Carbon isotopic chemostratigraphy of the Ediacaran-Cambrian successions in the northwestern Tarim Craton, NW China: Correlations with Gondwana supercontinent

Abstract

Among the three cratons (North China, Yangtze, and Tarim) in China, the Tarim Craton during Precambrian is the least known for its evolution due to its broad Phanerozoic cover. The affinity of the Tarim Craton with Gondwana supercontinent during the Cryogenian-Ediacaran interval has long been debated. In this contribution, we report carbon and oxygen isotopes of the Ediacaran-Cambrian siliciclastic‑carbonate from successions in the northwestern Tarim Craton. The results exhibit one pronounced negative and one positive carbon isotopic excursions (CIE) in the Ediacaran sections (N3 and P1), and a distinct negative CIE at the base of the Cambrian (N4). With the constraints of geochronological data, we proposed that the Ediacaran-lower Cambrian chemostratigraphy of the northwestern Tarim basin correlates well with the lower Ediacaran and lower Cambrian from Yangtze, Oman, Australia, Namibia, and Canada basins. N3 in the Tarim Craton possibly represents a new contribution to the Shuram-Wonoka anomaly globally. With these data, together with previously published tectonostratigraphic and paleogeographic reconstructions, we propose that the Tarim Craton may have been involved in the Pan-African Orogeny during the assembly of Gondwana, and was positioned close to the Yangtze, Oman, and Namibia cratons along the northern periphery of the Gondwana supercontinent