https://bereket-haileab.geology.sites.carleton.edu/files/original/ecd997bde750e581211fa16ba77bd666.jpg fcee5a864d333c165851c1469b31b911 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 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 BH250-68 Subject The topic of the resource Staurolite Garnet Schist Description An account of the resource Major Minerals: biotite, quartz, muscovite Minor Minerals: graphite, oxides BH250-68 is a biotite-muscovite schist collected from the Black Hills of South Dakota, similar in origin to BH250-67. However, this sample contains a greater abundance of micas and exhibits exceptionally well-developed foliation, characteristic of regional metamorphism. The well-aligned biotite and muscovite flakes define a prominent schistosity. Compared to BH250-67, the quartz grains in BH250-68 are larger and show striking undulose extinction under cross-polarized light, reflecting a history of dynamic recrystallization. Many of the biotite crystals contain zircon inclusions surrounded by pleochroic halos—classic features observable in thin section. Several quartz grains are ideal for producing uniaxial interference and flash figures, making this a particularly valuable sample for both teaching and research in optical mineralogy and metamorphic petrology. 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: Black Hills, South Dakota, USA Date A point or period of time associated with an event in the lifecycle of the resource November 17, 2009 Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample 68. Housed at Carleton College in Minnesota. Type The nature or genre of the resource Thin section Relation A related resource <iframe width="100%" height="600" style="border: 0;" src="https://carleton.maps.arcgis.com/apps/instant/media/index.html?appid=b997ed28774e44a0b2a87e4f01101296" 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=b997ed28774e44a0b2a87e4f01101296">here</a><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1n0O_-4Al9EkzZbZS5UAgMwnVl2KTYYoA/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1OA9E3fMaxYHyaIxpCV5edq2eV_hEsLnD/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1WeXYPDVvl04FyAaYE0yx8bkN3FMT6qs-/preview" allow="autoplay"></iframe> Creator An entity primarily responsible for making the resource Bereket Haileab Biotite-muscovite schist Black Hills geology metamorphic pleochroic halo in biotite Quartz optical properties Regional metamorphism schist Schistosity Undulose Extinction Zircon inclusions