Sunday, June 21, 2015

Not One, But Two Floors!

Just one day into our first week of excavation at Burrell Orchard, we discovered another clay floor.  This feature is some 20 to 25 cm higher than the floor we found last season and is situated about 2.0 meters to the east.  If the radar images of the deep floor are accurate, then this new floor, designated as Feature 15-05, partially overlaps the deeper floor, Feature 14-11.    Both clay strata appear to be similar in make-up, that is, they were made from nearly pure yellow clay probably derived from subsoil deposits below the midden (Figure 1).  

Figure 1. Exposed southern section of yellow clay floor (Feature 15-05) in Unit 496N 514E.
So far, we have identified Feature 15-05 at about 30 cm bd in Units 498N 514E and 496N 514E.  The portion we have exposed measures at least 3.0 m north to south and 1.5 m east to west.  But we don’t have it all, since the clay deposit runs eastward out of the excavated area.  On Friday, we took three one-inch core samples at 50 cm intervals eastward from Feature 15-05 (Figure 2).  The results revealed that this new clay floor extends to the east between 1.0 to 1.5 m.  Interestingly, the core taken at 1.0 meter contained samples of two stratified clay floors, something we see evidence for in Unit 498N 514E.  Later in the afternoon we opened a new 2.0 x 2.0 m unit at 496N 516E to expose more of the floor.  Once excavation started we quickly found the floor at only about 15 cm bd in this new unit.
 Figure 2. Taking core samples eastward from the upper clay floor (Feature 15-05).
Meanwhile, Brian S.’s crew continued to carefully excavate 10 cm-thick levels of midden soil in Unit 496N 512E.  At about 30 cm bd, they exposed a large cluster of FCR, as well as two ground-stone tools: one a small hand-held grinding stone or “mano” with distinctive polish on the flat side and a large (3.0 kg) pitted stone.  As its name indicates, the pitted stone is marked by several distinct, regular depressions on several faces the look to have been made by the use of a rotating implement (Figure 3).  These pits appear too regular to have been made by simple whacking this stone with another stone to crack nuts or flake flint cores.  In fact, the likely purpose of these pitted stones remains unknown. 

Figure 3. Pitted stone found within midden deposits in Unit 496N 512E.

The discovery of at least two stratified clay surfaces is exciting and much unexpected.  It makes our excavation more complex but also very exciting.  Who know what will turn up this coming week!

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