https://bereket-haileab.geology.sites.carleton.edu/files/original/03e2bbbed69630075576b46140fc10ca.jpg 08cbca5eac0f39df352b6bc28c7105a9 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 Igneous Rocks Subject The topic of the resource This collection covers both volcanic and intrusive rocks, including rhyolites, granites, diorites, andesites, basalts, gabbros, diabases, pumices, obsidians, syenites, phonolites, peridotites, carbonatites, dacites, trachyte, dunites, xenoliths, ignimbrites, and pegmatites. 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, chemical analyses (major elements, trace elements and REE analyses for selected samples). 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 BH250-72 Subject The topic of the resource Rhyolite Description An account of the resource Major Mineral: quartz <br />Minor Minerals: glassy groundmass, plagioclase, altered biotite<br /><br /><br />BH250-72 is a rhyolite sample collected from Shovel Point, located along the North Shore of Lake Superior in Minnesota. This outcrop is part of the Midcontinent Rift System and represents one of the oldest felsic volcanic rocks in the region, dating back to approximately 1.1 billion years ago. Chemically, BH250-72 is a felsic rock with high silica content (SiO₂ &gt;70%), setting it apart from the dominant basalt flows of the North Shore. It is enriched in alkali elements(Na₂O + K₂O), classifying it as a rhyolite, though in some flows, it verges on high-silica dacite. Trace element data show enrichment in incompatible elements such as Rb, Th, U, and light rare earth elements (LREEs). Mineralogically, BH250-72 is composed primarily of quartz, K-feldspar (orthoclase or microcline), sodic plagioclase, and devitrified volcanic glass. Minor and accessory minerals include biotite, magnetite/ilmenite, zircon, and apatite. The rock exhibits classic rhyolitic textures such as flow banding and spherulites, and contains phenocrysts of quartz and feldspar within a fine-grained or formerly glassy groundmass. The presence of rhyolite in this predominantly mafic volcanic sequence reflects significant magmatic differentiation of the parent mafic magmas, likely related to the processes that also formed the Duluth Gabbro Complex.<br /><br /><iframe width="1800" height="100" src="https://docs.google.com/spreadsheets/d/e/2PACX-1vS4nyqCmZQGn3t6vX4g4nhDPwHMBaKrigt1LaY2pykWbBGXB1wNb6FYArx625I-JTtD7lyg4uz1OS1r/pubhtml?gid=1549324518&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: Shovel Point, Minnesota, USA GPS Coordinates: 47°20'22.53"N, 91°11'6.11"W Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample 72. 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=7e843f1e394f4527b38b0bd1ef830667" 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=7e843f1e394f4527b38b0bd1ef830667">here</a><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1jeLyhEPBJsjPUB_itx0QP6m7PX-bl4ju/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/13T9T9rk-4oAAsFifoa0ERf97NQYWfp8b/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1pJhUh7N1MM1gMz_02gVad4wmCXI0IqYR/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/191Vkr70M5ey0l_pDr3DDNH9N-t3nTxNC/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/10j8wQAj_vJutYLdzkj_gu-As9x2auPrM/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1n3uDZR4Vx7NVl0i4TGDQeJKAzLnHauNK/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1EXJyJLvyDOFA6m7nQzpGxuteXX8qVryw/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1gVkJrpcoyhoP1oABz8nFeGju1mh_7Izk/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1WW-vkdS-TDSySv-jz3FR_vbfbz7iW-I-/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/15-3de4hx7UsRPUP6EBZq8YeepsGjFMcn/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1M9u6UH-mp8DUm4TxlrXMKhkHBb99xHft/preview" allow="autoplay"></iframe><br />TAS diagram of sample BH250-72. Creator An entity primarily responsible for making the resource Bereket Haileab Devitrified Glass Duluth Gabbro Complex felsic Felsic Volcanic Rock High-silica rhyolite igneous Lake Superior geology Magmatic Differentiation Midcontinent Rift Minnesota geology North Shore Volcanic Group Phenocrysts Quartz rhyolite Shovel Point volcanic