Benthic foraminifera distribution and sedimentary environmental evolution of a carbonate platform: A case study of the Guadalupian (middle Permian) in eastern Sichuan Basin

Benthic foraminifera are significant indicators of habitat changes and useful for paleoenvironmental reconstruction. During the Permian period, variation in species, individual sizes, morphological characteristics different assemblages, such as fusulinids, is a clue to paleoecological interpretations. The eastern part Sichuan Basin, located near equator middle Permian, Guadalupian was precipitated by thick beds marine carbonate rocks with numerous benthic foraminifera. In this study, we record species calculate frequency from 445 thin sections (Maokou Formation) rocks. Seven types foraminiferal biofacies recognized associated five sedimentary microfacies Erya Huilongchang sections, area. early small uniserial nodosariids Endothyrida dominated assemblages; Miliolida, Ammodiscidae, were common; however, Fusulinida, Schwagerina sp. Verbeekina sp., abundant late period. indicates shallow open platform marginal platform. our study area, deposited an grain shoals. This followed gradual shallowing environment shifted shoals period until paleoweathering abruptly terminated deposition at end