Test excavation projects performed under a general permit
shall be conducted in accordance with the following specifications and
performed under the direct supervision of an archaeologist listed in the SHPO
directory of qualified supervisory personnel (4.10.8.11
NMAC). Test excavations that deviate from these standards are allowed by
obtaining a project-specific excavation permit pursuant to 4.10.8 NMAC.
A. Test excavation shall be conducted in a
manner that the total surface disturbance resulting from the tests shall not
exceed five percent (5%) of the total surface area of the site or five percent
(5%) of the portion of the site that may be affected by a project, whichever is
less. Test excavation that proposes to excavate more than 5% of a site
constitutes excavation and shall follow the standards in
4.10.16.12
NMAC.
B. Site maps shall be
produced using a high-quality optical transit, total station or alidade.
Prepare a scaled map for each site and depict the grid layout, the datum, the
location and shape of all features, artifact concentrations, test excavation
units, auger tests, shovel tests, point-provenienced artifacts, site boundaries
and the relationship of the site to nearby physiographic and man-made features.
Each map shall contain the LA site number, north arrow, numbered metric scale,
legend for symbols used on the map, name(s) of the recorder(s) and date of
recording.
C. Controlled surface
collections shall be accomplished using a grid system or by point provenience.
The standard is 1-by-1 meter grid units for spatial control. Use of larger grid
units is allowable only when explicitly justified and supported in the test
excavation plan.
D. For systematic
auger holes and similar tests, explain the placement, interval, minimum number
of units and size of the area tested in square meters.
E. Test excavation of features is discouraged
for features including but not limited to hearths, rock alignments, pit
depressions, dispersed firecracked rock scatters, soil discolorations and other
potential feature areas. Tests of features may be conducted only when essential
to determine the research potential of the feature and fill shall be collected
for laboratory analysis. All tests shall use hand tools and shall adopt the
least destructive method to obtain the necessary information. Core the edge of
a feature to determine depth, integrity and content. Complete excavation of
features is prohibited.
F.
Excavation shall be conducted by natural stratigraphy or arbitrary levels until
natural strata are defined. Use 10-centimeter control or less for arbitrary
levels. Consider maintaining 10-centimeter control within natural strata.
Proposals to use levels thicker than the 10-centimeter control shall be clearly
justified and supported in the test excavation plan and may be conducted only
after the controlled excavation demonstrates the fill as noncultural or highly
disturbed.
G. Sediments removed
from all hand-excavation units shall be passed through a screen of no greater
than one-quarter inch (6.35mm). Use a smaller screen size when deemed
appropriate. Do not screen sediments from thermal features; collect
thermal-feature fill for laboratory analysis. Additionally, sediments from a
minimum of one hand-excavation unit comparably placed and of the same size as a
unit that produced moderate to high artifact yields shall be passed through a
screen of no greater than one-eighth inch (3.175 mm). Proposals to exclude
overburden or disturbed contexts shall only be considered after controlled
tests and fill screened to the standards have demonstrated that the fill is
noncultural or highly disturbed. Screening all fill through one-eighth inch
mesh is encouraged as standard practice.
H. Stratigraphic profiles shall be recorded
by scale diagram, photographs and narrative descriptions. All strata and soil
horizons shall be described using standard scientific terms. Describe the color
using Munsell terminology or equivalent.
I. Mechanical excavation units may be used to
define stratigraphy, locate subsurface features and cultural deposits and
remove sterile overburden. Trenches excavated with mechanical earth-moving
equipment shall conform to the following standards:
(1) collect surface artifacts prior to
excavation of trenches or stripping areas with mechanical earth-moving
equipment;
(2) depths for
mechanical excavation trenches shall conform to OSHA standards for excavation
safety ( 29 CFR
1926, Subpart P);
(3) document the location, depth, soil
profile, artifact yield and other pertinent information;
(4) clean at least one profile with a shovel
or trowel and inspect the profile for cultural features and material
remains;
(5) document the trench
profile in narrative, profile drawing and photographs; all strata and soil
horizons shall be described using standard scientific terminology; deposit
descriptions include but are not limited to sediment color, texture, moisture,
content, nature of inclusions, organic content and an inventory of cultural
materials; describe the color using Munsell terminology;
(6) examine the excavated area after the
removal of each extracted bucket load;
(7) examine backdirt for the presence of
artifacts; and
(8) if cultural
materials extend deeper than the bottom of the trench, systematically auger the
bottom of the trench to determine approximate depth of materials.
J. The bottom of the excavation
units and trenches shall be lined with landscape cloth or shall be marked in
some other fashion to indicate depth of disturbance.
K. Photographs may be in black-and-white
print, color print, color transparency or digitally captured images. For
greatest archival stability, black-and-white prints are recommended. At a
minimum, photograph features and profiles.
L.
Human burials. Excavation of
human burials is prohibited under test excavation. If human burials are
encountered, all work shall stop immediately in the area of the discovery.
Notify local law enforcement pursuant to
4.10.11 NMAC. Document the location of
the remains.
M.
Backfill. After completion of test excavation, backfill and restore the
site as nearly as possible to the pre-excavation condition, unless other
provisions have been made in the test excavation plan.
[For one study on the use of one-eighth inch screen size, see
Carmichael and Franklin (1997), Archaeological Screening Techniques and Their
Effects on the Recovery of Lithic Artifacts, In Archaeology of the
Jornada Mogollon: Proceedings from the 10th Jornada Mogollon
Conference.]