Journal of China University of Geosciences, Vol. 19, No. 5, p. 534–548, October 2008 ISSN 1002-0705 Printed in China Preliminary Estimation of Paleoproductivity via TOC and Habitat Types: Which Method Is More Reliable? —A Case Study on the Ordovician–Silurian Transitional Black Shales of the Upper Yangtze Platform, South China Su Wenbo* ( ) School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China Wang Yongbiao ( ) Key Laboratory of Biogeology and Environmental Geology of Ministry of Education, China University of Geosciences, Wuhan 430074, China; Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China Bradley D Cramer Division of Geological Sciences, School of Earth Sciences, The Ohio State University, Columbus, Ohio 43210, USA Axel Munnecke GeoZentrum Nordbayern, Fachgruppe Paläoumwelt, Universität Erlangen, Erlangen D-91054, Germany Li Zhiming ( ) Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China Fu Lipu ( ) Xi’an Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Xi’an 710054, China ABSTRACT: New total organic carbon (TOC) data from the two Ordovician–Silurian transitional graptolite-bearing black shale intervals, the Wufeng ( ) Formation and the Longmaxi ( ) Formation in Central Guizhou ( ) and West Hubei ( ), respectively, as well as previously reported TOC data from the same intervals in other places on the Yangtze platform of South China, have been used to produce an initial estimate of the primary paleoproductivity via a conventional inverse method (i.e., R pp-inverse ). The values of the R pp-inverse are estimated to be 32 (43–21) gC/(m 2 ·a) This study was financially supported by the National Natural Science Foundation of China (Nos. 40372057, 40772076) and the SINOPEC project (G0800-06-ZS-319). *Corresponding author: suwenbo@cugb.edu.cn Manuscript received May 20, 2008. Manuscript accepted July 1, 2008. (Wufeng Formation) and 21 (27–16) gC/(m 2 ·a) (Longmaxi Formation). Also, simultaneously, the habitat types (i.e., HT; cf., BA: benthic assemblage) and their temporal and spatial changes have been documented from the same succession, and an initial estimate of the primary paleoproductivity has been produced using a forward method (i.e., R pp-forward ). Being