Da Yooper's guide to Michigan Fossils

Fossil locations in Michigan are common to areas where Bedrock is exposed. Since much of the area is covered with glacial deposits, the choice Michigan fossil areas are the outcrops of the various formations. The Bedrock Map of Michigan shows the formations and their approximate locations. The youngest formations would be in the center of the Lower Peninsula and get older as they progress outward.

Michigan Fossil remains vary tremendously due to the enormous span of time involved (4.25 Billion Years). The oldest rocks to surface on earth (The Kewatin Period of the Early Precambrian, 4,500 MYA) outcrop in the Western Upper Peninsula, while the middle of the Michigan basin has been dated to the youngest Jurassic Period, (230 MYA) of the Mesozoic Era.

To determine the age of Michigan fossils first find the approximate location of a road cut or quarry where the bedrock is exposed and then try to determine the formation that is exposed by referring to the map.

The site Geological Time can be referred to for information on using Index Fossils to date a formation.