Milankovitch Forcing of Continental Monsoons Across the Equator of Pangaea

米兰科维奇强迫大陆季风穿过盘古大陆赤道

• 批准号: 9317227
• 负责人: Paul Olsen
• 金额: $ 38.72万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-15 至 1997-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9317227&HistoricalAwards=false
• 关键词: Milankovitch; Forcing; Continental; Monsoons; Across

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.

Olsen, Paul E. Kent, Dennis V. Columbia University，题目：横跨盘古大陆赤道的大陆季风的Milankovitch强迫。该奖项是针对晚三叠纪和早侏罗世盘古大陆赤道区气候的Milankovitch强迫的研究。记录介质由沉积在北美东部保存的早中生代裂谷中的湖相岩石组成，这些裂谷现在可以显示覆盖从6.5°横跨古赤道的纬度范围。这些湖相岩石由湖平面旋回组成，这些湖平面旋回记录了大约230至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，在时间和横向上扩展纽瓦克盆地取心项目中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，它将解决三个具体问题：1)赤道泛大陆在大约100年向北漂移时的气候区域趋势；2)赤道附近岁差周期强迫的频率增加了一倍；3)晚三叠纪—早侏罗世湿润带明显拓宽。第一项和最后一项对于完善盘古大陆全球气候模型的测试非常重要。第二种是一般的兴趣，反映了任何年龄的热带地区预期的米兰科维奇强迫的一般过程，但最容易通过研究这些独特的序列来解决。