Ice at the Equator: The Record and Implications of Alpine Glaciation Within the Ancestral Rocky Mountains of Western Pangea

俄克拉荷马大学Gerilyn Soreghan和Michael SoreghanEAR-0230332记录的前第四纪“冰库”发生在盘古超大陆间期(300My AGO)，当时已知大陆冰川覆盖了地球南极区(冈瓦瓦兰岛)的大部分地区。由于与我们现代冰库的主要相似之处，盘古海区间引起了地球科学家的兴趣，他们对改善我们对地球气候系统的理解感兴趣。然而，改善气候和构造模型的关键是关键的地质限制--特别是关于低纬盘古山脉和山脉冰川可能存在和范围的限制。到目前为止，还没有证据表明(晚古生代)冰川超出了南极地区的界限，这段时间内热带山脉的海拔高度仍然未知。对低纬冰的记录将有助于我们了解这段时间段的赤道气候条件和山脉海拔，从而影响气候和构造问题。这个项目涉及到对赤道西部盘古山脉(300年以前)的原始落基山脉是冰川的假设的调查。这一假说的初步证据以美国西部(科罗拉多州)保存下来的沉积物和地貌的形式出现，这些沉积物和地貌似乎是由(晚古生代)冰川过程塑造的。将对二叠纪-宾夕法尼亚(约310-280我的旧)卡特勒组和相关岩石的沉积属性、成分和分布进行研究，以检验这些沉积物记录了冰川影响的假设。这项研究还需要对地貌和第四纪沉积物进行分析，以评估原始落基山脉高地内保存的埋藏地形的来源(河流或冰川)和年代。确认赤道盘古山脉内的高山冰川将意味着比以前对这个时间和区域的设想更广泛的冰库条件和显著更高的海拔，并将为约束气候和构造模型提供必要的边界条件。因此，这项研究应该为对地球历史感兴趣的地球科学家以及对未来气候变化感兴趣并受其影响的一般社会提供有益的帮助。

Ice at the Equator: The Record and Implications of Alpine Glaciation within the Ancestral Rocky Mountains of Western PangeaGerilyn Soreghan and Michael SoreghanEAR-0230332, University of OklahomaABSTRACTThe best-documented pre-Quaternary "icehouse" occurred during the Pangean supercontinent interval (300 My ago), when continental glaciers are known to have covered much of the southern polar region of Earth (Gondwanaland). Owing to key similarities with our modern icehouse, the Pangean interval has intrigued geoscientists interested in improving our understanding of Earth's climate system. Critical to improving both climatic and tectonic models, however, are key geologic constraints-in particular, on the possible existence and extent of mountains and mountain glaciers in low-latitude Pangea. To date, evidence for (late Paleozoic) glaciers beyond the limits of the southern polar region has never been reported, and tropical mountain elevations for this interval remain unknown. Documentation of low-latitude ice would contribute to our understanding of both equatorial climate conditions and mountain elevations for this time interval, thus impacting both climatic and tectonic issues.This project involves investigation of the hypothesis that the Ancestral Rocky Mountains of equatorial western Pangea (300 My ago) were glaciated. Preliminary evidence for this hypothesis occurs in the form of preserved sediments and landforms in the western U.S. (Colorado) that appear to have been shaped by (late Paleozoic) glacial processes. Research on the depositional attributes, composition, and distribution of the Permo-Pennsylvanian (ca. 310-280 My old) Cutler Formation and related rocks will be conducted to test the hypothesis that these sediments record a glacial influence. The research will also entail analysis of landforms and Quaternary sediments to assess the origin (fluvial or glacial) and age of buried topography preserved within highlands of the Ancestral Rocky Mountains. Confirmation of alpine glaciation within equatorial Pangea would imply more extensive icehouse conditions and significantly higher elevations than previously envisaged for this time and region, and would provide needed boundary conditions for constraining climatic and tectonic models. Accordingly, this research should provide benefits to geoscientists interested in earth history in general, as well as general society interested in and impacted by future climate change.