Building a continent: Integration of surface geology, rock physics, and seismic observations to investigate the tectonic history of the contiguous United States

构建大陆：整合地表地质学、岩石物理学和地震观测来研究美国本土的构造历史

基本信息

批准号：
1735890
负责人：
Vera Schulte-Pelkum
金额：
$ 28.42万
依托单位：
University of Colorado at Boulder
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 2023-08-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1735890&HistoricalAwards=false
关键词：
Building continent Integration surface geology

项目摘要

The North American continent formed over billions of years via the collision of continental fragments and the rifting apart of larger continents. Geologists can read some of this history by looking at rocks exposed at the Earth's surface that were deformed in the past. The aim of this project is to extend this ability below the Earth's surface. While buried rocks cannot be seen and mapped directly, they are constantly traversed by seismic waves from earthquakes around the world. These waves are imprinted with information on the rocks they travel through before reaching the Earth's surface. We combine mapped rock deformation at the surface with seismic information from the subsurface in order to find out how to extract the imprinted information from the seismic data. The information can then be used to map how the Earth's crust was deformed. The project advances knowledge of Earth science by allowing us to read the record of past geological processes beneath the surface. Because current geological processes also deform rocks, the method can also be used to map the roots of earthquake-generating faults, which is useful for estimates of seismic hazard. The rock characteristics investigated in this process are also relevant to mapping geological resources. Additionally, accurate knowledge of the imprint of rock fabrics on the seismic signal enables us to avoid biases in other uses of the seismic data, such as for location and characterization of natural and human-made seismic sources.A stated goal of the EarthScope program is to derive constraints on the deformation history of the continent. This project aims to bridge the scales from microstructural rock fabrics measured in the laboratory, to deformation structures mapped on outcrop exposures, and to rock fabrics causing seismic anisotropy at km-scale seismic wavelengths. Project components are 1) integration of seismic anisotropy observations from multiple techniques and seismic networks, 2) contribution of existing digital structural data sets containing foliations, lineations, and mapped major ductile and brittle faults to existing EarthCube-funded and U. S. Geological Survey-held databases as well as calculation of bulk elasticity tensors from ~1:100,000 scale maps to hand samples and 3) synthesis and joint interpretation of seismic observations and structural data extracted from EarthCube-funded databases using straightforward correlations as well as an explicit scaling from elastic tensors representative of rock types to geological foliation maps to seismic wavelength-scale anisotropy.The ability to relate crustal seismic anisotropy to the strain history of the crust requires 1) a representative catalog of elastic properties of crustal rocks and how they average at scales of seismic wavelengths and 2) a compilation of major structural parameters such as orientations of dominant rock fabrics (foliation and lineation) in metamorphic and igneous rocks and their internal coherence in unique domains, as well as orientations of more discrete features such as fault zones, in order to enable quantitative comparisons to anisotropy measured seismically. The proposed work will centralize existing compilations and make them widely available online.

北美大陆通过大陆碎片和较大大陆的裂变而形成了数十亿年。地质学家可以通过查看过去变形的地球表面上暴露的岩石来阅读其中的一些历史。该项目的目的是将此能力扩展到地球表面以下。尽管无法直接看到和映射被埋葬的岩石，但它们不断地被世界各地地震中的地震浪潮所穿越。这些波浪印有有关它们在到达地球表面之前穿过的岩石的信息。我们将映射的岩石变形与地下的地震信息结合在一起，以了解如何从地震数据中提取烙印信息。然后，该信息可用于绘制地壳的变形方式。该项目通过允许我们阅读表面下过去地质过程的记录来提高地球科学的知识。由于当前的地质过程也变形了岩石，因此该方法也可以用于绘制地震生成断层的根部，这对于估计地震危害很有用。在此过程中研究的岩石特征也与映射地质资源有关。另外，对地震信号上岩石织物的烙印的准确了解使我们能够避免在地震数据的其他用途中偏见，例如自然和人制造的地震来源的位置和表征。得出对非洲大陆变形历史的约束。该项目旨在弥合从实验室测量的微结构岩体织物，映射在露头暴露上的变形结构，以及在KM尺度地震波长处引起地震性各向异性的岩石织物。项目组件是1）从多种技术和地震网络中进行地震各向异性观测的整合，2）现有的数字结构数据集的贡献，其中包含叶子，线条以及映射的主要延性和脆性断层，对现有的Earthcube资助以及美国的地理数据库，以及从〜1：100,000刻度图的计算大量弹性张量的计算，以及3）使用直接相关性以及从Earthcube资助的数据库中提取的地震观测和结构数据的合成和联合解释，并使用直截了当的相关性以及从弹性量量表中的显式缩放量表岩石类型的地质叶面图与地震波长各向异性。 2）主要结构参数的汇编，例如变质和火成岩中的主要岩石织物（叶叶和线植物）的方向及其在独特域中的内部连贯性，以及更离散的特征（例如故障区域）的方向，以便启用与各向异性的定量比较在地震中测量。拟议的工作将集中现有的汇编并使它们在线广泛使用。

项目成果

期刊论文数量（6）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Imaging the Tectonic Grain of the Northern Cordillera Orogen Using Transportable Array Receiver Functions

DOI：
10.1785/0220200182
发表时间：
2020-11
期刊：
Seismological Research Letters
影响因子：
3.3
作者：
V. Schulte‐Pelkum;J. Caine;James V. Jones;T. Becker
通讯作者：
V. Schulte‐Pelkum;J. Caine;James V. Jones;T. Becker

Tectonic Inheritance During Plate Boundary Evolution in Southern California Constrained From Seismic Anisotropy

DOI：
10.1029/2021gc010099
发表时间：
2021-08
期刊：
Geochemistry
影响因子：
3.7
作者：
V. Schulte‐Pelkum;T. Becker;W. Behr;M. Miller
通讯作者：
V. Schulte‐Pelkum;T. Becker;W. Behr;M. Miller

Confronting Solid‐State Shear Bias: Magmatic Fabric Contribution to Crustal Seismic Anisotropy

面对固态剪切偏差：岩浆组构对地壳地震各向异性的贡献

DOI：
10.1029/2022gl102399
发表时间：
2023
期刊：
Geophysical Research Letters
影响因子：
5.2
作者：
Frothingham, Michael G.;Mahan, Kevin H.;Schulte‐Pelkum, Vera;Goncalves, Philippe;Zucali, Michele
通讯作者：
Zucali, Michele

Don't judge an orogen by its cover: Kinematics of the Appalachian décollement from seismic anisotropy

不要以地貌来判断造山带：地震各向异性的阿巴拉契亚山脉运动学

DOI：
10.1130/g50323.1
发表时间：
2022
期刊：
Geology
影响因子：
5.8
作者：
Frothingham, Michael G.;Schulte-Pelkum, Vera;Mahan, Kevin H.;Merschat, Arthur J.;Mather, Makayla;Gomez, Zulliet Cabrera
通讯作者：
Gomez, Zulliet Cabrera

From Crystals to Crustal‐Scale Seismic Anisotropy: Bridging the Gap Between Rocks and Seismic Studies With Digital Geologic Map Data in Colorado

从晶体到地壳尺度地震各向异性：利用科罗拉多州数字地质图数据弥合岩石和地震研究之间的差距

DOI：
10.1029/2021tc006893
发表时间：
2022
期刊：
Tectonics
影响因子：
4.2
作者：
Frothingham, Michael G.;Mahan, Kevin H.;Schulte‐Pelkum, Vera;Caine, Jonathan Saul;Vollmer, Frederick W.
通讯作者：
Vollmer, Frederick W.