Developmental Characteristics of Turbidite and Its Implication on Petroleum Geology in Late-Triassic Ordos Basin

Unequal thickness of turbidite sandbodies are found in the deep-lake area of Triassic Yanchang Formation Ch7 and Ch6 member of Ordos Basin.Based on the integrated study of the sedimentary facies features,rock texture,structural attitude of the Ch6-Ch7 drilling core,the turbidite was caused by the delta-front landsliding.The turbidite is concluded into two types:the coarse grains fluxoturbidite was mainly developed with braid river delta-front which the clastic source was from southwest;the fine grains fluxoturbidite was mainly developed with meandering river delta-front which the clastics source was from northwest.Figuring out the developmental distribution and regular pattern of turbidite in the Ordos Triassic lake-basin not only directs the exploration of the turbidite reservoir in the deep lake,but also benefits the study on hydrocarbon accumulation of the turbidite on the deep-lake facies.