This type is similar to Archaic Feature Type 1 being an approximately 50 cm diameter hearth.  The difference is this feature type lacks an internal layer of thermally altered rock and is identified with late Middle Archaic and Late Archaic.  Like Archaic Type 1 these features too have a very low charcoal signature averaging 0.44 grams per liter.  This feature type is also very similar in form to Formative Feature Type 4 in size: being approximately 40 liters.  Most examples occurred isolated or in clusters of two similar to Archaic Type 1. 

 

This feature type also documents the first appearance of yucca in the archaeological record with the recovery of yucca as macrobotanical (plant) Specimen's # 1 and # 2 (see the food remains page).  However, the only difference between this feature type and the later Formative Type 4 is Formative period features have a significant increase in the quantity of charcoal and recovery of macrobotanical specimens # 1 and # 2.  Also, Formative period features occur in much larger clusters up to a dozen or more within an immediate area.

 

The presence of this feature in the archaeological record by 4820 B.P. suggests the exploitation of yucca that the regional population became so heavily reliant on during the Formative, possible began during the Middle Archaic