Regional geophysical data that are available over continental scales such as magnetic, gravity, and magnetotelluric data can provide a foundation towards identifying and understanding the footprints and deep plumbing systems underlying these important ore systems. Our project will use continental-scale geophysical data to map the locations of deep crustal and mantle structures that may act as controls on the emplacement of strategic mineral deposits and ultimately better define prospective domains for these deposits in the U.S.
Scientific Issue and Relevance
Iron-oxide-copper-gold (IOCG), igneous rare earth element (REE), and platinum group element (PGE) ore bodies are some of our most important strategic deposits in providing valuable metals that underpin domestic high technology and military industries. Stakeholders such as mining industry and academia have increasingly shown an interest in large scale data sets and their utility in mineral exploration. Regional geophysical data that is available over continental scales such as magnetic, gravity, and magnetotelluric data can provide a foundation towards identifying and understanding the footprints and deep plumbing systems underlying these important ore systems.
We expect that maps and other products from our project will (1) guide mining industry exploration strategy; (2) contribute to a better understanding of the tectonic evolution of the U.S.; and (3) improve our understanding of how heat, magma, and fluids interact at crustal and even lithospheric scales to form large mineralized systems.
Methodology to Address the Issue
Over the last several decades, the Mineral Resource Program has developed large-scale geophysical databases including magnetic and gravity data at continental scales. Now, with new EarthScopeUSArray magnetotelluric (MT) data online, we have the opportunity to combine magnetic, gravity, and electrical data over large areas within the conterminous U.S. The availability of these data provides a powerful tool to define individual and multi-parameter physical properties (magnetization, density, and electrical conductivity) and map major crustal boundaries, conduits, and prospective domains that underlie mineral deposits of strategic importance. We will use continental-scale geophysical data to map the locations of deep crustal and mantle structures that may act as controls on the emplacement of strategic mineral deposits and ultimately better define prospective domains for these deposits in the U.S.
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Regional and High-Resolution Gravity and Magnetics
Focus will be on mapping lithospheric architecture beneath the iron-oxide-apatite ± rare earth element and iron-oxide-copper-gold deposits in southeast Missouri. The deposits are hosted in the Mesoproterozoic granite and rhyolite rocks within the St. Francois Mountain terrane. We are combining neodymium (Nd) isotope data with magnetic and gravity data to evaluate major crustal boundaries in the area of iron-oxide mineralization. -
Magnetotellurics
EarthScope magnetotelluric data doesn't cover the entire U.S., so we will collect new magnetotelluric stations in southern Missouri and northern Arkansas. Collection of this data, in combination with EarthScope magnetotelluric data, will allow for comparison and integration with regional potential-field data over a large portion of the central and eastern continental U.S. The new data will fill in missing areas within the important Mesoproterozoic province in the midcontinent, which is host to iron-oxide-copper-gold deposits. We will use the new data to characterize the electrical properties associated with the major density and magnetization domains underlying iron mineralization in the deep crust.
Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center | Eastern Mineral and Environmental Resources Science Center
Below are other science projects associated with this project.
Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri—From the Ore Deposit Scale to a Global Deposit Model
Below are publications associated with this project.
Crustal architecture beneath the southern Midcontinent (USA) and controls on Mesoproterozoic iron-oxide mineralization from 3D geophysical models
Geochemistry, Nd-Pb Isotopes, and Pb-Pb Ages of the Mesoproterozoic Pea Ridge Iron Oxide-Apatite–Rare Earth Element Deposit, Southeast Missouri
Making it and breaking it in the Midwest: Continental assembly and rifting from modeling of EarthScope magnetotelluric data
Below are news stories associated with this project.
- Overview
Regional geophysical data that are available over continental scales such as magnetic, gravity, and magnetotelluric data can provide a foundation towards identifying and understanding the footprints and deep plumbing systems underlying these important ore systems. Our project will use continental-scale geophysical data to map the locations of deep crustal and mantle structures that may act as controls on the emplacement of strategic mineral deposits and ultimately better define prospective domains for these deposits in the U.S.
Scientific Issue and Relevance
Iron-oxide-copper-gold (IOCG), igneous rare earth element (REE), and platinum group element (PGE) ore bodies are some of our most important strategic deposits in providing valuable metals that underpin domestic high technology and military industries. Stakeholders such as mining industry and academia have increasingly shown an interest in large scale data sets and their utility in mineral exploration. Regional geophysical data that is available over continental scales such as magnetic, gravity, and magnetotelluric data can provide a foundation towards identifying and understanding the footprints and deep plumbing systems underlying these important ore systems.
We expect that maps and other products from our project will (1) guide mining industry exploration strategy; (2) contribute to a better understanding of the tectonic evolution of the U.S.; and (3) improve our understanding of how heat, magma, and fluids interact at crustal and even lithospheric scales to form large mineralized systems.
Methodology to Address the Issue
Over the last several decades, the Mineral Resource Program has developed large-scale geophysical databases including magnetic and gravity data at continental scales. Now, with new EarthScopeUSArray magnetotelluric (MT) data online, we have the opportunity to combine magnetic, gravity, and electrical data over large areas within the conterminous U.S. The availability of these data provides a powerful tool to define individual and multi-parameter physical properties (magnetization, density, and electrical conductivity) and map major crustal boundaries, conduits, and prospective domains that underlie mineral deposits of strategic importance. We will use continental-scale geophysical data to map the locations of deep crustal and mantle structures that may act as controls on the emplacement of strategic mineral deposits and ultimately better define prospective domains for these deposits in the U.S.
-
Regional and High-Resolution Gravity and Magnetics
Focus will be on mapping lithospheric architecture beneath the iron-oxide-apatite ± rare earth element and iron-oxide-copper-gold deposits in southeast Missouri. The deposits are hosted in the Mesoproterozoic granite and rhyolite rocks within the St. Francois Mountain terrane. We are combining neodymium (Nd) isotope data with magnetic and gravity data to evaluate major crustal boundaries in the area of iron-oxide mineralization. -
Magnetotellurics
EarthScope magnetotelluric data doesn't cover the entire U.S., so we will collect new magnetotelluric stations in southern Missouri and northern Arkansas. Collection of this data, in combination with EarthScope magnetotelluric data, will allow for comparison and integration with regional potential-field data over a large portion of the central and eastern continental U.S. The new data will fill in missing areas within the important Mesoproterozoic province in the midcontinent, which is host to iron-oxide-copper-gold deposits. We will use the new data to characterize the electrical properties associated with the major density and magnetization domains underlying iron mineralization in the deep crust.
Conceptual 3D model over part of the southern Midcontinent of the U.S. The connections, plumbing, and architecture between the mantle and crust are not known but play an important role in critical metal deposit location and formation. This project uses existing continental-scale magnetic, gravity and newly acquired magnetotelluric data to develop 3D models that advance the understanding of the crustal architecture between the Precambrian and Moho surfaces. Results are evaluated in the context of known critical metal mineralization and, importantly, point to major flow paths and morphologies with potential to control critical metal deposit emplacement.(Public domain.) Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center | Eastern Mineral and Environmental Resources Science Center
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- Science
Below are other science projects associated with this project.
Iron Oxide-Copper-Cobalt-Gold-Rare Earth Element Deposits of Southeast Missouri—From the Ore Deposit Scale to a Global Deposit Model
The project main objectives are to: 1) geologically, characterize the setting and origin of the iron-copper-cobalt-gold-rare earth element deposits, and advance the knowledge of rare earth element and Co potential within iron oxide-copper-gold (IOCG) deposits of southeast Missouri, and 2) geophysically delineate and characterize the subsurface Precambrian geology using existing ground and new... - Publications
Below are publications associated with this project.
Crustal architecture beneath the southern Midcontinent (USA) and controls on Mesoproterozoic iron-oxide mineralization from 3D geophysical models
Several types of critical mineral-bearing ore deposits in the southern Midcontinent region of the U.S. are hosted in Mesoproterozoic igneous rocks largely concealed beneath Paleozoic cover. Discerning the architecture of igneous intrusions and volcanic centers in the crust is fundamental to understanding the geologic evolution of this vast region and its mineral resources. To advance the understanAuthorsAnne E. McCafferty, Jeffrey D. Phillips, Albert H. Hofstra, Warren C. DayGeochemistry, Nd-Pb Isotopes, and Pb-Pb Ages of the Mesoproterozoic Pea Ridge Iron Oxide-Apatite–Rare Earth Element Deposit, Southeast Missouri
Iron oxide-apatite and iron oxide-copper-gold deposits occur within ~1.48 to 1.47 Ga volcanic rocks of the St. Francois Mountains terrane near a regional boundary separating crustal blocks having contrasting depleted-mantle Sm-Nd model ages (TDM). Major and trace element analyses and Nd and Pb isotope data were obtained to characterize the Pea Ridge deposit, improve identification of exploration tAuthorsRobert A. Ayuso, John F. Slack, Warren C. Day, Anne E. McCaffertyMaking it and breaking it in the Midwest: Continental assembly and rifting from modeling of EarthScope magnetotelluric data
A three-dimensional lithospheric-scale resistivity model of the North American mid-continent has been estimated based upon EarthScope magnetotelluric data. Details of the resistivity model are discussed in relation to lithospheric sutures, defined primarily from aeromagnetic and geochronologic data, which record the southward growth of the Laurentian margin in the Proterozoic. The resistivity signAuthorsPaul A. Bedrosian - News
Below are news stories associated with this project.