Conodont Succession of the Guadalupian–Lopingian Boundary Strata in Laibin of Guangxi, China and West Texas, USA

Mei Shilong, Jin Yugan and Bruce R. Wardlaw

pp. 53-76, 10 plates, in English

Abstract:

A carbonate sequence from the Artinskian to the Changhsingian Stage was fully developed in Laibin. Based on tightly collected samples from the Guadalupian–Lopingian boundary beds in the Tieqiao (Rail-Bridge) and Penglaitan (Penglai Islet) sections, a succession of fifteen conodont zones is recognized, which demonstrates the continuity of deposition around the boundary. Corresponding succession of its lower part was found in the Bird Mine Section of West Texas, USA. The first appearance of Clarkina postbitteri in monofacies beds coincides with the initial transgression of Lopingian sequence, and a major fanual turnover of Permian Period and thus, is regarded as the most attractive horizon for the Guadalupian–Lopingian boundary. Intra-species variations of Jinogondolella xuanhanensis, Clarkina postbitteri and Clarkina dukouensis are systematically illustrated by specimens from the Bird Mine, Tieqiao and Penglaitan sections. Two new sweetognathid conodonts of Guadalupian–Lopingian shallower water facies, Sweetognathus fengshanensis sp. nov. and Iranognathus erwini sp. nov., are briefly described.

Keywords: Permian, Lopingian, Guadalupian, conodonts, South China, West Texas