Jasper, chert, chalcedony, and flint are all forms of quartz, making their precise identification, like the rocks themselves, opaque. Chert is very abundant at my beach, Lake Michigan's Left Coast, and is represented by the caramel coloring in these samples. When chert bears the telltale red of jasper, it can be linked to Great Lakes … Continue reading Jasper and Chert
I am not sure what to call this piece of chert with jasper bands other than "banded chert." It is one of the many rocks of mysterious origin I find on the Lake Michigan coast of Ozaukee County, Wisconsin. Copyright, Disclaimer, Bibliography
I am working on trying to tell the difference between stromatolites and stromatoporoids. The former are fossils of blue-green algae, the latter are fossils of marine sponges. These fossils are in Lake Michigan chert. Copyright, Disclaimer, Bibliography
Glaciers carried all kinds of rocks to the southwestern shoreline of Lake Michigan. The famous Lake Michigan stones are rounded rocks of infinite colors and varieties. Identifying individual rocks and fossils on my beach in Ozaukee County, Wisconsin is a daunting task. It helps to know what might be expected given the geology of the … Continue reading Stromatolite
Luck is a matter of perspective. I have been lucky in different ways and different times in my life. As my self-education in geology expands, and my really nerdy hobby of collecting rocks extends to any available surface on my property, I consider myself lucky to live where I live. I live on Lake Michigan … Continue reading On Mother’s Day: What Luck!
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