Field Standards for Terrestrial Phase I Cultural Resources Surveys

Introduction

• The goal of a Phase I archaeological investigation is to locate and define the boundaries of every archaeological site within a project area.  For archaeological investigations, the project area and Area of Potential Effects (APE) can be regarded as the same thing.  This must include an assessment, with supporting documentation, of the eligibility of every site identified within the project area for the National Register of Historic Places (NRHP).  Such assessments apply to both newly reported and previously reported sites.  Cultural Resources Investigation Permits (CRIP), issued by the Division for excavations on state lands, are not required for Phase I surveys.

Survey Standards for Rural and Non-Urban Areas
Reconnaissance survey and monitoring standards are addressed in separate sections.

• For Phase I surveys, all portions of a survey area must be examined by systematic shovel testing whenever possible, in combination with systematic pedestrian survey, and/or additional techniques such as augering, coring, soil probes, or mechanically excavated trenching, depending upon the surface conditions and potential for deeply buried archaeological sites. 

• Surveys in inundated or marsh environments conducted by boat or airboat are limited to examination of exposed ground (such as remnant natural levees).  Systematic shovel testing at 30 m intervals should be undertaken on available surfaces, with visual examination of other environments for exposed archaeological deposits (such as in treefalls or shorelines).

• Professional judgment in the selection of strategy, the array of transects, and the placement of subsurface tests must be justified in the report that results from the Phase I project.  Field conditions that limit or prevent investigation of an area such as inundation, disturbance, standing crops, etc. must be delimited on a map of the project area and explained in the report.  Investigators are encouraged to discuss survey strategies with the Division prior to field work if difficult conditions are anticipated.

• Survey strategies must consider factors such as proximity to streams, topographic elevations, slopes, and roads, among other considerations, when determining high and low probabilities for cultural resources. 

• Survey transects must be 30 m apart with individual shovel tests placed at 30 m intervals for high probability areas, and 50 m apart with individual shovel tests placed at 50 m intervals for low probability areas.  Areas of low probability for cultural resources must be surveyed and tested.  Low probability does not mean “no probability” and areas so designated must be surveyed.  Survey shovel tests are not necessary on topographic slopes greater than 30 degrees (except inclines with intermittent level terraces that should be tested) or in other landforms where human occupation is unlikely such as swamps, filled relict channels etc.

• Each shovel test should attempt to extend to the subsoil, or to a depth of 50 cm, whichever comes first.  Each shovel test should be at least 30 x 30 cm in size.  The soil matrix for shovel tests must be screened through ¼ inch (or finer) mesh hardware cloth.  If screening is not possible or practical, conduct alternative methods (e.g. trowel sorting) for investigating the shovel test matrix.  The Division encourages investigators to employ additional techniques such as soil probes or augers to determine soil stratigraphy at depths greater than 50 cm where possible.

• The results of all shovel tests should be recorded in field notes or shovel test forms.

• The general soil stratigraphy revealed by shovel tests within a project area must be presented in reports with discussions of representative soil texture and color using Munsell Soil Color designations.

• The cultural material recovered from all shovel tests should be collected and recorded in field notes or shovel test forms.

• Deep testing is appropriate whenever there is a potential for sites to be buried below the depth of shovel tests.  Testing should occur to the depth of the project’s expected ground disturbance, whenever practical.  Representative profiles of augers, cores, soil probes, or mechanically excavated trenches must be presented in a report on the project and plotted on a map of the project area.  Samples of potential cultural deposits collected from augers, cores and trenches should be screened through ¼ inch or finer mesh.

• At least one overview photograph should be taken of each site to illustrate the setting, ground cover, etc.  It is preferable to include a person, building, or other common object in the photograph for scale.

• If shovel testing done as part of a Phase I survey indicates features or artifacts that suggest a site may be eligible for the National Register of Historic Places, additional investigation, usually Phase II testing, may be warranted.  The standards for Phase II field investigations in Louisiana should then be consulted. 

•  An investigator must contact the Louisiana Division of Archaeology as soon as possible if the demands of a particular project call for a Phase II assessment of an archaeological site before the submission of a Phase I report. 

• Terrestrial remote sensing methods provide another means of searching for and identifying sites not visible on the surface, or for delineating site boundaries.  Remote sensing surveys should use transects and spacing appropriate for the particular method employed; these decisions should be explained in the report.  Frequently used remote sensing techniques include ground penetrating radar (GPR), magnetometry, and soil resistivity, among others.

• Sites identified initially via remote sensing data should be confirmed in the field through shovel testing, soil probes, or some other subsurface testing technique unless the results of the remote sensing indicates there is a high probability of disturbing human remains.

• Remote sensing is not an acceptable substitute for other Phase I survey techniques.  It must be used in conjunction with systematic pedestrian surveys and shovel testing.

• Investigators are encouraged to consult with the Division concerning survey strategies prior to field work if substantial deviations from these standards are anticipated.  Any agreed revised strategies should be documented via email or letter and discussed in the report.  Any necessary deviations developed while in the field must also be fully discussed and justified in the report.

Survey Standards for Urban Areas

• An urban property is defined as any lot within the boundaries of a platted city block within an incorporated city, village or town.

• Investigators are strongly encouraged to discuss urban survey strategies with the Division as the research proposal is developed.  Deviations from these standards can be agreed upon prior to beginning fieldwork and described in the report.  Any deviations developed in the field, and their rationale, must be described in the report.

• If the property lies within a high site probability zone, at least one shovel test should be excavated for each 150 sq m of area .  If possible, at least two shovel tests should be placed where available historic maps (e.g., Sanborn Map Company) indicate subsurface features such as privies, wells, etc. are likely to be located.  At least one shovel test should be placed elsewhere on the lot to provide greater coverage.  This latter shovel test is particularly important in settings where there is a greater probability for Native American sites to be present.  If the lot is greater than 450 sq m in size, the additional shovel tests should be systematically placed (to the extent possible) across the property.

• If the property lies within a low site probability zone, a minimum of one (1) shovel test should be excavated for each 450 sq m of area.  It should be placed in the area where historic maps (if available) indicate the greatest likelihood of intact deposits would be located.

• In addition to shovel tests, the use of soil probes and/or augers is strongly encouraged to prospect for subsurface features.  Remote sensing can also be a very cost-effective means of assessing the potential for sub-surface features, especially when examining lots covered by paving, slabs or fill.

• Mechanically excavated trenches can be an effective survey strategy in some circumstances.  When the surface is obscured by paving, slabs, or fill, a mechanical methods may be employed to remove the overburden and expose areas for shovel testing.  Alternatively, a backhoe/trackhoe/other machine may trench across the lot with thorough examination of both trench walls.  In high site probability areas, at least 10 m of trench (can be discontinuous; i.e., two 5 m segments or four 3 m segments to accommodate lot size, buildings, utilities, etc.) should be excavated for each 450 sq m of area.  In low site probability areas, at least 10 m of trench should be excavated for each 900 sq m of area.

• If a site is identified, site boundaries are assumed to be the lot boundaries unless the investigator presents evidence documenting the continuation of the site outside the tested lot.  For some projects however, the investigator and the Division may agree prior to fieldwork on different site boundary definitions (for example, defining the city block as the site with individual loci (lots) within it).  The location of all shovel tests, probes, augers, and backhoe trenches must be shown on the project map (and site map if applicable).  Representative shovel test and trench profiles should be documented and presented in the report.

• Standards for site forms, artifact collection, and curation of collections and records are the same as for a regular Phase I survey and can be found in the Phase I survey standards (click here).

Survey Standards for Marsh and Inundated Areas

• Surveys in inundated or marsh environments conducted by boat or airboat are limited to examination of exposed ground (such as remnant natural levees).  Systematic shovel testing at 30 m intervals should be undertaken on available surfaces, with visual examination of other environments for exposed archaeological deposits (such as treefalls, dredged spoil deposits, banklines or eroding shorelines).

Human Remains

• In the event human remains should be encountered during a Phase I project, work must stop immediately in the vicinity of the uncovered human remains.  Notice regarding the discovery must be made to the appropriate local law enforcement agency and the appropriate Parish Coroner's Office following the provisions of the Louisiana Unmarked Human Burial Sites Preservation Act (R.S. 8:671-871, et seq.).  The State Archaeologist must be notified within 72 hours of the discovery.  Within 24-hours of notification, the State Archaeologist shall notify any Native American tribe that have indicated interest in the area where the discovery of human remains was made.  The local law enforcement officials shall assess the nature and age of the human skeletal remains. If the coroner determines that the human skeletal remains are older than 50 years of age, the Louisiana Division of Archaeology has jurisdiction over the remains and will work out appropriate plans among property owners, appropriate Tribes, living descendents, and other interested parties to insure compliance with existing state laws.  No remains will be removed from the site until jurisdiction is established and the appropriate permits obtained from the Division.

• Human remains discovered during a survey on federal or Tribal lands are the responsibility of the lead federal agency under the terms of the Native American Graves Protection and Repatriation Act (NAGPRA).

Defining Archaeological Site Boundaries

• In Louisiana, an archaeological site is defined as a locus that contains at least five artifacts and/or an intact feature, with either surface or subsurface provenience, that are at least fifty years old.  Surface scatter sites must consist of five or more artifacts within an area no greater than 30 x 30 m.  The Division of Archaeology will consider proposed exceptions to these conditions on a case-by-case basis.

• Investigators will submit an archaeological site form or site update form for all archaeological sites encountered within a Phase I project area.  The Division also encourages, but does not require, site forms or site form updates for archaeo-logical sites adjacent to or near project areas being surveyed if investigators visit the site. 

• If an archaeological site is identified during a pedestrian survey by artifacts visible on the ground surface, its boundaries are to be defined by measurement of the extent of the artifact scatter, preferably in cardinal or grid cardinal directions.  Shovel tests must be placed within a surface scatter site to determine the depth, if any, of the cultural deposits.  Site boundaries should also reflect the positive results of shovel testing that extends beyond a surface scatter of artifacts.

• Shovel testing for site definition is not necessary for portions of a site that are outside the project boundaries.  All documents concerning the site, however, must indicate that the site remains undefined beyond the project boundaries.  The site maps must show the site boundary at the project boundary in these instances.

• If an archaeological site is identified primarily by artifacts recovered during shovel testing, the boundaries should be defined by placing additional tests at 10 m intervals in the cardinal, or grid cardinal, directions from the original positive shovel test.  These cardinal shovel tests should continue until at least two negative tests along each direction are excavated.  Shovel testing for site definition should continue with additional shovel testing from each positive shovel test in the cardinal directions.  If, however, positive shovel tests for site definition extend to three consecutive tests at 10-meter intervals, the intervals between shovel tests may be extended to 20-meter intervals.  If there are two consecutive negative shovel tests at 20m shovel test intervals, site definition should continue with a shovel test 10 m from the last positive shovel test.  An example of this expanded cruciform pattern of site definition shovel testing is presented below. 

• Unless circumscribed by the boundaries of the project area, natural features such as streambeds or hill slopes, or man-made features such as ditches, driveways, or structures, nine (9) is the minimum number of shovel tests excavated for site definition.  This number is the result of the original positive shovel test; with two shovel tests in each of the four cardinal directions excavated in 10-meter intervals.

• If augering, coring, or soil probing identify an archaeological site during Phase I investigations, additional tests at 10 m intervals in the cardinal (or grid cardinal) directions from the original positive test must be excavated to define the limits.  Due to the relatively small sample size provided by these techniques, it is recognized that limits may be difficult to define and other factors such as topography, geological history, etc. can be used to infer probable site boundaries.  This information should be presented in the resulting site form and report for the Phase I investigation.

• If a site is identified within a mechanically excavated trench, cores or augers should be used to define the limits to avoid substantial impact to the site through numerous trenches.  If trenching is necessary, it should be limited to the minimum number of trenches necessary to provide approximate site limits.

• Investigators must provide the UTMs of the center point of an archaeological site by a Global Positioning System (GPS) device.  At least four additional GPS points are required to define the boundaries of sites that are greater than 400 m2 in area.

• Locations of cultural material that are more than 50 years old, but do not meet other qualifications for being recorded as a site should be considered Isolated Finds and included in the report on Phase I investigations.

• At the completion of the project, investigators must assess if an identified site is “eligible”, “not eligible”, or “undetermined” for nomination to the National Register of Historic Places (NRHP).  Federal guidelines do not recognize the frequently used term “potentially eligible” as a legitimate recommendation for the NRHP.  The recommendation of “undetermined” for a site indicates that further investigations are necessary at a site to determine its eligibility for the NRHP.  Documentation for these assessments should be provided in the report submitted to the Division of Archaeology.

Collection Standards

• The Division encourages, but does not require, the curation of diagnostic artifacts recovered from Isolated Finds as a result of Phase I investigations.  Investigators may return materials from Isolated Finds to property owners or discard them.

• Investigators must retain all non-bulk cultural material recovered during a Phase I investigation of an archaeological site.

• Investigators must separate all archaeological materials by their provenience for curation.

• Investigators can count or weigh bulk materials such as brick, mortar, plaster, shell, and gravel in the field or lab with only a representative 10% sample retained for curation.  Bulk material samples submitted for curation may not exceed 250 grams (10.5 oz.) each without prior approval by the Division of Archaeology.

• Investigators must retain all field notes, field forms, photographs, and other documentation for curation.

• Catalog numbers for each site must be obtained from the Division of Archaeology.

• Please see our Curation Standards for more specific information about curation standards.