Silurian soil pisolite

Soil pisolite from Pipe Creek Junior Quarry, Indiana, one of the few undolomitized Silurian patch reefs in the US Midwest. The geometric shapes come from when small concentrically-laminated spherules grow to occupy all the interspherule porosity.

Scanned in Dr. Franek Hasiuk's GeoFabLab (Department of Geological and Atmospheric Sciences, Iowa State University).

Scan specifications: Scanned with the MakerBot Digitizer Desktop 3D Scanner set on "medium".