https://bereket-haileab.geology.sites.carleton.edu/files/original/4a52ac0a72fcc630d3707329907a9db5.jpg 7f23764087ce2a9afcf19ab116fec08d 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 BH250-103 Subject The topic of the resource Forsterite Bearing Marble Description An account of the resource Major Minerals: Long prismatic altered forsterite, periclase, calcite, dolomite Sample BH250-103 is collected from the forsterite zone within the contact metamorphic aureole of the Alta Stock in Utah. This sample is mineralogically significant due to the presence of very long prismatic crystals of forsterite, which are now completely altered to serpentine. The pseudomorphic replacement preserves the original crystal habit of forsterite, making the alteration texture visually striking under the microscope. Additionally, periclase (MgO) is present in this sample as unaltered grains, along with some partially altered grains, especially when compared to the better-preserved periclase in the periclase zone of sample BH250-102. The alteration of periclase typically progresses to brucite (Mg(OH)₂) under retrograde metamorphic conditions. However, further petrographic or geochemical analysis would be required to confirm the specific alteration product present in this sample. The carbonate minerals, calcite and dolomite, occur as recrystallized grains displaying bimodal grain sizes: Very coarse-grained carbonates, which likely formed during the peak of contact metamorphism, Medium-grained carbonates, which may reflect recrystallization during retrograde metamorphism or subsequent hydrothermal fluid interactions. The coexistence of forsterite (altered to serpentine), periclase, and recrystallized carbonates reflects high-temperature, magnesium-rich skarn assemblages characteristic of contact metamorphism in carbonate protoliths. The textural relationships and mineral assemblage provide insights into the prograde and retrograde metamorphic history of the Alta Stock aureole. Summary of Alta Stock Metamorphic Progression (simplified): Talc Zone: Talc + dolomite Tremolite Zone: Tremolite + calcite/dolomite Forsterite Zone: Forsterite + calcite + diopside Periclase Zone: Periclase + calcite/dolomite 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: Alta, Utah, USA GPS Coordinates: 40°34'54.57"N, 111°36'39.25"W Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample BH250-103. 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=c0e3d6207fb44950955cac1503b0beaa" 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=c0e3d6207fb44950955cac1503b0beaa">here</a><br /><br /><iframe width="100%" height="480" iframe="" src="https://drive.google.com/file/d/12J8X3_fT4ionb6bWDhn39OnqbhTWVKTx/preview" allow="autoplay"></iframe> <iframe width="100%" height="480" src="https://drive.google.com/file/d/1jnhQi3CiVDtU2MczmFE0yzARMIfE-7kQ/preview" allow="autoplay"></iframe> <iframe width="100%" height="100%" src="https://drive.google.com/file/d/1GfX51B9QFpd3bh1LdKO9WAAQrNvIOk_Y/preview" allow="autoplay"></iframe> <iframe width="100%" height="480" src="https://drive.google.com/file/d/1fEamXcz3iCkXMdyaPiziwJotljV06DHR/preview" allow="autoplay"></iframe> <iframe width="100%" height="480" src="https://drive.google.com/file/d/1X_TP1vtnPZRnmY-3ML-aRkCmRHgGGHU8/preview" allow="autoplay"></iframe> <iframe width="100%" height="480" src="https://drive.google.com/file/d/1q0e0ERP7B6phVjhIJ79sE3wWIg5NKLqj/preview" allow="autoplay"></iframe> <iframe width="100%" height="480" src="https://drive.google.com/file/d/1QfpIE3ziuODqNjlLQwiwUo1JiDSfw8tE/preview" allow="autoplay"></iframe> <iframe width="100%" height="480" src="https://drive.google.com/file/d/1zJXlakJXjr62BcIuAQ_qAFwN9C22UPoC/preview" allow="autoplay"></iframe> <iframe width="100%" height="480" src="https://drive.google.com/file/d/101TrxNjsgeB-1YtazEODp8CWPnnkwUl2/preview" allow="autoplay"></iframe> Creator An entity primarily responsible for making the resource Bereket Haileab John Bowman Alta stock calc-silicate carbonate Carbonate Protolith contact metamorphism forsterite Forsterite Zone marble metamorphic Metamorphic Aureole Mg olivine Periclase Prograde Metamorphism Recrystallized Carbonates Retrograde Metamorphism Serpentinization skarn Skarn Assemblage Utah