This locus constitutes an area of darker, more compact soil in WSAD in the western area of the operation, at the same rough level as Locus 14 (brown clay matrix) and abutting the area of the 'doorway' between rooms WSAC and WSAD. The locus is delimited on the west side by two large rocks, and on the south by the wheelbarrow ramp. The matrix does not appear to be the same as the loamy overburden. The locus was declared 7.27.10 after noticing the color change while removing Locus 14, and produced the bone spindle whorl, Ar/Ts.WSAD.18.B.01. See notebook for sketch and elevations (given is center).