Published : 2025-10-18
On 18 October 1984, the Middle-Upper Proterozoic stratigraphic section (中上元古界地層剖面) in Jixian County, Tianjin, was listed as a national nature reserve, which marked the establishment of China's first national geological nature reserve.
The Middle-Upper Proterozoic National Nature Reserve covers an area of approximately 900 hectares, with its stratigraphic section distributed across the overlapping mountain ranges of the southern Yanshan Mountains (燕山).
It is renowned worldwide for features such as its complete rock strata, continuous outcrops, excellent preservation, clear top and bottom boundaries, simple structure, very slight metamorphism, and abundant palaeontological fossils.
With a total thickness of 9,200 metres, the stratigraphic section documents the geological evolution history spanning from 1.65 billion to 800 million years ago.
