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

赤道上的冰：古盘古落基山脉西部高山冰川的记录和意义[美]erilyn Soreghan和Michael Soreghan][美][美][美][美][美][美][美][美][美][美][美][美][美][美][美]由于与现代冰窖的关键相似之处，泛古宙间隔引起了对提高我们对地球气候系统理解感兴趣的地球科学家的兴趣。然而，对气候和构造模型的改进至关重要的是关键的地质限制，特别是低纬度盘古大陆山脉和高山冰川可能存在的范围。迄今为止，（晚古生代）冰川超出南极地区范围的证据从未被报道过，而这一区间的热带山脉海拔高度仍然未知。低纬度冰的记录将有助于我们了解赤道气候条件和这段时间间隔的山脉海拔，从而影响气候和构造问题。该项目涉及对赤道西盘古大陆祖先落基山脉（300万年前）被冰川覆盖的假设的调查。这一假设的初步证据出现在美国西部（科罗拉多州）保存下来的沉积物和地貌中，这些沉积物和地貌似乎是由（晚古生代）冰川作用形成的。对二叠系-宾夕法尼亚系（约310-280年）卡特勒组和相关岩石的沉积属性、组成和分布的研究将进行，以检验这些沉积物记录了冰川影响的假设。这项研究还将需要分析地貌和第四纪沉积物，以评估原始落基山脉高地内保存的埋藏地形的起源（河流或冰川）和年龄。证实赤道盘古大陆内的高山冰川作用将意味着比以前设想的这个时间和地区更广泛的冰库条件和明显更高的海拔，并将为限制气候和构造模型提供所需的边界条件。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和受其影响的一般社会提供好处。

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.