Milankovitch Forcing of Continental Monsoons Across the Equator of Pangaea

摘要ATM-9317227 Olsen，Paul E. 肯特，丹尼斯V.哥伦比亚大学标题：大陆季风穿越泛大陆赤道的米兰科维奇强迫 该奖项旨在研究晚三叠世和侏罗纪早期泛大陆赤道带的米兰科维奇气候强迫。 记录介质由保存在北美东部的早中生代裂谷中的湖相岩石组成，现在可以证明它覆盖了横跨古赤道的6.5 °的纬度范围。 这些湖相岩石组成的湖面周期，记录米兰科维奇迫使季风降水的间隔约230至199马。 这项工作将通过研究另外六个裂谷盆地的现有岩心和露头，在时间上和地理上向后扩展纽瓦克盆地取芯项目中开发的高分辨率旋回地层学、磁性地层学和古纬度框架。 这将产生一个时间-地理-气候矩阵，它将解决三个具体问题：1）赤道泛古陆向北漂移约10 o时气候的区域趋势; 2）赤道周围岁差周期强迫频率的加倍; 3）最后三叠世-早侏罗世湿润带的明显加宽。 其中第一个和最后一个对于完善泛大陆全球气候模型的测试非常重要。 第二个是一般的利益，反映米兰科维奇强迫预计在热带地区的任何年龄，但最容易解决的这些独特的序列的研究一般过程。

Abstract ATM-9317227 Olsen, Paul E. Kent, Dennis V. Columbia University Title: Milankovitch Forcing of Continental Monsoons Across the Equator of Pangaea This award is directed at an examination of Milankovitch forcing of climate in the equatorial zone of Late Triassic and earliest Jurassic Pangaea. The recording medium consists of lacustrine rocks laid down in Early Mesozoic rift valleys preserved in eastern North America that can now be shown to cover a latitudinal range from 6.5o straddling the paleoequator. These lacustrine rocks consist of lake level cycles that recorded Milankovitch forcing of monsoonal precipitation over the interval from about 230 to 199 Ma. This work will extend the high-resolution cyclostratigraphy, magnetostratigraphy, and paleolatitudinal framework developed in the Newark basin coring project backward in time and laterally in geography through the study available cores and outcrop in six additional rift basins. This will result in a time-geography- climate matrix which will address three specific problems: 1) regional trends in the climate of equatorial Pangaea as it drifted northward about 10o; 2) the doubling of the frequency of precession cycle forcing around the equator; and 3) the apparent broadening of the humid belts in the latest Triassic-Early Jurassic. The first and last of these are important for refining tests of global climate models of Pangaea. The second is of generic interest, reflecting general processes of Milankovitch forcing expected in tropical regions of any age but most readily addressed by study of these unique sequences.