Approximately 3 billion years ago, long before multicellular organisms roamed the earth, lush mounds of algae began to thrive along warm, shallow shorelines. These algal mats trapped sediment, which built up layer by layer into dome-shaped mounds. Such mounds are called stromatolites.
Many people view the earth and its lifeforms as what we see today. However, both have changed dramatically through time; the evidence for this comes from something most of us see every day, but think little about: rock. Much of the rock in Wisconsin contains fossils, the remains of an
Formula: SiO2.nH2O Amorphous Description: Opal is a mineraloid composed of spherical silica aggregates with various amounts of interstitial water. It forms under a wide range of low-temperature geological conditions. Opal may be deposited by silica secreting organisms such as diatoms
We've recently released a number of new publications available for purchase and free to download. Titles include Wisconsin's Geologic Past (poster); Glaciation of Wisconsin; and Quaternary Geology of Sheboygan County, Wisconsin.
Director’s Message The Wisconsin Geological and Natural History Survey (WGNHS) had another successful year in 2021. We began the year working remotely due to the Covid-19 pandemic, but restrictions started to ease during the spring as vaccinations became available and Covid infe
Ever wonder what Wisconsin’s most important rocks and minerals are? We’ve created a story map that will help satisfy that curiosity! Adapted from the WGNHS Rock Kit, this interactive story map takes viewers on a virtual tour of our state’s rocks and minerals. It̵
In accordance with guidelines from the Division of Extension and UW–Madison, WGNHS has reopened its offices to our employees and the public as of July 6, 2021. Throughout the long closure, our staff has been working remotely, conducting fieldwork, and continuing to do research on Wisc