BSRG Photo Archive

Trough cross-stratified shelly sandstone. Note that the majority of shells are in a hydrodynamically position (ie convex up). From the Tertiary of northern Chile.

Trough cross-stratified shelly sandstone. Note that the majority of shells are in a hydrodynamically position (i.e. convex up). From the Tertiary of northern Chile.

photo by John Howell