云南景谷盆地及陇川盆地新生代生物群特征及环境地质意义

BIOTIC CHARACTERS AND ENVIRONGEOLOGICAL SIGNIFICANCE IN CENOZOIC ERA IN JINGGU AND LONGCHUAN BASINS IN YUNNAN

通过对云南景谷盆地及陇川盆地新生代生物群特征的对比,探讨了新生代两大盆地环境演变:早中新世到上新世为湖盆发展期→湖盆扩大→萎缩期,气候为早期的干燥→中新世早期的温暖湿润→中新世中晚期的寒冷阴湿→上新世的干燥,而中新世中晚期湖盆的扩大形成的半深湖-深湖环境为油气的形成提供了有利条件。尽管两大盆地在沉积环境的演化上大体一致,但气候和沉积环境的演变和差异决定了两大断陷盆地生物面貌上的差异。

Comparison and study of the biotic characters in the Jinggu and Longchuan basins in Yunnan Province show that: (1)the two basins underwent the developing period, expanding period and shrinking period from early Miocene Epoch to Pliocene Epoch; (2)the climate in the region was dry in early Miocene Epoch , warm and humid in middle late Miocene Epoch and dry in Pliocene period; (3)the basins expanding in middle late Miocene Epoch formed a semi deep lake to deep lake environment. The environment is favorable for the formation oil and gas; (4)although the sedimentary environment in the two basins is cardinally identical , the evolution and difference in climate and sedimentary environemt decided the divergence of biotic characters in the two fault basins, and then the biota controlled the type and quality of fossil fuel.