Provenance and depositional systems during the depositional period of interval 8 of Upper Triassic Yanchang Formation in Qingyang area，Ordos Basin
Yang Binhu1,2, Bai Haiqiang1, Dai Yaquan1,2, Zha Li2, Li Jian1,2, Jin Wenqi2, Liu Xinju2
1 State Key laboratory of Dynamics，Northwest University，Xi'an 710069，Shaanxi 2 The First Petroleum Production Division of PetroChina Changqing Oilfield Company，Yanan 716000，Shaanxi
Abstract：Based on the field outcrop palaeo-current measurements and studies of the sandstone framework mineralogy and heavy mineral assemblages, we utilized clastic rock geochemical methods to define the provenance during the deposition of interval 8 of the Upper Triassic Yanchang Formation in Qingyang area，Ordos Basin. The results show that the palaeo-current in the study area was mainly SW-NE and NW-SE and SE-NW currents were of secondaryimportance. Distribution of heavy minerals is also characterized by obvious zoning patterns. The REE matching pattern of the interval 8 is a “right-declined” type. The average value of δEu is 0.67. The variation characteristics of trace elements are largely consistent with those shown by the Longshan Group of the Longxi Palaeo-land in the southwestern margin of the basin. According to the sandstone clastic components especially the lithic components and heavy mineral characteristics，the source rocks of interval 8 in Qingyang area were mainly derived from the Meso-Proterozoic to Paleozoic of the Longxi Palaeo-land, the granitoids along the Qilian Orogenic Belt and the Ordovician-Permian along the Qinling Orogenic Belt. The detrital source rocks are dominated by metamorphic and igneous rocks. According to the current drilling results combined with the field outcrops，it is proved that the interval 8 of Yanchang Formation was dominated by the fan delta depositional system with fan deltaic front and(semi)deep lacustrine turbidite fan subfacies being developed. The subaqueous distributary channel sandbodies of the delta front constitute the favorable facies belt for petroleum accumulation.
Yang Binhu,Bai Haiqiang,Dai Yaquan et al. Provenance and depositional systems during the depositional period of interval 8 of Upper Triassic Yanchang Formation in Qingyang area，Ordos Basin[J]. JOPC, 2008, 10(3): 251-259.
陈安宁，韩永林，杨阳，等. 2002. 鄂尔多斯盆地晚三叠世延长期大型三角洲沉积 ［J］. 低渗透油气田，7(2):1-4. 陈衍景，杨忠芳，赵太平，等. 1996. 沉积物微量元素示踪物源区和地壳成分的方法和现状 ［J］. 地质地球化学，18(3)：7-11. 付金华，郭正权，邓秀芹，等. 2005. 鄂尔多斯盆地西南地区上三叠统延长组沉积相及石油地质意义 ［J］. 古地理学报，7(1):34-44. 和钟铧，刘招君，张峰，等. 2001. 重矿物在盆地分析中的应用研究进展 ［J］. 地质科技情报，20(4): 29-32. 焦养全，李珍，周海民，等. 1998. 沉积盆地物质来源综合研究——以南堡老第三纪亚断陷盆地为例 ［J］. 岩相古地理， 18(5):16-20. 刘立，胡春燕. 1991. 砂岩中主要碎屑成分的物源区意义 ［J］. 岩相古地理，11(6):48-53. 刘少峰，柯爱蓉，吴丽云，等. 1997. 鄂尔多斯西南缘前陆盆地沉积物物源分析及其构造意义 ［J］. 沉积学报，15(1):156-160. 邵磊，刘志伟，朱伟林. 2000. 陆源碎屑岩地球化学在盆地分析中的应用 ［J］. 地学前缘，7(9): 297-304. 宋凯，吕剑文，杜金良，等.2002.鄂尔多斯盆地中部上三叠统延长组物源方向分析与三角洲沉积体系［J］.古地理学报，4（3）：59-66. 王锡福，陈安定. 1993. 鄂尔多斯盆地非地震油气勘探 ［M］. 北京:地质出版社. 汪正江，陈洪德，张锦泉. 2000. 物源分析的研究与展望 ［J］. 沉积与特提斯地质，20(4):104-110. 魏斌，魏红红，陈全红，等. 2003. 鄂尔多斯盆地上三叠统延长组物源分析 ［J］. 西北大学学报（自然科学版），33(4): 447-450. 武富礼，李文厚，李玉宏，等.2004.鄂尔多斯盆地上三叠统延长组三角洲沉积及演化［J］.古地理学报，6（3）：307-315. 杨守业，李先从. 1999. REE示踪沉积物源研究进展 ［J］. 地球科学进展，14(2):164-167. 杨忠明，孟宪峋. 2002. 再论祁连—北秦岭接合部位晚古生代前地层划分 ［J］. 甘肃地质学报，11(2):1-4. 于炳松，乐昌硕. 1998. 沉积岩物质成分所蕴含的地球深部信息 ［J］. 地学前缘，5(3):105-112. 赵红格，刘池洋. 2003. 物源分析方法及研究进展 ［J］. 沉积学报，21(3): 409-415. 赵文智，王新明，郭彦如，等. 2006. 鄂尔多斯盆地西部晚三叠世原型盆地恢复及其改造演化 ［J］. 石油勘探与开发，33(1):6-13. 周祖翼，毛凤鸣，廖宗廷，等. 2001. 裂变径迹年龄多成分分离技术及其在沉积盆地物源分析中的应用 ［J］. 沉积学报，19(3):456-458，473.Andrew C，Claire R H.1999. Processes controlling the composition of heavy mineral assemblages in sandstones ［J］. Sedimentary Geology，124(1-4):3-29. Chen Anning，Han Yonglin，Yang Yang，et al. 2002. The delta sediment of Late Triassic in Ordos Basin ［J］. Low Permeability Oil and Gas Fields，7(2):1-4(in Chinese with English abstract). Chen Yanjing，Yang Zhongfang，Zhao Taiping， et al. 1996. The methods and status of the trace element in sediments indicates source area and crust ingredients ［J］. Geology-Geochemistry，18(3)：7-11(in Chinese). Fu Jinhua，Guo Zhengquan，Deng Xiuqin，et al. 2005. Sedimentary facies of the Yanchang Formation of Upper Triassic and petroleum geological implication in southwestern Ordos Basin ［J］. Journal of Palaeogeography，7(1):34-44(in Chinese with English abstract). He Zhonghua，Liu Zhaojun，Zhang Feng，et al. 2001. Latest progress of heavy mineral research in the basin analysis ［J］. Geological Science and Technology Information，20(4): 29-32(in Chinese with English abstract). Hilmarvon E，Reinhard G. 1999. Provenance of Cretaceous synorganic sandstones in the Eastern Alps: Constrains from framework petrography，heavy mineral analysis and mineral chemistry ［J］. Sedimentary Geology，124(1-4): 81-111. Jiao Yangquan，Li Zhen，Zhou Haimin，et al. 1998. The integated study of sediment sources in sedimentary basins:An example from the Eogene Nanpu rift subbasin ［J］. Sedimentary Facies and Palaeogeography，18(5):16-20(in Chinese with English abstract). Liu Li，Hu Chunyan. 1991. Provenance signification of the main detrital composition in sandstone ［J］. Sedimentary Facies and Palaeogeography，11(6):48-53(in Chinese with English abstract). Liu Shaofeng，Ke Airong，Wu Liyun，et al. 1997. Sediment provenance analysis and its tectonic significance in the foreland basin of the Ordos southwestern margin ［J］. Acta Sedimentologica Sinica，15(1):156-160(in Chinese with English abstract). Mclennan S M，Hemming S，McDanial D K，et al. 1993. Geochemical Approaches to Sedimentation，Provenance，and Tectonics ［A］. Geological Society of American Special Paper，284: 21-40. Morton A，Hurst A. 1995. Correlation of Sandstones Using Heavy Minerals:An Example from the Statfjord Formation of the Snorre Field，Northern North Sea ［C］. In:Dunay R A(ed). Nonbiostratigraphical Methods of Dating and Correlation. Geological Society Special Publication，89:3-22. Shao Lei，Liu Zhiwei，Zhu Weilin. 2000. Application of sedimentary geochemistry of terrigenous clastic rock to basin analysis ［J］. Earth Science Frontier，7(9): 297-304(in Chinese with English abstract). Song Kai, Lü Jianwen, Du Jinliang, et al.2002.Source direction analysis and delta depositional systems of Yanchang Formation of the Upper Triassic in the central Ordos Basin［J］.Journal of Palaeogeography，4（3）：59-66(in Chinese with English abstract). Wang Xifu，Chen Anding. 1993. Non-seismic Exploration for Oil and Gas in Ordos Basin ［M］. Beijing:Geological Publishing House(in Chinese). Wang Zhengjiang，Chen Hongde，Zhang Jinquan. 2000. The research and prospect in provenance analysis ［J］. Sedimentary Geology and Tethyan Geology，20(4):104-110(in Chinese with English abstract). Wei Bin，Wei Honghong，Chen Quanhong，et al. 2003. Sediment provenance analysis of Yanchang Formation in Ordos Basin ［J］. Journal of Northwest University(Natural Science Edition)，33(4): 447-450(in Chinese with English abstract). Wu Fuli,Li Wenhou, Li Yuhong, et al.2004.Delta sediments and evolution of the Yanchang Formation of Upper Triassic in Ordos Basin［J］.Journal of Palaeogeography，6（3）：307-315(in Chinese with English abstract). Yang Shouye，Li Congxian. 1999. Research progress in REE tracer for sediment source ［J］. Advance in Earthsciences，14(2):164-167(in Chinese with English abstract). Yang Zhongming，Meng Xianxun. 2002. Expound the pre-Late Paleozoic stratum dividing of the junction of the Qilian mountain and north Qinling mountain ［J］. Acta Geologica Gansu，11(2):1-4(in Chinese with English abstract). Yu Bingsong，Le Changshuo. 1998. Sedimentary material composition contains the deep earth information ［J］. Earth Science Frontier，5(3):105-112(in Chinese with English abstract). Zhao Hongge，Liu Chiyang. 2003. Approaches and prospects of provenance analysis ［J］. Acta Sedimentologica Sinica，21(3):409-415(in Chinese with English abstract). Zhao Wenzhi，Wang Xinming，Guo Yanru， et al. 2006. Restoration and tectonic reworking of the Late Triassic basin in western Ordos Basin ［J］. Petroleum Exploration and Development，33(1): 6-13(in Chinese with English abstract). Zhou Zuyi，Mao Fengming，Liao Zongting，et al. 2001. Estimation of the multi-component fission track age data and its application in the provenance study of sedimentary basins ［J］. Acta Sedimentologica Sinica，19(3):456-458，473(in Chinese with English abstract).
