https://bereket-haileab.geology.sites.carleton.edu/files/original/ab7164c326ff266111ffa0049e509219.jpg ad0229fc4bd699d4cdef0e6049ff096f https://bereket-haileab.geology.sites.carleton.edu/files/original/03e7efbff5e2dd17c3e565d880b005d9.jpg 7c9fe3514d295c68e4a0641f0e3730c3 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 Sedimentary Rocks Subject The topic of the resource This collection includes sandstones, limestones, breccias, conglomerates, dolostones, shales, oolites, and BIF. 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. 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 BH250-128e Subject The topic of the resource Shakopee Dolostone (Upper part of the Prairie du Chien Group) Description An account of the resource Major Minerals: Quartz, dolomite BH250-128e is a sample of the Shakopee Dolostone collected from the Cannon River Wilderness Park area in Rice County, Minnesota. The Shakopee Dolostone forms the upper part of the Lower Ordovician Prairie du Chien Group and consists primarily of dolostone interbedded with varying amounts of sandstone, siltstone, shale, and chert. The Shakopee Dolostone overlies the Oneota Dolostone and records deposition in a warm, shallow-marine carbonate environment. Sandy and silty intervals indicate periodic influxes of siliciclastic sediment into the carbonate system. Later dolomitization altered much of the original limestone and may have obscured some primary sedimentary textures. Some exposures preserve stromatolites and other laminated structures formed by microbial mats. These features provide evidence of biological activity in shallow, commonly restricted marine environments during the Early Ordovician. Near the site where BH250-128e was collected, groundwater emerges as springs along or near the contact between the Shakopee Dolostone and the overlying St. Peter Sandstone. These springs support microbial communities associated with the oxidation of dissolved ferrous iron (Fe²⁺) to ferric iron (Fe³⁺). The resulting iron oxyhydroxide minerals form conspicuous reddish-orange coatings on the exposed Shakopee Dolostone. This modern process illustrates the close relationship among groundwater flow, microorganisms, oxidation–reduction reactions, and mineral precipitation. Related sample: BH250-128b — Oneota Dolostone Coverage The spatial or temporal topic of the resource, the spatial applicability of the resource, or the jurisdiction under which the resource is relevant Cannon River Wilderness Park GPS coordinates: 44°23'11.15"N, 93°12'4.06"W Creator An entity primarily responsible for making the resource Bereket Haileab Relation A related resource <iframe width="100%" height="480" src="https://drive.google.com/file/d/1kzcVbW3dVORosRzUG6jCeoZJ6U_D3lFy/preview" allow="autoplay"></iframe><iframe width="100%" height="480" src="https://drive.google.com/file/d/1SprYyka_lmbrSOFgiOuTot3pNtw13ptn/preview" allow="autoplay"></iframe><iframe width="100%" height="480" src="https://drive.google.com/file/d/1yNlvhlR9gPDF0tIuDMjYjcfHoJAG4s2l/preview" allow="autoplay"></iframe> Source A related resource from which the described resource is derived From the rock collection of Bereket Haileab. Sample BH250-128e. Housed at Carleton College in Minnesota. Type The nature or genre of the resource Thin section and hand sample Cannon River Wilderness Park carbonate platform Carbonate rock Dolomitization dolostone Early Ordovician ferric iron ferrous iron geomicrobiology groundwater discharge iron oxidation iron oxyhydroxide iron-rich groundwater Lower Ordovician microbial community microbial mat mineral precipitation Minnesota Prairie du Chien Group reddish-orange coating redox reactions Rice County sandstone Sedimentary rock Shakopee Dolostone Shakopee Formation shale shallow-marine environment siliciclastic sediment siltstone spring St. Peter Sandstone stratigraphic contact stromatolite