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

本项目通过对海洋盆地的板块构造重建，描述并量化了过去1.2亿年间海平面上升的长期格局。由于洋脊体积的变化而对白垩纪海平面上升的估计及其所依据的数据已成为许多地层学、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得脊体积随时间的变化有了新的、更系统的评估和新的计算。该项目生成了回溯至120 Ma的14个时间间隔的板块构造重建。确定了海底新时代与深度的关系，包括：1)沉积物卸载；2)单纯年龄与深度关系；3)观察到的年龄与深度关系。这些异常特征占用海洋体积，影响海平面变化。这些计算包括估计由于大陆地壳的破裂而引起的大陆面积的变化，以及估计大陆地壳的压缩和缩短，以确定它们对海洋体积的影响。估计了大型火成岩省热点形式的海洋火山作用的影响。更广泛的影响：了解海平面上升变化的历史是地层学、层序地层学、相分析、古地理、油气形成和聚集、全球气候变化、冰冻圈演化、大气成分变化和生物地理学研究的基础。海平面波动的影响几乎涉及沉积地质和地球系统演化的每一个方面。至少有5名学生（本科生和博士）积极参与研究并在区域和国家会议上传播结果。古地理图件既是科学研究的基础图件，也是科学教学的工具。为本研究编制的数据和结果可通过万维网上的数据库存储或收费光盘向公众提供。（与0418395/Scotese/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)