【摘要】 <正> 近十多年来,我们在进行我国陆相油田沉积相研究过程中,发现我国许多陆相油田的含油地层,大多为古代断陷湖相沉积。为结合我国东部中、新生代陆相油田的勘探和开发,自1978年起,中国科学院南京地理研究所湖泊研究室开展了对云南现代断陷湖泊沉积相的研究。沉积相具有双重性:既反映了沉积物的沉积特征;也反映了沉积物沉积时的沉积环境。沉积物的特征包括沉积物的物理特征,化学特征和生物特征。生物对环境变化反映最为灵更多还原

【Abstract】 Qianjin Lake, located in the Ningxia Hui Autonomous region, is a shallow and brackish lake with small surface area. Determination shows that in the uppermost lake sediments ostraeods bolong to 2 families, 2 genera and 5 species, of which only one species is new. According to the quantitative analysis, it is found that there exists a great quantity of Ilyocypris Kaifengensis and Limnocythere dubiosa Daday, distributed over the lake, while Limnocythere sancti-patricii Brady et Robertson, Limnocythere binoda Huang and Limnocythere trinoda Yang are of small quantity with a narrow distributing range in the basin.更多还原