About the Rocks & Fossils

Elizabeth G Fagan’s fossil-hunting grounds are the beaches of Lake Michigan. Specifically, the coastline consisting of Devonian dolomite bedrock in southeastern Wisconsin. Devonian bedrock in the region is surrounded by Silurian bedrock. Fagan calls her environs Lake Michigan’s Left Coast.

The region was heavily glaciated. As a result, the depths of Lake Michigan contain rocks and fossils from the Archean Eon (4 billion years ago) through the Paleozoic Periods (510–299 years million years ago.) Any and all of these may wash up on local beaches. The rise and fall of Lake Michigan waters beginning in 2014 created turmoil on the beaches, revealing millions of “new” stones.

The fossils Fagan finds are either weathered rock or impression fossils. They are not the same as fossils from land formations. These rocks have been subjected to thousands of years of wave action and erosion. The resulting relics are especially hard to identify. Fagan does her best, but misidentification is likely. Helpful feedback is appreciated; spam, trolling and self-righteous commentary are not.