Late Paleozoic Carbon Isotope Stratigraphy Records of Carbonate Rocks from Guizhou, South China

• Main Authors: Kuei-Shu Shen, 沈桂淑
• Other Authors: Horng-Sheng Mii
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/57634887256519304589

碩士 === 國立臺灣師範大學 === 地球科學系 === 102 === Stable carbon and oxygen isotope compositions of 1,134 carbonate rock samples, collected from Late Paleozoic Nashui section, Luokun section and Narao section, Guizhou (South China) were analyzed to explore the possibility of stratigraphic correlation using carbon isotope records and to estimate the extent of the variation in isotope records between shallow water and deep water environments of the same basin. Conodont biostratigraphy data was provided by Nanjing Institute of Geology and Palaeontology. Average stable carbon and oxygen isotope of Nashui section (N = 246; middle Carboniferous and middle Permian) are 3.2±1.3‰ and -5.6±2.4‰, respectively. Average stable carbon and oxygen isotope of Luokun section (N = 191; middle to late Carboniferous) are 2.3±1.4‰ and -5.2±1.7‰, respectively. Average stable carbon and oxygen isotope of Narao section (N = 583; middle Carboniferous to Permian) are 3.6±1.2‰ and -4.6±1.7‰, respectively. Carbon and oxygen isotope values of dark- colored carbonates (deep-water) are greater than those of light-colored carbonate rocks (shallow water) 0 ~ 2 ‰ and 0.1 ~ 4.5 ‰, respectively. Trends and magnitude of the carbon isotope stratigraphy among this study and those of China, North America, and Europe are comparable. Mean δ13C value increases from 2 ~ 3 ‰ during the Visean and Serpukhovian to Gzhelian – Asselian boundary, reaches the maximum. This positive δ13C excursion may be related to the expansion of continental ice volume. In Permian, the δ13C value declined during the Asselian in the South China and North America, potentially coincided with the shrinking of the Carboniferous – Permian ice sheet. In Kungurian period δ13C values of the South China and North America decreased first then increased again. This positive excursion may also be related to the development of ice volume. However, δ13C record at low latitudes (Urals) was opposite to those of South China and North America for Kungurian. In the Roadian, Wordian, Capitanian, δ13C values positive excursion of this study, consisted with the glacial record, coincided with δ13C records of South China, low latitudes, and North America. This study shows that carbonate rock stable carbon isotope stratigraphy records can be used for stratigraphic correlation with biostratigraphic controls. Positive excursion of δ13C records from both deep water and shallow water sections can be correlated globally and are consistent with the ice volume records.