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.

板块构造学的一个基本概念是，古代大陆边缘经历了从沉积物堆积的“被动”区域到以俯冲、火山作用和造山为主的“活动”区域的转变过程。这种转变发生的过程是通过俯冲起始的。然而，俯冲起始的现代例子和数值模型仍然存在很大争议。经常被引用为这一基本板块构造过程的经典例子，但人们对阿拉斯加北部和加拿大育空地区导致这一俯冲起始事件的关键事件的性质和时间知之甚少。这项研究促进了学术研究人员之间的合作。美国地质调查局 (USGS) 的三个美国机构和政府研究人员将参与研究计划，以更好地了解北美偏远且未被充分研究的地区的晚古生代构造事件。此外，研究团队将与美国鱼类和野生动物管理局以及美国地质勘探局合作，向公众传播北极阿拉斯加的地理知识，以增强美国的经济竞争力并促进下一代的培训。北美洲中古生代构造演化的最新模型（劳伦西亚）强调了环北极地体的边缘平行迁移，随后是从育空地区到北美洲的广泛大陆俯冲起始。然而，中古生代造山事件的时间、性质和持续时间仍然不明确，该项目将重点关注阿拉斯加北部北极阿拉斯加地体中的关键结构关系和独特的泥盆纪-石炭纪沉积岩和岩浆岩。三个主要组成部分：1）对同生岩石的检查以及区域物源数据集的开发；2）对区域中上泥盆统的岩石学、地球化学和地质年代学检查；火成岩；3）与区域地震数据相结合的现场结构研究，以重建阿拉斯加北极地区的泥盆纪-石炭纪变形样式这项工作将为北美西北部和大周界的古生代构造演化提供重要的新见解。 - 北极地区评估几种俯冲引发机制的可行性此外，该项目将为北极中生代构造重建提供新的穿透点，与多种相关。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审查标准进行评估，被认为值得支持。

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