Detrital zircon U–Pb ages and trace elements indicate the provenance of Early Carboniferous Li-rich claystone from central Guizhou, South China

Abstract

Lithium is of great importance for green energy technology, and most industrial Li is sourced from brine lakes and pegmatites. Recently, strong Li enrichment has been reported in the late Palaeozoic Jiujialu Formation (C1jj) in Guizhou, South China; however, the source and the sedimentary processes that formed the Jiujialu Formation remain unclear. We present the U–Pb ages and trace element compositions of detrital zircon grains from the Jiujialu Formation and underlying dolomite of the Loushanguan Group (Cam2–3ls), which indicate the grains in the Jiujialu Formation on the margin of the Central Guizhou Uplift and in a depression in southeast Guizhou have three primary age peaks (1000–900, ∼760, and ∼530 Ma). These ages are similar to those of Ordovician strata, indicating a contribution from the Ordovician strata to the Jiujialu Formation in these areas. Detrital zircon grains from the Jiujialu Formation in the core of the Central Guizhou Uplift and the Loushanguan Group have two primary age peaks at ∼760 and ∼530 Ma, which suggests that the underlying Loushanguan Group supplied most of the material to the Jiujialu Formation in this area. The age distribution of detrital zircon grains indicates that sediment erosion from the sedimentary stratal transport was limited, and deposition occurred near the direct source. In addition, the trace element compositions of the detrital zircon grains indicate that their original source was magmatic rocks of the South China Block. An early Palaeozoic intracontinental orogeny in South China uplifted subduction-related magmatic rocks (1000–900 Ma) in the northeast of the South China Block, exposing them to weathering and providing material for the Ordovician strata. This suggests that the weathering of sedimentary strata can form clay-type Li deposits in areas with carbonate bedrock, and that the provenance of Cambrian–Ordovician sedimentary strata in the Yangtze Block was controlled by an early Palaeozoic intracontinental orogeny.