首页|Newly discovered Ordovician Li-Be deposits at Tugeman in the Altyn-Tagh Orogen, NW China

Newly discovered Ordovician Li-Be deposits at Tugeman in the Altyn-Tagh Orogen, NW China

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  • NSTL
  • Elsevier
Magmatism was widespread in the Proterozoic to Early Paleozoic Altyn-Tagh Orogen of NW China. Rare metal deposits hosted by ca. 472 Ma pegmatite dykes with a monzogranitic geochemistry have recently been discov-ered in the orogen, including the Tugeman Li-Be deposit. The pegmatites contain spodumene - beryl (- columbite - tantalite - cassiterite), and are coeval with the ca. 482 Ma biotite monzogranite as a late-stage phase of the monzogranite, and both the monzogranite and pegmatite intrude orthogneiss and gneissic syenogranite. Two samples of biotite monzogranite yield weighted mean Laser Ablation-Inductively Coupled Plasma-Mass Spec-trometry (LA-ICP-MS) U-Pb zircon dates of 482 +/- 5 and 475 +/- 5 Ma, and columbite-tantalite dates of 472 +/- 8 Ma for the pegmatite, and minimum dates of 438-412 Ma for hosts of the columbite-tantalite. The gneissic sye-nogranite and orthogneiss in the deposit's wallrocks have zircon U-Pb ages of ca. 900 Ma. The geochemistry and Hf-Lu isotopic systematics indicated that the protoliths for the gneissic syenogranite and orthogneiss have a mantle source with a contribution from the Proterozoic crust, and the biotite monzogranite has a Proterozoic crustal source. The Tugeman Li-Be deposit, therefore, has a Precambrian crustal source and was deposited during the Ordovician, which we propose was a post-collision extensional event and a previously unknown mineralising event in China.

OrdovicianPegmatite Li-Be depositZircon and columbite-tantalite U-Pb datingGeochemistry and Hf isotopesTugeman areaAltyn-Tagh OrogenA-TYPE GRANITOIDSU-PB AGESSOUTH ALTYNLU-HFGEOCHEMICAL CHARACTERISTICSGEOLOGICAL SIGNIFICANCETRACE-ELEMENTZIRCONGEOCHRONOLOGYPEGMATITES

Gao, Yongbao、Zhao, Xinmin、Bagas, Leon、Wang, Yalei、Jin, Moushun、Zhang, Jiangwei、Lu, Lin、Gao, Yijie、Yan, Zhouquan、Teng, Jiaxin、Yang, Zhiquan

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China Geol Survey

Second Comprehens Geophys Survey Team Co

Xinjiang Bur Geol & Mineral Explorat & Dev

2021

10.1016/j.oregeorev.2021.104515

Ore Geology Reviews

Ore Geology Reviews

EISCI
ISSN：0169-1368
年,卷(期)：2021.139(Pt.B)
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