在藏北巴青县马如乡布曲组中发现中侏罗世Liostrea障积礁，据造礁生物不同可分为Liostrea障积礁和Cyanobacteria－Liostrea粘结—障积礁。它们多呈似层状和层状，单个礁体厚4～8m，累计总厚为20～25m。Liostrea是一种单体牡蛎状的双壳类动物，分为左右两瓣壳，左壳强烈膨凸，右壳扁平，系以左壳固着生活特化而成，在本区构成了Liostrea群落和Cyanobacteria－Liostrea群落，代表温暖、清洁的正常浅海环境。 Middle Jurassic Liostrea Barrier Reefs are found in the Buqu Formation of Maju Township, Baqing County, northern Tibet. According to different reef-building organisms, they can be divided into Liostrea Barrier Reefs and Cyanobacteria-Liostrea Barrier-Barrier Reefs. They are mostly layered and layered, a single reef thickness of 4 ~ 8m, the cumulative total thickness of 20 ~ 25m. Liostrea is a single oyster-like bivalve animal, which is divided into two shells. The left shell is strongly inflated, the right shell is flattened and the left shell is fixed. It constitutes Liostrea community and Cyanobacteria-Liostrea community, representing a warm, clean, normal, shallow-sea environment.