Study on the Lithofacies Palogeography of Ordovician in Ordos
|School||Shandong University of Science and Technology|
|Course||Mineral prospecting and exploration|
|Keywords||Ordos region Cambrian Stratigraphic division and correlation Sedimentary facies Lithofacies palaeogeography Paleogeographic evolution|
Summary of the study area is located in the western part of the North China platform , the north Yinshan sector, bounded by West Helan Mountain , is bounded by the Qinling Mountains to the south . In the study area were deposited mainly in the Cambrian , a marine carbonate rocks , the thickness of the lateral variation greater in northern thin , the West , the eastern edge of thick stratigraphic thickness of the region as a whole range of 100-1300 meters . A wide range of study area , all over lithostratigraphic units vary , according to the latest international division of Cambrian standard (four ten -order system ) as well as the aspect of the data of the study area Cambrian lithology , stratigraphy , structure and ancient topography regional stratigraphic re- division and correlation of the Ordos Basin, Cambrian divided into the Newfoundland system ( deletion ) , the second system ( third -order and fourth -order ) , the third system ( fifth order , Gushan order Guzhang order ) Furongian ( Bi -order row , ninth order , 10th order ) , in accordance with the new standard to establish stratigraphic framework . In this paper, on the basis of full use of the results of previous studies , the comprehensive utilization of wild outcrops, drilling and logging data , through the deposition of the Cambrian sedimentary system to conduct a comprehensive analysis of a typical sedimentary facies analysis , and ultimately identified in the study area a tidal flat, restricted platform , open platform , shoal , platform margin , beach between the sea sedimentary facies . Sedimentary facies analysis based on this article to order ( system ) six lithofacies paleogeographic map prepared for the unit , and explore the the paleogeographic evolution characteristics of the different stages of the Cambrian .