1 Research Institute of Exploration and Development，Petrochina Changqing Oilfield Company，Xi'an 710021，Shaanxi 2 Training Center of CNPC Changqing Petroleum，Xi'an 710021，Shaanxi
Abstract The Indosinian Movement at the end of the Triassic uplifted the whole Ordos Basin. The top of the Yanchang Formation suffered a strong weathering and fluvial erosion which formed a palaeogeomorphic landscape with widely distributed streams, ditches and pools alternated，uplands and lowlands. Based on the compilation of stratigraphic isopach maps of the interval 10 of Yanan and Fuxian formations and the top surface structure contour map of the Yanchang Formation，the pre-Jurassic palaeogeomorphic framework was divided into valley，slope，terrace land，upland，plain and burial hill. It had a great control on the sedimentary facies types，sedimentary facies belts distribution，and the structure formation of the Fuxian Formation and the Lower Yanan Formation of Lower Jurassic. The incision of the palaeo-valley not only decreased the distance between the Lower Yanan Formation and the hydrocarbon source intervals，but also provided hydrocarbon migration pathways. If there existed profitable reservoirs combining with anticline and nose-uplifting structures，they can entrap hydrocarbons and form hydrocarbon reservoir. The formation water characteristics show that the slope area has the best preservation conditions，and the slope mouth，terrace land and burial hill on the pre-Jurassic palaeogeomorphic slope are the profitable areas for the exploration of the Lower Yanan Formation.
About author: Guo Zhengquan，born in 1963，graduated from Geology Department of Northwest University in 1989. Now he is engaged in petroleum geology.
Cite this article:
Guo Zhengquan,Zhang Lirong,Chu Meijuan et al. Pre-Jurassic palaeogeomorphic control on the hydrocarbon accumulation in the Lower Yanan Formation in southern Ordos Basin[J]. JOURNAL OF PALAEOGEOGRAPHY, 2008, 10(1): 63-71.
Guo Zhengquan,Zhang Lirong,Chu Meijuan et al. Pre-Jurassic palaeogeomorphic control on the hydrocarbon accumulation in the Lower Yanan Formation in southern Ordos Basin[J]. JOPC, 2008, 10(1): 63-71.
陈安定.1989.陕甘宁盆地中生界生油层特征 ［M］.见：中国含油气盆地烃源岩评价编委会.中国含油气盆地烃源岩评价.北京：石油工业出版社，421-437. 顾家裕，张兴阳，郭彬程.2006.塔里木盆地东河砂岩沉积和储层特征及综合分析 ［J］.古地理学报，8(3):285-294. 郭正权，潘令红，刘显阳，等.2001.鄂尔多斯盆地侏罗系古地貌油田形成条件与分布规律 ［J］.中国石油勘探，6(4):20-27. 黄第藩，王则民，石国世.1997.陕甘宁地区印支期古地貌特征及其石油地质意义 ［M］.中国陆相大油田.北京：石油工业出版社，239-247. 时志强，韩永林，赵俊兴.2002.鄂尔多斯盆地早侏罗世富县期冲积扇沉积 ［J］. 成都理工学院学报，29（4）:390-393. 宋国初，李克勤，凌升阶.1997.陕甘宁盆地大油田形成与分布 ［M］.中国陆相大油田.北京：石油工业出版社，276-279. 宋凯，吕剑文，凌升阶，等.2003.鄂尔多斯盆地定边—吴旗地区前侏罗纪古地貌与油藏 ［J］.古地理学报，5(4):497-507. 张吉来，朱广社，陈德平，等.2006.马岭油田北三区延安组Ｙ8～Ｙ10油层沉积微相研究 ［J］. 石油天然气学报(江汉石油学院学报)，28(3):185-186. 张文正，李剑锋.2001.鄂尔多斯盆地油气源研究 ［J］.中国石油勘探，6(4): 28-36. 朱筱敏，杨俊生，张喜林.2004.岩相古地理研究与油气勘探 ［J］.古地理学报，6（1）:101-109. Chen Anding. 1989. Oil-generating Strata Characteristic of Mesozoic in Shanganning Basin ［M］.In: Editorial Committee of Hydrocarbon Evaluation in China Petroliferous Basin. Evaluation on Hydrocarbon in China Petroliferous Basin. Beijing: Petroleum Industry Press，421-437(in Chinese with English abstract). Gu Jiayu，Zhang Xingyang，Guo Bincheng. 2006. Characteristics of sedimentation and reservoir of the Donghe Sandstone in Tarim Basin and their synthetic analysis ［J］. Journal of Palaeogeography，8(3): 285-294(in Chinese with English abstract). Guo Zhengquan，Pan Linghong，Liu Xianyang，et al. 2001. The formation conditions and distribution of Jurassic palaeogeomorphological oilfield in Ordos Basin ［J］. China Petroleum Exploration，6（4）:20-27(in Chinese with English abstract). Huang Difan，Wang Zemin，Shi Guoshi. 1997. Palaeogeomorphology Characteristics of Indosinian Epoch and Petroleum Geology Significance in Shaanxi-Gansu-Ningxia ［M］. Major Nonmarine Oil Field of China. Beijing：Petroleum Industry Press，239-247(in Chinese with English abstract). Shi Zhiqiang，Han Yonglin，Zhao Junxing. 2002. Alluvial fan deposit of Fuxian Formation of pre-Jurassic in Ordos Basin ［J］. Journal of Chengdu University of Technology，29（4）:390-393(in Chinese with English abstract). Song Guochu，Li Keqin，Ling Shengjie. 1997. Formation and Distribution of Major Oil and Natural Gas Cumulation in Shanganning Basin ［M］. Major Nonmarine Oil Field of China. Beijing∶Petroleum Industry Press，276-279(in Chinese with English abstract). Song Kai，Lü Jianwen，Ling Shengjie，et al. 2003. Paleogeomorphic features of the pre-Jurassic and oil reservoir of Dingbian-Wuqi area in Ordos Basin ［J］. Journal of Palaeogeography，5（4）:497-507(in Chinese with English abstract). Zhang Jilai，Zhu Guangshe，Chen Deping，et al. 2006. Research on sedimetary microfacies about Yan 8～Yan 10 of Yan′an Formation in the third north district of Maling Oilfield ［J］. Journal of Oil and Gas Technology，28(3):185-186(in Chinese with English abstract). Zhang Wenzheng，Li Jianfeng. 2001. Research on oil and gas origin in Ordos Basin ［J］. China Petroleum Exploration，6（4）:28-36(in Chinese with English abstract). Zhu Xiaomin，Yang Junsheng，Zhang Xilin. 2004. Application of lithofacies palaeogeography in petroleum exploration ［J］. Journal of Palaeogeography，6(1):101-109(in Chinese with English abstract).
