Belt Supergroup

The Belt Supergroup is a large, ancient rock formation in northwestern Montana, formed around 1.5 billion years ago. Composed mainly of sedimentary rocks like shale and sandstone, it records a significant period of Earth's history when the region was covered by a deep, oxygen-rich sea. These rocks contain clues about the environment, climate, and biological activity of that time. Geologists study the Belt Supergroup to understand early Earth conditions and the development of complex life, making it an important window into the planet's deep past.