Chapter 4 – Report 36PH037

Completion of the Phase IB/II testing at Site 36PH037 resulted in the excavation of seven machine-excavated trenches, with Trench 5 excavation discontinued due to an impenetrable concrete road surface. Remains of the former Dyottville Glass Works were exposed and consisted of a brick floor and probable furnace foundation within the main glass house building. Mica-schist stone foundations were also encountered that may be related to Thomas Dyott–era (circa 1810–1840) or earlier factory buildings. A probable nineteenth-century ground surface or factory floor was also exposed. Other historic features identified included three separate, probable early-twentieth-century, creosote-coated wooden conduits for electrical or telephone lines, an associated brick service manhole, and a brick sewer line possibly dating to the mid-to-late nineteenth century. Early twentieth-century rail lines and wood railroad ties embedded in concrete were exposed close to the road surface within the tested area. Deeply buried prehistoric artifact-bearing soil horizons containing Early through Late Woodland cultural deposits were identified in two test trenches (3 and 6). In Trench 3, Native American artifact deposits were recovered from multiple, intact, stratified soil horizons originally formed along the margins of Gunner’s Run. Descriptions of specific soil horizons, building remains and other features, and the recovered artifact assemblage are presented in the sections below.

Trench 1

Trench 1 measured 5 x 37 feet in size, was the southernmost trench excavated, and was located 10 feet west of the fence line bordering the adjacent property. The upper asphalt and Belgian block road surface was approximately 1 foot thick and overlaid mixed fill deposits ranging in thickness from 2.5 to 3.5 feet and consisting of brick, stone, and concrete building rubble. A brick floor and stone and brick foundation remains were uncovered directly beneath the fill deposits (Figures 11 and 12). Sections of these foundations exposed in the trench profile extended upward to within approximately 1.5 feet below current road grade. A thin lens of black cinders containing glass waste from the glass factory (primarily slag and crucible fragments) was identified directly overlying the brick floor. The brick floor (Structure 2) was embedded into a silt loam fill matrix, appeared to be one course thick, and exhibited a subtly undulating appearance, possibly a result of settling over time. The location of Trench 1 within the glass furnace structure suggests the brick likely represented the interior floor of the furnace area.

Brick structures (Structures 1 and 3) were identified at the north and south ends of the trench. Structure 1, at the south end of the trench, consisted of a partially exposed mortared brick foundation extending at least 10 feet north-south and continuing into the west wall of the trench. The foundation was set on a rough stone base extended at least six courses of brick above the surrounding brick floor. The top of the foundation appeared to be truncated during later road construction (Figure 13). Structure 1 was likely a portion of the glass factory heating furnace shown on the 1878 Hexamer map.

Structure 3 at the northern end of the trench, also partially exposed, extended 10 feet into the south end of the adjacent Trench 2. This structure was constructed of brick and stone and was characterized by a flat surface forming a platform-like feature or possibly the base of an oven (Figure 14). Structure 3 was likely a section of the glass house furnace exterior wall or a tempering oven shown on the 1878 Hexamer map.

EU 4 was placed along the south side of Structure 3 and exposed the south side of the platform, revealing brick approximately three courses thick with stone edging. This portion of the structure was set directly onto a sand base overlying silty sand and rubble fill, approximately 0.8 feet thick (Figure 15). Mottled silt fill mixed with mortar, stone, and brick fragments extended at least 2 feet below the rubble layer. A section of vertical brick wall was identified running along the south side of Structure 3 and may have formed the south supporting wall of the platform floor, or could have represented an entirely separate foundation wall associated with an earlier historic building.

The remains of a stone foundation apparently unrelated to Structure 3 were exposed approximately 1.6 feet below the bottom of the brick platform floor (see Figure Figure 14 and Figure 15). Two possible sections of wall were exposed, separated by mottled sand with pebbles fill. EU 4 was discontinued at a depth of 6 feet below the present road grade, with fill deposits and stone building rubble continuing further in depth and into the east and west walls of the trench. The stone foundation appeared to be related to an earlier building or construction episode, possibly associated with the Thomas Dyott–era glassworks or the Hewson calico printing works.

Trench 2

Trench 2, located northwest of Trench 1, measured 5 feet wide and extended 30 feet north-south. The majority of the trench revealed a similar stratigraphy to that found in Trench 1, and consisted of mixed fill deposits, some 3.8 feet thick. These fill horizons were underlain by an apparent nineteenth-century artificial ground or living surface associated with the Dyottville Glass Works complex. Deposits associated with this surface consisted of very compact black silt loam fill with crushed shell, and measured approximately 0.7 feet thick. Additional fill deposits consisting of silt loam with gravel inclusions extended to a depth of 6.8 feet below present road grade. Fill deposits appeared to continue further in depth; however, the presence of excessive groundwater prevented deeper testing (Figures 16 and 17). The northern portion of Structure 3 was exposed (described above) in the southern end of Trench 2 at a depth of approximately 3.4 feet below present street grade (Figure 18).

Trench 3

Historic Component

Trench 3 was located 39 feet north of Trench 2 and measured 5 x 35 feet in size (Figures 19 and 20). The location of this trench was moved 5 feet to the east due the presence of a water main, and the north end of the trench was expanded 3 feet west to avoid a water pipe. Testing revealed a 1.4-foot-thick layer of asphalt and Belgian block overlying mixed fill deposits 6.4 feet thick (building rubble, slag and coal ash deposits, and utility disturbances).

Three stone wall foundations were identified and partially exposed directly beneath the fill deposits in the north-central area of Trench 3, and are interpreted as being elements of the same structure (Figures 21 and 22). Each wall was constructed of massive mica-schist blocks and was aligned on a diagonal axis through the trench. Wall 1 was 2 feet thick and was the northernmost wall in Trench 3, running in a southwest-northeast orientation. Wall 2, located 2.5 feet south of Wall 1, was similar in thickness and orientation. A builder’s trench approximately 3 feet wide and consisting of silt loam (10YR4/3) separated the two foundations. Wall 3 (1.5 feet thick) ran in a southeast-northwest orientation, with the northwest end abutting the south side of Wall 2.

Based on the 1878 Hexamer map, the identified walls appear to be foundations related to what was, at that time, the carpentry shop of the Dyottville Glass Works. These foundations appear to be of very similar construction as those earlier walls underlying Structure 3, in Trench 1, and likely date to at least the first half of the nineteenth century. Structures associated with these foundations could have initially been built as part of the Thomas Dyott–era glassworks, the 1816 Hewson glassworks, or potentially the eighteenth-century Hewson calico printing works. If this is the case, then these structures likely served quite different functions during earlier periods of use.

Prehistoric Component

Four EUs were placed in Trench 3. Two initial, opportunistic excavation units (EUs 1–2) with irregular dimensions were placed to test potential intact soil deposits between and extending below the foundation walls. EU 1 was located between Walls 1 and 2, and EU 2 was situated between Walls 2 and 3. Large quantities of Early–Late Woodland prehistoric artifacts were identified in a series of stacked Ab soil horizons extending some 3–four feet beneath the bottom of the stone foundations. EU 3 and 5 (5 x 6 feet in size; unit size determined by available shoring box dimensions) were then placed in the southern and northern ends of the trench, respectively, to more thoroughly explore and document these artifact levels. The completion of these EUs produced a Native American artifact assemblage comprising some 2,488 total artifacts. Prehistoric lithic debitage constituted the single largest class of artifacts recovered (n=1,612); however, various stone tools, prehistoric ceramics, fire-cracked rock (FCR), and other artifacts were abundant. A more detailed discussion of the stratigraphy and prehistoric cultural deposits identified within each of these EUs is provided below.

Excavation Units 1–3, and 5

Beneath the fill-related deposits, unit excavation in Trench 3 (EUs 1–3 and 5) identified intact soil horizons at approximately 6.5–7.5 feet below current street grade (Figures 23 and 24). Testing revealed a relatively uniform profile within Trench 3, consisting of a series of Ab- and Cg-horizon strata formed in the active Gunner’s Run floodplain (Figure 25 and 26). Each EU yielded a similar soil/sediment sequence, characterized by the presence of at least three buried living surfaces (Ab horizons) and intervening C-horizon deposits. In all cases, intact soil horizons were identified immediately below a historic fill episode (AC soils) marked by the presence of mixed historic and Native American artifacts. More detailed descriptions of these intact horizons are provided in Table 1 below.

According to geomorphologist Daniel Wagner, deeply buried soils identified in Trench 3 were likely formed during normal flood-driven alleviation from Gunner’s Run. In addition, some of the vertical accretion that built the floodplain could have been in response to rising sea levels late in the Holocene period. At present, all intact soil horizons below the AC fill deposits are thoroughly waterlogged, raising questions about their past ability to support Native American activity. However, it is entirely possible that current impeded drainage conditions are largely the result of long-term and extensive historic period modification of this vicinity. By the same token, lower sea levels experienced during the earlier parts of the Holocene period may have left this landform drier that present conditions suggest. Also, annual seasonal fluctuations may have resulted in episodic drying of the floodplain and created conditions more favorable to short-term, potentially task-specific activities to be carried out in close proximity to the active Gunner’s Run stream channel (Wagner, personal communication, August 22, 2011).

Dyottville Trench 3 Intact Soil Sequence Summary

HorizonThicknessProperties
AC0.25 - 0.55 ft.Dark brown (10YR 3/3) and brown (10YR 4/3) mixed fine sandy loam and loam; friable consistence; historic fill
2Ab0.8 ft.Very dark grayish brown (10 YR 3/2) fine sandy loam to loam; friable to very friable consistence
2Ab/2Cg0.4/1.0 ft.Black (N1) and dark grayish brown (10YR 4/2) fine sandy loam; very friable consistence [Note: during excavation this stratum was designated a CA/C horizon, with the upper portion having a darker color than the overlying 2Ab, but otherwise exhibiting an indistinct transition from one to the next horizon]
3Ab0.3 ft.Black (2.5Y 2.5/1 and N1) silt loam; organic fibers; friable consistence
3Cg0.4 ft.Dark grayish brown (10YR 4/2) loam; micaceous; friable consistence
Table 4.1

Significant numbers of Native American artifacts tentatively dated to the Early Woodland through Later Woodland culture periods were recovered from three distinct strata in this buried soil sequence. Specific soil horizons identified as apparent prehistoric occupation surfaces consist of the 2Ab, 2Ab/2Cg (upper portion only), and 3Ab levels[1]. Native American artifacts contained in the overlying AC horizon are contained in what has been interpreted as a historic fill layer, and therefore have been redeposited from some other, possibly nearby, location. Historic artifacts within this matrix are few in number, highly fragmentary, and primarily temporally non-diagnostic in nature; as a result, no accurate dating of this layer has so far been possible. Each of these prehistoric horizons contained a variety of Native American cultural materials and showed no evidence of either vertical or horizontal sorting of artifacts by size of functional classification. Moreover, lithic raw material representation exhibited statistically significant variation between these horizons (Pearson’s Chi Squared Test; P<.0001), supporting the interpretation that the recovered artifact assemblages from these strata are likely associated with a succession of distinct Native American occupations of the Gunner’s Run floodplain. It should be pointed out that waterlogged conditions within these soil horizons have resulted in the preservation of significant quantities of botanical materials (wood, charcoal, plant fibers, etc.), suggesting that more thorough excavations are likely to yield important information related to the past natural ecology of the Gunner’s Run drainage, as well as potential floral and/or faunal-based Native American cultural materials. Charcoal samples were recovered from all artifact-bearing soils within Trench 3 and have been submitted for C-14 dating (results still pending). More detailed discussions of the prehistoric lithic artifacts recovered from Trench 3 are presented below.

Trench 4

Trench 4, located 10 feet northwest of Trench 2, was placed to straddle the northeast corner of the glass house building and the open courtyard area shown on the 1875 Hopkins and 1878 Hexamer maps. Trench 4 excavation also aimed to investigate the extent of potential prehistoric horizons. Trench 4 initially measured 5 x 35 feet, but was reduced to 5 x 15 feet due to the presence of a 2-foot-thick concrete bed that had to be removed using a machine-operated jackhammer. The concrete bed appears to extend west across the intersection of Dyott Street and Richmond Street, and is related to rail lines for the Cramp shipbuilding industry that encompassed this area in the early twentieth century. The rail lines remain extant and consist of large gage steel rails and wooden ties embedded into the concrete road bed. Machine excavation revealed multiple fill deposits beneath the concrete bed, extending to a depth of at least 4.5 feet below the present road surface (Figure 27). A bucket auger was used to determine the depth of fill and to confirm the presence of the prehistoric floodplain deposits previously identified in Trench 3. Intact soils were encountered at depth of 8 feet below the existing road surface and did not appear to be stratified, as in Trench 3.

Trench 5

Trench 5 excavation was discontinued due to the presence of a 2-foot-thick concrete road bed, rail lines, and wooden railroad ties embedded into the concrete. Investigation below the concrete road surface was carried out in Trench 4.

Trench 6

Trench 6 measured 7 x 27 feet and was located 30 feet north of Trench 3, along the northern boundary of the historic Dyottville property (Figure 28). Mixed fill deposits were encountered beneath the asphalt and Belgian block road, and extended to depths of approximately 7 feet below the existing road surface. A rectangular brick shaft with rounded corners was exposed at approximately 2.5 feet below the present road grade, and measured 3.5 x 4.7 feet in size (exterior dimensions). Also at this elevation, a concrete footing or slab—20 feet long, 2 feet wide, and 1.4 feet thick—extending east-west across the trench, was exposed 9 feet south of the north trench wall (Figure 29). The shaft was constructed of mortared bricks arranged in alternating header and stretcher courses to a depth of 3.6 feet below the top course. Fill within the shaft consisted of lenses of silt loam with pebbles and brick fragments overlying a very compact silt loam floor.

Openings measuring approximately 2.5 x 3 feet were identified on the north and south sides of the shaft, and into these openings were inserted multiple wooden pipes or conduits bundled together within a wooden outer frame (Figure 30). The wooden conduits extended north and south of the shaft and probably contained telephone or electrical wiring. This type of conduit was in common use in the late nineteenth and early twentieth centuries. The conduit on the south side of the shaft measured 1.2 feet wide, angled to the southwest, and continued into the southwest corner of the trench. The north conduit measured 0.8 feet wide, extended straight out of the north wall of the shaft, and into the north wall of the trench. The brick shaft probably functioned as a junction box or manhole providing access for installation of the telephone lines. It is likely that similar structures will occur throughout other portions of Richmond Street where this type of conduit was installed in the past. An additional 1-foot-wide wooden conduit was exposed along the east trench wall at a depth of 4 feet below road grade. This conduit ran the entire length of the trench and continued beyond the north and south walls.

Auger probing in the north half of the trench revealed additional fill deposits overlying intact A-horizon soils at approximately 7.4 feet below the present road grade. EU 6 was then placed in the northern half of the trench to further investigate these deposits.

Excavation Unit 6

EU 6 revealed a buried soil profile that differed considerably with those recorded in Trench 3. Represented by upper Ab and ABb soils overlying weak subsoils, this profile lacked the stratified sequence found to the south and was indicative of stream terrace formation along Gunner’s Run (Figures 31,32,33). More interestingly, the limited degree of subsoil development indicates that this terrace was established sometime during the Late Holocene period, perhaps not more than some 4,000–5,000 years ago (B.P). As such, this terrace represents a (thus far) unique context within Philadelphia, in that it is the only known location where Native American artifact deposits have been identified within Holocene-age soil deposits (all other previously identified prehistoric sites in the city are contained within Pleistocene-age soils). This terrace additionally stands out in that it formed in direct association with the development of the adjacent Gunner’s Run drainage, not the Delaware River channel (Wagner, personal communication, August 22, 2011). More detailed descriptions of identified soil horizons are presented in Table 2 below.

Excavation Unit 6 Soil Descriptions

HorizonDepth (ft)*Properties
2Ab0 - 0.8Very dark gray (10YR 3/1) silt loam; weak, fine subangular blocky structure; friable consistence; clear, wavy boundary
2ABb0.8 - 1.0Dark brown (10YR 3/3) and dark grayish brown (10YR 4/2) loam to silt loam; structureless, massive; friable consistence; clear, wavy boundary
2Bwb11.0 - 1.8Dark brown (7.5 YR 3/4) and brown (7.5YR 4/3) loam; weak to moderate, medium subangular blocky structure; few patchy clay films; friable consistence; clear, smooth boundary
2Bwb21.8 - 2.3+Dark brown (7.5YR 3/4) to dark reddish brown (5YR 3/4) fine sandy loam; moderate, medium subangular blocky structure; few patchy clay films; friable consistence
*Depths indicated were measured from the top of the 2Ab horizon.
Table 4.2

Geomorphological examinations of the 2Ab and 2ABb soils within EU 6 indicated that they had not been previously impacted during historic plowing or other agricultural activities, and therefore have the potential to provide extremely significant information related to Native American lifeways and the specific occupation/exploitation of this landscape. In particular, horizontal artifact patterning and any features should be well preserved within these soils. As in Trench 3, all intact soils identified in EU 6 were thoroughly waterlogged; however, these current conditions are most likely the result of historic period modification of the surrounding ground surface. The absence of subsoil drainage mottling in these deposits suggests that this terrace setting would have originally been no worse than moderately well-drained, and therefore well-suited for human occupation (Wagner, personal communication, August 22, 2011). The current waterlogged state of these soils has resulted in excellent preservation of organic materials with both the 2Ab and 2ABb horizons, and both charcoal and wood samples were recovered during testing. Selected samples of charcoal have been submitted for C-14 dating (results still pending).

Trench 7

Trench 7 measured 10 x 12 feet in size and was located along the north side of Schirra Drive, near the intersection with Richmond Street (Figure 34). A substantial, 2-foot-thick concrete floor was exposed beneath the asphalt and was removed with a machine-operated jackhammer. Mixed fill deposits were exposed beneath the concrete, extending to a depth of at least 10 feet below road grade. At this depth, water began to rapidly fill up the trench and the excavation was discontinued. This location was the site of a substantial Cramp ship yard building and boiler house dating to the early twentieth century, and appears to have been constructed to a depth that removed the historic A horizon and any potential evidence of earlier buildings. At this time, the full horizontal extent of this deep disturbance remains unknown. It is possible that intact archaeological deposits dating to both the historic and prehistoric periods could be located within the vicinity of Trench 7.