Earth Science Frontiers ›› 2023, Vol. 30 ›› Issue (5): 275-297.DOI: 10.13745/j.esf.sf.2023.5.9

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Metallogenic epoch, magmatic evolution and metallogenic significance of the Gabo lithium pegmatite deposit, Himalayan metallogenic belt, Tibet

GUO Weikang1(), LI Guangming1,*(), FU Jiangang1, ZHANG Hai1, ZHANG Linkui1, WU Jianyang1, DONG Suiliang1, YANG Yulin2   

  1. 1. Chengdu Center, China Geological Survey (Geosciences Innovation Center of Southwest China), Chengdu 610218, China
    2. Chengdu University of Technology, Chengdu 610059, China
  • Received:2022-11-29 Revised:2022-12-28 Online:2023-09-25 Published:2023-10-20
  • Contact: LI Guangming

Abstract:

In recent years rare-metal metallogeny of the Himalayan leucogranite belt has attracted much attention, and the discovery of the Cuonadong and Qiongjiagang rare-metal deposits sets a prelude to the rare-metal exploration and research in the Himalayas. According to previous researches the Himalayan metallogenic belt is expected to become a new world-class Li-Be-W-Sn metallogenic belt. One example is the Gabo lithium pegmatite deposit in northeastern Kulagangri Dome. This study focuses on the metallogenic characteristics, formation age and magmatic evolution of the Gabo pegmatite deposit. Rare-metal (Li, Be, Rb, Nb, Ta) minerals of the Gabo pregmatites include spodumene, elbaite, lepidolite, petalite, columbite-tantalite and beryl. The pegmatites have simple zonal structures. Spodumene mainly occurs as fine albite-spodumene or massive microline-spodumene zones, where the former is the main component of ore body. Monazite U-Pb dating results show that the Gabo pegmatites were formed in the Early Miocene (23-21 Ma) coinciding with the period of peak activity of the southern Tibet detachment system (STDS), which indicate a close genetic relationship between pegmatite formation and STDS activities. According to their petrology, mineralogy and geochemistry, the Gabo pegmatites are highly differentiated and evolved, where plagioclase, zircon, mica and other minerals were formed during fractional crystallization of pegmatite-forming melts. According to chemical compositional analysis muscovite is the main mica type in the Gabo pegmatites, whilst the occurrence of lepidolite is indicative of high-level pegmatite differentiation as the increase of magmatic differentiation led to decrease of Fe-Mn contents and increase of Li content in mica. The Gabo lithium pegmatite deposit is an important achievement in rare-metal prospecting based on metallogenic models of the Himalayan leucogranite, which in turn greatly improves the metallogenic models.

Key words: lithium pegmatite deposit, Kulagangri Dome, Himalayan metallogenic belt, leucogranites, Gabo

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