【摘要】 河南汝州、鲁山一带罗圈组冰积层之上的东坡组以页岩、粉砂质页岩及粉砂岩为主.笔者发现了东坡组夹有白云岩透镜体及白云质粉砂岩、砂岩.白云质粉砂岩具有与东坡组页岩不协调的软沉积变形.白云岩透镜体和白云质粉砂岩具有明显的δ13C负偏.白云岩透镜体的δ13C为-4.19‰～-6.18‰.白云质粉砂岩的δ13C大部分为-2‰～-4‰之间.因此认为,东坡组的白云岩透镜体及白云质粉砂岩、砂岩与华南震旦纪盖帽白云岩及南华纪Sturtian冰期冰积层之上的碳酸盐丘和菱锰矿类似,为冰积层中的天然气水合物泄漏释放的CO2和海水中的Mg2+发生快速反应快速沉淀而成的,即东坡组的白云岩、白云质粉砂岩、砂岩为冷泉成因.更多还原

【Abstract】 Sinian Dongpo Formation overlying tillite of Luoquan Formation consists mainly of shales,silty shales and siltstones.Lenticular dolomites,dolomitic siltstones and sandstones are unexpectedly found in Dongpo Formation.Soft-sediment reformation occurs in dolomitic siltstones which are inconsistent with the shales of Dongpo Formation.Negative anomaly of δ13C is found in lenticular dolomites and dolomitic siltstones.δ13C of lenticular dolomites is-4.19‰ to-6.18‰ andδ13C of dolomitic siltstones mostly between-2‰ to-4‰.So it is considered that lenticular dolomites,dolomitic siltstones and sandstones in Dongpo Formation,similar to cap dolomite of Sinian and seep carbonates overlying tillite of Sturtian ice-age in South China,have been formed by interaction between CO2 seeped from gas hydrate and Mg2+ in sea water,that is,lenticular dolomites,dolomitic siltstones and sandstones in Dongpo Formation are the cause of formation of cold spring.更多还原