Key signatures of turbidite and sandy debris and core examples in Liaohe Basin

Gravity flow is a widely-distributed fluid type in nature. Various classification schemes of gravity flow are proposed by different researchers from different viewpoints. The scheme of turbidity flow and debris flow is adopted in this paper. The sedimentary characteristics of turbidite and sandy debrite are summarized and discussed to clarify most typical facies marks of these two rock types. The study shows that turbidite and sandy debris can be identified by the following typical characteristics during the outcrop and core observation: If the graded bedding is developed in sandstone,it should be identified as turbidite;if the muddy rip-up clast or no bedding structure(massive sandstone)is developed in sandstone,it should be identified as sandy debris. These characteristics are the most reliable signatures to distinguish turbidite and sandy debris. In addition,some other sedimentary structures such as deformation bedding,climbing ripple cross bedding,wavy bedding,parallel bedding,scouring surface,lithologic abrupt interface,and flute cast also have certain indicative significance. It is necessary to make a comprehensive judgment based on the sedimentary background,vertical combination of lithofacies,geophysics and other materials when these characteristics are presented in the study.