Geochemistry and Tectonic Depositional Settings of Jurassic Terrigenous Sediments in the Upper Amur and Zeya-Dep Troughs of the Eastern Central Asia Fold Belt

摘要

The Upper Amur and Zeya-Dep troughs filled by thick deformed Mesozoic setlimentary sequences are located along the southern periphery of the Mongol-Okhotsk orogenic belt (Fig. 1). The geodynamic environments of the formation of these structures are debatable. Some authors consider them as representing passive continental margins, while others assume their orogenic nature. The relation between the formation of the Upper Amur trough and orogenic processes that accompanied development of the Mongol-Okhotsk belt has been noted by many researchers (e.g.,), who considered this trough as a foreland basin.