Collaborative Research: Equatorial Glaciation and Landscape Burial in the Late Paleozoic: Implications for Pangaean Climate and Tectonics

合作研究：晚古生代赤道冰川作用和景观埋藏：对盘古大陆气候和构造的影响

• 批准号: 1849623
• 负责人: Gerilyn Soreghan
• 金额: $ 44.9万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1849623&HistoricalAwards=false
• 关键词: Collaborative; Research; Equatorial; Glaciation; Landscape

Climate has varied widely through Earth history. Just as study of human history helps humankind better understand our future, study of Earth's climate history aids in better understanding current and future climate systems. This study is examining whether glaciers existed near Earth's equator at low elevations some 300 million years ago. First, seismic instruments are used to see below the ground surface of Unaweep Canyon (Colorado); this canyon was located near the equator 300 million years ago and now contains features that suggest ancient glaciers may have existed during that time. Peering below the ground surface allows researchers to see the canyon shape and features, including the amount of sediment fill. Next, researchers drill out core samples from the sediment. Detailed analyses of this sediment can reveal the age of the canyon, the past climate of the region, including whether glaciers existed, and how the present-day landscape formed. If it is determined that glaciers existed in this region millions of years ago, understanding of the climate system during that time would need major revision. Computer climate models then help researchers understand characteristics of winds, ocean temperatures, volcanic eruptions, and plant cover needed to produce the climate signal revealed in the core samples. This project includes education for high-school students from the Southern Ute Indian tribe, career training and preparation for university students, and collaboration with art students to create displays and presentations about the research results.This work tests the hypothesis that low-elevation uplands of equatorial Pangaea hosted glaciers during the Late Paleozoic. To test this, geophysics, thermochronology, and coring are used to determine the depth and nature of sediment fill and 3D basement shape of Unaweep Canyon (Colorado), a globally unique landform hypothesized to archive a paleolandscape modified by Permo-Pennsylvanian equatorial glaciation. Evidence for low-latitude glaciation would radically change understanding of the late Paleozoic icehouse, a critical interval for evolution of land animals and plants, and spur research on influences of alternative boundary conditions, climate forcings, and model configurations. Documenting an upland glacial landscape preserved for 300 (or possibly 600) My would also significantly challenge understanding of landscape genesis, evolution, and burial, and feedbacks between tectonics and climate. This research involves outreach to secondary-school students from the Southern Ute Indian tribe, training of STEM undergraduate and graduate students, and interfacing with art students to create impactful public outreach.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.

地球历史上的气候变化很大。正如研究人类历史有助于人类更好地了解我们的未来，研究地球的气候历史有助于更好地了解当前和未来的气候系统。这项研究正在研究大约3亿年前地球赤道附近低海拔地区是否存在冰川。首先，地震仪器被用来观察Unaweep峡谷（科罗拉多州）的地表以下;这个峡谷位于3亿年前的赤道附近，现在包含的特征表明古代冰川可能在那段时间存在。在地表以下窥视，研究人员可以看到峡谷的形状和特征，包括沉积物填充量。接下来，研究人员从沉积物中钻取岩芯样本。对这些沉积物的详细分析可以揭示峡谷的年龄，该地区过去的气候，包括冰川是否存在，以及现在的景观是如何形成的。如果确定数百万年前该地区存在冰川，那么对当时气候系统的理解将需要进行重大修改。然后，计算机气候模型帮助研究人员了解风、海洋温度、火山爆发和植物覆盖的特征，这些特征是产生核心样本中揭示的气候信号所必需的。该项目包括对南乌特印第安部落的高中生进行教育，对大学生进行职业培训和准备，并与艺术学生合作制作关于研究成果的展示和演示。这项工作验证了赤道泛大陆低海拔高地在晚古生代期间拥有冰川的假设。为了测试这一点，地球物理学，热年代学，和取芯是用来确定的深度和性质的沉积物填充和三维基底形状的Unaweep峡谷（科罗拉多），全球独特的地貌假设存档修改二叠纪-宾夕法尼亚赤道冰川的古景观。低纬度冰川作用的证据将从根本上改变对晚古生代冰库的理解，这是陆地动物和植物进化的关键时期，并刺激了对替代边界条件，气候强迫和模式配置影响的研究。记录保存了300年（或可能600年）的高地冰川景观也将极大地挑战对景观起源、演化和埋藏以及构造和气候之间反馈的理解。这项研究涉及到南乌特印第安部落的中学生，STEM本科生和研究生的培训，以及与艺术学生的交流，以创造有影响力的公共宣传。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响力审查标准进行评估，被认为值得支持。

项目成果

Imaging an Enigmatic Paleovalley with Passive Seismic Methods (Unaweep Canyon, Colorado, United States)

使用被动地震方法对神秘的古山谷进行成像（美国科罗拉多州乌纳威普峡谷）

• DOI: 10.1785/0320220048
• 发表时间: 2023
• 期刊: The Seismic Record
• 作者: Dangwal, Deepankar;Behm, Michael;Chen, Xiaowei;Soreghan, Gerilyn S.
• 通讯作者: Soreghan, Gerilyn S.

Seismic Reflection and Electrical Resistivity Imaging Support Pre‐Quaternary Glaciation in the Rocky Mountains (Unaweep Canyon, Colorado)

地震反射和电阻率成像支持落基山脉第四纪冰川作用之前（科罗拉多州乌纳威普峡谷）

• DOI: 10.1029/2021gl094706
• 发表时间: 2021
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Patterson, Anna;Behm, Michael;Chwatal, Werner;Flores‐Orozco, Adrian;Wang, Yichuan;Soreghan, Gerilyn S.
• 通讯作者: Soreghan, Gerilyn S.

Hydrologic characterization of an alpine valley infill through integration of ERT, active seismic and active/passive surface wave interferometry (Unaweep Canyon, US)

通过集成 ERT、主动地震和主动/被动表面波干涉测量法对高山山谷填充物进行水文表征（Unaweep Canyon，美国）

• DOI: 10.5194/egusphere-egu2020-6199
• 发表时间: 2020
• 期刊: EGU General Assembly
• 作者: Behm, M.