Collaborative Research: Carnian-Norian Magnetostratigraphy and Biostratigraphy at Silica Brezova (Slovakia)

9417895最近从土耳其的两个海洋剖面和纽瓦克裂谷盆地的一个厚的陆相(湖)剖面获得的高质量卡尼安-诺里安磁性地层学并不容易对比。即使两个土耳其段之间的相关性也是有问题的，并通过假设这两个浓缩段在晚三叠世时位于相反的半球而得到便利。在Silica Brezova(斯洛伐克)发现的200米厚的卡尼安-诺里安(上三叠统)剖面为解决卡尼安-诺里安磁性地层对比中的不确定性提供了机会。硅质Brezova剖面包含所有晚卡尼期和诺里期牙形刺带，分布在一段特别厚(未浓缩)的“哈尔斯塔特石灰岩”相中。牙形刺蚀变指数接近1，表明包含该剖面的逆冲单元没有明显的埋藏。对硅质Brezova剖面中段(Lacian)35m的磁性地层进行了初步研究，得到了清晰的极性分带和正褶皱测试。200米硅质Brezova剖面的磁性地层学和生物地层学应该提供从纽瓦德盆地到海洋领域的高分辨率旋回地层学的首次对比，这对于建立连接海洋和非海相地层的综合晚三叠世时间尺度至关重要。

9417895 Channell High quality Carnian-Norian magnetostratigraphies derived recently from two marine sections in Turkey and a thick continental (lacustrine) section in the Newark Rift Basin are not easily correlated. The correlation even between the two Turkish sections is problematic, and is facilitated by supposing that the two condensed sections were in opposite hemispheres in Late Triassic time. A 200m thick Carnian-Norian (Upper Triassic) section at Silica Brezova (Slovakia) provides the opportunity to resolve the uncertainties in Carnian-Norian magnetostratigraphic correlations. The Silica Brezova section contains all Late Carnian and Norian conodont zones in an exceptionally thick (uncondensed) section of "Hallstatt Limestone" facies. The conodont alteration indices are close to 1, indicating no appreciable burial of the thrust unit which contains the section. A pilot magnetostratigraphic study on a 35m interval from the middle (Lacian) part of the Silica Brezova section has yielded a clear polarity zonation and a positive fold test. Magnetostratigraphy and biostratigraphy of the 200m Silica Brezova section should provide a first correlation of the high resolution cyclostratigraphy from the Neward Basin to the marine realm which is essential to the development of an integrated Late Triassic timescale linking marine and non-marine stratigraphies.