Ordovician Platteville Formation, Saint Paul, MN

platteville_st_paul

platteville_st_paul_closeup

reduced file size version (more functional for some computers): platteville_st_paul_reduced

Finely bedded Ordovician carbonates and marls of the Platteville Formation, Mississippi River bluffs, Saint Paul, MN. Close up of coarse shell lag within the bed that crops out halfway up the section on the right side of the image below.