Search

This paper discusses the clayrocks widespread at the Permian-Triassic boundary, which are mostly of volcanic origin. Volcanogenetic textures, structures and minerals such as high-temperature quartz are found in clayrocks at the Permian-Triassic boundary in many places. Thousands of microspherules have been collected from the Boundary clayrocks, many of which exhibit the typical features of the process from melting to cooling and solidification, indicating that they were formed by volcanic eruption or extraterrestrial impact. Volcanic effects on the Permian- Triassic mass extinction may be reflected in conodonts, algae and ammonoids. The Boundary clayrocks are found in many Permian- Triassic sections along the coast of Tethys. Their orighin remains to be studied.

A, B satellite data were pretreated, on board the Environment and disaster monitoring and forecasting satellite of China. The research carries out a series of steps to discriminate sugarcane, selects the sugarcane plots and samples, analyses the spectral characteristics, classifies the satellite data with decision tree classification and supervised classification, the plantation data of Guangxi base library of remote sensing information and slope data as ancillary. The comparison between information from Remote sensing discrimination and official statistics shows that combination of decision tree classification and supervised classification method can effectively discriminate sugarcane.

Introduction In the Late Permian, a large-scale regression occurred worldwide and the extent of the sea shrank enormously. As a result, there is a stratigraphic gap between Permian and Triassic rocks in many areas of the world. South China, however, possesses the most widely distributed, fairly continuous marine Permo-Triassic sequences known anywhere in the world. Thus studies of South Chinese Permian and Triassic conodonts are helpful to research on conodont biostratigraphy, biofacies, and Permo-Triassic events and a great deal of work has been done by Wang & Wang (1981, 1983), Wang & Cao (1981), Wang & Dai (1981), Ding (1983), and Yang et al ., (1987). Wang & Wang (1981) divided the Permian and Triassic of South China into 15 conodont zones, four Upper Permian and 11 Lower Triassic, and this scale provides a good basis for future research. Wang & Wang's contributions deal mostly with the determination of stratigraphic age, however, and little attention has been focused on the relationships between conodonts and sediment types or on the nature of the temporal changes in conodont faunas. The purpose of the present study is thus to discuss Permian and Triassic conodont faunas and to demonstrate that the distribution of conodonts in this interval is related to the distribution of sedimentary facies. Stratigraphy In South China, marine Permian and Triassic facies occur south of a line joining Lianyun Harbor (Jiangsu Province), Xiang Fan (Hubei Province), and Tianshui (Gansu Province). The area north of this line was continental; hence the Permo-Triassic sections considered in this report are all south of the line, on the Yangtze Platform, which lies east of the ancient Kangdian Land and west of Cathaysia.