https://bereket-haileab.geology.sites.carleton.edu/files/original/310563a5a5fa1a43ac0a154abac4e167.jpg 7f218a92d2ad58ebfad12241a1dd783a 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 BH250-192 Subject The topic of the resource Gabbro Description An account of the resource Major Minerals: olivine, clinopyroxene, plagioclase Minor Minerals: serpentine The Duluth Gabbro, also known as the Duluth Complex, is a large, layered mafic intrusive body located in northeastern Minnesota, USA. It is part of the Midcontinent Rift System and is one of the most studied examples of Proterozoic layered intrusions in North America. Several BH250 samples belong to this gabbro, including BH250-11, 50, 189, 192, and 193. This gabbro is globally recognized as a classic example of a layered mafic intrusion, and the term Duluth Gabbro / Duluth Complex is widely used in both academic and geological literature. It is approximately 1.1 billion years old (Mesoproterozoic). Mineralogy: Major minerals (vary by zone): Plagioclase feldspar: Predominantly labradorite to bytownite (An50–An80) Clinopyroxene: Mainly augite Orthopyroxene: Common in more evolved layers, typically bronzite or hypersthene Olivine: Present in the ultramafic base, ranging from forsteritic to fayalitic Oxide minerals: Magnetite and ilmenite, especially abundant in oxide-rich zones Accessory/Minor minerals: Amphibole (e.g., hornblende, actinolite), especially in altered zones Biotite and chlorite, commonly in more evolved or hydrothermally altered portions Serpentine, typically associated with olivine alteration Textures and Structures: The Duluth Gabbro displays prominent layered cumulate textures, indicating crystal settling and magmatic differentiation within a large magma chamber. Rhythmic layering, adcumulates, and mesocumulates throughout the complex point to open-system magmatic processes with periodic magma recharge. These features are visible at numerous outcrops across the complex. Geochemistry: Compositionally mafic to ultramafic. Enriched in Fe, Mg, Ca, and Ti; depleted in Si and alkalis. Basal ultramafic rocks contain high concentrations of Cr and Ni, indicating early-stage cumulate formation. Rare Earth Element (REE) patterns show moderate Light REE (LREE) enrichment and negative europium (Eu) anomalies in some evolved units. 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: Silver Bay, Minnesota, USA Nearby Geographic Features: Lake Superior Date A point or period of time associated with an event in the lifecycle of the resource Fall 2014 Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample 192. Housed at Carleton College in Minnesota. Contributor An entity responsible for making contributions to the resource Bereket Haileab Type The nature or genre of the resource Hand sample and 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=8133fcef371d4c9883d4859855dfe591" 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=8133fcef371d4c9883d4859855dfe591">here</a><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1ynZStFsW2jmWJLlykoDCDxV6j02MI54o/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1wk3Uz2eBS3lead_bWywdj0oXPj6o7Taa/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1HCX0iVJ79cx7roTwnPzoaV7CY3FYyHtW/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1poOIGR-XvjuvPIFf63stmPUjijtSzHjQ/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1i6chaGWq08QmSkM181E_MgFtW346gq4O/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/16SOlnYQ4OBb-lGVZcsl0ywKb1u9CYK2g/preview" allow="autoplay"></iframe> Creator An entity primarily responsible for making the resource Bereket Haileab Clinopyroxene Crystal Differentiation Cumulate texture Duluth Complex Duluth Gabbro gabbro igneous Ilmenite Layered mafic intrusion mafic Mafic-Ultramafic Rock Magnetite olivine Orthopyroxene Plagioclase plutonic Proterozoic Geology