Descriptive Attribute	Value(s)
Architectural or Soil Locus?	Soil
Definition	Yellow wadi fill.
Description	This level of coarse, yellow soil appeared over the tunnel capstones. Although this locus represents only the soil covering the capstones for the east tunnel in the south of SP 4, this level was also visible in the balk over all four tunnels and was present in the Trench 1, 1993 sondage. The soil was loosely-packed with medium-sized, wadi stones that made it a very dense level. There were no inclusions in this locus. This level is believed to have served as a sealant for the tunnels. There are many crevices in between the capstones and this soil. With its plethora of wadi stones, this level of soil formed a dense cover for the tunnels and would have prevented the looser levels of fill from falling into the tunnels. It was put down directly over the capstones and post-dates Locus 20, ashlar wall, as it runs up against the south face of the wall. Packing for the Tunnels. The north and the east tunnels came to a corner in the southeast portion of the SP 4 excavation. The corner where the tunnels met was tightly-packed with levels of rock and hard fill. This packing filled the 2.5 m expanse of the trench from east to west and extended as far north as the large ashlars in the north would allow; it originally extended 1.42 m, reaching Locus 16, large ashlars and then 1.0 m when the ashlars of Locus 24, step were uncovered. The majority of SP 4 was filled with repeated levels of rock and fill, but this section of the trench was distinct from the northern area of excavation in the orderly fashion with which the ashlars were placed and the hardness of the soil levels.
Top (m)	Top elevation: 903.626 m at southeast.
Stage	Stage 1
Phase	II
Phase Description	Phase II: First period of major Nabataean construction at the Great Temple complex in the 1st c. BCE. At this...
Stage Description	Construction of the underground canalization system: ashlar wall and the Central Staircase. Packing of the channels and construction of the steps.
Bottom (m)	Bottom elevation: 903.496 m at southeast.