Collaborative Research: An Alaskan perspective on middle Paleozoic terrane translation, contraction, and subduction initiation in northwestern Laurentia

合作研究：从阿拉斯加角度看待劳伦西亚西北部中古生代地体的平移、收缩和俯冲起始

• 批准号: 1947071
• 负责人: William McClelland
• 金额: $ 27.89万
• 依托单位: University of Iowa
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1947071&HistoricalAwards=false
• 关键词: Collaborative; Research; Alaskan; perspective; middle

A fundamental concept in plate tectonics is that ancient continental margins undergo a conversion process from “passive” zones of sediment accumulation to “active” zones dominated by subduction, volcanism, and mountain building. The process by which this transition occurs is through subduction initiation along continental margins. However, modern examples and numerical models of subduction initiation remain highly contentious. The late Paleozoic (ca. 450–300 million years ago) conversion of northwestern North America from a passive to an active margin is often cited as a classic example of this fundamental plate tectonic process, but very little is known about the nature and timing of key events in northern Alaska and Yukon, Canada, that led to this subduction initiation event. This study promotes collaboration between academic researchers at three U.S. institutions and government researchers at the United States Geological Survey (USGS) to better inform our understanding of late Paleozoic tectonic events in a remote and understudied region of North America. A diverse group of undergraduate and graduate students will participate in research initiatives at each institution. In addition, the research team will collaborate with the United States Fish and Wildlife Service and the USGS to disseminate geologic knowledge of Arctic Alaska to the public, to enhance the economic competitiveness of the U.S. and facilitate the training of the next generation of Arctic Earth scientists.Recent models for the middle Paleozoic tectonic evolution of North America (Laurentia) highlight margin-parallel transport of circum-Arctic terranes followed by widespread continental subduction initiation from the Yukon to Nevada. However, the timing, nature, and duration of middle Paleozoic orogenic events remain ambiguous. This project will focus on key structural relationships and unique Devonian–Carboniferous synorogenic sedimentary and magmatic rocks within the Arctic Alaska terrane of northern Alaska. The research consists of three major components: 1) the examination of synorogenic rocks coupled with the development of a regional provenance dataset; 2) a petrological, geochemical, and geochronological examination of regional Middle to Upper Devonian igneous rocks; and 3) a field-based structural study integrated with regional seismic datasets to reconstruct the style of Devonian–Carboniferous deformation in Arctic Alaska. This work will provide critical new insights into the Paleozoic tectonic evolution of northwestern North America and the greater circum-Arctic region to assess the viability of several subduction initiation mechanisms. In addition, this project will provide new piercing points for Mesozoic tectonic reconstructions of the Arctic, with relevance to several subdisciplines of the geosciences.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.

板块构造中的一个基本概念是，在转换过程中，古老的连续边缘从沉积物积累的“被动”区域到以俯冲，火山和山区建筑为主的“活跃”区域。这种过渡发生的过程是通过沿连续边缘的俯冲计划。但是，俯冲计划的现代实例和数值模型仍然高度争议。已故的古生代（大约450-3亿年前）北美西北部从被动边缘转换为活跃边缘，通常被认为是这一基本板块构造过程的经典示例，但对加拿大北部和Yukon北部的关键事件的性质和时机知之甚少。这项研究促进了美国三家机构的学术研究人员与美国地质调查局（USGS）的政府研究人员之间的合作，以更好地了解我们对北美偏远和知识范围内的古生代构造事件的理解。一组群组的本科生和研究生将参加每个机构的研究计划。此外，研究团队将与美国鱼类和野生动物服务局和USGS合作，将阿拉斯加北极的地质知识传播给公众，增强美国的经济竞争力，并支持下一代北极地球科学家的培训。从育空地区到内华达州的宽度连续俯冲计划。然而，中古生代造基因事件的时机，性质和持续时间仍然模棱两可。该项目将着重于关键的结构关系以及独特的泥盆纪 - 碳纤维协同沉积物和岩浆岩石，在阿拉斯加北部的阿拉斯加地形内。该研究由三个主要组成部分组成：1）对协同岩石的检查以及区域出处数据集的开发； 2）区域中部至泥盆纪火成岩岩石的岩石学，地球化学和年代学检查； 3）基于野外的结构研究，该研究与区域地震数据集集成在一起，以重建北极阿拉斯加泥盆纪 - 碳纤维变形的风格。这项工作将为北美西北部和更大的北极地区的古生代构造演化提供关键的新见解，以评估几种俯冲倡议机制的生存能力。此外，该项目将为北极的中生代构造重建提供新的刺穿点，并与地球科学的几个子学科有关。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准来通过评估来诚实地支持。

项目成果

THE ROLE OF TRANSCURRENT STRUCTURES IN THE PALEOZOIC EVOLUTION OF THE NORTHERN LAURENTIAN MARGIN

跨流构造在北劳伦斯边缘古生代演化中的作用

• DOI: 10.1130/abs/2022am-377537
• 发表时间: 2022
• 期刊: Geological Society of America Abstracts with Programs
• 作者: McClelland, Bill;Kosminska, Karolina;Gilotti, Jane A.;Faehnrich, Karol;Strauss, Justin;Colpron, Maurice
• 通讯作者: Colpron, Maurice

GEOLOGY AND U-PB GEOCHRONOLOGY OF THE ERNIE LAKE AREA, CENTRAL BROOKS RANGE (ALASKA): IMPLICATIONS FOR CRETACEOUS ALLOCHTHON STACKING, PALINSPASTIC RESTORATIONS, AND PRE-CRETACEOUS ARCTIC TECTONICS

中央布鲁克山脉（阿拉斯加）厄尼湖地区的地质学和 U-PB 地质年代学：对白垩纪异土堆积、古痉挛恢复和白垩纪前北极构造的影响

• DOI: 10.1130/abs/2022am-377640
• 发表时间: 2022
• 期刊: Geological Society of America Abstracts with Programs
• 作者: Vogl, James;Titus, Jason;Mulrooney, Laura;McClelland, Bill
• 通讯作者: McClelland, Bill

NEW GEOLOGIC MAPPING IN THE ARCTIC D-1 SW and NW 7.5’ QUADRANGLES, NORTHEASTERN BROOKS RANGE, ALASKA

阿拉斯加布鲁克山脉东北部北极 D-1 西南和西北 7.5 英尺四边形的新地质测绘

• DOI: 10.1130/abs/2022am-378097
• 发表时间: 2022
• 期刊: Geological Society of America Abstracts with Programs
• 作者: Lockett, Alec;Geier, George;Fame, Michelle;Kroeger, Emma;Nelson, Lyle L.;Connors, Christopher;Strauss, Justin;McClelland, Bill
• 通讯作者: McClelland, Bill

NEW INSIGHTS INTO DEVONIAN–CARBONIFEROUS GEOLOGICAL RELATIONSHIPS IN THE NORTHEASTERN BROOKS RANGE OF ALASKA

对阿拉斯加东北部布鲁克斯山脉泥盆纪与石炭纪地质关系的新见解

• DOI: 10.1130/abs/2022am-377521
• 发表时间: 2022
• 期刊: Geological Society of America Abstracts with Programs
• 作者: Geier, George;Lockett, Alec;McClelland, William C.;Connors, Christopher;Fame, Michelle;Strauss, Justin
• 通讯作者: Strauss, Justin