Belt Basin

The Beltian Geosyncline, also known as the Belt Series, refers to a significant geological formation in the Northern Rocky Mountain region of North America. This linear trough contains Precambrian rocks, dating back approximately 4 billion to 542 million years ago. The rocks are primarily composed of thick deposits of sandstones, shales, and limestones, with thicknesses reaching up to 11,000 meters (about 36,000 feet).12

These Beltian rocks are visible in areas like Glacier National Park and the Little Belt Mountains in Montana, which give the formation its name. Evidence from ripple marks and mud-cracked shales suggests deposition in shallow water and on floodplains. Fossils found include stromatolites and burrows of ancient organisms. In geology, a basin is generally a broad, shallow trough in bedrock, distinct from a river basin, though they can overlap.123