An Unexplored Realm in the Heartland of the Southern Gulf ... - Famsi

intersection on the numbered rows and lettered columns. The red diamonds indicate
which specimens were used in the subsequent elemental analysis. At the four corners of
the grid maps are the GPS coordinates for the corner points that define the limits and
location of each collection zone.
Posthole diggers were used to remove the upper 0.25 to 0.30 m of humus at each
extraction point in order to obtain soils below the plowzone. This measurement was
determined by the relatively consistent plowzone level observed along the exposed river
cut. The extracted upper level soils were deposited next to the hole and checked for
cultural material. Some burned clay fragments and ceramic sherds were recovered (see
Ceramic Section in Chapter 5). Specimens from Plaza I (Soil Survey I) were taken from a
40 by 50 m unit using a sampling matrix where samples were collected at regular 5 m
intervals (Figure 4.26). In Plaza II (Soil Survey II) an 80 by 90 m area was laid out in a
similar grid matrix, but the collection points were staggered on alternating rows (Figure
4.27).
The soil specimen was collected from the bottom of each of the original
postholes. The sample was extracted from a depth of approximately 0.3 to 0.4 m. A
stainless steel trowel was used to take each sample. The soil was placed in sterile plastic
bags that had been marked with the proper survey and grid coordinates. After the soil had
air-dried, the bags were sealed and packaged for return to the University of South Florida
for analysis.
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