New Mexico Administrative Code › Title 4 - CULTURAL RESOURCES › Chapter 10 - CULTURAL PROPERTIES AND HISTORIC PRESERVATION › Part 16 - STANDARDS FOR EXCAVATION AND TEST EXCAVATION › Section 4.10.16.12 - EXCAVATION STANDARDS

Current through Register Vol. 35, No. 13, July 16, 2024
A.
				Excavation shall be designed to recover information about those significant
				values for which a property is considered eligible for inclusion in the
				national register or listed on the state register. Excavation shall be guided
				by an explicit research design that identifies specific research topics,
				research questions and appropriate analyses. Field studies may include
				collection of surface and subsurface artifacts, subsurface tests to identify
				buried cultural lenses and features, controlled excavation of features and
				activity areas, and collection of specialized samples and specimens
				(radiocarbon, archeomagnetic, dendrochronological, flotation, pollen,
				paleoenvironmental, source materials). Use of mechanical earth-moving equipment
				may be appropriate. Laboratory analyses and analytical tasks include
				processing, cataloguing, analyses and curation of materials, analysis of
				specialized samples and preparation and production of technical and popular
				reports summarizing the results of the excavation program. All excavation and
				shall be performed under the direct supervision of an archaeologist listed in
				the SHPO directory of qualified supervisory personnel (4.10.8.11
				NMAC).
B. The research design
				establishes the standards for excavation. Example standards are provided below.
				Exceptions to these standards may be proposed but shall be explained and
				justified in the research design.
(1) Site
				maps shall be produced with high-quality optical transit, total station or
				alidade. Prepare a map for each site and depict the grid layout, the location
				of the datum, the location and shape of all features, artifact concentrations,
				test excavation units, point-provenienced artifacts, site boundaries and the
				relationship of the site to nearby physiographic and man-made features. Each
				map shall contain the site number, north arrow, numbered metric scale, legend
				for symbols used on the map, name(s) of the recorder(s) and date of
				recording.
(2) Controlled surface
				collections shall be accomplished using a grid system or by point provenience.
				The size of the grid system is determined by the needs of the research design
				and shall be clearly justified and supported. Use of a grid system with 1-by-1
				meter spatial control is standard. Maintain tight spatial control.
(3) All features visible on the surface shall
				be completely excavated unless the research design proposes a sampling
				strategy. Any decision to sample features shall be fully explained and
				justified in the research design. Consider whether the sample will produce
				sufficient specimens and special samples for analysis and if the sampling will
				provide sufficient relevant data to address the research questions. Features
				shall be excavated in profile in order to obtain a view of the cross section
				and shall be recorded in three dimensions. Profiles of the cross section shall
				be recorded by scale diagram and color transparencies. Plan view and cross
				section drawings of each excavated feature shall be prepared. All structures
				and features shall be recorded noting size, shape, construction detail, fill,
				probable function and relationship to other features and artifact activity
				areas. Separate feature forms shall be prepared for each feature. All features
				shall be numbered and labeled to correspond to the feature form.
(4) Excavation shall be conducted by natural
				stratigraphy or arbitrary levels until natural strata are defined. Proposals to
				use levels greater than 10-centimeter control shall be clearly justified and
				supported in the research design. Consider maintaining 10-centimeter control
				within natural strata.
(5)
				Sediments removed from all hand-excavation units shall be passed through a
				screen of no greater than one-quarter inch (6.35mm). Consider using a smaller
				screen size. 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 to 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
				sediments from being screened shall be clearly justified and supported in the
				research design.
(6) Stratigraphic
				profiles shall be recorded by scale diagram, photographs and narrative
				descriptions. Deposit descriptions include but are not limited to sediment
				color, texture, moisture content, nature of inclusions, organic content, and an
				inventory of cultural materials, if any. Describe the color using Munsell
				terminology.
(7) 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:
(a) collect surface artifacts prior to
				excavation of trenches or scraping areas with mechanical earth-moving
				equipment;
(b) depths for
				mechanically excavated trenches shall conform to OSHA standards for excavation
				safety ( 29 CFR 1926, Subpart P);
(c) document the location, depth, soil
				profile, artifact yield and other pertinent information;
(d) clean at least one profile with a shovel
				or trowel and inspect the profile for cultural features and material
				remains;
(e) document the profile
				in narrative, profile drawing and photographs; deposit descriptions include but
				are not limited to sediment color, texture, moisture content, nature of
				inclusions, organic content, and an inventory of cultural materials, if
				any;
(f) examine the excavated area
				after the removal of each extracted bucket load; and
(g) examine backdirt for the presence of
				artifacts.
(8)
Post-excavation mechanical excavation
. Mechanical stripping or scraping
				may be employed following excavations. The stripping serves the purpose of
				disclosing features not found during the testing, trenching or excavation and
				provides a check on the reliability of the excavation sampling design. Features
				exposed during the mechanical stripping shall be mapped in relation to the site
				datum. All features shall be fully described and a sample of datable specimens
				and artifacts shall be collected. If all features are not proposed to be
				excavated, explain how features will be chosen for excavation and why.
				Sufficient analytical studies shall be performed to interpret
				function.
(9) The bottom of the
				excavation units and trenches shall be lined with landscape cloth or marked in
				some other fashion to indicate depth of disturbance, unless the site will be
				destroyed by construction.
(10)
				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.
(11)
Human
				burials.
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. Do not excavate human burials if they can be left in place. If
				excavation of human burials proves necessary, such excavation shall only be
				conducted pursuant to 4.10.11 NMAC.
(12)
Backfill.
After completion
				of excavation, the site shall be backfilled and restored as nearly as possible
				to the pre-excavation condition, unless other provisions have been made in the
				permit application pursuant to 4.10.8 NMAC.