期刊
INTERNATIONAL GEOLOGY REVIEW
卷 61, 期 3, 页码 280-295出版社
TAYLOR & FRANCIS INC
DOI: 10.1080/00206814.2017.1423521
关键词
Tarim Craton; A-type granite; U-Pb-Hf isotopes; breakup of the Rodinia
类别
资金
- National Science and Technology Major Project [2016ZX05004001]
- National Natural Science Foundation of China [41472103]
Due to sparse data for deciphering the late Neoproterozoic tectonic history, there is still considerable debate on whether long-lasting superplume-related or long-duration subduction-related dynamics dominated the Tarim Craton. In this contribution, our field investigations detail the late Neoproterozoic siliciclastic successions, and we report the first granitic conglomerates with zircon U-Pb ages of 753.9 +/- 3.7 Ma in the SW Tarim Craton. Importantly, detrital zircons from the thick Cryogenian sedimentary basin also contain a major zircon population at ca. 750 Ma. Together with seismic data, this suggests a large ca. 750 Ma magmatic event in the SW Tarim Craton. Geochemically, the granitic clasts exhibit A-type granite features with high SiO2, high alkali but extremely low K, high FeOT/MgO and Ga/Al, and high high-field strength elements (HFSEs) (i.e. Nb, Hf, and Ta) with significant depletion in Rb, K, Sr, P, Eu, and Ti, and significant negative Eu anomalies (Eu* = 0.13-0.36), showing ferroan granite affinities. Including the detrital zircons, the ca. 750 Ma zircons have a large range of negative epsilon Hf(t) values (-19.46 to -1.16). Elemental and zircon Hf isotope data suggest that the granites were derived from Palaeoproterozoic reworked continental crust and are probably related to crustal thinning and extension. By comparison with previous studies, we conclude that Rodinia breakup was diachronous in the outer parts of the supercontinent.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据