Baraboo Quartzite
Baraboo Quartzite is a Precambrian geological formation[1] of quartzite, found in the region of Baraboo, Wisconsin. While pure quartzite is usually white or gray, Baraboo Quartzite is typically dark purple to maroon in color, due to the presence of iron (hematite) and other impurities.[2] Baraboo Quartzite may display strata created by progressive deposition of layers of sand in the original sandstone from which the quartzite was formed (through metamorphism).[2] Specimens of Baraboo quartzite may also display ripple marks that appear visually similar to the patterns one might see in the sand at a beach. Ripples indicate that the sandstone from which the quartzite was metamorphosed was originally water-laid sediment.[3]
Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts.
Uses
Because of its hardness and angular shape, crushed quartzite is often used as railway ballast.[4] Quartzite is a decorative stone and may be used to cover walls, as roofing tiles, as flooring, and stairsteps. Crushed quartzite is sometimes used in road construction.
Occurrences
Formations of quartzite can be found in throughout the Baraboo Hills in south-central Wisconsin. Many notable formations can be seen in Devil's Lake State Park.[5]
-
Devil's Doorway rock formation at Devil's Lake State Park -
Chimney Rock -
Boulder field on Eastern bluff at Devil's Lake
References
- ^ Hanson, G. F., Geology of the Barabou District, Wisconsin, The University of Wisconsin Extension, 1970, Information Circular 14
- ^ a b Montgomery, Keith. "Baraboo Quartzite". Retrieved 2013-10-14.
- ^ Montgomery, Keith. "Baraboo Quartzite". Retrieved 2013-10-14.
- ^ Railroad Ballast
- ^ Geology by Lightplane Geology.wisc.edu (1923-07-13). Retrieved on 2011-06-05.