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

基本信息

批准号：
1736167
负责人：
Haiying Gao
金额：
$ 27.49万
依托单位：
University of Massachusetts Amherst
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 2021-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1736167&HistoricalAwards=false
关键词：
Collaborative Research Constraints Lithospheric Structure

项目摘要

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.

威尔逊构造周期是导致地球上大陆壳的生长和修饰的最基本过程之一。它涉及海盆的关闭，大陆碰撞，大陆的裂谷（分离）以及新海盆的形成。北美东部提供了祖先大西洋，“伊亚佩斯”和现代大西洋开放期间该大陆东部增长的完整记录。该区域已被用作板块构造的类型部分和模型数十年。尽管以前的大陆碎片之间的表面边界越来越众所周知，但持续的问题涉及与大陆深层地壳和地幔部分的生长和稳定相关的时间和过程。该项目的总体目标以及Earthscope项目的长期主题是整合高分辨率的地球物理和地质数据，以建立一个真正的四维（时空）模型，以供这个经典地区的大陆壳增长。地震站的密度和分布非常出色，包括可运输的地球阵列和许多长期运行的永久地震站。新的地质，地球化学和地质学数据已导致构造历史的修订，并重新评估北部阿巴拉契亚人的地层边界和祖先。该提案旨在了解纽约和新英格兰在纽约和新英格兰的大陆岩石圈（构造板块的地壳和地幔部分）的特征，以确定在地面，尤其是在深度上的不同地面之间的边界，并解决有关北阿帕拉奇人的构造历史的长期开放问题。该项目中开发的新模型和假设将对北美大陆的特征，深层地壳和地幔的性质以及我们对一般大陆增长的理解具有广泛的影响。该项目旨在将北美东部岩石圈的室内结构与构造历史相关联，并吸引广泛的陆上组装。具体来说，该提案将解决以下科学问题：（1）什么是大陆岩石圈？我们可以鉴定出不同的岩石圈块和斜圈内边界吗？这些结构的起源是什么？（2）主要的地形边界在哪里？地质边界在多大程度上可以扩展到深度？北美大陆的主要地层何时增加？为了解决这些问题，该项目将开发出北美东部的地壳和地幔岩石圈的全面地震模型。高级波传播模拟和反演将提供一种有力的方法来限制外壳和地幔岩石圈的三维地震特征。远距离接收器功能分析将用于识别和描述尖锐的速度/密度不连续性。侧面可变和深度依赖性各向异性将通过接收器功能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合成以及新的表面岩石样品的收集将补充地震成分。地质，地质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。该项目将支持早期女性地球科学家的职业发展，并帮助UMass Amherst的新地震学小组的发展。地震研究和教学的扩展具有吸引五大地质财团的本科和研究生的杰出潜力。它将支持UMass和Rutgers的本科生和研究生的培训。该项目的发现将通过女子公司尤里卡（Eureka）介绍给8至12年级的女孩！计划（一个国家组织），这是霍利奥克，马萨诸塞州和马萨诸塞州女孩公司之间的强大合作。将向新英格兰的学校，大学和大学上传表面地质汇编，并提供批评，协作和教育用途。