The continued fragmentation of Gondwana produced scattered equatorial landmasses which included Laurentia (North America), Siberia, Baltica and relict Gondwana Africa, South America, Asia, India, Australia, Antarctica, Arabia). The Panthalassic Ocean dominated the Northern Hemisphere, while a fledgling Iapetus (the ancient Atlantic Ocean) continued to spread in the Southern Hemisphere.
Image Source:Northern Arizona University webssite http://vishnu.glg.nau.edu/rcb/Cambrian.html
In Middle to Late Cambrian, marine shales and limestones were deposited above the Early Cambrian quartz sandstones as the vast Sauk seas inundated much of North America. This marine transgression is recorded in rocks of the Grand Canyon, where the Tapeats Sandstone is overlain by the Bright Angel Shale and the Muav Limestone. The transgression is also documented in Central Wisconsin where the Early Cambrian Mt. Simon sandstone is overlain by the Eau Claire Shale and the limestone and dolostone of the Tunnel City and Trempealeau Groups.
Image Source: C.R. Scotese http://www.scotese.com/
Return to NORTH AMERICA or CLASS 5 MAIN PAGE