Collaborative Research: Constraints on the Lithospheric Structure and Accretionary History of New England: Integrating Seismic and Geologic data sets

合作研究：新英格兰岩石圈结构和增生历史的约束：整合地震和地质数据集

• 批准号: 1735912
• 负责人: Vadim Levin
• 金额: $ 16.43万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1735912&HistoricalAwards=false
• 关键词: Collaborative; Research; Constraints; Lithospheric; Structure

The Wilson tectonic cycle is one of the most fundamental processes leading to growth and modification of continental crust on Earth. It involves the closing of ocean basins, collision of continents, rifting (separation) of continents, and formation of new ocean basins. Eastern North America provides a complete record of the eastward growth of the continent during the closing of the ancestral Atlantic ocean, ?Iapetus?, and the opening of the modern Atlantic ocean. The region has been used as a type section and model of plate tectonics for decades. Although the surface boundaries between former continental fragments are increasingly well known, a persistent question involves the timing and processes involved with the growth and stabilization of the deep crust and mantle parts of the continent. The overall goal of this project, and a long-term theme of the EarthScope project in general, is to integrate high-resolution geophysical and geological data in order to build a truly four-dimensional (space and time) model for the growth of continental crust in this classic region. The density and distribution of seismic stations are excellent, including the EarthScope Transportable Array and many long-running permanent seismic stations. New geological, geochemical, and geochronological data have led to revision of the tectonic history and a re-assessment of terrane boundaries and ancestry in the northern Appalachians. This proposal aims to understand the characteristics of continental lithosphere (the crust and mantle parts of the tectonic plates) in New York and New England, to identify the boundaries between distinct terranes both at the surface and especially at depth, and to address long-standing open questions about the tectonic history of the northern Appalachians. New models and hypotheses developed in this project will have wide implications for character of the North American continent, the nature of the deep crust and mantle, and our understanding of continental growth in general.This project seeks to associate the interior structure of the lithosphere of Eastern North America with its tectonic history, and to draw broad inferences for the nature of continental assembly. Specifically, this proposal will address the following scientific questions: (1) What is continental lithosphere? Can we identify distinct lithospheric blocks and intra-lithospheric boundaries? What are the origins of these structures? (2) What/where are the major terrane boundaries? To what extent can geological boundaries be extended to depth? When were the major terranes added to the North American continent? To address these questions, the project will develop a comprehensive seismic model of the crust and the mantle lithosphere in eastern North America. An advanced wave propagation simulation and inversion will provide a powerful way to constrain the three-dimensional seismic features of the crust and the mantle lithosphere. Teleseismic receiver function analysis will be used to identify and delineate sharp velocity/density discontinuities. Laterally variable and depth-dependent anisotropy will be resolved with receiver functions and shear-wave splitting studies, and used to highlight patterns of lithospheric deformation. Compilation and synthesis of existing geological data sets, and collection of new surface rock samples will complement the seismic component. A systematic integration of geological, geochronological and geochemical data sets will inform a re-assessment of the regional tectonic framework. The project will support the career development of an early-career female geoscientist and help the development of a new seismology group at UMass Amherst. Expansion of seismology research and teaching has outstanding potential to attract undergraduate and graduate students at the Five-College Geology Consortium. It will support training of undergraduate and graduate students at UMass and Rutgers. Findings from this project will be introduced to 8th-12th grade girls through the Girls Inc. Eureka! Program (a national organization), a strong STEM-based collaboration between Girls Inc. of Holyoke, MA and UMass. Surficial geologic compilations will be uploaded and made available to schools, colleges, and universities throughout New England for critiques, collaboration, and educational use.

威尔逊构造旋回是导致地球陆壳生长和改造的最基本过程之一。它包括海洋盆地的闭合、大陆的碰撞、大陆的断裂（分离）和新海洋盆地的形成。北美东部提供了一个完整的记录，在古老的大西洋关闭期间，大陆向东生长，？土卫八？以及现代大西洋的形成几十年来，该地区一直被用作板块构造的典型剖面和模型。虽然前大陆碎片之间的表面边界越来越为人所知，但一个持续存在的问题涉及大陆深部地壳和地幔部分的生长和稳定所涉及的时间和过程。该项目的总体目标，也是地球镜项目的一个长期主题，是综合高分辨率地球物理和地质数据，以便为这一典型区域的大陆地壳生长建立一个真正的四维（空间和时间）模型。地震台站的密度和分布非常好，包括EarthScope移动式阵列和许多长期运行的常设地震台站。新的地质学、地球化学和年代学数据导致了对构造历史的修正，并重新评估了北方阿巴拉契亚山脉的边界和起源。该建议旨在了解纽约和新英格兰大陆岩石圈（构造板块的地壳和地幔部分）的特征，以确定在表面和特别是在深度上不同的岩石圈之间的边界，并解决长期悬而未决的关于北方阿巴拉契亚山脉构造历史的问题。该项目提出的新模型和假说将对北美大陆的性质、地壳和地幔的性质以及我们对大陆生长的一般认识产生广泛的影响。该项目试图将北美东部岩石圈的内部结构与其构造历史联系起来，并对大陆组装的性质作出广泛的推论。 具体而言，本建议将解决以下科学问题：（1）什么是大陆岩石圈？我们能识别出不同的岩石圈块体和岩石圈内边界吗？这些结构的起源是什么？(2)主要的边界在哪里？地质界线能延伸到什么程度？北美大陆的主要殖民地是什么时候增加的？ 为了解决这些问题，该项目将开发北美东部地壳和地幔岩石圈的综合地震模型。先进的地震波传播模拟和反演技术将为研究地壳和地幔岩石圈的三维地震特征提供有力的手段。遥测接收器功能分析将用于识别和描绘尖锐的速度/密度不连续性。横向变量和深度相关的各向异性将通过接收函数和剪切波分裂研究来解决，并用于突出岩石圈变形的模式。现有地质数据集的汇编和综合以及新的地表岩石样本的收集将补充地震部分。地质、年代学和地球化学数据集的系统整合将为区域构造框架的重新评估提供信息。 该项目将支持一个早期职业女性地球科学家的职业发展，并帮助马萨诸塞大学阿默斯特分校发展一个新的地震学小组。地震学研究和教学的扩大具有吸引五所大学地质学联合会的本科生和研究生的突出潜力。它将支持马萨诸塞大学和罗格斯大学的本科生和研究生的培训。该项目的调查结果将通过女孩公司介绍给8 - 12年级的女孩。尤里卡！计划（一个国家组织），一个强大的STEM为基础的合作女孩公司。来自霍利奥克、马萨诸塞州和马萨诸塞大学。地表地质汇编将被上传并提供给整个新英格兰的学校、学院和大学，以供批评、合作和教育使用。

项目成果

Seismic Anisotropic Layering in the Yilgarn and Superior Cratonic Lithosphere

• DOI: 10.1029/2020jb021575
• 发表时间: 2021-08
• 期刊: Journal of Geophysical Research: Solid Earth
• 作者: Xiaoran Chen;V. Levin;Huaiyu Yuan;M. Klaser;Yiran Li

Localized Anisotropic Domains Beneath Eastern North America

北美东部下方的局部各向异性域

• DOI: 10.1029/2019gc008518
• 发表时间: 2019
• 期刊: Geosystems
• 作者: Li, Yiran;Levin, Vadim;Elkington, Stephen;Hlavaty, Janine
• 通讯作者: Hlavaty, Janine

Small Shear Wave Splitting Delays Suggest Weak Anisotropy in Cratonic Mantle Lithosphere

小剪切波分裂延迟表明克拉通地幔岩石圈存在弱各向异性

• DOI: 10.1029/2021gl093861
• 发表时间: 2021
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Chen, Xiaoran;Levin, Vadim;Yuan, Huaiyu
• 通讯作者: Yuan, Huaiyu

Systematic Mapping of Upper Mantle Seismic Discontinuities Beneath Northeastern North America

北美东北部下方上地幔地震不连续性的系统测绘

• DOI: 10.1029/2021gc009710
• 发表时间: 2021
• 期刊: Geosystems
• 作者: Li, Yiran;Levin, Vadim;Nikulin, Alex;Chen, Xiaoran
• 通讯作者: Chen, Xiaoran