Baraboo Syncline geological section

Here is a geological section of the syncline, displaying the features described in the main page. The pink Baraboo Quartzite is folded up with an underlying rhyolite lava (brown) and a small number of slightly later rocks, including slate and dolomite. The quartzite layer is over 5000 ft thick!

The horizontal rocks that are found around and inside the ranges are much younger sedimentary rocks. Roughly 1 billion years elapsed between the deposition and folding of the Baraboo Quartzite, and the oldest (lowest) of these younger rock layers! Further explanation of the ages and history of the rocks and landforms will be made later.