Sioux Quartzite

Sioux Quartzite at Falls Park, Sioux Falls, South Dakota
Cross-bedding in the Sioux Quartzite, Blue Mounds State Park, Minnesota, United States.

The Sioux Quartzite is a Proterozoic quartzite that is found in the region around the intersection of Minnesota, South Dakota, and Iowa, and correlates with other rock units throughout the upper midwestern and southwestern United States. It was formed by braided river deposits, and its correlative units are thought to possibly define a large sedimentary wedge that once covered the passive margin on the then-southern side of the North American craton. In human history, it provided the catlinite, or pipestone, that was used by the Plains Indians to carve ceremonial pipes. With the arrival of Europeans, it was heavily quarried for building stone, and was used in many prominent structures in Sioux Falls, South Dakota and shipped to construction sites around the Midwest. Sioux Quartzite has been and continues to be quarried in Jasper, Minnesota at the Jasper Stone Company and Quarry, which itself was posted to the National Register of Historic Places on January 5, 1978.[1] Jasper, Minnesota contains many turn-of-the-century quartzite buildings, including the school, churches and several other public and private structures, mostly abandoned.