Gypsum Layer in Spearfish Formation, SD
![Image: Gypsum Layer in Spearfish Formation, SD](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/gypsum1.jpg?itok=SxXeaMOO)
Detailed Description
Spearfish Formation near Spearfish, SD. The Spearfish Formation is a red, silty shale with interbedded red sandstone and siltstone. The formation contains massive gypsum deposits, which is the white layer in the photograph.
Sources/Usage
Public Domain.