Genesis of the Jiada pegmatite lithium deposit in the Ke’eryin ore field, western Sichuan, China: Evidence from whole-rock trace element and Li isotope

• DOI: 10.1016/j.oregeorev.2024.106106
• Publication Date: 2024-06-13T19:15:52Z
• Authors: Xin Li; Hongzhang Dai; Fan Huang; Denghong Wang; Shanbao Liu; Jinhua Qin; Haiyang Zhu; Genhou Wang
• Keywords: Pegmatite; Trace element; Ore genesis

The origin and petrogenesis of pegmatite-type lithium deposits within the Songpan-Garze Fold Belt (SGFB) western China remain subjects debate. To provide further insight on this subject, study investigated whole-rock trace elements Li isotopic compositions two-mica monzogranite (TMG) from Ke'eryin composite pluton, Jiada albite pegmatite (AP) albite-spodumene (ASP) their metasedimentary wall rocks ore field in eastern SGFB. Modeling muscovite-dehydration melting based (e.g., Li, Rb, Sr) Rayleigh dehydration modeling related to isotopes suggest that pegmatites are unlikely have originated low-degree partial metasandstone (MS) Zhuwo Formation. Variations isotope between TMG consistent with evolution trend magmatic fractionation. However, AP ASP display inverse variation characteristics muscovite compositions, exhibiting lower concentrations higher δ7Li values than ASP. Furthermore, patterns do not align perfectly Rayleigh-type fractional crystallization processes, implying other geological processes would be also involved formation pegmatites. Collectively considering behavior during various observed variations can explained by aqueous fluid enrichment pegmatitic melt evolution. This suggests exsolution jointly contributed mineralization deposit. Moreover, rock (MS2) those MS (MS1), primarily due metasomatism 6Li-enriched fluids expelled kinetic diffusion isotopes. high highly mobile elements, especially Cs, combined low value metasandstone, could serve as effective tracers for locating concealed orebodies evaluating metallogenic potential mineralization.