蒙古-鄂霍茨克洋东段关闭对松辽盆地形成与演化的影响

Impacts of the closure of eastern Mongolia-Okhotsk Ocean on formation and evolution of Songliao Basin

冯志强 董立 童英 冯子辉 张顺 吴高奎 任强

Zhiqiang Feng Li Dong Ying Tong Zihui Feng Shun Zhang Gaokui Wu Qiang Ren

松辽盆地是位于中国东北的大型白垩系陆相含油气盆地，前人普遍认为其形成和演化主要受西太平洋板块向西俯冲作用的影响和控制。那么，环西太平洋构造带仅在中国东北形成大型坳陷盆地的动力机制是什么，松辽盆地在坳陷阶段之前发育火石岭组和营城组2套断陷期火山岩的诱因是什么，中国东北地区大规模发育中生代岩浆岩的主控因素是什么。显然，这些现象很难单纯用古太平洋板块活动控制来解释。本文在充分吸收已有科研成果的基础上，从区域动力学背景、火山岩时空分布特征以及沉积盆地构造演化的角度，分析了蒙古-鄂霍茨克洋东段的闭合对松辽盆地形成与演化的影响，指出蒙古-鄂霍茨克洋关闭是中生代东北亚最重要的一次大地构造事件，板块的俯冲、碰撞、挤压、拉张以及岩浆活动等作用对该区盆-山格局的形成和演化都具有重要的影响；并提出了松辽盆地可能存在的蒙古-鄂霍茨克洋和西太平洋板块双向俯冲成因模式，厘定了两者对中国东北地区多期次挤压和拉张作用的转换时间，从全新的角度认识了松辽盆地的形成和演化过程，合理地诠释了中国东北部晚侏罗世-早白垩世有别于西太平洋南部地区的岩浆岩发育特征。

Songliao Basin is a large non-marine petroliferous basin of the Cretaceous in Northeast China.It is generally believed that its tectonic evolution is mainly controlled by the westward subduction of the Western Pacific Plate.What is the dynamic mechanism in forming a large depression basin only in Northeast China within the Western Pacific tectonic belt? Why are there two stages of volcanism (Huoshiling Formation and Yingcheng Formation) developed in the rifting stage of Songliao Basin? Why are the Mesozoic magmatic rocks prone to get developed in Northeast China? Obviously, it's difficult to explain these questions merely by Pacific Plate activities.The closure of Mongolia-Okhotsk Ocean is the most important tectonic event in Northeast Asia in the Mesozoic.There is no doubt that the plate subduction, collision, subsequent compression, extension and magmatic activity would have significant effects on the formation and evolution of the basins and mountains in Northeast Asia.Based on existing research results, this paper analyzes the influence of the closure of the eastern Mongolia-Okhotsk Ocean on the formation and evolution of Songliao Basin from the perspectives of regional dynamics, temporal and spatial distribution characteristics of volcanic rocks and tectonic evolution of sedimentary basins.Besides, a genetic model of bidirectional subduction between the Mongolia-Okhotsk Ocean and the West Pacific Plate is proposed for the formation of Songliao Basin, under the effect of which multiple transitions between compression and extension mechanisms in Northeast China are delineated.In all, the formation and evolution of Songliao Basin are re-recognized from brand-new perspectives, while reasonably interpreting the differential magmatic activities between Northeast China and southern West Pacific during the Late Jurassic and Early Cretaceous.

10.11743/ogg20210201