The Permian system is well developed in various fades over wide areas in China, and it has been intensively studied by Chinese geologists since the 1930s. In his study of the Permian of South China, involving marine as well as paralic fades, Huang Jiqing (T. K. Huang, 1932) adopted a tripartite subdivision, namely, the Lower Permian (Chuanshan), the Middle Permian (Yanghsin), and the Upper Permian (Loping). In the same year Li Siguang (J. S. Lee) and Zhu Sen (1932) were dividing the Permian in the Longtan district, Nanjing, into the Lower Permian Chuanshan Limestone, the Middle Permian Chihsia beds and Kufeng beds, and the Upper Permian Longtan coal series. The Lower Permian was then regarded as correlative to the Lower Permian of international usage. Sun Yunzhu (Y. C. Sun, 1939) subsequently suggested a bipartite subdivision for the Permian of South China: the Lower Permian Yanghsin Series and the Upper Permian Loping Series. He considered the Chuanshan Series to be Upper Carboniferous, based in part on the regional disconformity recognized between the Chuanshan and Yanghsin series, marking what is called the Qiang-Gui or Yunnan movement. For a long time, such a twofold division of the Permian system was followed by all workers in China, a usage endorsed by two national stratigraphic congresses in China, held in 1959 and 1979.

In so many features the Permian and Triassic periods differed from the present that if we could be transported back to that distant past, surely we would think that we were on another planet. The plants and animals would be largely unrecognizable – no mammals, and none of our modern trees or grasses. Although the nature and dispositions of the seas, lands, and mountains during that time are subject to different interpretations and conflicting views, who can doubt that the world's geography would be unrecognizable? The climate would have varied widely, from very cold at the beginning of the Permian (perhaps not unlike the glacial climate of the world a few thousand years ago) to a hot, dry climate during the Triassic, like nothing we see at present, followed by a warm climate continuing into the Jurassic.

Major changes in faunas were associated with the beginning of the Jurassic period, as reviewed by Boucot (1990), Dickins (1993a), and Hallam (1981). Boucot stated that “the modern marine … benthic fauna and communities really begin with the Jurassic.” In the latter part of the Permian and during the Triassic the earth was wracked by vast earthquakes, and great mountain chains were formed. There was magmatic-volcanic activity on an enormous scale. Some of those events are described in this volume, and some of the most interesting problems for future investigation are considered.

Introduction

It has long been clear that waning stages of the Permian Period and initial phases of the Triassic make up an interval of time during which there were profound changes in the Earth's internal and surficial features, in its atmosphere and climate, and, conspicuously, in its biota. Unfortunately, however, rocks that record this fascinating segment of Earth history are greatly restricted in distribution by comparison with those from which we reconstruct events in earlier Paleozoic or later Mesozoic history. Furthermore, subsequent orogenic cycles have dismembered, effaced, and in other ways complicated the record. In combination, these factors make development of a stratigraphic scale for the Permo-Triassic boundary interval difficult, and this, in turn, serves to insure that the history of the latest Permian and earliest Triassic has been reconstructed thus far in only very general outline.

Project of 203 of the International Geological Correlation Programme (IGCP) was organized in 1984 with the aim of integrating modern studies of rocks and fossils in the Permo-Triassic boundary interval into an internally coherent and well-controlled body of information from which it might ultimately be possible to infer something meaningful about the history of late Paleozoic and early Mesozoic times. The attention of project participants naturally focused on Permian and Triassic strata in the eastern part of the Tethyan realm, in South China and India, for marine rock sequences of this age are most continuously developed there. However, close cooperation with students of the Permian and Triassic in Italy, Hungary, Yugoslavia, Israel, the Soviet Union, Australia, and New Zealand has enabled development of a data base that now includes information for essentially the entire length and breadth of the former Tethys seaway.

The 16 reports that make up this volume constitute the final report of Project 203 of the International Geological Correlation Programme, which dealt with Permo-Triassic events of the East Tethys and their intercontinental correlation. During the five-year life of Project 203, participants met twice in Beijing, and once each in Columbus, Ohio (USA) and Brescia (Italy), to exchange views, consider new data, and examine pertinent sections in the field. These conferences have provided new insight into the stratigraphy, classification, and relations of strata within the Permo-Triassic boundary interval, and a wider appreciation of the problems involved in the correlation and interpretation of these rocks, which document an unusually significant period in Earth history.

It will be clear to the reader that the 40 contributors to this volume are in substantial agreement in their interpretation of many features of the Permo-Triassic boundary interval, but disagree, at least by implication, in their evaluation of others. Although as editors we have strived to achieve readability and uniformity in basic terminology, we have also attempted to avoid interference with strongly held individual views, even though they run contrary to those of other contributors. In brief, it would be inappropriate to suggest that in five short years participants in Project 203 solved all problems with respect to the Permo-Triassic boundary interval – for many of these are likely to persist as long as vigorous study continues. We do suggest, however, that data and ideas gathered and expressed during the five-year life of Project 203 and summarized in this volume are important contributions toward understanding and interpreting the rock and fossil record of the late Permian and early Triassic.