New Mexico Administrative Code
Title 4 - CULTURAL RESOURCES
Chapter 10 - CULTURAL PROPERTIES AND HISTORIC PRESERVATION
Part 16 - STANDARDS FOR EXCAVATION AND TEST EXCAVATION
Section 4.10.16.9 - TEST EXCAVATION STANDARDS UNDER A GENERAL PERMIT
Current through Register Vol. 35, No. 18, September 24, 2024
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:
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.]
