Collaborative Research: Pacific coast Campanian-- Maastrichtian Chronostratigraphy

本文拟对南加利福尼亚和下加利福尼亚州上白垩统Rosario组进行生物地层学、磁地层学和锶同位素地层学研究。人们早就知道，在罗萨里奥组的各个层位都有非常丰富的大型化石。然而，迄今为止，对这些剖面的生物地层学研究相对较少，特别是在下加利福尼亚州暴露的露头。我们已经确定了位于下加利福尼亚州的三个目标区段，它们有望大大增加我们对太平洋海岸上白垩纪年代地层学的理解。我们最近发现，这些部分的软体动物化石是由太平洋沿岸、墨西哥湾沿岸和欧洲物种的混合组合组成的。最重要的是欧洲地带性指数菊石，在这里首次从太平洋沿岸地区发现。我们的目标剖面已经进行了部分磁地层学取样。通过将更完整的磁地层学采样与修订后的生物地层学相结合，我们将首次在太平洋沿岸上白垩纪地层与欧洲的层型剖面，以及墨西哥湾沿岸、西部内陆和大西洋沿岸平原的特提斯剖面之间建立一级对比。

9418283 Kirschvink We propose to investigate the biostratigraphy, magnetostratigraphy, and strontium isotope stratigraphy of the Upper Cretaceous Rosario Formation of southern California and Baja California. It has long been known that macrofossils are extremely abundant from various horizons of the Rosario Formation. Nevertheless, there has been relatively little study to date investigating the biostratigraphy of these sections, especially outcrops exposed in Baja California. We have identified three target sections located in Baja California that hold the promise of greatly increasing our understanding of Upper Cretaceous chronostratigraphy of the Pacific Coast. We have recently discovered that molluscan fossils from these sections are composed of a mixed assemblage of Pacific Coast endemics and Gulf Coast and European species. Of greatest importance are European zonal index ammonites, recognized here for the first time form the Pacific Coast region. Our target sections have already been partially sampled for magnetostratigraphy. By integrating a more complete magnetostratigraphic sampling with a revised biostratigraphy, we will produce, for the first time, a first order correlation between Pacific Coast Upper Cretaceous strata and the stratotype sections in Europe, and with Tethyan sections of the Gulf Coast, Western Interior and Atlantic Coast Plain.