https://bereket-haileab.geology.sites.carleton.edu/files/original/8b3fc5948d2957a2d60b844ce95be1be.jpg edd495d8957a7a6d7f1acfe905b4ec24 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 BH250-226 Subject The topic of the resource Diabase Description An account of the resource Major Minerals: plagioclase, augite, olivine Diabase This sample is a classic example of diabase (also called dolerite), a medium-grained mafic igneous rock that forms when basaltic magma cools in shallow subsurface environments such as dikes, sills, and small intrusive bodies. Diabase is compositionally similar to basalt and gabbro, but it differs primarily in cooling history and texture. Because it cools at an intermediate rate—slower than basalt erupted at the surface but faster than deeply crystallized gabbro—it typically develops a distinctive medium-grained texture visible in hand sample and thin section. This specimen is composed primarily of plagioclase, augite, and olivine, a mineral assemblage consistent with relatively magnesium- and iron-rich mafic magma. In thin section, plagioclase commonly occurs as elongated laths that may form an interlocking framework, while augite fills spaces between feldspar crystals in a classic ophitic to subophitic texture, where larger pyroxene crystals partially enclose plagioclase laths. Olivine, if preserved, may occur as early-formed crystals and can sometimes show alteration to iddingsite, serpentine, or iron oxides if the rock has undergone weathering. Diabase plays an important role in both regional geology and plate tectonics because it commonly forms during crustal extension, continental rifting, and large igneous events. Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample 226. Housed at Carleton College in Minnesota. Contributor An entity responsible for making contributions to the resource John Goodge 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=88a9957e13084e1c8494d2aaad145247" 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=88a9957e13084e1c8494d2aaad145247">here</a><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1N8k3DRjYdCg3SDaepliUEGn1c7dGmMJT/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1ebjl3T_MSy7ZyPqRvhFtvCXv6g6qkOjG/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1B8ZaBC_T56YZ-8IcLBx-M0_lWIxK6Lx_/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1bCjFus21uLCxEiuC2pMx--dgy_-h5XvL/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1duoLcysEQyhUtKk578iNoKKI01fbiA6n/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1fVqW8iDc_n0yLLT618ImqbqoTkPXrpt5/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/153oZRY_KRAcknOCKm0-NCk52vwAWFkbl/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1YtvKkbxYa3lfElXoV_Mc5nHzxO5_ARKs/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1J4Eniw3kD1AwAOKSjF_5oEuJGrc_Yu3n/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1xUqJ9jqalYLlB1qF9MTAmdfb_l7-zi0c/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1jotB0D3MfswcgJCFhK11cVbiHUJT8YkK/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/1G9oiYLLq4dctNUw1ZioEo0SI2fLzm_PI/preview" allow="autoplay"></iframe><br /><br /><iframe width="100%" height="480" src="https://drive.google.com/file/d/10GqqmZohBKU5zboEqWwzY9QlISVCHpfd/preview" allow="autoplay"></iframe> Creator An entity primarily responsible for making the resource Bereket Haileab Augite diabase dike dolerite igneous mafic Mafic igneous rock olivine ophitic texture plutonic sill