I've picked up several rocks along Lake Michigan with fossil shapes of this form, arcs segmented down the middle by closely set, nearly parallel lines. This hunk of iron-stained limestone contains one of the largest and most distinct impressions. Trilobites molted, shed their exoskeletons to inhabit larger ones. I believe these shapes and the others … Continue reading Trilobite


Hurricane Sandy ("Superstorm Sandy") kicked up 23-foot waves on Lake Michigan off Chicago in late October, 2012. Afterward, lots and lots of sharp-cornered and beautifully caramel-colored chert appeared on Montrose Dog Beach. Here are some Hurricane Sandy souvenirs. Copyright, Disclaimer, Bibliography