Geochemical characteristics and its sedimentary environment significance of the Ordovician in the western margin of Ordos Basin
Xi Shengli Zheng Congbin Li Zhenhong
1 The Geology Department of Northwest University Xi'an 710061 Shaanxi
2 Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029
3 Research Institute of Exploration and Development of Changqing Oil Field Branch Xi’an 710054,Shaanxi
Clinothem slope facies is very advantageous to development of source rock of marine facies in the western margin of Ordos BasinAccording to the element geochemical characteristics,the relationships between element geochemistry and sedimentary environment,and the relationships between the distribution of source rock and heatflow of oceanfloor are discussed in this article by the numbers through analyzing the rules of element concentrate and transference and the change of sedimentary water mass and oxidationreduction condition on the different horizons and the different areasThe conclusion is that water mass depth and reduction and biocoenosis and the heatflow of oceanfloor are very important to the development of source rocksIn the Zhuozishan Formation on the north of the western margin and Sandaogou Formation on the south of the western margin,the preservation of organism is very difficult,because during their deposition,the water mass was very shallow and widen,and the reduction was weakIn the Kelimoli Formation and Wulalike Formation on the north of western margin and the first section of Pingliang Formation on the south of the western margin,the abundance of organism is very high,because during their deposition the water mass was very occlusive and the reduction was very strong,also heatflow of the ocean floor was very activeThese analyses provide the basement of element geochemical characteristic for evaluating the reservoir of the gas
. Geochemical characteristics and its sedimentary environment significance of the Ordovician in the western margin of Ordos Basin[J]. JOPC, 2004, 6(2): 196-206.