Research on Northern Qaidam tectonic attributes during Devonian

Key words:  Northern Qaidam tectonic belt  Devonian  detrital component  sedimentary system distribution  tectonic attribute

Abstract:

Using rock core and outcrop data, a series of studies were conducted under the sedimentology theories to investigate the formation thickness, detrital components, detrital zircon age, stratigraphic onlap, and the distribution of Devonian sedimentary system in the Northeast Qaidam area. The results show that the Devonian sedimentary system developed in the northern Qaidam area (including Northern Qaidam tectonic belt and Oulongbuke microplate) is distributed from south to north; the orogenic belt composed by several pre-Devonian tectonicslices is the main provenance of the northern margin in the Qaidam area. The northern Qaidam Caledonia tectonic belt in this period was neither a rift valley nor a foreland basin, but a orogenic belt consisting of multiple pre-Devonian geological bodies. The uplift of the orogenic belt started from about 465 Ma years ago, its denudation started from 430 Ma years ago, its uplift history perhaps lasted to the Late Carboniferous even to the Early Permian. The orogenic belt had been existing for at least 190Ma years, including the mountain uplift period (465-430 Ma years ago) and the mountain erosion period(430-275 Ma years ago).