东北大三江地区早白垩世岩相古地理研究

Study on Early Cretaceous Lithofacies Paleogeography in Dasanjiang Area of Northeast China

通过大量野外观察,结合岩芯、测井及地震剖面资料,研究东北大三江地区早白垩世穆棱组、城子河组的沉积相;并在对各个沉积相带的沉积特征和时空展布归纳和总结的基础上,编制了一套早白垩世穆棱组、城子河组岩相古地理图。结果表明:城子河组和穆棱组沉积相类型丰富,以滨浅湖、三角洲平原等浅水沉积为主,夹数层沼泽相煤和海相夹层;在古隆起的边缘有扇三角洲、辫状河相存在,向盆内过渡为滨浅湖和半深湖。城子河组沉积时期,汤原断陷周边发育扇三角洲沉积,绥滨坳陷和前进坳陷以三角洲和滨浅湖沉积为主,局部发育半深湖,并发育海相夹层和沼泽沉积;鸡西盆地和勃利盆地以三角洲和滨浅湖沉积为主,虎林盆地以滨浅湖沉积为主,局部发育半深湖,并发育海相夹层和沼泽沉积;穆棱组沉积时期,汤原断陷周边发育扇三角洲沉积,绥滨坳陷和前进坳陷地层不太发育,鸡西盆地和勃利盆地以三角洲和滨浅湖沉积为主,局部发育半深湖,并发育海相夹层和沼泽沉积,虎林盆地南部凹陷以滨浅湖沉积为主。早白垩世穆棱组、城子河组时期,张广才岭和桦南隆起是盆地主要物源供给区。

According to field observation, analysis of cores, logging and seismic data, sedimentary facies of Early Cretaceous Muling Formation and Chengzihe Formation in Dasanjiang area of Northeast China was conducted; sedimentary feature and temporal spatial distribution of each sedimentary facies belt were summarized, and then lithofacies paleogeography maps of Muling Formation and Chengzihe Formation were drawn up. The results showed that types of sedimentary facies in Muling Formation and Chengzihe Formation were rich, shallow-water sedimentary including shore shallow lacustrine and delta plain was predominant with a little coal beds, with swamp facies and marine interlayers; fan delta and braided river existed in the margin of palaeohigh, and changed to shore shallow lacustrine and semi-deep lake from the margin to the depocenter of the basin. Fan delta deposit developed around Tangyuan rift during the sedimentary period of Chengzihe Formation, delta and shore shallow lacustrine were the main sedimentary facies in Suibin rift and Qianjin rift, and semi deep lake, marine interlayer and swamp deposit developed partially; delta and shore shallow lacustrine were the main sedimentary facies in JixiBasin and Boli Basin, and shore deep lake, marine interlayer and shallow lacustrine deposit developed in Hulin Basin, and semi- swamp deposit developed partially; fan delta deposit developed around Tangyuan rift during the sedimentary period of Muling Formation, the strata in Suibin rift and Qianjin rift developed insignificantly, delta and shore shallow lacustrine were the main sedimentary facies in Jixi Basin and Boli Basin, and semi-deep lake, marine interlayer and swamp deposit developed partially, while shore shallow lacustrine was the main sedimentary facies in the southern sag of Hulin Basin. Zhangguangcai Mountain and Huanan uplift were the major material source of the basin during the sedimentary period of Early Cretaceous Chengzihe Formation and Muling Formation.