PERMIAN-TRIASSIC MICROBIALITES FROM HUBEI PROVINCE, SOUTH CHINA

This page currently authored by Steve Kershaw but further contributions may come from other authors

This page gives details of earliest Triassic microbialites at the excellent locality of Chongyang in Hubei Province

CREDITS:

Photographs on this page  were taken in 2010 during fieldwork kindly hosted by Wang Yongbiao and colleagues. Thus photos here are temporary pending any replacements by better images.

Photo on right shows the layered microbialite overlying pale-grey coloured Changhsingian (Late Permian) limestones . Red arrow is the contact; Blue arrow shows where the top of the microbialite is located.

Photo below shows a general view of the top level of the microbialite, the platform indicating the biostromal nature of the microbial unit.

Photo below shows the top surface of the microbialite. The layered structure lower down gives way upwards to a series of 1-m domal tops comprising thick branching thrombolite, overlain by grainstones.

Photo below shows close-up of columns of thrombolite, in this case with a narrow gap between two areas of domes (arrowed).

Photo on right shows enlargement of previous photo.

Photo below shows close-up of thrombolite c.100 m along strike from previous photos and lower down in the microbialite unit.

Photo right shows close-up of columns of of thick-branched thrombolite near top of microbialite.

Photo below shows small polished sample of vertical section of stromatolite from the middle of the microbialite unit. Note that in Sichuan/Chongqing, stromatolites are very rare.

Photo below shows small polished sample of vertical section of thrombolite from the upper part of the microbialite unit.

Photo below shows close-up of oncolitic unit above the microbialite.

Photo below shows view of thrombolite near top of the microbialite.