Collaborative Research: Have Ridge Volumes Changed Over the Past 160 Ma?

Kominz0418076该项目利用洋盆的板块构造重建，描述并量化了过去1.2亿年来海平面变化的长期模式。由于洋脊体积的变化，对白垩纪海平面的估计及其所依据的数据一直是许多地层学、构造学和气候学研究的基石。最近全球数据库的改进和围绕旧结果的争议使我们能够对一段时间内的脊线体积进行新的、更系统的评估和新的计算。该项目正在进行14个时间间隔的板块构造重建，时间间隔回到120 Ma。确定了新的海底年龄-深度关系，包括：1)沉积物卸荷；2)纯年龄-深度关系；3)观测年龄-深度关系。这些异常特征占据了海量，影响了海平面的变化。这些计算包括估计由于大陆解体而伸展的大陆面积，以及大陆地壳的压缩和缩短，以确定其对海洋体积的影响。估计了以大型火成岩省热点的形式出现的海洋火山作用的影响。更广泛的影响：了解海平面变化的历史对于地层学、层序地层学、相分析、古地理、碳氢化合物的形成和聚集、全球气候变化、冰冻圈的演化、大气成分的变化和生物地理学的研究是基本的。海平面波动的影响几乎涉及到沉积地质学和地球系统演化的方方面面。至少有5000名学生(本科生和博士生)积极参与这项研究，并在区域和国家会议上传播研究成果。古地理地图是科学界的资源，既是未来研究的基础地图，也是教学工具。为这项研究汇编的数据和结果可通过万维网或CD上的数据库存储向公众提供。(与0418395/苏格兰/德克萨斯大学阿灵顿分校合作项目)

Kominz0418076This project describes and quantifies the long-term pattern of eustatic sea level change during the last 120 million years using plate tectonic reconstructions of the ocean basins. Estimates of Cretaceous eustatic sea level as a result of changing ocean ridge volume and the data on which they were based have been a cornerstone of many studies of stratigraphy, tectonics and climatology. Recent improvements global databases and controversy surrounding the older results allow a new, more systematic assessment and new calculations of ridge volumes through time. This project is generating plate tectonic reconstructions for 14 time intervals back to 120 Ma. New age vs. depth relations for seafloor are determined including: 1) Sediment unloading; 2) Pure age vs. depth relation; and 3) Observed age vs. depth relation. These anomalous features take up ocean volume and impact sea-level change. These calculations include estimates of changing area of continents through stretching of continental crust due to breakup, and of compression and shortening of continental crust to determine their effect on ocean volume. The impact of oceanic volcanism in the form of large igneous provinces hot spots is estimated. Broader Impacts:Understanding the history of eustatic sea level change is fundamental to the study of stratigraphy, sequence stratigraphy, facies analysis, paleogeography, hydrocarbon formation and accumulation, global climate change, the evolution of the cryosphere, the changing composition of the atmosphere and biogeography. The effects of sea level fluctuations touch nearly every aspect of sedimentary geology and Earth System evolution.At least 5 students (both undergraduate and PhD) are active participants in the research and in dissemination of the results at regional and national meetings. The paleogeographic maps are resources for the scientific community both as base maps for future research and as teaching tools. Data and results compiled for this study are available to the public through data base storage available on the world wide web or at cost on CD.(Collaborative Project with 0418395/Scotese/University of Texas at Arlington)