Midcontinent rift system
Prominent examples of rift failure include the North Sea, the West African Rift System and the Midcontinent Rift underlying the Great Lakes of North America. Rifting stopped in these cases because ...Over the course of about 10 million years, the Midcontinent Rift System opened a massive fissure on its way to becoming a new ocean basin. But for reasons geologists don't entirely understand ...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.
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Comparisons between the Midcontinent rift system and the Voisey Bay and Noril'sk settings point to several similarities that suggest that the Midcontinent rift is a likely setting for Ni-Cu mineralization. The continental rifting and associated voluminous igneous activity in all three regions formed in response to the rise of a hot plume of ...The Midcontinent Rift System of North America is a ~1.1 Ga large igneous province comprising mainly flood basalts and intrusive rocks. We present new data for the Pillar Lake Volcanics and ...The faults responsible for the monocline are newly recognized components of a well-known regional fault system that partly closed and inverted the Midcontinent rift system. Resetting of biotite ages on the upper plate of the faults indicates that faulting and uplift occurred at about 1060 +/−20 Ma and followed very shortly after extension ...This paper presents a suite of two-dimensional mathematical models of basin-scale groundwater flow and heat transfer for the middle Proterozoic Midcontinent Rift System. The models were used to assess the hydrodynamic driving mechanisms responsible for main-stage stratiform copper mineralization of the basal Nonesuch Formation during the post ...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.Microbially induced sedimentary structures (MISS) are primarily known from transitional marine (tidal) and shallow-marine settings. New results from the ca. 1.1 Ga Midcontinent Rift System of ...The Mesoproterozoic (~1.1 Ga) North American Midcontinent Rift System (MRS) has been of widespread interest to researchers studying its economic mineral deposits, continental rifting processes, and the evolution of early terrestrial life and environments. For their age, the MRS rocks are well preserved and have not been deeply buried, yet a thorough understanding of the regional thermal ...Colleen Taylor, Darrell Etherington, and Matthew Lynley discuss Apple's WWDC, Oculus VR Consumer Rift, and the resignation of Twitter's CEO Dick Costolo Colleen Taylor, Darrell Etherington, and Matthew Lynley discuss Apple's WWDC, Oculus VR...The Proterozoic Midcontinent Rift System (MCRS) is considered one of the most important tectonic features in North America and was formed during a continental breakup event at 1.1 Ga (billion years). The MCRS is totally covered by Phanerozoic sedimentary rocks except in the Lake Superior region. Consequently, the geologicalAbstract. Continental rifting at 1.1 Ga produced approximately 1.3 × 10 6 km 3 of igneous rocks over a rift length of 2200 km (Midcontinent Rift System, MRS). These constitute one of the largest as well as oldest flood basalt provinces. Both geophysical (Hutchinson et al. 1990) and geochemical evidence (Nicholson and Shirey 1990) suggest that ...The Mesoproterozoic Midcontinent Rift System (MRS), formed about 1.1 Ga, is a large arcuate structure located in central North America. It is the most striking …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.Dec 8, 2022 · 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 Proterozoic Midcontinent Rift System of North America is remarkably similar to Phanerozoic rifted continental margins and flood basalt provinces. Like the younger analogues, the volcanism within this older rift can be explained by decompression melting and rapid extrusion of igneous material during lithospheric extension above a broad ...Aug 4, 2016 · 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... The Keweenawan Midcontinent rift system was imposed upon the terrane suture in our study area at ca. 1100 Ma. This event nearly separated the ancient continent and imparted enormous volumes of mafic magma to various depths in the crust (Hinze et al., 1997; Nicholson et al., 1997; Vervoort et al., 2007; Stein et al., 2015), engendering numerous high-grade base and precious metal deposits ...Midcontinent Rift. The Midcontinent Rift (MCR), a 3000-km-long band of more than 2 million km 3 of buried igneous and sedimentary rocks that outcrop near Lake Superior, has been extensively studied, as reviewed by Ojakangas et al. (2001) and S. Stein et al. (2018). To the south, it is buried by younger sediments, but easily traced because the ...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 exposed 1100 Ma (Keweenawan) Midcontinent Rift system in northeastern Minnesota; however, prior to this study, geochronological data were insufficient to allow rigorous interpretation of intrusive ...Stein proposes a three-armed rift system, formed of the Midcontinent Rift and the two arms that split Laurentia and Amazonia. “In a lot of locations, when the continents break apart you seem to ...
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 …Abstract. A variety of data have been compiled in eastern Nebraska and adjacent areas that are pertinent to understanding the complex Precambrian history of the Midcontinent USA. Petrographie analysis has been done for samples from wells penetrating the Precambrian surface. Chemical analysis is available for rock types such as rift basalt ...The Texaco 1 Poersch well in Kansas (11,300 ft TD) was the first significant exploration test of the Mid-Continent Rift System (MRS). An upper succession of rift-related rocks (2846-7429 ft) contains approximately 90% mafic igneous rocks with minor pegmatites and 10% oxidized siltstone and arkose.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].Thorleifson, L. H., ed., 2008, Potential capacity for geologic carbon sequestration in the Midcontinent Rift System in Minnesota, Minnesota Geological Survey Open File Report OFR-08-01, 138 p. Series/Report Number
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.MIDCONTINENT RIFT SYSTEM BIBLIOGRAPHY By Steven A. Hauck December 1995 Technical Report NRRI/TR-95/33 Funded by the Natural Resources Research Institute In ...…
Reader Q&A - also see RECOMMENDED ARTICLES & FAQs. Two prominent Precambrian features of central North Ameri. Possible cause: The 1.1 Ga Midcontinent Rift of North America is a failed intracontinental .
Magmatic Ni-Cu-PGE mineralization in the ~ 1.1 Ga Midcontinent Rift System (Fig. 1) in North America can be broadly divided into three types (see a recent review by Ripley, 2014).Disseminated sulfide mineralization occurs within multiple, sheet-like intrusions that comprise a large portion of the Duluth Complex.Halls, 1997; Riller et al., 1999). Recently, the Midcontinent rift system has been interpreted as the failed arm of a triple junction as seafloor spread-ing between Laurentia and Amazonia was established (Stein et al., 2015, 2016). The volume of magmatism appears to require mantle hotspot input beyond passive rifting (Stein et al., 2015, 2016).Two prominent Precambrian features of central North America (Fig. 1) record opposite ends of the Wilson cycle.One, the Midcontinent Rift (MCR), is a 3000-km long horseshoe-shaped band of more than 2 million km 3 of buried igneous and sedimentary rocks that outcrop near Lake Superior (Ojakangas et al., 2001; S. Stein et al., 2018).To the south, it is buried by younger sediments, but easily ...
The structure and geometry of the 1.1-b.y.-old Midcontinent Rift system under Lake Superior is interpreted from 20 seismic reflection profiles recorded during the early and mid-1980s. The seismic ...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 ...
Geophysical investigations have had a prominent role in New Insights into North America’s Midcontinent Rift. Solving the Midwest’s Biggest Geologic Mystery. Mysterious Midcontinent Rift is a Geological Hybrid. Sharing Lake Superior’s Secrets. North America’s broken heart (Nature) A real rift in the midcontinent (Earth magazine) The Midcontinent Rift System (MRS) is an example of a matic-doThe Mesoproterozoic Midcontinent Rift System 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 located near the margin of the MRS. New geochronological and geophysical data together support an MRS affinity for the NEIIC. A dike swarm imaged in ...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 volcanic rocks and clastic sediments. For most of its extent it is buried beneath Paleozoic rocks but can be traced by its strong gravity and magnetic anomalies. The rocks of the rift system are exposed ... The U.S. Department of Energy's Office of Scientif Keweenawan Supergroup. The Keweenawan Supergroup is a supergroup of volcanic and sedimentary rocks that fill the Midcontinent Rift System in the U.S. states of Michigan, Wisconsin, and Minnesota. [1] [2] It is about 30 kilometers (19 mi) thick and it formed about 1.1 billion years ago. [3] Opening of the Midcontinent Rift System and, presumably, the East CoThe continental lithosphere which hosts the MidcoThe approximately 1.1 Ga Nonesuch Formation, nor 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 demonstr The North American Midcontinent Rift System (MRS) is host t 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.Halls, 1997; Riller et al., 1999). Recently, the Midcontinent rift system has been interpreted as the failed arm of a triple junction as seafloor spread-ing between Laurentia and Amazonia was established (Stein et al., 2015, 2016). The volume of magmatism appears to require mantle hotspot input beyond passive rifting (Stein et al., 2015, 2016). The 1.1 Ga Midcontinent rift system of Nort[Pseudosections of magnetotelluric (MT) responses for thThe Midcontinent Rift System (MRS) is a Middle Proterozoic failed rif Magmatism that accompanied the 1.1 Ga Midcontinent rift system (MRS) is attributed to the upwelling and decompression melting of a mantle plume beneath North America. Five distinctive flood-basalt compositions are recognized in the rift-related basalt succession along the south shore of western Lake Superior, based on stratigraphically correlated major element, trace element, and Nd isotopic analy