- The St. Peter Sandstone is an Ordovician geological formation. It belongs to the Chazyan stage of the Champlainian series in North American regional stratigraphy, equivalent to the late Darriwilian global stage. This sandstone originated as a sheet of sand in clear, shallow water near the shore of a Paleozoic sea and consists of fine-to-medium-size, well-rounded quartz grains with frosted surfaces. The extent of the formation spans north–south from Minnesota to Arkansas and east–west from Illinois into Nebraska and South Dakota. The formation was named by David Dale Owen (1847) after the Minnesota River, then known as the St. Peter River. The type locality is at the confluence of the Mississippi and Minnesota Rivers near Fort Snelling, Minnesota. In eastern Missouri, the stone consists of quartz sand that is 99.44% silica.
- Cape Verde (Wikipedia)
Cape Verde (/ˈvɜːrd(i)/, VURD(-ee)) or Cabo Verde (/ˌkɑːboʊ ˈvɜːrdeɪ/ KAH-boh VUR-day, /ˌkæboʊ -/ KAB-oh -, local Portuguese: [ˈkabu ˈveɾdɨ]), officially the Republic of Cabo Verde, is an island country and archipelagic state of West Africa in the central Atlantic Ocean, consisting of ten volcanic islands with a combined land area of about 4,033 square kilometres (1,557 sq mi). These islands lie between 600 and 850 kilometres (320 and 460 nautical miles) west of Cap-Vert, the westernmost point of continental Africa. The Cape Verde islands form part of the Macaronesia ecoregion, along with the Azores, the Canary Islands, Madeira and the Savage Isles.