为明确小型断陷湖盆烃源岩形成机理,开展了烃源岩形成、分布和地球化学特征的研究,综合有机质供给、保存和稀释对烃源岩形成的影响,建立了小型断陷湖盆烃源岩形成的3种模式:边界断层活动强、沉积速率大的湖盆,有机质供给量大,保存条件差,烃源岩形成主要受有机质供给控制,主要发育于有机质供给量大的深洼带;边界断层活动弱、沉积速率小的湖盆,有机质供给量小,有机质保存条件好,烃源岩形成主要受有机质保存条件控制,主要发育于还原程度强的缓坡带;边界断层活动强度和沉积速率居中的湖盆,有机质供给量较大,保存条件较好,烃源岩形成受沉积速率、有机质供给和保存的综合控制,在深洼带和近洼缓坡带均有发育.%To recognize forming mechanism of source rocks in small-scale faulted lacustrine basins,the paper studies formation,distribution and geochemical characteristics of source rocks,and establishes 3 source rock formation patterns in small-scale faulted lacustrine basins by integrating the influences of organic matter supply,preservation and dilution on source rock forming.In a lacustrine basin with active boundary fault and high depositional rate,organic matter supply is sufficient but its preservation condition is poor,the source rock is mainly constrained by the organic matter supply and is mainly developed in deep depressions with abundant organic matter supply;in a lacustrine basin with inactive boundary fault and low depositional rate,the organic matter supply is of small quantity and its preservation condition is good,the source rock is mainly controlled by organic matter preservation conditions and is mostly distributed in gentle slopes with high reduction degree;in a lacustrine basin with moderate-active boundary fault and moderate depositional rate,the organic matter supply is of large quantity and its preservation condition is relatively good,the source rock is controlled by depositional rate,organic matter supply and preservation,and is developed in both deep depressions and near-depression gentle slopes.
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