Milankovitch Forcing of Continental Monsoons Across the Equator of Pangaea

摘要ATM-9317227奥尔森、保罗·E·肯特、丹尼斯·V·哥伦比亚大学题目：盘古大陆季风的米兰科维奇强迫该奖项旨在研究晚三叠世和早侏罗世联合古陆赤道地区气候的米兰科维奇强迫。记录介质由沉积在北美东部保存下来的早中生代裂谷中的湖相岩石组成，现在可以证明，这些裂谷覆盖的纬度范围从横跨古赤道的6.5度。这些湖相岩石由湖平面旋回组成，记录了约230-199 Ma期间季风降水的米兰科维奇强迫。这项工作将通过研究另外六个裂谷盆地的可用岩心和露头，在时间和地理上向后扩展纽瓦克盆地开发的高分辨率旋回地层学、磁地层学和古纬度格架。这将产生一个时间-地理-气候矩阵，该矩阵将解决三个具体问题：1)赤道盘古大陆向北漂移约10度时气候的区域趋势；2)赤道周围岁差周期强迫的频率翻一番；以及3)晚三叠世-早侏罗世湿润带的明显加宽。其中的第一个也是最后一个对于改进泛古大陆全球气候模型的测试非常重要。第二个是普遍感兴趣的，反映了米兰科维奇强迫的一般过程，预计在任何年龄的热带地区，但最容易通过研究这些独特的序列来解决。

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.