Magnetostratigraphy of the Precambrian-Cambrian Boundary Section at Meishucun, China

梅树村前寒武纪-寒武纪边界剖面磁性地层

• 批准号: 8816772
• 负责人: Rob Van der Voo
• 金额: $ 10.42万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-02-01 至 1992-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8816772&HistoricalAwards=false
• 关键词: Magnetostratigraphy; Precambrian; Cambrian; Boundary; Section

A sequence of platform carbonates and phosphorites in southwest China, near Kunming, contains the Precambrian-Cambrian boundary and is well studied in terms of lithologies and faunal content. It has been proposed as a global stratotype for the boundary. We have obtained preliminary magnetostratigraphic data which show eight reversals and yield a paleopole which is unlike any paleopoles thus far observed for the South China block for any Phanerozoic rocks. This proposal requests funds to collect an additional 1600 paleomagnetic samples over several parallel sections, in order to test the preliminary magnetostratigraphic polarity determinations. The promising preliminary data suggest that this section could provide a standard for the magnetostratigraphy of the Precambrian-Cambrian boundary, with which other sections could be compared (e.g., in Siberia, Australia, Mongolia, North America, Europe or Morocco). Given that the boundary is associated with the first appearance of diverse shelly fossil assemblages, it is a feature of primary importance in stratigraphy and earth history. A reliable reversal record for the Chinese boundary section would be of great value in internal correlation.

一套台地碳酸盐岩和磷块岩序列， 中国西南部，靠近昆明，包含前寒武纪-寒武纪 边界，并在岩性和动物群方面进行了很好的研究 内容 它被认为是全球性的层型， 边界 获得了初步的磁性地层资料 显示了八次反转，并产生了一个不同于 迄今为止在华南地块观察到的任何古极点， 任何显生宙岩石。 这项建议要求资金收集额外的1600 古地磁样本在几个平行的部分，以 测试初步的磁性地层极性 决心。 有希望的初步数据表明， 剖面可以为 前寒武纪-寒武纪界线， 可以进行比较（例如，在西伯利亚，澳大利亚，蒙古，北 美洲、欧洲或摩洛哥）。 如果边界是 与第一次出现不同的贝壳化石有关 这是一个非常重要的特征， 地层学和地球历史。 一个可靠的逆转记录， 中国边界段将在内部具有很大价值， 相关性