柴西第三纪湖相碳酸盐共沉积特征

摘要

从碳酸盐化学共沉积的角度,对柴达木西部第三纪湖相碳酸盐沉积特征进行了分析.结果表明,该区碳酸盐的沉积主要是由于吸附和包裹共沉积作用产生,共沉积作用加快了碳酸盐的沉积速度,促进了以碳酸盐为主的成分层和以碎屑颗粒为主的成分层的更快分异.在外力的作用下,不同成分层产生错动,易在碳酸盐为主的成分层中产生裂缝,同时共沉积作用对保存微孔隙起到了一定的作用,从而使部分柴西湖相碳酸盐岩层成为有效储集层.%The codepositional mechanism of tertiary lake facies carbonate in the western Qaidam basin was realized in chemical codeposition process. The results show that; 1) the codeposition is mainly due to the adsorption and coating of carbonate. 2) It increases the depositional rate of carbonate and promotes the separation between carbonate layer and debris grain layer. 3) Under the action of some forces, the movement between the layers will easily produces fractures in carbonate layer, and the codeposition plays a role in protecting miropores, which makes the part of lake facie carbon rock zones in the western Qaidam basin become the effective reservoirs.