Midcontinent rift system
The Midcontinent Rift System (MRS) of central North America is a 1.1-Ga, 2500-km long structural feature that has been interpreted as a triple-junction rift developed over a mantle plume. As much as 20 km of subaerial lava flows , mainly flood basalts , are overlain by as much as 10 km of sedimentary rocks that are mostly continental fluvial ...Jun 15, 2020 · The ca. 1100 Ma old Midcontinent Rift System (MRS) 1 is arguably the most significant non-orogenic tectonic feature of mid-North America because of its major disturbance of the lithosphere, vast extent, impact on latter tectonism of the region, and its earth resources. It is the most prominent feature of gravity and magnetic anomaly maps of ... 1 Introduction [2] The Mid-Continent Rift System (MCRS) is one of the most prominent features on the Bouguer gravity map of the central United States (Figure 1).The rift formed at ~1.1 Ga, recorded by two pulses of magmatic activity lasting ~15 Myr [White, 1997], making it one of the most extensive paleorifts in the world [Hinze et al., 1997].
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The 1.1 Ga Midcontinent rift system of North America is one of the world's major continental rifts and hosts a variety of mineral deposits. The rocks and mineral deposits of this 2000 km long rift are exposed only in the Lake Superior region. In the Lake Superior region, the rift cuts across Precambrian basement terranes ranging in age from ∼ ...The Midcontinent Rift System is a major tectonic feature that formed about 1.1 to 1.2 b.y. ago in Precambrian crust that had a long and complex history but that was a rigid crustal block for ..._____ faulting produced by _____ forces, can be found within the rocks of the East Continent-Midcontinent rift system. (Hint: which types of faults and stresses are found in rifts) A) Normal, compressional. Normal, tensional. Homo erectus had a _____ when compared to Homo sapiens. All of the above (larger jaw, more elongate skull, smaller brainThe U.S. Department of Energy's Office of Scientific and Technical InformationBut the 2000 km long Midcontinent Rift System is an extraordinary example of plate tectonic processes, and it spans half a dozen states in the Midwest! Most of it is concealed by deposits that have accumulated over the past 1.1 billion years, so much of what we know about the rift comes from geophysics, which is giving exciting new insights ...Called the Midcontinent Rift (MCR), this 3000-kilometer-long feature, made of 1.1-billion-year-old igneous and sedimentary rocks, extends underground across the central United States. It stands...General Information. Title: Precise U-Pb ages of Duluth Complex and related mafic intrusions, northeastern Minnesota; geochronological insights to physical, petrogenetic, paleomagnetic and tectonomagnetic processes associated with 1.1 Ga Midcontinent Rift System Author(s): Paces, J.B., and Miller, J.D., Jr. Publishing Organization: American Geophysical UnionThe Midcontinent Rift system and surrounding Precambrian rocks are known to host highly significant mineral resources. Our project objectives are to increase understanding of this system through the integration of new and legacy geophysical data with geochemical and borehole data, map the lithology and structure of PreCambrian rocks, and develop an integrated 3D geologic model of the region.Long considered, but not proven, to be related to the ∼1.1 Ga Midcontinent Rift System (MRS), the NEIIC is comparable in areal extent to the richly mineralized Duluth Complex and is similarly ...The Midcontinent rift system is a 1.1-b.y.-old structure extending from Kansas, through the Lake Superior region, and into southern Michigan. The rift is filled with thick sequences of basaltic ...The project objective is to assess the Duluth Complex and related mafic-ultramafic intrusions in the 1.1 Ga Midcontinent Rift System in the Lake Superior region. Our current activities focus on a Keweenawan igneous intrusion to determine how much platinum-group elements are present, how much could be found, and how it formed.We report the ages of detrital zircons (207Pb/206Pb LA-ICPMS; ) from 12 clastic units that are representative of the Mesoproterozoic Midcontinent Rift System (MRS) of North America.Sulfide accumulations range from disseminated at both Eagle and East Eagle to semimassive and massive at Eagle. U-Pb baddeleyite dating gives a crystallization age of 1107.2 ± 5.7 Ma for the Eagle intrusion, coeval with eruption of picritic basalts at the base of the volcanic succession in the Midcontinent Rift System (MRS).[A map of North America shows the Midcontinent Rift System as a red line curving through the Great Lakes and down through the midwestern United States.] 1.1 billion years ago, the North American continent began to split in half. [Black Hat stands at a lectern with a "Vote 2020" sign on it. He gestures to an image of the globe with a giant ...Volcanism in the Midcontinent Rift system is supposed to have lasted between 1109 Ma and 1083 Ma based on U/Pb zircon ages. The first crystallization of celadonite is recorded in the lower part of ...We report the ages of detrital zircons (207 Pb/ 206 Pb LA-ICPMS; n p 1188) from 12 clastic units that are representative of the Mesoproterozoic Midcontinent Rift System (MRS) of North America.Magmatism of the MRS spanned 1115-1085 Ma. The Puckwunge, Nopeming, and Bessemer basal sandstones and the Oronto and Bayfield Group sandstones received a predominance of Keweenaw Rift-Grenville (1.3-1.0 ...We report the ages of detrital zircons (207Pb/206Pb LA-ICPMS; ) from 12 clastic units that are representative of the Mesoproterozoic Midcontinent Rift System (MRS) of North America. Magmatism of ...Precise resolution of the timing of igneous activity is crucial to understanding the dynamic processes associated with continental rifting. Mafic intrusive rocks constitute a major portion of the e...The Midcontinent Rift System (MRS) of North America represents a major thermal-tectonic rifting event ca. 1.1 Ga marked by a huge volume of igneous rock emplaced in a relatively short time span of ~30 million years, followed by deposition of a thick package of clastic sediments with subsequent faulting (Wold and Hinze, 1982).Uncertainty exists in the configuration and extent of the Midcontinent Rift System (MRS) because of deficiencies in geophysical data and limited information from …The U.S. Department of Energy's Office of Scientific and Technical Information
The Midcontinent rift is an example of lithospheric extension and flood basalt volcanism induced when a new mantle plume arrived near the base of the lithosphere. Very large volumes of basaltic magma were generated and partly erupted before substantial lithospheric extension began. Volcanism continued, along with extension and deep rift subsidence, for the ensuing 15 m.y.A 70‐km‐long seismic reflection profile in western Michigan provides new insight into the nature, distribution, and structure of the Keweenawan Supergroup volcanic and overlying sedimentary rocks and the controversial Keweenaw fault along the southern boundary of the Midcontinent Rift System in the Lake Superior basin. Interpretation of the 5‐s reflection data constrained by surface ...The Midcontinent Rift system and surrounding Precambrian rocks are known to host highly significant mineral resources. Our project objectives are to increase understanding of this system through the integration of new and legacy geophysical data with geochemical and borehole data, map the lithology and structure of PreCambrian rocks, and develop an integrated 3D geologic model of the region.The Middle Proterozoic Midcontinent Rift System (MRS) of North America is a failed rift that formed in response to region-wide stresses about 1,100 Ma. In Iowa, the MRS is buried beneath 2,200?3,500 ft of Paleozoic and Mesozoic sedimentary rocks and Quaternary glaciogenic deposits. An extremely large volume of sediments was deposited within basins associated with the rift at several stages ...
The Midcontinent Rift System (MRS) is a Late Mesoproterozoic (∼1.1 Ga) sequence of volcanic and sedimentary rocks exposed in the Lake Superior Region of North America. The MRS continues to be the focus of much research due to its economic mineral deposits as well as its archive of Precambrian life and tectonic processes. In order to constrain ...The Keweenaw Peninsula lies on the southern flank of the Mid-Continent Rift system (MCR) of North America. The MCR extends for about 2,000 kilometres from Kansas northeast through Lake Superior, then southeast through the lower peninsula of Michigan where it ends abruptly near Detroit, Michigan. The MCR began forming around 1,100 million years ...…
Reader Q&A - also see RECOMMENDED ARTICLES & FAQs. The Keweenaw Fault (KF) has been interpreted as a -boundin. Possible cause: We present a detailed velocity model across the 1.1 billion year old Midcontinent .
The Midcontinent Rift System (MRS) is a 1.1 Ga sequence of voluminous basaltic eruptions and multiple intrusions followed by widespread sedimentation that extends across the Midcontinent and northern Great Lakes region of North America. Previous workers have commonly used seismic-reflection data (Great Lakes International Multidisciplinary Program on Crustal Evolution [GLIMPCE] line A) to demonstrSandstones along the northern portion of the Precambrian Mid-continent Rift System (MRS) have been petrographically and chemically analyzed for major elements and a variety of trace elements, including the REE. After the initial extrusion of the abundant basalts along the MRS, dominantly volcaniclastic sandstones of the Oronto Group were deposited.
The Mesoproterozoic Midcontinent Rift System (MRS) of North America hosts a diverse suite of magmatic and hydrothermal mineral deposits in the Lake Superior region where rift rocks are exposed at or near the surface. Historically, hydrothermal deposits, such as Michigan’s native copper deposits and the White Pine sediment-hosted …The Midcontinent Rift System (MRS) or Keweenawan Rift is a 2,000 km (1,200 mi) long geological rift in the center of the North American continent and south-central part of the North American plate. It formed when the continent's core, the North American craton , began to split apart during the Mesoproterozoic era of the Precambrian , about 1.1 ...
Grenville orogenic belt. In Precambrian: Orogenic belts. …was the The continental lithosphere which hosts the Midcontinent Rift (MCR) system comprises a crustal assemblage ranging in age from 3.6 to 1.5 Ga. The most voluminous igneous activity along the MCR occurred within Late Archean (2.7 Ga) crust, presumably due to magmatism associated with a rising mantle plume. Two major arms of the rift extend to the ... The Mesoproterozoic Midcontinent Rift System (MRS) of NorCompressional-wave seismic velocity (velocity) and bulk density (den The Mid-Continent Rift System (MCRS) is a 3000-km long failed rift system that formed within the Precambrian continent of Laurentia, nearly splitting North America apart about 1.1 billion years ago. The well is located on the flank of a linear rocks of the Midcontinent Rift System (MRS). The MRS is a failed rift, a great rip through the earth's crust, that stretches for a thousand miles from eastern Lake Superior, across the center of Iowa, and south into Kansas (Fig. 1). The rift formed about 1.1 billion years ago, and had it continued to spread, it would have formed a new ocean.Abstract: The Keweenaw fault system along Lake Superior's south shore in Michigan, USA is one of the most significant fault systems associated with North America's Midcontinent Rift System. Reverse slip has thrust Portage Lake Volcanics (ca. 1.1 Ga) southeastward over Jacobsville Sandstone (ca. 1.0 Ga). The U.S. Department of Energy's Office of Scientific and TecAug 10, 1993 · Mafic intrusive rocks constitute a major portion The Midcontinent rift System was imposed upon and ref The ocean floor is a landscape shaped by volcanoes, rift valleys and submerged mountain ranges, but most of the floor is covered in thick, featureless sediment layers. These areas are called the abyssal plains.Compressional-wave seismic velocity (velocity) and bulk density (density) data were compiled from published sources for rock suites and earth materials that are significant for geophysical modeling of the Mesoproterozoic Midcontinent Rift System in the Lake Superior region. The data include laboratory measurements of outcrop and drill core samples, seismic refraction studies, and a sonic log ... @article{osti_6434014, title = {Mid-continent rift system: a front Failed rifting of the North American craton in the Mesoproterozoic left the Midcontinent Rift system (Stein et al., 2016, Van Schmus and Hinze, 1985), and disintegration of the Rodinia supercontinent in the Neoprotozoic left the Reelfoot rift and other rift systems near the eastern margin of the North American continent (Johnston and Kanter ... 21 Ara 2022 ... The Midcontinent Rift System (MRS) o[The Midcontinent Rift System (MRS) of central North AmericThe prerift crust, however, was thinned 25-30 km beneath The Midcontinent Rift System (MRS; Wold and Hinze, 1982) is recognized by a significant elongate magnetic and gravity anomaly extending northeastward from south-central Kansas into the Lake Superior region and hence southeastward into the Michigan basin (Figure 45). Van Schmus and Hinze (1985) and Dickas (1984, 1986) provide …