Practice of geological mapping method in Wandashan orogenic belt of Heilongjiang Province and its significance

The Wandashan accetionary orogenic belt (also called Nadanhada terrane), is located on the continental margin of Northeast Asia. It is connected with the Sikhote-Alin orogenic belt in Far East of Russia, which together constitute a great proportion of circum-Pacific orogenic zone. These orogenic belts were closely related to the paleo-Pacific Ocean subduction. So far the research has suggested that these orogenic belts consist of such complex geological blocks as exotic terrain, small continent, island arc, oceanic crust, seamount, oceanic plateau and ophiolite. Nevertheless, the traditional rock-stratigraphy geological mapping method is not suitable for the study area and it can not reflect the composition and tectonic properties of the complex. Therefore, this geological mapping practice was aimed at the complex structural area of the orogenic belt and, based on the traditional field geological survey method, the authors used the non-Smith stratigraphic mapping method to carry out the systematic geological mapping work. The results obtained by the authors should be significant for the understanding of tectonic evolution of Wandashan orogenic belt and also will play an exemplary role for orogenic belt mapping.