New Madrid Seismic Zone
![Sand dike and sill exposed in drainage ditch in southeastern Missouri](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/sanddike.jpg?itok=GPzbUZTa)
Detailed Description
Photograph of sand dike and sill exposed in drainage ditch in southeastern Missouri. Sand dike intruded weathered sand; sill emplaced below weathered clay. Layering within the dike and sill indicate that they formed during two or more events. For scale, knife is 8 cm long.
Sources/Usage
Public Domain.