Distribution characteristics of different Huaiyuan unconformities in Ordos Basin
MAO Danfeng1, HE Dengfa1, BAO Hongping2, WEI Liubin2, CHENG Xiang1, GOU Junyi1, SHI Jing1, XU Yanhua1
1 School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China; 2 Exploration and Development Research Institute of Changqing Oil Field Branch, Petrochina, Xi'an 710018, China
Abstract:The Huaiyuan Movement is an important tectonic event in the early Paleozoic of the North China Platform,resulting in a regional unconformity. Based on outcrop data,geological maps,drilling data and new seismic data,the identification marks,types and distributions of unconformities formed during the Huaiyuan movement in the Ordos Basin were analyzed. The results show that(1)sandy conglomerate and weathered crust developed near the unconformity surface;additionally,high acoustic time,high gamma values,high content of trace elements(U,Th and K),high thorium-uranium ratios,low resistivity,and low density of logging curves occurred near the unconformity surface. The seismic response of the unconformity is characterized by a strong phase,and there are obvious differences in amplitude intensity,frequency and continuity in the wave groups on both sides of the unconformity. In addition,the truncation point reflections can be observed in local domain. (2)The Huaiyuan movement caused both parallel-unconformity and low-angle cutting unconformity in the basin. The former was widely distributed in the basin and its periphery areas,and the latter was distributed near the paleo-uplift in the basin. (3)The Ordos Basin and its periphery areas were affected by three stages of the Huaiyuan tectonic movement: during the depositional period of the Zhangxia Formation in the Middle Cambrian,uplift first occurred in the southeast region of the basin and then moved to the northwest direction;at the end of the Sanshanzi Formation deposition period in the late Cambrian,paleo-uplifts developed in the basin,and they were subjected to erosion; at the end of the late Cambrian, before the Ordovician Majiagou Formation was deposited,the negative drift of carbon isotopes first occurred in the bottom layer of Majiagou Formation due to the influence of global sea level decline. These results provides a reference for the research of new fields of oil and gas exploration in Lower Paleozoic in the Ordos Basin.
MAO Danfeng,HE Dengfa,BAO Hongping et al. Distribution characteristics of different Huaiyuan unconformities in Ordos Basin[J]. JOPC, 2024, 26(1): 119-131.
[1] 安徽地质矿产局. 1987. 安徽省区域地质志. 北京: 地质出版社. [Bureau of Geology and Mineral Exploration of Anhui Provincial. 1987. Regional Geology of Anhui Province. Beijing: Geological Publishing House] [2] 蔡忠贤,秦玉娟,贾振远. 1997. 鄂尔多斯地区南缘寒武纪层序地层和海平面变化. 地球科学, 22(5): 484-490. [Cai Z X,Qin Y J,Jia Z Y.1997. Sequence stratigraphy and sea level changes of Cambrian in the southern margin of Ordos Basin. Earth Science, 22(5): 484-490] [3] 曹金舟,冯乔,赵伟,周书昌,王千遥,刘振,卢玉杰,李颖莉. 2011. 鄂尔多斯盆地南缘奥陶纪层序地层分析. 沉积学报, 29(2): 286-292. [Cao J Z,Feng Q,Zhao W,Zhou S C,Wang Q Y,Liu Z,Lu Y J,Li Y L.2011. Sequence stratigraphy of Ordovician strata in the south part of Ordos area. Acta Sedimentologica Sinica, 29(2): 286-292] [4] 陈安清. 2010. 鄂尔多斯地块早古生代盆地演化与物质聚集规律. 成都理工大学博士学位论文. [Chen A Q.2010. Basin evolution and sediments accumulation during Eopaleozoic in Ordos Continental Block. Doctoral dissertation of Chengdu University of Technology] [5] 付金华,刘新社,魏柳斌,任军峰,古永红,王前平,师平平. 2022. 鄂尔多斯盆地奥陶系盐下马家沟组四段天然气勘探突破及意义. 中国石油勘探, 27(2): 47-58. [Fu J H,Liu X S,Wei L B,Ren J F,Gu Y H,Wang Q P,Shi P P.2022. Breakthrough and significance of natural gas exploration in the fourth member of Majiagou Formation of subsalt Ordovician in Ordos Basin. China Petroleum Exploration, 27(2): 47-58] [6] 何登发. 2018. “下削上超”地层不整合的基本类型与地质意义. 石油勘探与开发, 45(6): 995-1006. [He D F.2018. Basic types and geologic significances of “truncation and onlap”unconformities. Petroleum Exploration and Development, 45(6): 995-1006] [7] 何登发,邵东波,崔永平,包洪平,开百泽,傅定伍,曹毓戈. 2018. 鄂尔多斯盆地西缘马家滩古隆起的厘定、成因及地质意义. 石油学报, 39(6): 609-619. [He D F,Shao D B,Cui Y P,Bao H P,Kai B Z,Fu D W,Cao Y G.2018. Delineation,formation,and geological significance of Majiatan paleo-uplift at the western margin of Ordos Basin. Acta Petrolei Sinica, 39(6): 609-619] [8] 何登发,包洪平,开百泽,魏柳斌,许艳华,马静辉,成祥. 2021. 鄂尔多斯盆地及其邻区关键构造变革期次及其特征. 石油学报, 42(10): 1255-1269. [He D F,Bao H P,Kai B Z,Wei L B,Xu Y H,Ma J H,Cheng X.2021. Critical tectonic modification periods and its geologic features of Ordos Basin and adjacent area. Acta Petrolei Sinica, 42(10): 1255-1269] [9] 何自新,等. 2004. 鄂尔多斯盆地地质剖面图集. 北京: 石油工业出版社. [He Z X, et al.2004. Geological Profile Atlas of Ordos Basin. Beijing: Petroleum Industry Press] [10] 李攀,李永强,经俭波,曹正林,袁选俊. 2020. 准噶尔盆地西北部P-T转换期不整合的发育演化特征及意义. 古地理学报, 22(4): 697-714. [Li P,Li Y Q,Jing J B,Cao Z L,Yuan X J.2020. Unconformities formed during the P-T transition in the northwestern Junggar Basin: nature,evolution and implications. Journal of Palaeogeography(Chinese Edition), 22(4): 697-714] [11] 李相博,王宏波,黄军平,张才利,张艳,王雅婷,张雷,王菁,刘化清. 2021. 鄂尔多斯盆地怀远运动不整合面特征及油气勘探意义. 石油与天然气地质, 42(5): 1043-1055. [Li X B,Wang H B,Huang J P,Zhang C L,Zhang Y,Wang Y T,Zhang L,Wang J,Liu H Q.2021. Characteristics of unconformity resulted from Huaiyuan Movement in Ordos Basin and its significance for oil and gas exploration. Oil & Gas Geology, 42(5): 1043-1055] [12] 李文厚,陈强,李智超,王若谷,王妍,马瑶. 2012. 鄂尔多斯地区早古生代岩相古地理. 古地理学报, 14(1): 85-100. [Li W H,Chen Q,Li Z C,Wang R G,Wang Y,Ma Y.2012. Lithofacies palaeogeography of the Early Paleozoic in Ordos area. Journal of Palaeogeography(Chinese Edition), 14(1): 85-100] [13] 刘化清,李相博,马玉虎,白云来,黄军平. 2021. 鄂尔多斯盆地怀远运动不整合面与深层天然气勘探领域. 天然气工业, 41(6): 1-12. [Liu H Q,Li X B,Ma Y H,Bai Y L,Huang J P.2021. The unconformity caused by the Huaiyuan movement and the deep natural gas exploration field in the Ordos Basin. Natural Gas Industry, 41(6): 1-12] [14] 刘克奇,蔡忠贤,张淑贞,赵桂青. 2006. 塔中地区奥陶系碳酸盐岩不整合带的结构. 地球科学与环境学报, 28(2): 41-44. [Liu K Q,Cai Z X,Zhang S Z,Zhao G Q.2006. Structure of Ordovician carbonate unconformity zone in Tazhong area. Journal of Earth Sciences and Environment, 28(2): 41-44] [15] 毛丹凤,何登发,包洪平,魏柳斌,许艳华,成祥,苟钧壹,武赛军. 2023. 鄂尔多斯盆地乌审旗古隆起的分布、演化及构造属性. 石油勘探与开发, 50(4): 755-766. [Mao D F,He D F,Bao H P,Wei L B,Xu Y H,Cheng X,Gou J Y,Wu S J.2023. Distribution,evolution and structural properties of Wushenqi paleo-uplift in Ordos Basin. Petroleum Exploration and Development, 50(4): 755-766] [16] 宋奠南. 2001. 对怀远运动的再认识. 山东地质, 17(1): 19-23,51. [Song D N.2001. Re-recognization of Huaiyuan movement. Geology of Shandong, 17(1): 19-23,51] [17] 任纪舜,徐芹芹,邓平,肖黎微. 2016. 构造旋回与大地构造年表. 地球学报, 37(5): 528-534. [Ren J S,Xu Q Q,Deng P,Xiao L W.2016. Tectonic cycles and tectonic timescale. Acta Geoscientica Sinica, 37(5): 528-534] [18] 山西省地质矿产局. 1989. 山西省区域地质志. 北京: 地质出版社,1-782. [Shanxi Bureau of Geology and Mineral Resources. 1989. Regional Geology of Shanxi Province. Beijing: Geological Publishing House,1-782] [19] 师平平,肖安成,付金华,吴磊,周义军,王依平,覃素华,张万福. 2021. 鄂尔多斯地块南缘奥陶纪前陆盆地的沉积大地构造格架与演化. 岩石学报, 37(8): 2531-2546. [Shi P P,Xiao A C,Fu J H,Wu L,Zhou Y J,Wang Y P,Qin S H,Zhang W F.2021. The sedimentary and tectonic framework of the Ordovician foreland basin in the southern margin of the Ordos Block and its evolution. Acta Petrologica Sinica, 37(8): 2531-2546] [20] 汤中立. 2002. 华北古陆西南缘(龙首山—祁连山)成矿系统及成矿构造动力学. 北京: 地质出版社. [Tang Z L.2002. Metallogenic System and Tectonic Dynamics of the Southwestern Margin of North China Ancient Land(Longshoushan-Qilian Mountains). Beijing: Geological Publishing House] [21] 田树刚,章雨旭. 1997. 华北地台北部奥陶纪露头层序地层. 地球学报, 18(1): 87-97. [Tian S G,Zhang Y X.1997. Ordovician outcrop sequence-stratigraphy in northern North China platform. Acta Geoscientia Sinica, 18(1): 87-97] [22] 熊加贝,何登发. 2022. 鄂尔多斯盆地加里东期不整合面类型及分布特征. 古地理学报, 24(5): 970-988. [Xiong J B,He D F.2022. Types and distribution characteristics of the Caledonian unconformities in Ordos Basin. Journal of Palaeogeography(Chinese Edition), 24(5): 970-988] [23] 杨俊杰. 2002. 鄂尔多斯盆地构造演化与油气分布规律. 北京: 石油工业出版社,228. [Yang J J.2002. Tectonic Evolution and Hydrocarbon Distribution in Ordos Basin. Beijing: Petroleum Industry Press,228] [24] 张春林,姚泾利,李程善,邢凤存,范立勇,莫午零,朱秋影,曾旭. 2021. 鄂尔多斯盆地深层寒武系碳酸盐岩储层特征与主控因素. 石油与天然气地质, 42(3): 604-614. [Zhang C L,Yao J L,Li C S,Xing F C,Fan L Y,Mo W L,Zhu Q Y,Zeng X.2021. Characteristics of deep Cambrian carbonate reservoirs in the Ordos Basin and main control factors. Oil & Gas Geology, 42(3): 604-614] [25] 张军涛,张玉银,谷宁,金晓辉,张涛,刘四洪,贾会冲,杨佳奇,刘玲,高晓鹏. 2023. 鄂尔多斯盆地乌审旗隆起东北侧怀远运动不整合特征及其对岩溶储层形成的意义. 石油与天然气地质, 44(1): 101-109. [Zhang J T,Zhang Y Y,Gu N,Jin X H,Zhang T,Liu S H,Jia H C,Yang J Q,Liu L,Gao X P.2023. Unconformity characteristics of Huaiyuan movement in the northeast of Wushenqi paleo-uplift in Ordos Basin and its implications for karst reservoir generation. Oil & Gas Geology, 44(1): 101-109] [26] Mitchum R M,Vail P R,Sangree J B.1977. Seismic stratigraphy and global changes of sea level,part 6: stratigraphic interpretation of seismic reflection patterns in depositional sequences. In: Pay C E(ed). Seismic Stratigraphy: Applications to Hydrocarbon Exploration. AAPG Memoir, 26: 117-133.