https://bereket-haileab.geology.sites.carleton.edu/files/original/ab6bc0dedaae044ca3630c7979100c2d.jpg da426dccfac2d5c606a3b40e90b4c7e0 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 Metamorphic Rocks Subject The topic of the resource This collection includes slates, phyllites, schists, gneisses, eclogites, marbles, quartzites, skarns, granulites, and mylonites. 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 BH250-52 Subject The topic of the resource Garnet-Biotite-Orthopyroxene-Schist Description An account of the resource <p data-start="56" data-end="181">Major Minerals: Quartz, plagioclase, albite, biotite, hypersthene<br data-start="125" data-end="128" />Minor Minerals: Garnet, clinopyroxene</p> <p data-start="183" data-end="284">Optical Features: Biotite displays bird's-eye maple interference pattern and strong pleochroism</p> <p data-start="286" data-end="361">Texture: Strong foliation; pre-kinematic (pre-tectonic) garnet growth<br /><br /></p> <p>BH250-52 is a garnet-bearing schist, part of the high-grade metamorphic suite exposed in the Minnesota River Valley, including the area around Granite Falls. These rocks occur within a Precambrian migmatitic terrane composed of granitic gneisses, amphibolitic gneisses, and paragneisses. Many of these metamorphic rocks contain garnet, biotite, and hypersthene, indicative of deep crustal metamorphism.</p> <p>The schist protolith is pelitic in composition and likely formed during early Archean crustal development, with many surrounding gneissic bodies dated to 2610 Ma old (Bickford et al. 2019), 2671 Ma (Emma Watson, class of 2023). Metamorphism occurred under upper amphibolite to granulite facies conditions, with estimated peak temperatures of 650–750 °C and pressures of 4.5–7.5 kbar.</p> <p>Typical garnet schists here feature garnet porphyroblasts set in a matrix of biotite and other micas, quartz, and feldspar, with possible inclusions of cordierite or sillimanite. Foliation bands and migmatitic textures are well developed, visible both in hand sample and in thin section.</p> <br /><br /><iframe width="1800" height="100" src="https://docs.google.com/spreadsheets/d/e/2PACX-1vS4nyqCmZQGn3t6vX4g4nhDPwHMBaKrigt1LaY2pykWbBGXB1wNb6FYArx625I-JTtD7lyg4uz1OS1r/pubhtml?gid=1635347740&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: Granite Falls, Minnesota, USA GPS Coordinates: 44 48 06.07 N, 95 32 26.18 W Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample 52. 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=e07e55b5c17240af8f9ba25cef1fae08" 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=e07e55b5c17240af8f9ba25cef1fae08">here</a><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1L69d5nYELqDJEoUJeHxVp27Jnt3K_6X6/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1Aj3WYyssGnPYP3XlLKi2okhcDZrBKGcU/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1lyERziyGLWx_peltxatcBJP4fARfDdo4/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1VwIScCjzf1iJqgf_7z-Bd57Uxnz6ST_H/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1C-Ti7CNZz8pBK410U9ZhhEjfhSxuJCMY/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/17Klg52W8l0YOEh8LzNHMdakj0kXSgpdt/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1B8EIIRCnT8HMBP9W3a_Yd7CZdPv0rnMU/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1K020pEYNEGeUKvvWNVuwjUCiJdAqP4Ck/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1KCG9yzEto287JQOyTL3QQPLk1Db_idcw/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1-mriHK9qDKoVgJf3isl3dPFbeUEHZ86B/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1CC0rbX6DWatM6xI8sqqTyJE1a6vwibq2/preview" allow="autoplay"></iframe><br />TAS diagram of sample BH250-52. Creator An entity primarily responsible for making the resource Bereket Haileab Biotite pleochroism Bird's-Eye Extinction Clinopyroxene Foliated Metamorphic Rock Garnet Granite Falls Minnesota Hypersthene metamorphic Metamorphic Texture Minnesota Rive Valley Orthopyroxene Pre-Kinematic Garnet schist Strong Foliation