Sedimentary environments and sedimentary model of carbonate rocks in the Cenozoic lacustrine basin,western Qaidam Basin
Ji Youliang1, 2, Ma Dade3, Xue Jianqin3, Wang Peng3, Wu Yanxiong3, Zeng Li1, 2, Jin Li1, 2
1 College of Geosciences,China University of Petroleum(Beijing),Beijing 102249; 2 State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249; 3 Exploration and Development Research Institute of Qinghai Oilfield,PetroChina,Dunhuang 736202,Gansu
Abstract：This paper focuses on the lacustrine carbonate strata of the Ganchaigou Formation of Cenozoic in western Qaidam Basin. Based on field outcrop survey,core sample identification, analysis data, and well logging data,the types distribution and sedimentary facies of carbonate deposits in the study area were studied. By analyzing the forming control factors,corresponding depositional model is established to guide the exploration. Research shows that the western Qaidam Basin is a typical saline lacustrine basin. There are four types and 11 kinds of lacustrine carbonates including grain limestone,algal limestone,crystal limestone and peperite carbonate developed in western Qaidam Basin which were mainly deposited in five microfacies of lime-mud flats,grain bank,algal reef,lake-bay and semi-deep lake facies. By analyzing the spatial and temporal distribution characteristics of different carbonates and microfacies,the conclusion is made that the development of lacustrine carbonates in western Qaidam Basin is mainly controlled by the basin tectonic movements,injection of terrigenous clastics,water palaeosalinity under the ancient climate and palaeotopography with different palaeo-water-depth. On this basis,a comprehensive vertical depositional model of lacustrine carbonate with associated gypsum-salt rock in western Qaidam Basin is established. The research indicated that, during the sedimentary period of the Ganchaigou Formation in western Qaidam Basin, the lacustrine basin was typical saline lacustrine basin with stable tectonic activities; whereas the lake level reached the peak. Carbonate rocks, which were developed in the transgression stage, were frequently interbedded with clastic rocks due to the high￣frequency lake level changes. In the low￣water season, clastic beach bars or delta front deposits were developed at basin slope; while at lake transgression stage, oolitic banks and algal limestones were developed at the basin break in slope, and marlite and lime mudstones were developed in the depression area of the basin.
Ji Youliang,Ma Dade,Xue Jianqin et al. Sedimentary environments and sedimentary model of carbonate rocks in the Cenozoic lacustrine basin,western Qaidam Basin[J]. JOPC, 2017, 19(5): 757-772.
[1] 党玉琪,尹成明,赵东升. 2004. 柴达木盆地西部地区古近纪与新近纪沉积相. 古地理学报,6(3): 297-306. [Dang Y Q,Yin C M,Zhao D S. 2004. Paleogene and Neogene sedimentary facies in the western Qaidam Basin. Journal of Palaeogeography(Chinese Edition),6(3): 297-306] [2] 郭泽清,郑得文,刘卫红,钟建华,温志峰. 2008. 柴达木盆地西部古近纪—新近纪湖相生物礁的发现及意义. 地层学杂志,32(1): 60-68. [Guo Z Q,Zheng D W,Liu W H,Zhong J H,Wen Z F. 2008. Discovery of the Paleogene-Neogene Lacustrine reefs in the western Qaidam Basin and Their Implications. Journal of Stratigraphy,32(1): 60-68] [3] 纪友亮,冯建辉,王声朗,谈玉明,张宏安,王德仁. 2005. 东濮凹陷下第三系沙三段盐岩和膏盐岩的成因. 沉积学报,23(2): 224-230. [Ji Y L,Feng J H,Wang S L,Tan Y M,Zhang H A,Wang D R. 2005. Genesis of salt rock and gypsum salt rocks in the third member of Shahejie Formation in Dongpu Depression. Chinese Journal of Sedimentology,23(2): 224-230] [4] 李明杰,郑孟林,曹春潮,张军勇. 2005. 柴达木古近纪—新近纪盆地的形成演化. 西北大学学报: 自然科学版,35(1): 87-90. [Li M J,Zheng M L,Cao C C,Zhang J Y. 2005. Paleogene evolution of the Qaidam-Paleogene-Neogene basin. Journal of Northwest University: Natural Science Edition,35(1): 87-90] [5] 任晓娟,臧士宾,魏金星. 2012. 柴西第三纪湖相碳酸盐岩共沉积特征. 西北地质,45(3): 57-63. [Ren X J,Zang S B,Wei J X. 2012. Characteristics of Tertiary lacustrine carbonate sediments in western Qaidam Basin. Northwest Geology,45(3): 57-63] [6] 宋华颖,伊海生,范爱春,马血,孙瑕. 2010. 柴达木盆地西部西岔沟剖面湖相碳酸盐岩岩石学特征与沉积环境分析. 中国地质,37(1): 117-126. [Song H Y,Yi H S,Fan A C,Ma X,Sun X. 2010. Characteristics and sedimentary environments of lacustrine carbonate rocks in Xi Chagou section,western Qaidam Basin. China Geology,37(1): 117-126] [7] 王英华,周书欣,张秀莲. 1993. 中国湖相碳酸盐岩. 江苏徐州: 中国矿业大学出版社,3-147. [Wang Y H,Zhou S X,Zhang X L. 1993. Lacustrine carbonate rocks in China. Jiangsu Xuzhou: China University of Mining and Technology Press,3-147] [8] 温志峰,钟建华,郭泽清,刘云田,李勇,高剑波,徐小林,王海侨. 2004. 柴西地区第三纪叠层石岩石学特点与油气储集特征. 石油勘探与开发,31(3): 49-53. [Wen Z F,Zhong J H,Guo Z Q,Liu Y T,Li Y,Gao J B,Xu X L,Wang H Q. 2004. Characteristics of the Tertiary stromatolitic rocks and characteristics of oil and gas reservoirs in Qaidam Basin. Petroleum Exploration and Development,31(3): 49-53] [9] 温志峰,钟建华,王芳,李勇,王海侨,高剑波. 2005. 柴西生物礁储集层的测井响应特征与最优判别. 新疆石油地质,26(2): 17-20. [Wen Z F,Zhong J H,Wang F,Li Y,Wang H Q,Gao J B. 2005. Logging response characteristics and best discrimination of chesy reef reservoirs. Xinjiang Petroleum Geology,26(2): 17-20] [10] 吴因业,靳久强,李永铁,江波,郭彬程,方向. 2003. 柴达木盆地西部古近系湖侵体系域及相关储集体. 古地理学报,5(2): 232-243.[Wu Y Y,Jin J Q,Li Y T,Jiang B,Guo B C,Fang X. 2003. Transgression system and associated reservoirs of the Paleogene in western Qaidam Basin. Journal of Palaeogeography (Chinese Edition),5(2): 232-243] [11] 张敏,尹成明,寿建峰,陈子炓,张跃中. 2004. 柴达木盆地西部地区古近系及新近系碳酸盐岩沉积相. 古地理学报,6(4): 391-400. [Zhang M,Yin C M,Shou J F,Chen Z L,Zhang Y Z. 2004. Carbonate sedimentary facies of the Paleogene and Neogene in the western Qaidam Basin. Journal of Palaeogeography(Chinese Edition),6(4): 391-400] [12] 赵澄林. 2001. 沉积学原理. 北京: 石油工业出版社. [Zhao Z L. 2001. Principles of Sedimentology. Beijing: Petroleum Industry Press] [13] Keith M L, Weker J N. 1964. Carbon and oxygen isotopic composition of selected limestones and fossils. Geochimica et Cosmochimica Acta, 28(10-11): 1787-1816. [14] Wilkinson B H,Pope B N,Owen R M. 1980. Nearshore ooid formation in a modern temperate region marl lake. Journal of Geology,88(6): 697-704.
