BH250-61
Title
BH250-61
Subject
Sandstone (Orienta sandstone)
Description
Major Minerals: quartz, plagioclase, minnesotaite
Minor Minerals: muscovite, biotite
BH250-61 is a sample collected from Amnicon Falls State Park and represents an arkosic sandstone belonging to the Orienta Sandstone, which is prominently exposed in the park in northwestern Wisconsin.
Mineralogy:
Quartz: Subrounded to angular, forming the dominant framework component.
Feldspar: Both plagioclase and K-feldspar are present, reflecting the arkosic character of the rock.
Lithic Fragments: Volcanic and metamorphic rock fragments contribute to the overall mineralogical immaturity of this sandstone.
Accessory Minerals:
Muscovite and biotite (present in minor amounts)
Magnetite, zircon, and other heavy minerals are present as detrital components.
Cement:
Hematite is abundant as a cementing agent, imparting the rock’s characteristic reddish to pinkish color.
The Orienta Sandstone is stratigraphically and lithologically correlated with other Proterozoic red-bed sandstones in the Lake Superior region, including the Jacobsville (BH250-154), Hinckley, and Freda sandstones.
For more information see, BH250 – Sandstone Overview with Petrographic Notes
Minor Minerals: muscovite, biotite
BH250-61 is a sample collected from Amnicon Falls State Park and represents an arkosic sandstone belonging to the Orienta Sandstone, which is prominently exposed in the park in northwestern Wisconsin.
Mineralogy:
Quartz: Subrounded to angular, forming the dominant framework component.
Feldspar: Both plagioclase and K-feldspar are present, reflecting the arkosic character of the rock.
Lithic Fragments: Volcanic and metamorphic rock fragments contribute to the overall mineralogical immaturity of this sandstone.
Accessory Minerals:
Muscovite and biotite (present in minor amounts)
Magnetite, zircon, and other heavy minerals are present as detrital components.
Cement:
Hematite is abundant as a cementing agent, imparting the rock’s characteristic reddish to pinkish color.
The Orienta Sandstone is stratigraphically and lithologically correlated with other Proterozoic red-bed sandstones in the Lake Superior region, including the Jacobsville (BH250-154), Hinckley, and Freda sandstones.
For more information see, BH250 – Sandstone Overview with Petrographic Notes
Coverage
Location: Little Amnicon Falls State Park, Minnesota, USA
Creator
Bereket Haileab
Source
From the rock collection of Bereket Haileab. Sample BH250-61. Housed at Carleton College in Minnesota.
Type
Thin section and hand sample
Relation
Collection
Citation
Bereket Haileab, “BH250-61,” BH250 Mineralogy Teaching Collection, accessed April 25, 2026, https://bereket-haileab.geology.sites.carleton.edu/items/show/71.