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5.0 FIELD INVESTIGATIONS

5.1 OVERVIEW

The objective of the present study was to identify archeological sites that could be affected by the NASM project, evaluate the significance of those sites, and assist in developing measures to reduce or minimize project impacts on sites found to be significant. To accomplish this, Dames & Moore conducted archeological field reconnaissance on selected portions of the NASM project area. Information from these investigations has been incorporated into the project throughout the planning, siting, and design phases, enabling NASM to avoid adverse effects to historic properties.

During Phase I field investigations, eight archeological sites were identified and investigated within the project area; two of them were potentially significant. The first, Historic Site B (44FX2259), was located in the area of a proposed taxiway. Because the inventory took place early in the planning process, the design was changed to resite the taxiway to a different location; that new location was surveyed for archeological sites as well (none was found). Potential impacts to Historic Site B were thus avoided. The second site, the Pump Site, was discovered in the west cloverleaf of the planned interchange at Route 28 and Gate 4. A Phase II evaluation was carried out and it was determined that the site is not significant.

5.2 AREA OF POTENTIAL EFFECT

Review of the NASM center Draft Master Plan at the start of the fieldwork (October 1995) indicated that ground disturbing activities will be undertaken on a total of approximately 168 acres of property at Dulles Airport. These construction and landscaping activities are associated with the proposed taxiway, access roads, parking areas, highway interchange and the museum building itself. In 1997, an additional 7 acres were added for a utility corridor, jeep access road, and a new route for the taxiway. Together these areas constitute the zone in which an archeological resource, if present, could be disturbed by the project. This 175-acre area thus constitutes the Area of Potential Effect for archeological resources, and was the focus of subsurface archeological testing for the Phase I field reconnaissance, and Phase II site evaluation (See Figure 3-1). The Area of Potential Effect lies primarily within three larger NASM areas, the Central Parcel, the North Parcel and the East Parcel. Areas outside of the 175 acres but within these three NASM parcels will not be subject to development or to ground disturbing activity, and were therefore not subject to archeological investigation.

Broken down by the approximate area within each parcel, the 175-acre Area of Potential Effect includes:

  • 80 acres in the Central Parcel, including the footprint of the proposed building, parking lot, taxiway, utility corridor, jeep road, and access roadway;

  • 25 acres in the North Parcel, including the two corridor alternatives for the taxiway to the Dulles Airport runway;

  • 40 acres in the East Parcel for the roadway and western half of Route 28 interchange;

  • 30 acres abutting the east side of the East Parcel for the eastern half of the Route 28 interchange; it is on private land to be acquired in support of the project by the Virginia Department of Transportation.

5.3 FIELDWORK

Fieldwork for the Phase I study began with initial reconnaissance in October 1995; shovel testing was conducted from October 1995 through January 1996, and again from March through May 1996. Fieldwork was halted between January and March due to inclement weather. Finally, Phase II investigation of the Pump Site and additional Phase I testing was completed in July and August of 1997. The Dames & Moore field team conducting the work included Principal Investigator, Dr. Emlen Myers and Crew Chiefs, Susan Travis and Heather Crowl. The size of the field crew varied from two to seven people at a time. Weather conditions throughout the period of the fieldwork also varied, although they were generally good. Early winter foliage in the deciduous and coniferous woods of the project area allowed excellent line-of-site inspection of the project area at the beginning of fieldwork. Leaf and pine-needle litter in wooded areas and grass in unwooded areas, however, limited archeological surface visibility to 10 percent or less.

5.4 PHASE I METHODOLOGY

Intensive field reconnaissance included planning and grid setup, field survey, and analysis/reporting. Planning and setup involved consultation with the VDHR and MWAA to ensure that the proposed methodology for field investigation would be appropriate, and focused background research to expand the relevant information provided by MWAA to Dames & Moore for the 1995 site constraints phase of the NEPA process.

The intensive field reconnaissance included three components: walkover survey, shovel testing, and remapping of previously known sites. Walkover survey consisted of visual observation of current surface conditions to look for indications of archeological resources and to identify areas of potential previous disturbance. Shovel testing, the primary means of investigation for the fieldwork, was based on a grid of observation points established at an interval of 75 feet (approximately 8 points per acre). The grid of observation points was laid out using a compass and cloth measuring tape; a transit was used in some areas with a long line-of-sight for greater accuracy. Each observation point was flagged and labeled with a unique letter and number to facilitate field recording and subsequent mapping and analysis.

In theory, a 75-foot interval yielded a total of approximately 1,400 observation points distributed over the 175-acre Area of Potential Effect. The actual zone of investigation was extended beyond the 175-acre area of investigation, however, in order to ensure that all construction areas would be surveyed. As a result, the field grid included 1,650 observations points. A shovel test pit was excavated at each observation point unless field conditions precluded excavation. The protocol for this decision-making was that shovel test pits were dug unless one of the following established criteria was met:

  • ground slope of 15 percent or more off horizontal;

  • the presence of statutory wetlands;

  • substantial ground disturbance that ruled out the presence of archeological resources.

On the basis of these criteria, 1307 observation points were shovel tested.

Shovel test pits were approximately 1? feet in diameter and measured an average of 1? to 2 feet in depth. Field archeologists excavated shovel test pits into sterile subsoil, except where they encountered an impenetrable object, where the pit filled completely with water, or where subsoil was located below the limits of hand excavation (found primarily along drainages). Soils recovered from the shovel test pits were sifted through ?-inch hardware cloth mesh in order to retrieve any cultural materials (Figure 5-1). As each shovel test pit was completed, the field crew filled out a standard Dames & Moore shovel test pit form, recording observations derived from shovel testing (Figure 5-2). They noted the depth, soil description, and cultural materials recovered from each stratum, and sketched the soil profile of each shovel test pit. Even where conditions precluded the excavation of an observation point, a form was completed to record the field conditions and reasons for not excavating. Historic and prehistoric artifacts were placed in bags labeled with the shovel test pit number and excavation level.

Additional shovel test pits were excavated on a 25-foot interval around shovel tests that yielded cultural material. These additional radial tests allowed field archeologists to determine whether an artifact was an isolated find or part of a more extensive deposit or site.

To help understand the stratigraphy of the sampled area, soils were described according to standardized texture and color descriptions. The texture of soil may be sandy, silty, or clayey, or any combination thereof (a mixture of all three is referred to as a "loam"). The color of the soil is described by standardized color descriptions presented in a Munsell Color Chart. The Munsell book displays 251 standard color chips, arranged systematically, against which a sample of soil is compared. The colors are arranged by three variables known as Hue, Value, and Chroma in the Munsell system.


FIGURE 5-1:
Excavating and Screening a Shovel Test Pit,
West Cloverleaf, View from the East

The Hue indicates the relation of the color to red and yellow, and is represented in the notation by a number and a letter or letter combination. The numbers are from 0 to 10 indicating the amount of red or yellow within that hue; the hues become more red and less yellow as the numbers increase. The letter or letter combination uses the first letter of the hue (i.e. R for red, Y for yellow, and YR for yellowish red). The notation for Value consists of numbers from 0 for absolute black to 10 for absolute white, and indicates relative lightness of the soil color. For example, a 6 indicates that the value is 60 percent of the way from black to white. The notation for Chroma consists of numbers 0 for neutral to about 20 for very strong, and indicates how far from a neutral of the same lightness a color is. To write a Munsell notation, the order is Hue, Value, Chroma, with a space between the hue letter and the value number, and a diagonal line between the value and chroma (e.g. 10YR 5/6).


FIGURE 5-2:
Recording a Shovel Test Pit,
West Cloverleaf, View from the East

In addition to the standardized notations for describing soils, the Munsell book also lists standardized color names, which follow the Munsell notation in the soil descriptions (e.g. 10YR 5/6 yellowish brown). Following this comes the designation of texture in a standard soil description (e.g. 10YR 5/6 yellowish brown silty clay loam).

Soil observations recorded using this method were employed to confirm and refine Soil Conservation Service (SCS) data available for the project area (SCS 1974). The soils encountered during the shovel testing conformed closely to the published SCS data and are presented in the Findings (Section 6) of this report.

To facilitate the investigations, field archeologists divided the Area of Potential Effect into eight sections located within the three project parcels. These sections are the central parcel, the east and west cloverleaves of the Barnsfield Road/Route 28 Interchange, the utility corridor, and four access routes: the east parcel road, central parcel road, jeep road, and two alternatives of the north taxiway (see Figure 3-1). Descriptions of each of the sections and the specific procedures employed for each are discussed below.

5.4.1 Central Parcel

The central parcel constitutes the largest part of the Area of Potential Effect. It includes the proposed footprint of the museum, parking lot, and service roads. Most of the area is planted with rows of loblolly pines. In the eastern area of the central parcel cedar trees predominate. The northern section is a young deciduous forest, with a wetland and a few large oak trees. Gravel service roads cut across the central area. Two main streams run through the area; the Cain Branch flows along its southern boundary. Logging operations and storm drain construction has disturbed the soil in many areas, especially in the southern part of the parcel. Figures 5-3, 5-4, 5-5, and 5-6 are representative photographs of the field conditions encountered in the central parcel.

The observation point grid over the central area was laid out from a baseline established along an existing gravel road that runs adjacent to the western boundary of the Central Parcel. The road allowed a clear direction line-of-sight, and the baseline was established using a transit. (All remaining layout, in the central parcel and elsewhere, was accomplished with a compass and cloth measuring tape.) The baseline ran in an approximately north-south orientation (363.5E) and included 36 points lettered A through JJ. Perpendicular transects were laid out to the west off of the baseline. Observation points were numbered up to 24 on each of the lettered transects. Archeologists investigated 838 observation points and excavated 741 shovel test pits in the central parcel. The remaining 97 observation points were not excavated because they were in wetlands, streams, or disturbed areas along the gravel roads.

5.4.2 Barnsfield Road/Route 28 Interchange

The proposed interchange at Route 28 (east and west cloverleaves) is in the east parcel area. Route 28 currently separates the east and west cloverleaf areas.

FIGURE 5-4:
Planted Pines, Central Parcel,
in the Vicinity of Site 44FX693,
View from the West
FIGURE 5-3:
Gravel Service Road, Central Parcel,
View from the East
FIGURE 5-6
Grass Field, North Taxiway,
View from the Southwest
FIGURE 5-5
Deciduous Woods, Central Parcel,
View from the East

West Cloverleaf. The west cloverleaf is located within the east parcel. Rows of loblolly pines are planted across the west cloverleaf, as in the central parcel. The far western part of the cloverleaf is in an open field with short, mowed grass to provide safe access to the runways. Thick undergrowth is present in much of the area. A stream marks the southern boundary of the west cloverleaf. A large artificial mound is located in the middle of the area, probably a spoil pile created during construction of Route 28. The baseline for shovel test pit placement within the east cloverleaf area was laid out along the edge of a gravel service road that runs in a north-south direction parallel to Route 28. The 27 transects were labeled A through AA, from north to south. The length of the transects conformed to the proposed footprint of each cloverleaf, and varied from 2 to 13 observation points long. Layout was accomplished with compass and cloth tape. Twelve additional shovel test pits were excavated outside the footprint of the southwest cloverleaf in order to define the boundaries of a site. Two hundred thirty-seven observation points were investigated; 173 shovel test pits were excavated. Disturbance (Route 28, a gravel road and the large mound) was the main reason observation points were not excavated.

East Cloverleaf. The east cloverleaf (a mirror image of the west cloverleaf), is located on the east side of Route 28. The area is located outside of Dulles Airport on privately owned property that will be acquired for the proposed Route 28 interchange. The area is relatively flat but includes a drainage ditch associated with Route 28 on its western edge and a slight upward slope as one approaches its eastern edge. Ground cover consists of grasses, small scrub pines and junipers; substantial wetland areas are present. Various utility lines and Route 28 have disturbed a large part of the area. A baseline for the east cloverleaf was laid out parallel to Route 28 along a power line. The 27 transects were labeled A through AA, from north to south. Perpendicular transects were laid out to the east off of the baseline. The length of the transects conformed to the proposed footprint of each cloverleaf, and varied from two to ten observation points long. Of the 193 observation points in the east cloverleaf, only 80 were excavated; the remainder were either in wetlands or were disturbed.

5.4.3 Automobile Access Roads, Utility Corridor, and Taxiways

Two roads are proposed to allow access to the museum (see Figure 1-2). A public access road will connect the proposed interchange at Route 28 north of Barnsfield Road with the north end of the parking lot east of the museum. The other road will provide access to the parking lot from the south at Route 50; this road will be primarily for employee and emergency vehicle use. A gravel road south of the central parcel will provide security access to the museum area from the perimeter gravel access road. An area was investigated along the western edge of the central parcel for construction of utility lines. Two alternative areas were investigated as potential locations for a taxiway that will connect the NASM Center to Dulles Airport to provide access for aircraft. Observation points in these irregularly shaped linear areas were laid out using a compass and cloth tape; point locations were checked against field flagging placed for the Dames & Moore wetland delineation for the project.

East Parcel Road. The east parcel road will connect the proposed interchange at Route 28 to the museum. The proposed road runs west from the west cloverleaf across a mown field to an area of sparse deciduous trees, connecting with the east side of the central parcel (see Figure 3-1). The road was investigated through two parallel transects arbitrarily labeled W and X that followed the center of the proposed road. The transects originate from and continue transects L and M of the west cloverleaf. A total of 60 observation points was investigated and 56 shovel test pits were excavated. Two observation points were in a disturbed gravel road; two were in wetlands.

Central Parcel Road. The central parcel road will provide emergency vehicle and possible visitor access to the museum from Route 50. The road lies in the southern portion of the central parcel in an area of young mixed coniferous and deciduous woods. The proposed road crosses numerous seasonal streams and the Cain Branch. The road was investigated using a single transect (arbitrarily labeled Q) with numbered observation points from 1 to 38. The transect followed the center of the proposed road. Thirty-four test pits were excavated along the central parcel road; four test pits not excavated were in wetlands and the Cain Branch.

Jeep Road. The jeep road will connect the southern airport property perimeter road to the museum facility. The road is in the southern portion of the central parcel, and crosses the central parcel road. Vegetation along the route for the jeep road included young deciduous trees and a moderately dense under story of poison ivy, poison oak, blackberry and other plants. The road was investigated using a single transect (arbitrarily labeled M) with numbered observation points from 1 to 25. The transect followed the center of the proposed road. Twenty test pits were excavated along the jeep road; five test pits not excavated were on a steep slope down to the Cain Branch or were within the Cain Branch.

Utility Corridor. The utility corridor runs over gently rolling slopes of the south western portion of the central parcel. A single transect (labeled L) was investigated south of the central parcel, extending to Route 50. Vegetation is primarily loblolly pines planted in rows. Twenty-one shovel test pits were excavated along the utility corridor.

North Taxiway. The north taxiway will provide access for air craft going to and from the runway for demonstrations and for initial transportation to the museum. Two alternative locations were considered for the taxiway. The first alternative (alternative A) runs from existing runway 36R to the northeast of the central parcel area (see Figure 3-1). The majority of the north taxiway is in an open field of short mown grass that has been cleared for safe landing on the runways (see Figure 5-6). The remainder of the taxiway is in young deciduous forest, with occasional large trees. The route crosses one wetland area with a spring. The taxiway was investigated using two parallel transects arbitrarily labeled Y and Z. Observation points along this route were numbered from 1 (in the north along the paved access road from gate 4) to 38 (where the transects meet the central area). The far northern area between the runway and the paved road was investigated using a series of five transects labeled east to west A through E. Transects were placed in this area to guarantee coverage and minimize the possible need to return to the area and schedule around runway traffic. A total of 153 observation points was investigated along the first alternative route of the proposed taxiway; 137 shovel test pits were excavated.

The second alternative (alternative B) initially follows the route of alternative A from the runway south. Rather than bending to meet the central parcel at shovel test pit JJ-11, it continues further west and intersects the central parcel at shovel test pit JJ-1. Alternative B avoids both a large wetland and an archaeological site. It passes across a mown field and young deciduous forests, and traverses two streams. Forty-six additional shovel test pits were investigated along two transects (arbitrarily labeled E and F) of the second alternative taxiway.

5.4.4 Remapping of Previously Known Sites

The next step in the intensive Phase I field reconnaissance was to revisit and confirm the presence of the seven archeological sites in the area of the central parcel that had been identified previously (based on the VDHR inventory) and to assess their current condition and potential significance. These prehistoric sites were mainly ephemeral lithic scatters. They include: FX691, FX692, FX693, FX694, FX1558, FX1559, and FX1560. Archeologists used walkover reconnaissance and the results of the shovel test survey to confirm the location and condition of known sites. Of the seven sites, only the first four were identified again.

5.5 PHASE II METHODOLOGY

The objective of the Phase II investigation of the Pump Site (44FX2257) was to evaluate the significance of the site and its eligibility for inclusion in the National Register of Historic Places. Phase II objectives were to define the site boundary, cultural affiliation, and site date, to understand the subsurface content of the site, and to investigate the stratigraphic integrity of the site. On the basis of the Phase II evaluation, the Pump Site does not appear to be eligible for inclusion in the National Register of Historic Places because it lacks integrity; no intact strata or features were found below the plowzone.

The Phase II evaluation of the Pump Site was completed in July 1997. The fieldwork involved excavation of eight 5 by 5 foot test units, and excavation of approximately 32 shovel test pits. The test units were used to evaluate the subsurface contents and stratigraphic integrity of the site, and the additional shovel test pits helped to define the site boundaries and the locations of artifact concentrations within the site.

Because the Pump Site was located on the project area boundary for the west cloverleaf of the Barnsfield Road/Route 28 interchange, the Phase I survey did not determine if the site extended outside of the Area of Potential Effect to the west. Thus, 12 of the Phase II shovel text pits were excavated outside of the Area of Potential Effect to define the western boundary of the Pump Site.

In general the Phase II shovel test pits confirmed the spatial extent and artifactual content of the site indicated by the Phase I testing. The Pump Site was found to lie entirely within the Area of Potential Effect and to contain eighteenth century through early twentieth century domestic artifacts.

The Pump Site includes a small knoll with gentle slopes down on each side. A hand operated water pump is located approximately 100 feet northwest of the main site area. A clearing is located on the top of and on the western slope of the knoll. Loblolly pines planted across the remainder of the west cloverleaf do not grow in this area; it is vegetated with vines, blackberry, green briar, shrubs, and a rose bush. Cedar and pine trees surround the clearing.

Placement of the eight Phase II test units was designed to investigate areas of high artifact concentration identified through shovel test pits, and to investigate the variety of topographic and vegetation conditions present at the site. Units 1 and 7 were located near the western base of a small knoll, adjacent to the most productive Phase I shovel test (T-5). Unit 1 was inside the clearing, five feet south of shovel test pit T-5; Unit 7 was outside of the clearing, ten feet north of test pit T-5. Unit 3 was placed on the western slope of the knoll where a brick fragment was found on the surface. Unit 4 was placed five feet northwest of the water pump in order to investigate the pump area and the possible presence of earlier resources in the immediate area. Unit 5 is on the north side of the knoll-top, adjacent to shovel test pit T-4 which included a kaolin pipe bowl fragment. Unit 6 was placed in the clearing near the top of the knoll. Unit 8 is on the east side of the knoll-top. Unit 2 was placed near the bottom of the gentle down slope to the east, adjacent to shovel test pit U-3.

Phase II units were excavated according to natural stratigraphy. Flat shovels and trowels were used to carefully excavate layers of soil so that soil changes and soil stains or features, if present, would be seen. One corner of each unit was used as the datum point for the unit from which depth measurements were made. A unit form describing the soil color and texture, artifacts recovered, depths, and general observations was filled out for each stratigraphic layer within each unit. Soil excavated from the units was screened through ?-inch hardware mesh to recover artifacts. Artifacts were bagged in the field according to provenience within each unit, and transported to the Dames & Moore laboratory in Bethesda, Maryland, for analysis.


Introduction Chap. 2: Historic Preservation Compliance
Chap. 3: Project Area Description Chap. 4: Background Research
Chap. 5: Field Investigations Chap. 6: Laboratory Investigations
Chap. 7: Archeological Findings of Phase I Survey Chap. 8: Archeological Findings of Phase II Survey
Chap. 9: Summary and Recommendations Chap. 10: Bibliography
Related Archaeology Websites

 


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