Distribution and mineralogical characteristics of amber in the Upper cretaceous Gaogou Formation in Xixia, Henan Province, china

The Xixia amber is the largest known Mesozoic amber deposit in China to date. Here we analyse amber collected over the years from 12 localities in the Upper Cretaceous Gaogou Formation in Xixia, Henan, including physical property tests and Fourier transform infrared spectroscopy (FT-IR) analysis. The main preservation forms of the Xixia amber include nest-like, vein-like, and layered irregular shapes, as well as gravel-like forms resulting from secondary transportation. Recent discoveries include numerous small-grained amber specimens preserved in grey-black silty shale rich in plant debris, suggesting a near-in-situ depositional environment. The Xixia Basin’s Late Cretaceous strata are renowned for their abundance in dinosaur eggs. In-depth research on the Xixia amber will help to understand the geological history and ecosystem evolution of the Xixia Basin during the Late Cretaceous, as well as the global distribution characteristics of Cretaceous amber.