If you’ve ever looked through clear waters at a beach or gentle flowing river to the sand below, you’ve likely seen ripple marks formed by the moving water. The image above actually shows preserved “fossil” ripple marks in the 1.7 billion-year-old Baraboo (Wisconsin) quartzite. These ripple marks were formed when the marine sandstone was initially deposited… Continue reading Ripple Marks
If you’re a structural geologist or geology student in the midcontinent region, you’ve most likely made the pilgrimage to Van Hise Rock. Located near Rock Springs, Wis., in the Baraboo quartzite range, Van Hise Rock is among the best-known structural geology landmarks in the Midwest. Van Hise Rock provides spectacular exposure of the nearly vertical… Continue reading Van Hise Rock
Folded quartzite and phyllite, with axial planar cleavage in the phyllite South limb of the Baraboo (Wis.) syncline Image by author
Here’s some lovely cross bedding in the ~1.7 Ga quartzite from Baraboo, WI!