![Sample our Geography journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5937/TOC-Subject-Sample-2021-Geography.jpg"})
Abstract
The Wufeng Formation black shales (upper Katian to lower Hirnantian) are widely distributed on the Yangtze Platform in South China. Data from 389 sections that span the stratigraphic interval of the Wufeng Formation were captured through the GBDB online database. By using the GBDB online analytical functions and the ArcGIS software, we have visualized the dynamic changes of the geographic distribution of the Wufeng Formation black shales and calculated their sedimentary variables, such as distribution area, rock volume and mean thickness. The distribution area of the Wufeng Formation decreased through the study interval, which likely represents the effect of the global sea-level fall (resulting from the growth of the Gondwana ice sheets) and the gradual uplift of the study area. The extremely low sedimentary rate on the Yangtze Platform reflects a very restricted terrigenous supply during the Late Ordovician. To the south of the Yangtze Platform, there are two areas in which coeval sediments are over 1000 m thick, which probably represent environments with sustained subsidence of the underlying crust and more proximal terrigenous sediment sources.
Acknowledgements
This study was supported by Chinese Academy of Sciences (Grant No. KZCX2-EW-111), MOST (2011ZX05005-001-006HZ), National Natural Science Foundation of China (41221001, 41290260, 41272042 and 41202004) and Natural Sciences and Engineering Research Council of Canada (MJM). This is a contribution to the Geobiodiversity Database project (www.geobiodiversity.com) and the IGCP Project 591 – The Early to Middle Paleozoic Revolution.