Nonstructure 9.3-N, extramural surface

Features


Wall: other (Feature 5) Top of page
General description
Check dam.
Use history
This wall served to control erosion. This wall is believed to postdate the construction of the two check dams to the north (F-3 and F-4) because they rest on bedrock and this wall was built on a five to ten centimeter of fill that rests on bedrock. This wall may have been constructed as an additional retaining feature that assisted in water/erosion control. There are no natural deposits between this wall and the two check dam walls to the north, suggesting this wall added strength to the larger water/erosion control system rather than replacing the other check dams.
Associated features
F-3, F-4.
Excavation procedure
Not excavated; only exposed and documented.
Portion excavated
Portion within Nonstructure 9, Segment 3.
Horizontal location
Located near cliff edge, immediately west of the main drainage; portion of wall exposed during excavation is located at the southeast end of Nonstructure 9, Segment 3.
Vertical location
Wall rests on Surface 3, which is the top of a constructional fill deposit (Stratum F on Map 187).
Construction
Wall was constructed by placing unshaped, irregular stones on top of constructional fill; fill may or may not have been deposited to build this wall; fill appears to have provided support for wall (F-4) to the north; this is a uncoursed, dry-laid wall; see Masonry form 334 for architectural details.
Remodeling/ modification
Yes. From Slide 652-32.
Thermal alteration
Yes. From Slide 652-32.
Sooting
Yes. From Slide 652-32.
Sealed
Yes. Constructional fill (Stratum C on Map 187) rests on top of wall along northeast profile; it is unclear if this fill was part of a larger water/erosion control system that included F-3, F-4, and F-5 or if the fill was deposited to replace this wall. It is also possible the fill was not deposited on top of the wall as it stops short of the wall in the southwest profile. Fill along northeast profile may have eroded and was redeposited on top of the wall.
Preservation
Good.
Degree of preservation
The informal nature of construction makes it difficult to assess the condition of the wall; wall leans to the southeast.
Shape in plan view
Actual: 
Inferred: 
Shape in cross section
Actual:  irregular.
Inferred:  irregular.
Shape comments
Dimensions
 
Actual
Complete?
Inferred
Comments
Length
100
No
300
Wall extends beyond excavation unit to the southwest; actual length=length exposed in excavation unit; inferred length is based on visible wall sections within and outside of excavation unit.
Width
74
No
140
Thickness; wall extends beyond excavation unit to the southeast; inferred length based on visible wall sections within and ouside of excavation unit.
Height
58
No
Incomplete height based on rubble found adjacent to wall during excavation.
Depth
No
Stratigraphy
Stratum
Interpretation
Inclusions
Disturbance
Color
Texture