Tortoise burrow (penknife for scale) in feldspar-rich sediment. Thedeposit consists mostly of medium-grained, angular fragments of feldsparcrystals and subangular quartz grains derived from the local granitoidsand migmatites that are present on the upper parts of the bajada. Theshape of the entrance arch of the burrow is similiar to that of a tortoiseshell. Abundant tortoise signs have been noted in this type of sediment.