After the establishment of the global stratotype section and point (GSSP) of the Permian Triassic boundary (PTB), the definition of the accessory section and point (ASP) of the terrestrial Permian Triassic boundary ...After the establishment of the global stratotype section and point (GSSP) of the Permian Triassic boundary (PTB), the definition of the accessory section and point (ASP) of the terrestrial Permian Triassic boundary (TPTB) is now on the agenda. However, all good TPTB sections so far known have the following shortcomings: (1) the exact TPTB horizon is difficult to define paleontologically with high resolution, and (2) accurate correlation between marine and terrestrial PTBs is hard to attain. In order to enhance the understanding of the nature of the global life crisis in both the marine and terrestrial environments across the Paleozoic Mesozoic transition, these shortcomings need to be addressed. In western Guizhou and eastern Yunnan, Southwest China, some fossiliferous PTB sections which include marine, paralic and terrestrial are well developed, allowing bed to bed correlation of the PTB sequences. Fortunately, the marine PTB sequence in this area is almost the same as found at the Meishan Section, where the GSSP of the PTB is located, which may provide a reliable auxiliary marker for high resolution demarcation of the TPTB. These features found in western Guizhou and eastern Yunnan make this area a good place to study the ASP of the TPTB, so we propose to study the ASP of the TPTB in this area.展开更多
川西高原位于青藏高原的东南边缘,气候主要受印度洋季风、高原季风的影响。广泛分布于川西高原的黄土-古土壤序列是高原周缘地区连续的古气候记录类型之一,记录了上述环流系统的演化过程及其与青藏高原阶段性演化的关系,对探讨高原隆升...川西高原位于青藏高原的东南边缘,气候主要受印度洋季风、高原季风的影响。广泛分布于川西高原的黄土-古土壤序列是高原周缘地区连续的古气候记录类型之一,记录了上述环流系统的演化过程及其与青藏高原阶段性演化的关系,对探讨高原隆升的环境响应具有重要意义。对川西甘孜地区甘孜-A剖面进行了系统的磁性地层学研究。结果表明,B/M界线出现在L7的底部,并且在剖面下部出现了松山负向期的贾拉米洛正向极性亚带。以古地磁界限点作为时间控制点外推该剖面典型风尘沉积的底界年龄约为1.16 Ma BP。展开更多
文摘After the establishment of the global stratotype section and point (GSSP) of the Permian Triassic boundary (PTB), the definition of the accessory section and point (ASP) of the terrestrial Permian Triassic boundary (TPTB) is now on the agenda. However, all good TPTB sections so far known have the following shortcomings: (1) the exact TPTB horizon is difficult to define paleontologically with high resolution, and (2) accurate correlation between marine and terrestrial PTBs is hard to attain. In order to enhance the understanding of the nature of the global life crisis in both the marine and terrestrial environments across the Paleozoic Mesozoic transition, these shortcomings need to be addressed. In western Guizhou and eastern Yunnan, Southwest China, some fossiliferous PTB sections which include marine, paralic and terrestrial are well developed, allowing bed to bed correlation of the PTB sequences. Fortunately, the marine PTB sequence in this area is almost the same as found at the Meishan Section, where the GSSP of the PTB is located, which may provide a reliable auxiliary marker for high resolution demarcation of the TPTB. These features found in western Guizhou and eastern Yunnan make this area a good place to study the ASP of the TPTB, so we propose to study the ASP of the TPTB in this area.
文摘川西高原位于青藏高原的东南边缘,气候主要受印度洋季风、高原季风的影响。广泛分布于川西高原的黄土-古土壤序列是高原周缘地区连续的古气候记录类型之一,记录了上述环流系统的演化过程及其与青藏高原阶段性演化的关系,对探讨高原隆升的环境响应具有重要意义。对川西甘孜地区甘孜-A剖面进行了系统的磁性地层学研究。结果表明,B/M界线出现在L7的底部,并且在剖面下部出现了松山负向期的贾拉米洛正向极性亚带。以古地磁界限点作为时间控制点外推该剖面典型风尘沉积的底界年龄约为1.16 Ma BP。
