WebThe cichlid fishes of the East African Great Lakes are the largest extant vertebrate radiation identified to date. These lakes and their surrounding waters support over 2,000 species of cichlid fish, many of which are descended from a single common ancestor within the past 10 Ma. The extraordinary East African cichlid diversity is intricately linked to the … WebThe Great Lakes are a product of glacial scour and were partially or totally covered by glacier ice at least six times since 0.78 Ma. During retreat of the last ice sheet large …
Great Lakes Rocks: 4 Billion Years of Geologic History in …
WebThe Canadian Shield ( French: Bouclier canadien [buklje kanadjɛ̃] ), also called the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the … WebThe geologic story of the Great Lakes region is one of the most remarkable of any place on Earth. Great Lakes Rocks takes readers on this fascinating journey through geologic history, beginning with an investigation of the surface features--the hills and valleys, waterfalls and caves, and the Great Lakes themselves--encountered on a daily basis. As … shark upholstery tool
Stream corridor and upland sources of fluvial sediment and …
WebApr 19, 2024 · History: The Central Great Lakes Geologic Mapping Coalition was formed on December 17, 1998, as a collaboration between the Illinois State Geological Survey, … WebThe Appalachians are among the oldest mountains on Earth, born of powerful upheavals within the terrestrial crust and sculpted by the ceaseless action of water upon the surface. The two types of rock that characterize the present Appalachian ranges tell much of the story of the mountains’ long existence. First there are the most ancient crystalline rocks. … WebDec 28, 2010 · About 500 million years ago, the oldest rocks in the area sat at the bottom of an ancient sea. Oxygen-poor mud and debris settled on the sea floor and hardened into rock that has persisted over... shark universal overhead guard