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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 ...The Midcontinent Rift is an ancient rift system that could have split the country into two parts a billion years ago. In this live interview at the Sheldon Concert Hall in St. Louis, geologist Michael Wysession discusses how seismologists are using data from earthquakes and gravity measurements to characterize this underground geological scar.The U.S. Department of Energy's Office of Scientific and Technical InformationThe 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.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].The Mesoproterozoic Midcontinent Rift System (MRS) of North America hosts a diverse suite of magmatic and hydrothermal mineral deposits in the Lake …The Midcontinent Rift System is a 1.1 Ga failed continental rift in the Midwestern United States and Canada (Fig. 1).This area contains ~ 1 – 2 × 10 6 km 3 of …nition of a previously unrecognized rift complex, which is herein named the East Continent Rift Basin (ECRB). The basin is a regionally extensive feature, extending from northwestern Ohio to central Kentucky, and west­ ward across Indiana. It is interpreted to be an extension of the middle Proterozoic (Keweenawan) Midcontinent Rift System (MRS).The Midcontinent Rift system and surrounding Precambrian rocks are known to host highly significant mineral resources. Our project objectives are to increase …True amplitude processing of The Great Lakes International Multidisciplinary Program on Crustal Evolution seismic reflection data from the Midcontinent Rift System of North America shows large differ...Previous Cu isotope work has documented a clear disparity between δ65Cu values of sheet-style (–0.5 to 0.5‰) and conduit-style (0.5–2.0‰) intrusions associated with the Midcontinent Rift ...Abstract. Recent drilling of the midcontinent rift system in northeastern Kansas reveals a transposed Keweenawan stratigraphy of mafic volcanic rocks overlying thick elastic sedimentary rocks. A reprocessed version of COCORP Kansas Line 1 indicates that the drillhole penetrated a series of west-dipping reflectors associated with a reverse fault ...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 ∼ ...Aug 3, 2020 · The Midcontinent Rift System (MRS) of North America is one of the world’s largest continental rifts and has an age of 1.1 Ga (giga-annum). The MRS 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. rift arm to the east. The Nebraska segment of the Mid-Continent Rift System parallels fabrics within the earlier Central Plains Orogen [35]. In the southern part of the study area, within eastern Kansas, the Mid-Continent Rift System is cut by a series of NW-SE trending dextral strike-slip faults, on which there have been historical earthquakes ...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 ...We often hear that it’s important to speak your truth — to express your honest feelings, thoughts, and per We often hear that it’s important to speak your truth — to express your honest feelings, thoughts, and perceptions. But how often do ...The Keweenaw fault is perhaps the most significant fault associated with the Midcontinent Rift System of the north-central United States. The fault, parallel to the south edge of the rift, has ...Figure 1--The midcontinent rift system (shaded area) extends from the surface in Minnesota, northern Michigan, and northern Wisconsin into the subsurface in Iowa, Nebraska, and Kansas. We have analyzed cuttings and cores from four wells drilled into the southern portion of the MRS in northeastern Kansas and have compared the composition of ...Geophysical investigations have had a prominent role in studying the 1100 Ma Midcontinent Rift system because of limited surface exposures and deep drilling of the rift rocks. Gravity and magnetic anomaly data delineate the rift system—its central volcanic-filled graben and overlying and adjacent post-rift sedimentary basins—and the major ...We interpret this resistor to be mafic volcanic and intrusive rocks of the Midcontinent rift event, which correlate spatially with a high Bouguer gravity anomaly similarly modeled. the rift here coincides with the lower-crustal reaches of the suture, but the specific influence of the suture on rift emplacement is unclear.... Mid-Continent Rift System (MCRS). The rift failed, leaving a 2000 km long belt of volcanic and sedimentary rocks left from the early rifting stage. We have ...The graphic, inset, shows gravity mapping done of the Midcontinent Rift System by the U.S. Geological Survey: “MRS volcanic rocks (shown as warmer, reddish colors) that occupy the center of the rift are more dense than the MRS sedimentary rocks (shown as cooler bluish colors) that flank both sides of the volcanics.” At left, a diagram …

Midcontinent Rift System is part of WikiProject Geology, an attempt at creating a standardized, informative, comprehensive and easy-to-use geology resource. If you would like to participate, you can choose to edit this article, or visit the project page for more information.J. B. Paces and J. D. Miller, Jr., “Precise U-Pb Ages of Duluth Complex and Related Mafic Intrusions, Northeastern Minnesota: Geochronological Insights to Physical, Petrogenetic, Paleomagnetic, and Tectonomagmatic Processes Associated with the 1.1 Ga Midcontinent Rift System,” J. Geophys. Res. 98, 997–14013 (1993).Growing interest in the Midcontinent Rift System over the past several years, fostered in part by the potential of this Keweenawan rift as a frontier hydrocarbon province, has led to an increased number of deeply penetrating seismic-reflection profiles over the structure. Two studies by the Consortium for Continental Reflection Profiling ...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 late Mesoproterozoic Midcontinent Rift (MCR) is a prominent tectonomagmatic feature that extends >2000 km through the Laurentia craton (Fig. 1; Ojakangas et al., 2001; Woodruff et al., 2020).In the vicinity of Lake Superior, there is a well-exposed >10-km-thick succession of ca. 1110–1083 Ma rift-related volcanic rocks …

The North American Midcontinent Rift System (MRS) is a major magmatic continental rift that stretches approximately 2200 km from Kansas northeast to the Lake Superior region, where it curves ...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 ...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 from…

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs. Mar 7, 2023 · Prominent examples of rift failure . Possible cause: The Midcontinent Rift System (MRS) of central North America is a 1.1-Ga, 2500-km long st.