"What Milwaukee is Made Of" is Lake Effect's new series exploring the geological origins of Milwaukee’s building materials. How many million years ago did they form? Where in the world have they been? What brought them to Milwaukee?
This debut episode focuses on Wauwatosa dolostone, sometimes referred to as Wauwatosa limestone or Milwaukee County limestone. As the name suggests, the stone was quarried locally, and was used in buildings across Wisconsin, including in the Pfister Hotel in downtown Milwaukee. But that’s only the most recent part of the stone’s history.
Wauawatosa dolostone was originally formed around 425 million years ago, when the land now known as Milwaukee was located around where the middle of South America is today. The stone was formed at the bottom of a shallow sea from sediments filtering down and settling at the bottom.
Geologist Raymond Wiggers explains that the sea in which Wauwatosa dolostone was formed was teeming with life.
"Lots of sunlight, dry air, but the sea was absolutely teeming with life," Wiggers says. "This was the time of first great coral reefs, the ancestors of the modern coral reefs in various warm waters of the world today."
Between its formation, Wauwatosa dolostone was there when the supercontinent Pangea formed and then broke apart again, saw dinosaurs emerge and go extinct, and slowly but surely moved to where Milwaukee is today.
After being covered by younger rock that was eroded away by the Menomonee River, Wauwatosa dolostone was visible by the time it began to be quarried extensively around 200 years ago. Wiggers said that the Wauwatosa dolostone had distinct advantages for buildings going up around Wisconsin, in addition to its durability and location.
"If you're a mason, you can chisel or shape it how you want to," Wiggers says. "If you go to the Pfister Hotel, you will see [...] all these rugged projections and beveling around the edges. Masons can do that for decorative effect."
Today, the stone can be found at the base of the Pfister Hotel in Milwaukee, Eaton Chapel in Beloit and in buildings across Wisconsin.
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