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HomeMy WebLinkAboutSD-20-40 - Supplemental - 0500 Old Farm Road (14) August 6, 2019 Andrew Gill O’Brien Brothers Agency 1855 Williston Road South Burlington, VT 05403 RE: End of Field Letter for Archaeological Phase II Site Evaluation for Pre-Contact Era Native American Sites VT-CH-1076 and VT-CH-1199 for the O’Brien Brothers Agency Home Farm Project, South Burlington, Chittenden County, Vermont Dear Andrew: From June 20th-28th, 2019, the University of Vermont Consulting Archaeology Program (UVM CAP) conducted archaeological Phase II site evaluations at pre-Contact era Native American sites VT-CH-1076 and VT-CH-1199 for the proposed O’Brien Brothers Agency Home Farm project located in South Burlington, Chittenden County, Vermont. These Phase II studies followed previous Phase I site identification studies conducted by the UVM CAP in 2009 and 2016, which resulted in the identification of pre-Contact era Native American sites VT-CH- 1076 and VT-CH-1199, respectively. Site VT-CH-1076 was identified based on the recovery of numerous lithic artifacts from the surface of the plowed field within on the west side of Kimball Avenue to the north of a tributary of Potash Brook (Figure 1). Site VT-CH-1199 was identified during a Phase I study that included both surface survey and subsurface test pit sampling within agricultural fields located to the west of VT-CH-1076 between Old Farm Road and Kimball Avenue (see Figure 1). Because deposits at site VT-CH-1199 were spread over a large area, the concentrations of Native American archaeological deposits were divided into five spatially discrete areas, designated as Loci 1-5 (see Figure 1). Field Methods Site VT-CH-1199 was first identified in 2016 and, during the recently completed 2019 Phase II study, no visible evidence of the subsurface test pits could be relocated. As a result, the locations of the Phase I Survey test pits and surface finds were reconstructed using Global Positioning System (GPS) data collected in 2016. From these data, an arbitrary horizontal grid was established across the site to correlate the testing within separate loci. A baseline was first established by designating Phase I, Transect 12, Test Pit 4 as grid coordinate N100 E100, SW, and the Transect 12 azimuth as the angle for the E100 baseline. Once established, the horizontal metric grid was extended across the larger site area to include Locus 3, Locus 4 and Locus 5. The metric grid was not extended to Locus 1 as the 2016 subsurface testing in this portion of the site was oriented along a different azimuth and would not conform to the Phase II grid. Instead, the 2 original azimuth orientation of the Phase I transects within Locus 1 was used to align the Phase II test pits (Figure 2). Once the grid had been established, 50 x 50 cm (20 x 20 in) test pits were aligned within each locus at 5 m (16 ft) metric grid intervals. The extent of subsurface testing was determined by positive Phase I and Phase II test pits and the location of surface finds. All soils were excavated in systematic 10 cm (4 in) vertical levels with respected to the local soil stratigraphy and screened through 0.32 cm (1/8 in) mesh screens. A representative wall of each test pit was schematically profiled according to the soil strata’s color and texture. When artifacts were identified, they were collected in appropriately labelled plastic bags and entered into a field catalog. The locations of select test pits were recorded with a handheld GPS to further anchor the grid geospatially. Given that the agricultural field was to be hayed, several labelled plastic pin flags at Locus 2 and 3 were sunk to ground level in order to preserve them. At Locus 1, 4 and 5, where no positive test pits were identified, all pin flags were removed. At site VT-CH-1076, a unique horizontal metric grid was established (separate from that of VT-CH-1199). Two linear rows of test pits, spaced 10 m (33 ft) apart were emplaced at the northern edge of the known site area in order to better assess site boundary in this portion of the project area. The test pits along each metric grid line were offset by 5 m (16 ft) to provide optimal coverage. The excavation methodology followed that employed at site VT-CH-1199. Site VT-CH-1199 Phase II Results Locus 1 Locus 1 of site VT-CH-1199 was identified by the recovery of a quartzite tool recovered from the plowzone stratum of Phase I Transect 14, Test Pit 6 (see Figure 2). The Phase II testing included the excavation of four test pits spaced at 5 m (16 ft) intervals in cardinal directions around Transect 14, Test Pit 6. No additional artifacts were recovered. The soil stratigraphy included a 20-30 cm (8-12 in) thick uppermost historic era plowzone characterized as very dark brown silt loam. Beneath the plowzone, dark yellowish brown fine sandy loam subsoil was encountered to depths of 50 cm (20 in). Locus 2 Locus 2 of site VT-CH-1199 was identified by the recovery of one lithic debitage specimen each from Phase I Transect 11, Test Pit 7, Transect 12, Test Pit 4 and a test pit located 5 m (16 ft) to the south of Transect 12, Test Pit 4 (designated N95 E100)(Figure 3). Two of the debitage specimens were derived from Hathaway chert and the other from quartzite. All of the debitage was recovered from a plowzone context. In addition, one quartzite debitage specimen was recovered from the plowed surface approximately 18 m (59 ft) to the east of Transect 12, Test Pit 4 (see Figure 3). 3 To initiate the Phase II study of Locus 2, Transect 11, Test Pit 7 and Transect 12, Test Pit 4 were re-located via the use of the 2016 GPS data. A total of 25 50 x 50 cm (20 x 20 in) test pits were excavated at Locus 2 during the Phase II study (see Figure 3). Five of the test pits were excavated in the vicinity of Transect 12, Test Pit 4 and none produced additional artifacts. Two test pits, emplaced in the vicinity of the surface-collected artifact located to the east also did not produce artifacts. A total of 18 test pits were excavated in the vicinity of Transect 11, Test Pit 7 (see Figure 3). Of these, six produced pre-Contact era lithic artifacts (see Figure 3). The total Phase II artifact inventory for the positive test pits included 8 specimens of quartzite debitage. Of this total, three were recovered from Test Pit N125 E95, and the remainder as singular artifacts from the other five test pits. In Test Pit N125 E95, two of the quartzite debitage specimens were recovered from a plowzone context and the third debitage specimen from the intact subsoil. As lithic debitage is not temporally diagnostic, the age(s) of Locus 2 are not known at present. The local soils include one or two plowzone strata that terminate at depths from 25-44 cm (9.8-17.3 in) below the ground surface. The plowzone is characterized as very dark brown to dark grayish brown silt loam. Beneath the plowzone, the intact subsoil was characterized as dark yellowish brown to light olive brown fine sandy loam with light gravel content. Based on the horizontal distribution of the Phase I and II subsurface collected artifacts, Locus 2 encompasses a combined area of approximately 500 sq. m (5,382 sq. ft). This size approximation excludes the isolated quartzite debitage recovered during the Phase I surface inspection. Locus 3 Locus 3 was identified during the 2016 Phase I surface inspection by the recovery of five lithic artifacts from the plowed ground surface (Figure 4). These artifacts include two temporally diagnostic projectile points dateable to the Late Archaic period, ca. 6,000-3,000 calendar years before present, two lithic debitage specimens and a fragment of fire-cracked rock. To assess the locus, a total of 27 test pits were excavated and of these, seven, or 26%, produced pre-Contact era Native American lithic artifacts. The Phase II artifact inventory includes a non-typeable quartzite projectile point fragment, a chert drill/projectile point, a ground incised “sinew” stone, a possible quartzite tool, nine quartzite and one chert debitage specimens, and one fragment of fire-cracked rock. Two of the quartzite debitage specimens were recovered from the intact subsoil of Test Pit N130 E150, and the remaining artifacts were recovered from a plowzone context. The local soils include one plowzone strata that terminates at depths from 20-35 cm (8- 13.7 in) below the ground surface. The plowzone is characterized as very dark brown to dark 4 grayish brown silt loam. Beneath the plowzone, the intact subsoil was characterized as dark yellowish brown to light olive brown fine sandy loam with light gravel content. Based on the horizontal distribution of the test pits producing artifacts and surface collected material, Locus 3 encompasses approximately 400 sq. m (4,305 sq. ft). The locus occupies a portion of a generally south-north level terrace that overlooks a tributary of Potash Brook to the east. Between the tributary and level terrace, the landform slopes moderately east and down to the tributary. To the west of the level terrace, the landform begins to rise incrementally up to Locus 2. The northern portion of the terrace is defined by a shallow swale that leads down and east to the tributary. Locus 4 Locus 4 of site VT-CH-1199 was identified by the recovery of a quartzite lithic tool fragment and two chert debitage specimens during the 2016 Phase I surface inspection (Figure 5). This locus is located on a level terrace just north of Locus 3, on the north side of a small swale. The tool represents a small fragment of a modified flake processing tool. All three of the Phase I artifacts were found within a level terrace that overlooks the Potash tributary to the east. A total of nine 50 x 50 cm (20 x 20 in) Phase II test pits were excavated at Locus 4 (see Figure 5) to test the landform in the vicinity of the surface finds. No artifacts were recovered from these test pits. The soils identified at Locus 4 include one or two historic era plowzones that extended to depths from 24-30 cm (9.4-12 in) below the ground surface and were characterized as grayish brown to brown silt loam. Beneath the plowzone(s), intact subsoil comprised of dark yellowish brown silt loam was present to depths of 40-55 cm (16-21.6 in). Locus 5 Locus 5 of site VT-CH-1199 was identified by the recovery of five lithic artifacts during the 2016 Phase I surface inspection. These artifacts include two quartzite lithic tools and three quartzite debitage specimens. The tools represent an early stage biface and a large modified flake. Four of the artifacts were loosely clustered along a treeline margin along a terrace edge, and the fifth was isolated in the central portion of the field to the south (Figure 6). Three test pits, designated N245 E120, E125 and E130, were excavated in the vicinity of the isolated quartzite debitage specimen (see Figure 6). No additional artifacts were recovered from these test pits. The soils encountered in these test pits were comprised of sandy loam and were highly saturated. A total of 11 50 x 50 cm (20 x 20 in) test pits were excavated among the loosely clustered Phase I surface-collected artifacts (see Figure 6). No additional artifacts were recovered from these test pits. The soils in this portion of the locus included an uppermost historic era plowzone and intact subsoil beneath and were comprised of fine sandy loam. 5 Site VT-CH-1076 Phase II Results Site VT-CH-1076 was identified in 2009 during a surface inspection of a small agricultural field parcel located along the northern side of a Potash Brook tributary and southwest of Kimball Avenue (Figure 7). A dense concentration of lithic artifacts were recovered along the margins of the terrace overlooking the tributary. This dense concentration of artifacts extended south from Kimball Avenue for approximately 80 m (262.4 ft). From the eastern margins of the field and terrace edge above the tributary, the artifact concentration extended northwest for approximately 40 m (131 ft) into the field and to the limits of the Phase I plowing. As presently known, the densest concentration of lithic artifacts and portion of the site with the highest data potential lies along the eastern margin of the plowed field adjacent to the wetland/stream. Given that site VT-CH-1076 is likely significant based on the density of artifacts recovered during the Phase I Survey, the Phase II study was intended to sample the area at the edge of the Phase I surface inspection to better define the site boundary to the north. To do this, a horizontal metric grid was established (separate from that employed at neighboring VT-CH- 1199) and a total of 12 50 x 50 cm (20 x 20 in) test pits were excavated. The test pits were located southwest to northeast along the toe of slope of and across a gently rising landform (see Figure 7). No artifacts were recovered from these test pits. The soils encountered in these test pits include one or two uppermost historic plowzones that generally extended to a depth of 30 cm (12 in). The plowzone(s) is characterized as dark brown silt loam. Beneath the plowzone, intact subsoil, characterized as olive brown silt loam, was excavated to depths of 45-60 cm (18-24 in). Conclusions and Recommendations The Phase II evaluation of site VT-CH-1199 included the excavation of a total of 79 test pits within the five designated site loci. Based on the cumulative Phase I and II results, the UVM CAP determines that Loci 1, 2, 4 and 5 do not contain significant Native American cultural deposits in these portions of broadly defined site VT-CH-1199. These assessments are based on the cumulative results of the Phase I surface survey and subsurface testing, the results of the Phase II testing, and the density and integrity of site deposits. We recommend therefore that proposed project construction will not have an adverse effect on significant archaeological resources in these four areas and that no further study is necessary prior to project construction. Within Locus 3 of site VT-CH-1199, the cumulative Phase I and II studies resulted in the recovery of significant site deposits including temporally diagnostic projectile points and three- four other stone tools, including a drill/projectile point and a “sinew” stone. The high proportion of lithic tools within the inventory from Locus 3 stands out and highlights the site area’s potential to contain multiple classes of data that can be assigned to specific time periods and site 6 functions. In addition, a limited quantity of lithic debitage also was recovered. Two of the debitage specimens were recovered from an intact subsoil, indicating that some of the archaeological resources in Locus 3 may have escaped plow disturbance. In summary, the UVM CAP recommends that Locus 3 of site VT-CH-1199 is significant and is eligible for inclusion on the State and National Register of Historic Places (NRHP). As such, any proposed project-related ground disturbance within the limits of Locus 3 would likely have an adverse effect on the significant site and, therefore, every effort should be made to avoid it and preserve it. If preservation and avoidance is not possible, then the UVM CAP recommends Phase III Data Recovery in Locus 3 prior to construction. Likewise, site VT-CH-1076 contains substantial site deposits as well and should also be considered significant. As with site VT-CH-1199, site VT-CH-1076 cannot be avoided and preserved in the context of the proposed project, then archaeological Phase III Data Recovery is recommended. The recommendations for both site VT-CH-1199 and site VT-CH-1076 are provisional, pending review by the Vermont Division for Historic Preservation (VDHP). Please feel free to contact us if you have questions regarding this study. Sincerely, Geoffrey A. Mandel Research Supervisor John G. Crock, Ph.D. UVM CAP Director 7 Figure 1. Aerial photo showing the location of sites VT-CH-1199 and VT-CH-1076 within the O’Brien Home Farm project area in South Burlington, Vermont. Note that the rough site boundaries depicted are based on the distribution of artifacts collected from the surface during the Phase I study in 2016 and positive test pits excavated as part of the Phase I, and the recently completed Phase II study in 2019. 8 Figure 2. Map showing the location of archaeological Phase I and Phase II 0.5 m x 0.5 m test pits and Phase I surface collected artifacts at Locus 1 of site VT-CH-1199 within the O’Brien Home Farm project area in South Burlington, Vermont. VT-CH-1199 Locus 1 9 Figure 3. Map showing the location of archaeological Phase I and Phase II 0.5 m x 0.5 m test pits and Phase I surface collected artifacts at Locus 3 of site VT-CH-1199 within the O’Brien Home Farm project area in South Burlington, Vermont. Note “LDEB” = lithic debitage. VT-CH-1199 Locus 2 10 Figure 4. Map showing the location of archaeological Phase II 0.5 m x 0.5 m test pits and Phase I surface collected artifacts at Locus 3 of site VT-CH-1199 within the O’Brien Home Farm project area in South Burlington, Vermont. Note “LTFL”= lithic flaked tool; “LTGR”= lithic groundstone tool; and “LDEB” = lithic debitage. VT-CH-1199 Locus 3 11 Figure 5. Map showing the location of archaeological Phase II 0.5 m x 0.5 m test pits and Phase I surface collected artifacts at Locus 4 of site VT-CH-1199 within the O’Brien Home Farm project area in South Burlington, Vermont. VT-CH-1199 Locus 4 12 Figure 6. Map showing the location of archaeological Phase II 0.5 m x 0.5 m test pits and Phase I surface collected artifacts at Locus 5 of site VT-CH-1199 within the O’Brien Home Farm project area in South Burlington, Vermont. VT-CH-1199 Locus 5 13 Figure 7. Map showing the location of archaeological Phase II 0.5 m x 0.5 m test pits and Phase I surface collected artifacts at site VT-CH-1076 within the O’Brien Home Farm project area, South Burlington, Vermont.