鄂尔多斯盆地及其邻区关键构造变革期次及其特征

鄂尔多斯盆地为典型的克拉通内盆地，油、气、煤、盐、铀等矿产资源丰富。研究构造运动的期次、序列与性质将为揭示克拉通盆地的成因与演化过程奠定基础，同时也将为探讨多种能源、矿产资源赋存的内在机制提供依据。基于近年来的高精度区域反射地震剖面和深井资料，结合周缘地质露头分析，通过厘定鄂尔多斯盆地的关键构造变革时期，建立了盆地演化的时-空框架。研究表明，鄂尔多斯盆地由下至上发育10个区域不整合面，分别为长城系、蓟县系、震旦系、寒武系、奥陶系、石炭系、三叠系、侏罗系、白垩系和第四系底界不整合面；盆地发育中元古界、寒武系-奥陶系、上石炭统-三叠系、侏罗系、下白垩统和新生界6个构造-地层层序。鄂尔多斯盆地的形成与演化受控于周缘板块构造作用，经历了中元古代早-中期大陆裂解、寒武纪-中奥陶世被动大陆边缘、晚奥陶世主动大陆边缘形成与碰撞造山、晚石炭世-二叠纪末期周缘裂解、中生代早期大型陆内坳陷、中生代中-晚期陆内前陆盆地和新生代周缘断陷等演化过程。鄂尔多斯盆地岩石圈深部的构造作用相对活跃，盆地内部发育中奥陶世、中-晚三叠世、早白垩世与晚中新世4期中酸性、中基性火山活动，其中，早白垩世晚期的火山活动强烈。结合周缘板块构造事件、盆内岩浆活动和盆地沉降-隆升过程分析，鄂尔多斯盆地经历了新元古代、晚奥陶世、中-晚三叠世、晚侏罗世-早白垩世、新生代5个关键构造变革期，这些构造变革期控制了盆地的构造演化和地质结构，对鄂尔多斯盆地的油气分布产生了深远影响。

Critical tectonic modification periods and its geologic features of Ordos Basin and adjacent area

Ordos Basin is a typical intracratonic basin, rich in mineral resources such as oil and gas, coal, salt, and uranium. Studying the periods, sequences and attributes of tectonic movement of the basin will not only lay the foundation for revealing the origin and evolution process of the craton basin, but also provide a basis for exploring the internal occurrence mechanism of the multiple energy and mineral resources. Based on high-resolution reflection seismic profile and deep-well data in recent years, in combination with the analysis of peripheral geological outcrops, this paper establishes a spatio-temporal framework of basin evolution by determining the key tectonic evolution periods of Ordos Basin. Studies have shown that there are 10 regional unconformities developed from bottom to top in the Ordos Basin, namely the basal unconformities in the Changchengnian, the Jixianian, the Sinian, the Cambrian, the Ordovician, the Carboniferous, the Triassic, the Jurassic, the Cretaceous and the Quaternary. Six tectono-stratigraphic sequences developed in the Mesoproterozoic, the Cambrian to Ordovician, the Upper Carboniferous to Triassic, the Jurassic, the Lower Cretaceous and the Cenozoic in the basin. The formation and evolution of Ordos Basin was controlled by the tectonization of the peripheral plates. It experienced the continental breakup in the early and middle period of the Mesoproterozoic, the development of passive continental margin during the Cambrian to the Middle Ordovician, the formation of active continental margin and collision orogeny in the Late Ordovician, the periphery breakup during the Late Carboniferous to the end of the Permian, the development of large-scale intracontinental depressions during the Early Mesozoic and intracontinental foreland basins during the Middle to Late Mesozoic, and peripheral fault depressions during the Cenozoic and other evolution processes. Tectonism in the deep lithosphere of Ordos Basin is relatively active. The basin is subjected to four periods of intermediate-acid or mafic-intermediate volcanic activities in the Middle Ordovician, the Middle and Late Triassic, the Early Cretaceous, and the Late Miocene, especially much extensive in the late period of the Early Cretaceous. Further, through analyzing the tectonic events of peripheral plates, intrabasin magmatic activity and basin subsidence-uplifting process, it is believed that Ordos Basin has experienced five key tectonic modification periods of the Neoproterozoic, the Late Ordovician, the Middle to Late Triassic, the Late Jurassic to Early Cretaceous, and the Cenozoic. These tectonic modification periods control the tectonic evolution and geological architecture of the basin, and have a profound impact on the distribution of oil and gas in Ordos Basin.