note the geological era and periods in which south saint paul and southeastern minnesota might have been covered bt oceans
3 answers
South Saint Paul and southeastern Minnesota were most likely covered by oceans during the Paleozoic Era, specifically the Silurian Period (443-419 million years ago) and the Devonian Period (419-359 million years ago). During these periods, the area was submerged under a shallow sea known as the Western Interior Seaway, which covered much of North America. Evidence of marine fossils found in sedimentary rocks in the area also support this theory.
summarize what happened during the mid continental rift and how southeastern minnesota was affected
During the Mid-Continental Rift, which occurred roughly 1.1 billion years ago, the North American continent began to split apart, resulting in a long, narrow crack or rift. This rift extended from what is now Lake Superior southwestward into Kansas. This process created volcanic activity which formed an extensive lava flow that created the basalt bedrock in southeastern Minnesota. The rift movement also resulted in the formation of many faults and fissures in the bedrock, which have influenced the area's hydrology and created features like the karst topography and the caves in the region. As a result, southeastern Minnesota has a unique geological landscape that has been shaped by the Mid-Continental Rift movement, making it a popular destination for geologists and tourists alike to study these features.