西藏噶大克地区中生代地层及双壳类化石组合

THE MESOZOIC STRATA AND COMBINATION OF BIVALVE FOSSILS IN GEDAKE AREA, XIZANG

文章较详细地研究了西藏噶大克地区三叠、侏罗、白垩纪地层及其双壳类化石的地理分布和组合特征。

Gedake area in Xizang consist of Zada, Pulan, Geer county in the Ali district and Part of Zhongba, Geji, Gaize county. This area is about one hundred thousand km^2. The Yaluzangbujiang rift crosses through its middle section in NNW direction and breaks up it into Himalayan stratiraphic region and Gangdise stratigraphic region. In Gedake area, the Mesozoic strata widely spread, Cretaceous is dispersed in this two stratigraphic regions, but Triassic and Jurassic are ohly discovered in Himalayan stratigraphic region. The writer has been to this region two times(1983, 1985) for resarch work, collecting lairly abundant bivalve fossils and inforination of Mesozoic stratigraphic section. This Paper describes Mesozoic strata and geographic history of this area, discusses geographic distribution and assemblage characteristics of Mesozoic bivalves. This study has both theoretical and practical significance for knowlng evolution of Mesozic geographic history in Xizang, understanding stratigraphic division and rrelation and reconstruction of pa1aeoclimatology and palaeography.