Assessing the paleoenvironmental and geobiological significance of carbonates from the Eocene-Oligocene boundary of the White River Group

地质记录提供了过去气候和古代生态系统的档案。重建过去的气候是我们理解地球历史的关键，并提供了对现代生态系统如何应对当前和未来气候变化的洞察。这项研究将调查南达科他州西南部古湖泊沉积物中保存的气候变化程度和生态系统对这些变化的响应。这些结果将加强我们对地球历史这一关键时期的了解，并为改进预测现代气候变化影响的模型提供必要的知识。这项研究还将为本科生和研究生提供专业培训，并在南达科他州矿产地质博物馆和荒地国家公园为游客开发有关该地区岩石科学重要性的教育资源。该项目由沉积地质学和古生物学计划(SGP)和已建立的促进竞争研究计划(EPSCoR)联合资助。始新世-渐新世的转变发生在约3400万年前，其特征是全球平均降温约2.5摄氏度，南极永久冰盖的形成，以及海洋生态系统的灭绝事件。然而，在这段时间里，北美内陆气候变化的程度和生态系统对这些变化的反应尚不清楚。在此期间，保存在南达科他州荒原中的湖泊沉积记录了这些变化，但以前只得到了有限的研究。这项研究有两个主要目的：1)识别这些湖泊沉积的范围，了解它们的沉积学和地层学；2)从时间和空间上分析这些岩石的地球化学成分，以重建古环境条件的变化。这些努力将更好地了解地球对气候变化的反应。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The geologic record provides an archive of past climates and ancient ecosystems. Reconstructing past climates is key to our understanding of Earth history and provides insight into how modern ecosystems may react to current and future climatic changes. This study will investigate the degree of climatic change and the ecosystem response to these changes preserved in ancient lake deposits from southwestern South Dakota during the transition into the modern “icehouse” climate. These results will enhance our understanding of this key interval of Earth history and provide knowledge necessary to improve models for predicting the effects of modern climate change. This study will also provide professional training for undergraduate and graduate students and enable the development of educational resources at the South Dakota Mines Museum of Geology and Badlands National Park for visitors on the scientific importance of the rocks in this region. This project is jointly funded by the Sedimentary Geology and Paleobiology Program (SGP) and the Established Program to Stimulate Competitive Research (EPSCoR).The Eocene-Oligocene Transition occurred ~34 million years ago and was characterized by an average global cooling of ~2.5oC, the formation of permanent Antarctic ice caps, and an extinction event in ocean ecosystems. However, the degree of climatic change and the ecosystem response to these changes in the interior of North America during this time is unclear. Lake deposits formed during this time that are preserved in the Badlands of South Dakota provide a record of these changes but have previously received only limited study. This research has two primary objectives: 1) to identify the extent of these lake deposits and understand their sedimentology and stratigraphy, and 2) to analyze the geochemical composition of these rocks through time and space to reconstruct changes in paleoenvironmental conditions. These efforts will provide a better understanding of terrestrial responses to climate change.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.