https://bereket-haileab.geology.sites.carleton.edu/files/original/f700e5d1295c0b9a4ffb1c3e8a24f08f.jpg c438640f0143f73847e758b87bc89aee Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource Sedimentary Rocks Subject The topic of the resource This collection includes sandstones, limestones, breccias, conglomerates, dolostones, shales, oolites, and BIF. Creator An entity primarily responsible for making the resource Bereket Haileab Source A related resource from which the described resource is derived Housed in Anderson Hall, Carleton College. Format The file format, physical medium, or dimensions of the resource Thin sections, thin section scans, hand samples, hand sample images, photomicrographs. Thin section and hand sample Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Title A name given to the resource BH250-167 Subject The topic of the resource Nopeming Sandstone, Northshore Volcanics Description An account of the resource Major Minerals: quartz, clinopyroxene, orthopyroxene <br />Minor Mineral: glass<br /><br /> <p>The contact between the North Shore Volcanic Group (NSVG) and the underlying sedimentary rocks (Nopeming Sandsonte) exposed near Eldes Corner, Minnesota, represents a geologically significant boundary associated with the development of the Midcontinent Rift System during the Mesoproterozoic era. In this area west of Duluth, the contact is a nonconformity, where younger volcanic rocks of the NSVG overlie older metamorphosed sedimentary rocks, primarily of the Paleoproterozoic Thomson Formation.</p> <p>In some zones, thermal metamorphism and baked contacts are observed, where lava flows of the NSVG were emplaced directly over wet sediments or low-grade metasediments, resulting in localized contact metamorphism.</p> <p>This contact is important for understanding:<br />The base of the North Shore Volcanic Group. The interaction between rift-related magmatism and older Proterozoic sediments. The early stages of Midcontinent Rift volcanism.<br /><br /></p> <p>The Nopeming Sandstone is a quartzose sandstone, ranging from subarkosic to arkosic in composition. This is well observed in sample BH250-167. At its contact with overlying basalt flows, chilled margins and baked zones are present, indicating thermal alteration of the sandstone during lava emplacement. In some areas, individual sand grains appear to have been rolled or pushed by the advancing flow and may be cemented by volcanic glass derived from the chilled margins.</p> <p>Overall, this outcrop marks a key stratigraphic and tectonic unconformity in the midcontinent rift.</p> <iframe width="1800" height="100" src="https://docs.google.com/spreadsheets/d/e/2PACX-1vS4nyqCmZQGn3t6vX4g4nhDPwHMBaKrigt1LaY2pykWbBGXB1wNb6FYArx625I-JTtD7lyg4uz1OS1r/pubhtml?gid=1222505996&amp;single=true&amp;widget=true&amp;headers=false"></iframe> Coverage The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant Location: Eldes Corner, Minnesota, USA GPS Coordinates: 46.719913, -92.274972 Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample BH250-167. Housed at Carleton College in Minnesota. Type The nature or genre of the resource Thin section and hand sample Relation A related resource <iframe width="100%" height="600" style="border: 0;" src="https://carleton.maps.arcgis.com/apps/instant/media/index.html?appid=69538e8a6e6d455a9030e7493c7ca8fb" frameborder="0" allowfullscreen="allowfullscreen">iFrames are not supported on this page.</iframe><br />View on ArcGIS Online <a href="https://carleton.maps.arcgis.com/home/item.html?id=69538e8a6e6d455a9030e7493c7ca8fb">here</a><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1WByTCQrV-jzwDiDwEtiwr3vmtTVCQwIN/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1iH4lDoJUKbMkmYlm-NFZpGtKwfJoDSuy/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1-j8yZpkVMP6BheW1IXdKR9jn3aFizAif/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/158hIAFCo-MtBKKm7MrkuZIaaP-GFNuVA/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1dBd61Qc8aj8v_4Y5Btj4wIouE5HVmnsH/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1e5oXmJYDmZj84e6qgQnQol6Pc3Mz17dy/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1EyWLTHKrJUiqak2XaQ-MZMk76Jah6Wc_/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1YXreyHpwBmlyyM5cmcw7qHPJsWl6sNJD/preview" allow="autoplay"></iframe><br />TAS diagram of sample BH250-167. Creator An entity primarily responsible for making the resource Bereket Haileab Baked contacts basalt Basalt flows Chilled margins contact metamorphism Eldes Corner igneous mafic Mesoproterozoic Midcontinent Rift nonconformity Nopeming Sandstone North Shore Volcanic Group sandstone sedimentary siliciclastic volcanic Volcanic glass cement