Big Hill Formation

The Big Hill Formation is a geologic formation in Michigan. It preserves fossils dating back to the Ordovician period. A fossiliferous site on the Stonington Peninsula (in Delta County) includes a dolomite bed of the Big Hill Formation which has abundant and well-preserved fossils. The most common fossils are soft-bodied medusae (jellyfish), followed by linguloid brachiopods, algae, and arthropods (namely chasmataspidids, leperditid ostracods, and eurypterids). This site is considered a Konservat-Lagerstätte, and is commonly referred to as the Big Hill Lagerstätte or Big Hill Biota.