Date of site: Middle Palaeolithic
Comments: This is a photograph of a polished, polyester-impregnated block of an in situ hearth from the lower part of the Middle Palaeolithic layers in the center of the cave. The gray ash overlies a darker, organic-rich substrate. Horizontal dimension is about 88 mm.

         
Date of site: Middle Palaeolithic
Comments: Illustrated in this low magnification photomicrograph is the lower part of a phosphatized calcitic stalagmite that has formed on top of silt and clay that has also been subjected to phosphatic diagenesis. The large circular feature in the central part of the photograph is a result of burrowing by a modern wasp. Plane Polarized Light; width of photograph is about 65 mm.

Bois-Roche Cave
Charente-Maritime, France

         
Type of site: Hyaena den
Date of site: Late Pleistocene
Comments: This sample illustrates coarse sand size, beige-colored grains of phosphatic coprolites, a common feature in hyaena dens. These are associated in the cave either with massive sandy clays, or shown here, with finely bedded silt and clay which were deposited by runoff emanating from the entrance. Plane Polarized light; maximum length of photo is about 3 mm.

Dust Cave
Tennessee River, Northern Alabama

         
Date of site: Late Paleoindian through Archaic.
Comments: This macrophotograph illustrates crude bedding of clay and ash, mixed with charcoal at the base. The materials were presumably reworked from in situ hearths and mixed with clay washed in from the entrance of the cave by runoff. Plane Polarized Light; length of photo is about 70 mm.

Wilson-Leonard
Williamson Co., Texas

         
Date of site: Paleoindian through Late Prehistoric.
Comments: These two photomicrographs from the Paleoindian layers show a secondary accumulation of nodular calcium carbonate in the upper part of the photograph. The lower part illustrates precipitation of iron as shown by the reddish staining. The co-precipitation of both these materials appear to be related to alternate wet and dry seasons. The left photo was taken in plane polarized light (PPL), whereas the right is the same view in cross-polarized light (XPL). The maximum length of the field is about 3 mm.