High-resolution chronostratigraphic and biofacies analysis of the marine Cretaceous on the North American Pacific coast

北美太平洋沿岸海相白垩纪高分辨率年代地层和生物相分析

基本信息

批准号：
14255001
负责人：
TANABE Kazushige
金额：
$ 15.23万
依托单位：
The University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

This study has its aims to establish chronostratigraphy and international correlation of the Cretaceous deposits in the north Pacific regions as well as to consider the establishment of the north Pacific bioprovince from analysis of yielded macro faunas. For this purpose, international field expedition has been carried out in 2002-2004 for the marine Cretaceous deposits on the U.S.Pacific coast. The marine Cretaceous deposits (Great Valley Sequence) widely exposed along the Sacramento Valley, northern California and those in the Talkeetna Mountains, southern Alaska have been studied from the lithostratigraphic, biostratigraphic and magnetostratigraphic points of view. As a result of our field and laboratory studies successively collected fossil samples and sediment core samples, detailed mega-and microfossil biostratigraphic frameworks have been established for the Barremian to Turonian sequence in the North Fork Cottonwood Creek, northern California. Also, five magnetostratigraphic stages, i.e., M5,M3,M1,M0r,C34n (with M-1r reversal horizon) were recognized in the Barremian to Lower Albian sequence. This is the first report of the high-resolution Early to Middle Cretaceous biochronology and magnetostraligraphy in the North pacific regions. We have also recognized the continuous highly fossiliferous marine Campanian to Maastrichtiain strata from the Talkeetna Mountains, southern Alaska.

本研究的目的是建立北太平洋地区白垩纪沉积物的年代地层学和国际对比，并通过对产生的大型动物群的分析来考虑建立北太平洋生物省。为此，2002-2004年对美国太平洋沿岸海相白垩系矿床进行了国际野外考察。从岩石地层学、生物地层学和磁性地层学的角度对北加州萨克拉门托山谷和阿拉斯加南部塔尔基特纳山脉广泛出露的海相白垩纪沉积物（大山谷层序）进行了研究。由于我们的实地和实验室研究相继收集了化石样本和沉积物岩心样本，已经为加利福尼亚州北部北福克卡顿伍德溪的巴列姆阶到土伦阶序列建立了详细的巨型和微体化石生物地层框架。此外，在巴列姆阶至下阿尔比阶层序中还识别出了五个磁性地层阶段，即M5、M3、M1、M0r、C34n（具有M-1r反转层位）。这是北太平洋地区早至中白垩世生物年代学和磁地层学的第一份高分辨率报告。我们还认识到来自阿拉斯加南部塔尔基特纳山脉的连续的富含化石的海洋坎帕尼亚到马斯特里赫特地层。