Banded Iron Formation, stromatolite, jasper, Lake Michigans Left Coast, Elizabeth G Fagan, Roscoes Relics

Time and Deep Time

To get a sense of the scale of Earth history, imagine walking back in time, 100 years per step—every pace equal to more than three human generations. A mile takes you 175,000 years into the past. [Twenty miles], a hard day's walk to be sure, correspond to more than 3 million years. But to make … Continue reading Time and Deep Time

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Crinoid stem, Devonian or later, Lake Michigans Left Coast, Elizabeth Fagan, Roscoes Relics

Brachiopods, Lucy, and Extinction

Lake Michigan's Left Coast reveals Paleozoic limestone and dolomite dating to the Devonian Period (420–350 million years ago). Abundant in rocks from the Paleozoic are fossilized brachiopods, marine animals with upper and lower hard shells hinged at the rear. Though they first appear in rocks dating to the early Cambrian Period (540–485 million years ago), brachiopods reached … Continue reading Brachiopods, Lucy, and Extinction

Crinoid stem, Devonian or later, Lake Michigans Left Coast, Elizabeth Fagan, Roscoes Relics

Crinoid Stem, Devonian Period or Later

On Lake Michigan's Left Coast, there are thousands of ghostly images in the millions of rocks on the beach. They were highly eroded, nearly unrecognizable fossils. Imagine my surprise when, one day, this hunk of limestone appeared at my feet, incredibly clear fossil side up. I was astonished. My research says this fossil impression, with … Continue reading Crinoid Stem, Devonian Period or Later

Faces of extinction, fossils on Lake Michigans Left Coast, Elizabeth Fagan dba Roscoes Relics

Faces of Extinction 2

Over its 4.6 billion-year history, Earth has changed many times, in many ways. Homo sapiens, the name we give ourselves, evolved a few million years ago, a tiny point in time when Earth's conditions were just so. A peculiar trait of a certain subgroup of Homo sapiens, aka humans, put itself at the center of … Continue reading Faces of Extinction 2