鄂尔多斯盆地伊盟隆起南部构造边界厘定及其油气勘探意义

Delineation of the southern structural boundary of the Yimeng Uplift in the Ordos Basin and its implications for hydrocarbon exploration

田刚 卢明德 薛海军 汶小岗 马丽 袁安龙 宋立军 蒲仁海 贾会冲 陈杰 陈硕 吴大林 杨明慧

Gang TIAN Mingde LU Haijun XUE Xiaogang WEN Li MA Anlong YUAN Lijun SONG Renhai PU Huichong JIA Jie CHEN Shuo CHEN Dalin WU Minghui YANG

有关鄂尔多斯盆地北部伊盟隆起与伊陕斜坡两个构造单元边界的认识至今存在分歧。通过对盆地北部基底起伏、地层展布、基底断裂、构造演化过程及油气分布特征等多方面研究分析，结果表明：盆地北部WE—NE向基底断裂以中元古代之前分隔不同构造单元边界的新召北-泊尔江海子南基底先存断裂带（F4+F10）为界，呈对冲构造样式控制了伊盟隆起的形成；杭锦旗断裂带横贯盆地北部，是由上述基底先存断裂带在加里东期选择性活化、呈雁列式展布的泊尔江海子、乌兰吉林庙和三眼井等大型基底断裂组成。在海西期、印支期和燕山期杭锦旗断裂带持续继承性活动，控制了盆地北部各时期构造-沉积演化格局。以杭锦旗断裂带为界，南部和北部构造活动强度、烃源岩展布和成熟度、储层特征和物性变化以及油气圈闭类型等均存在较大差异，揭示该断裂带控制了盆地北部油气形成与分布。因此，以杭锦旗断裂带作为伊盟隆起和伊陕斜坡两大构造单元的边界更为合理，这对深化鄂尔多斯盆地北部地质认识和指导油气勘探方向具有重要意义。

The boundary between two tectonic units in the northern Ordos Basin， namely the Yimeng Uplift and the Yishan Slope， remains controversial. In this study， we analyze the basement relief， stratigraphic distribution， basement faults， tectonic evolution， and hydrocarbon distribution characteristics in the northern Ordos Basin. The results indicate that the EW-NE-striking basement faults in the northern Ordos Basin governed the formation of the Yimeng Uplift as ramp structures. Among these basement faults， the pre-existing Xinzhao North-Porjianghaizi South （F4+F10） basement fault zone serves to separate the structural units before the Mesoproterozoic. The Hangjinqi fault zone （HFZ） runs across the northern Ordos Basin and consists primarily of three large-scale basement faults arranged in en echelon arrays， including the Porjianghaizi， Wulanjilinmiao， and Sanyanjing faults， which evolves from the selectively reactivated basement fault zone pre-existing as mentioned above during the Caledonian. During the Hercynian， Indosinian， and Yanshanian， The HFZ continued its inherited activities， having governed the tectono-sedimentary evolutionary framework of the northern Ordos Basin throughout various geological periods. The northern and southern basin separated by the HFZ exhibit significant differences in tectonic activity intensity， distribution and maturity of source rocks， variations in reservoirs and their physical properties， and hydrocarbon trap types. It can be concluded thereby that the HFZ controls the hydrocarbon generation and distribution in the northern Ordos Basin. It is， thereby， more reasonable to take the HFZ as the boundary between Yimeng Uplift and Yishan Slope， which will be of great significance to deepening understanding on the geology of the northern Ordos Basin and thereby guiding the hydrocarbon exploration therein.

10.11743/ogg20250108