Evaluation of Carbonate Platform Records to Track Greenhouse, Transitional and Icehouse Worlds through the Paleozoic

通过古生代追踪温室、过渡和冰室世界的碳酸盐台地记录的评估J. F.阅读弗吉尼亚理工学院和州立大学ERA-0341753摘要海洋碳酸盐浅海架作为全球海平面变化的量尺，部分原因是气候和全球冰量。 因此，我们建议使用它们来重建海平面的历史，在他们的成长过程中，使用相结合的实地研究，文献检索和计算机建模。 这将提供对5.5亿至2.5亿年前全球冰量和气候变化的深入了解，其分辨率高于以前的尝试。 碳酸盐岩台地记录了由地球轨道驱动的相对高频的气候变化，这些变化在岩石记录中留下了独特的特征，这取决于当时地球的全球气候。 在温室时期，碳酸盐岩台地在许多小的（几米）海平面变化的影响下发展，这些变化是由岁差驱动的（大约15到20万年的周期）。 当地球两极有大量的冰时，海平面的变化可能很大（高达100米或更高），并且往往是由重力和偏心率（大约4万年，100到40万年）驱动的。 在这两个末端成员之间，当地球含有适量的全球冰时，海平面的变化可能是几十米或更少，这样的过渡状态似乎占据了地质记录的相当大的一部分，过去被忽视了。 此外，许多碳酸盐岩中的巨型油田似乎是在这种过渡性气候状态下形成的。 因此，这项研究将为全球气候变化提供一个长期窗口。 它还将阐明全球气候如何影响容纳大型油田的碳酸盐岩储层的地质分布。

Evaluation of Carbonate Platform Records to Track Greenhouse, Transitional and Icehouse Worlds through the PaleozoicJ. F. Read Virginia Polytechnic Institute and State UniversityERA-0341753ABSTRACTShallow marine carbonate shelves act as dipsticks to global sea level changes driven in part by climate and global ice volume. Thus we propose to use them to reconstruct sea level history during their growth using a combination of field studies, literature search, and computer modeling. This will provide insight into global ice volume and climate changes from 550 to 250 million years ago, at higher resolution than has been attempted previously. Carbonate platforms record relatively high frequency climate changes driven by the earths orbit that leave a distinctive signature in the rock record depending on the earth's global climate at the time. During greenhouse times, carbonate platforms develop under the influence of many small (few meter) sea level changes driven by precession (roughly 15 to 20 thousand year periods). When the earth has abundant ice at the poles, sea level changes may be large (up to 100 m or more) and tend to be driven by obliquity and eccentricity (roughly 40 thousand, 100 to 400 thousand year periods). Between these two end members, when the earth contained moderate amounts of global ice, sea level changes likely were a few tens of meters or less. Such transitional states appear to occupy a significant amount of the geological record, and have been overlooked in the past. In addition, many of the giant oil fields in carbonate rocks appear to have formed under such transitional climatic states. The study will thus provide a long term window into global climate change. It will also clarify how global climate has influenced the geological distribution of carbonate reservoirs hosting giant petroleum fields.