Locus 13 is ​​a layer of heavily carbon-included dark brown soil. The layer is 1.26 m wide and extends from the northern edge of the OC2/Workshop floor (Locus 2) for 1.10m. The plaster collapse layer (Locus 14) abuts and covers Locus 13 in a line that is parallel to the OC2/Workshop floor. Locus 13 is 0.80 m long on the western extent between Locus 2 and Locus 14 and 0.97 m long between Locus 2 and Locus 14 in the eastern extent.

The soil is a clay and soil mixture of loose compaction. The layer contains frequent inclusions of carbon, ceramics, a small amount of vitrified terra cotta fragments and 3 bones. Frequent inclusions of small red and brown chert added to the dark color of the layer. A soil sample was taken from the layer for flotation which will be processed in 2023.

The color, compaction, and composition of Locus 13 is similar to that of Locus 7. Locus 7 was a similar carbon-included layer with frequent inclusions of red and brown chert, along with a high volume of bone.

Locus 13 and Locus 7 functioned as a leveling course for the preparation of the construction of the OC2/Workshop floor.