Ordovician-Early Silurian (Llandovery) Stratigraphy And
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Ordovician−Early Silurian (Llandovery) Stratigraphy and Palaeontology of the Upper Yangtze Platform, South China Zhan Renbin and Jin Jisuo with additional contributions from Rong Jiayu, Chen Xu, Zhou Zhiyi, Wang Zhihao, Zhang Yuandong, Liu Jianbo, Chen Pengfei, Yuan Wenwei, Fan Junxuan, Zhang Yunbai, and Wu Rongchang Post-Conference Field Excursion for The Tenth International Symposium on the Ordovician System The Third International Symposium on the Silurian System IGCP 503 Annual Meeting Nanjing, June 2007 Science Press Beijing ·2· Acknowledgements Responsible Editress: Hu Xiaochun Ordovician−Early Silurian (Llandovery) Stratigraphy and Palaeontology of the Upper Yangtze Platform, South China Zhan Renbin and Jin Jisuo Copyright © 2007 by Science Press Published by Science Press http://www. sciencep. com 16 Donghuangchenggen North Street Beijing 100717 P. R. China Printed in Beijing, 2007 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of the copyright owner. ISBN 978-7-03-018893-9/Q⋅1845 Acknowledgements ·3· Acknowledgements The Chinese Academy of Sciences The Ministry of Science and Technology of China The National Natural Science Foundation of China The Nanjing Institute of Geology and Palaeontology, CAS State Key Laboratory of Palaeobiology and Stratigraphy, NIGPAS Yichang Institute of Geology and Mineral Resources, CAGS Government of Tongzi County, Guizhou Province Government of Chongqing District Government of Yichang City, Hubei Province Acknowledgements ·5· List of Authors and Contributors Authors: Zhan Renbin State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China <[email protected]> Jin Jisuo Department of Earth Sciences, University of Western Ontario, London, ON N6A 5B7, Canada <[email protected]> Additional contributors: Rong Jiayu State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Chen Xu State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Zhou Zhiyi Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Wang Zhihao Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Zhang Yuandong State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Liu Jianbo Department of Geology, Peking University, Beijing 100871, China Chen Pengfei Department of Earth Sciences, University of Western Ontario, London, ON N6A 5B7, Canada Yuan Wenwei Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Fan Junxuan Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Zhang Yunbai Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Wu Rongchang State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China Contents ·7· Contents Chapter 1 Introduction ................................................................................................................ 1 1.1. Major geographical features of South China ...................................................................... 1 1.2. Tourist attractions............................................................................................................... 3 1.3. Previous geological work ...................................................................................................7 1.4. Acknowledgements ............................................................................................................ 9 Chapter 2 Geological Setting of the Upper Yangtze Platform................................................ 11 2.1. Plate tectonic setting of the South China Palaeoplate....................................................... 11 2.2. Sedimentary facies of the Upper Yangtze Platform ......................................................... 12 Chapter 3 Ordovician–Early Silurian Stratigraphy and Palaeontology of the Upper Yangtze Platform ..................................................................................................... 24 3.1. Stratigraphical nomenclature............................................................................................ 24 3.2. Lithostratigraphical units visited during the field excursion ............................................ 26 3.3. Ordovician and Early Silurian biozonations of the Upper Yangtze Platform .......................... 82 3.4. Ordovician-Silurian boundary of the Upper Yangtze Platform......................................... 108 Chapter 4 Road Log of Field Excursion ................................................................................. 110 4.1. Notes on the excursion ................................................................................................... 110 4.2. Excursion itinerary (July 1–July 7, 2007)....................................................................... 111 4.3. Road log and notes on stops ........................................................................................... 112 References..................................................................................................................................... 145 Index ............................................................................................................................................. 165 Chapter 1 Introduction Chapter 1 Introduction 1.1. Major geographical features of South China From the majestic Himalaya Mountain Range in the southwest to the lowlands of southeast China, three major geomorphological elements mark the landscape: 1) the Qing-Zang (Qinghai-Tibet) Plateau, with an average elevation of 4500 m above sea level; 2) the Yun-Gui (Yunnan-Guizhou) Plateau, which steps down to an elevation of 1000 –3000 m; and 3) the Yangtze-Pearl rivers flood plains, averaging about 200 m above sea level. During this field excursion, we will visit the Yun-Gui Plateau (mainly the portion in Guizhou Province), the eastern margin of the Sichuan Basin north of the Yun-Gui Plateau in the Chongqing District, and the western Hubei hills within the upper part of the Middle Yangtze River drainage (Fig. 1). The basic framework of the Chinese topography was formed during the Mesozoic Yanshan Orogeny (Xing 1980). Weathering and erosion during the Palaeogene reduced the middle and lower reaches of the Yangtze River drainage regions to peneplains. During the Neogene, continued erosion, coupled with the uplifting of the Tibetan block, heightened the contrast between the three-stepped “mega-terraces” from the southwest to the southeast China. Guizhou Province is located in the eastern part of the Yun-Gui Plateau. It is surrounded by Hunan Province, Guangxi Autonomous Region, Yunnan and Sichuan provinces, and Chongqing District. Most parts of Guizhou Province are mountainous, with a humid climate, and its capital city, Guiyang, is in the central part of the province. Because of its geographical isolation and limited road and other infrastructure, Guizhou is home to a few dozen ethnic minorities, and is one of the least developed provinces of China. This is described vividly, perhaps with a touch of humour, by a Chinese saying about Guizhou: “flat land stretches no more than three feet, sunny weather lasts no more than three days, and one’s pocket has no more than three pennies”. In the last two decades, however, many national- and provincial-level highways and local paved roads have been built. Numerous hidden treasures, from its beautiful natural scenery, cultural and historical heritage, to various economic resources, are opened up to the rest of China and the world. At present, the province is enjoying a rapidly growing economy. Chongqing District (or Chongqing Zhixiashi) used to be the eastern part of Sichuan Province. In 1997, Chongqing District, a municipality directly under the central government, was established as a formal political division equivalent to a separate province. In the Chinese political division system, Chongqing is the fourth city to achieve such a rank, after Beijing, Shanghai, and Tianjin. Chongqing city proper is located at the confluence of the Jialing River and the Yangtze River. It is a true “mountain city”, as it is perched on steep mountain slopes beside the rivers, and bicycles are rarely seen in the city although they are the most popular transportation in China. Born out of ·2· Chapter 1 Introduction Sichuan Province, Chongqing features all types of the famous Sichuan cuisine, spicy dishes and spicy hot pots prepared by “spicy girls” (in China, young women from Sichuan are referred to as Sichuan La Mei—literally the “hot and spicy sisters of Sichuan”—an endearing reference to their capacity for hardworking, enduring hardships, and getting work done efficiently and resourcefully). Fig. 1. Simplified map of China showing the field excursion route (thick dash line) and travel directions (arrows) starting from Nanjing (Jiangsu Province) and ending in Yichang (Hubei Province).