Early Carboniferous paleomagnetic results from the northeastern margin of the Qinghai–Tibetan plateau and their implications

Abstract

We conducted paleomagnetic investigations on limestone from the Lower Carboniferous Huaitoutala Formation in the Qaidam Basin near Delingha City, Qinghai Province, China. The characteristic remanent magnetization (D = 5.8°, I = −25.7°, k = 114.3, α₉₅ = 4.8°) passes a fold test and indicates a paleopole position of −39.2°N, 90.4°E and a paleolatitude of 13.5°N for the Qaidam Block for the early Carboniferous. Based on global tectonic reconstructions and paleontological evidence, we suggest that the Qaidam Block was adjacent to, but independent from, the North China, South China, Alashan–Hexi and Tarimblocks at this time. This result suggests that Pre-Carboniferous sutures reported around the QaidamBasin represent collisional eventswithin Gondwana, rather than the final sutures that gave rise to the present tectonic configuration