckx.2024.01.005

中图分类号：

学科分类号：

摘要：

The newly discovered carbonatite in the Dagele area is vital for understanding the geological processes in the East Kunlun Orogen. In this contribution, we discuss the genesis of the carbonatite on the basis of major, trace and rare earth elements, and isotope compositions. The carbonatite is mainly composed of CaO (24.17%-30.40%), MgO (15.56%-18.91%), SiO2 (0.61%-6.25%), and CO2 (25.09%-36.09%). The carbonatite belongs to magnesia carbonatite, with CaO/(CaO+MgO+FeOT+MnO) mole ratios varying from 0.41 to 0.51. The carbonatite is extremely enriched in light rare earth elements, with ∑REE contents varying from 515 μg/g to 1863 μg/g, and (La/Yb)N of 284 to 589, without significant Eu and Ce anomalies. The carbonatite is enriched in Nb, Sr, Th, U, Pb, P, with Nb contents varying from 126 μg/g to 5009 μg/g (average 1568 μg/g). On the contrast, the carbonatite is depleted in Rb, K, Ti, Ba, Zr, Hf elements, and HREE, which have concentrations close to those of the primitive mantle. The carbonatite is characterized by relatively low (87Sr/86Sr)i (0.703718-0.703964) and εNd(t) (-1.07 - -0.33) values, and mantle like δ13CV-PDB (-8.5% to -5.7%) and δ18OV-SMOW (8.9% to 14.4%). The isotopic compositions and trace element characteristics indicate that the Dagele carbonatite was derived from a mantle source, and was subjected to hydrothermal alteration. It can be inferred that the carbonatite might have been closely related to the asthenosphere mantle upwelling following the Early Devonian collision in East Kunlun. © 2024 Science Press. All rights reserved.

引用

页码：97 / 113

页数：16

共 53 条

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