Geometry and Timing of Upper Oligocene to Miocene Depostional Sequences on the U.S Middle Atlantic Margin

美国中大西洋边缘上渐新世至中新世沉积层序的几何结构和形成时间

• 批准号: 9203344
• 负责人: Gregory Mountain
• 金额: $ 31.7万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 1995-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9203344&HistoricalAwards=false
• 关键词: Geometry; Timing; Upper; Oligocene; Miocene

Global cycles of sea-level rise and fall have operated throughout much of Earth's history. The exact timing and size of these eustatic changes, however, are as yet comparatively poorly- constrained, particularly for Pre-Pleistocene time. Detailed sea- level history curves are, in turn, essential to understanding the complex interplay between astronomical forcing mechanisms, and glacial and sea-level maxima and minima. The geologic record spanning Oligocene to Miocene time may offer key information as to the nature and timing of sea-level changes. This time-span was characterized by a number of sea-level cycles, reflecting ice-sheet waxing and waning. The Oligocene-Miocene record is particularly well-preserved in sedimentary rocks of the Mid-Atlantic coastal plain, and continental shelf-slope-rise region. This project seeks to refine the sea-level history curves for Oligocene-Miocene time through examination of high-resolution seismic reflection, Sr-isotope, delta-Oxygen-18, and other stratigraphic data from the U.S. Mid-Atlantic coast. It is a renewal; previous work focused on the collection and preliminary analysis of the seismic reflection and biostratigraphic data. The project will impact planning and design of an upcoming Ocean Drilling Project Leg offshore New Jersey. The principal investigators are an interdisciplinary team who are well-qualified to perform this research project.

全球海平面上升和下降的周期在地球历史的大部分时间里都在运行。然而，这些海平面变化的确切时间和大小目前还没有得到相对较好的限制，特别是在更新世之前。反过来，详细的海平面历史曲线对于理解天文强迫机制与冰川和海平面最大值和最小值之间的复杂相互作用至关重要。从渐新世到中新世的地质记录可能提供有关海平面变化的性质和时间的关键信息。这一时间跨度的特点是若干海平面周期，反映了冰盖的消长。在大西洋中部沿海平原和陆架斜坡隆起区的沉积岩中，渐新世-中新世记录保存尤为完好。该项目旨在通过对美国大西洋中部海岸的高分辨率地震反射、锶同位素、三角洲氧18等地层数据的研究，精炼渐新世-中新世时期的海平面历史曲线。这是一次更新；以前的工作侧重于地震反射和生物地层数据的收集和初步分析。该项目将影响即将到来的新泽西州近海大洋钻探项目LEG的规划和设计。主要研究人员是一个跨学科的团队，他们有很好的资格来执行这项研究项目。