The Songpan-Garze orogenic belt on the northeastern margin of the Tibetan Plateau is one of China's most important lithium metallogenic belts,with the Ke'eryin lithium ore field in the central region being one of the most significant pegmatite-type lithium resource bases.Based on extensive geological and mineral exploration and survey work,this paper systematically summarizes the geological characteristics,geochemical features,and magmatic and metallogenic ages of typical deposits within the ore field.It also refines the metallogenic model of the Ke'eryin lithium ore field and further identifies regional exploration directions,which is of great significance for understanding the metallogenic regularity of pegmatite-type lithium deposits and guiding deep exploration.The deposit types within the ore field are all granite related pegmatite-type rare metal deposits,with spodumene being the primary ore mineral.The granite-pegmatite and the Xikang Group metasedimentary rocks have nearly identical Sr-Nd-Hf isotopic compositions,indicating that the source material for mineralization originated from the Xikang Group.From granite to pegmatite,both primary minerals and whole-rockδ7Li values increase,indicating that pegmatite formed from the differentiation of granite magma.From albite pegmatite to albite-spodumene pegmatite,primary mineral δ7 Li values increase while whole-rock δ7 Li values decrease,suggesting fractional crystallization and enrichment of exsolved fluids during pegmatite magma evolution.The Ke'eryin composite pluton and pegmatite share overlapping isotopic ages,indicating they are products of the same orogenic event,formed during the Late Indosinian orogenic stage when the tectonic regime transitioned from compression to extension.Based on these characteristics,the previously proposed magmatic and metallogenic model for the Ke'eryin ore field has been refined,suggesting that a lithium-rich source area,suitable tectonic setting,extensive and intense magmatic fractional crystallization,and the enrichment of aqueous fluids collectively contributed to the formation of the Ke'eryin lithium ore field.Additionally,the exploration indicators of the Ke'eryin lithium ore field are summarized,and potential exploration directions are predicted.
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