Figure 3. Resistance map of the area around a circular enclosure shown in Figure 2. Low resistance areas (dark) correspond to an interior ditch.

The preliminary results suggest that remote sensing can be an efficient and non-destructive means of documenting earthwork features at the Hopeton Earthworks and similar sites.

Excavations

Subsequently, Dr. John Weymouth (University of Nebraska, Lincoln) conducted further analysis of the remote sensing data in light of the information revealed through excavation. This further analysis suggested that several additional pit features may have gone undetected during the excavations. During the summer of 1996, additional excavations were targeted at these anomalies and successfully identified several additional refuse-filled pits.

Near-surface geophysical remote sensing greatly aids in the identification of buried archeological deposits. The findings underscore the necessity of truly inter-disciplinary cooperation between geophysics and archeology.

Further processing and data analysis are continuing under the direction of Dr. William S. Dancey (Ohio State University). Results will be summarized in a future issue of Hopewell Archeology and elsewhere.

 

click on image to enlarge		Earthwork Construction
Figure 4. Profile of the trench dug along the northwest wall segment of the Hopeton Earthworks. This is the west profile and represents data recorded in the 1996 field season.		Monumental geometric earthwork enclosures have long stood as a testament to the remarkable scale and complexity of Ohio Hopewell corporate-ceremonial life. Nevertheless, few investigations have specifically targeted earthwork walls as a focus for archeological investigation.
During the summer of 1996, a wall segment at the Hopeton Earthworks was explored by means of a 1 m x 14 m hand-excavated trench located near the northwest corner of the large square enclosure (Figures 2, 4). One goal of the investigation was to establish a baseline assessment of the current condition of the earthworks. The excavations demonstrated that almost half of the wall segment's original 4 m of relief has been lost to plowing and erosion. The wall retained a high degree of integrity below the disturbed surface. Future management will seek to maintain a stable vegetative cover and monitor the earthwork for change from this baseline condition. A second goal of the investigation was to document earthwork construction methods and assess the intensity and frequency of construction episodes. The excavations encountered a deep, highly organic, undisturbed A horizon consistent with a prairie soil beneath the wall. This suggests that a prairie opening in the bottomland hardwood forest was selected for earthwork construction to avoid extensive forest clearance. At least three principal construction episodes were identified. A prepared surface composed of thin (ca. 1 cm) strata of sand and clay atop an irregular deposit of silt loam soil lay on the original ground surface. This surface was overlain by a deposit of wood charcoal that had burned in situ. Flotation processing of this charcoal deposit yielded many small flecks of mica but no other cultural materials, suggesting a ceremonial context. The first construction episode concluded when this deposit was capped with a low (ca. 20 cm) mantle of yellowish-brown silt loam soil. The second episode raised the wall to at least 2 m in height with a massive unit of yellowish-brown silt loam soil. The final episode added another massive unit of reddish-brown clay loam soil to the exterior aspect of the wall. The pace and timing of these three episodes remain unclear. Individual basket loads were occasionally evident throughout the wall. A final goal of the investigation was to begin to build intra-site and intersite chronologies of earthwork construction and use in the central Scioto region. Wood charcoal from the deposit at the base of the wall was dated to 1930 ± 60 radiocarbon years before the present (Beta-96598, A.D. 20 ± 60, uncalibrated). Interestingly, the calibrated date of this sample is contemporary with four samples drawn from sub-mound and sub-earthwork features at the Mound City Group, located only 3 km west of the Hopeton Earthworks. If this chronology proves accurate, it suggests that these two mound and earthwork complexes may have functioned together as a single closely related unit. These investigations at Hopeton provide several important insights. Site selection may have been influenced by the distribution of open, prairie environments. Earthwork construction was conducted within the context of a non-mortuary ceremonialism as evidenced by the prepared surface, burning and exotic raw materials (mica) associated with the initial construction episode. The color and placement of various soils may also bear symbolic significance. Earthwork construction involved multiple episodes, an observation that must be taken into account when estimating the pace and intensity of labor investment in monumental architecture. The apparent contemporaneity of geographically proximate mound and earth-work centers such as Mound City and Hopeton has significant implications for reconstructions of the regional Hopewellian social landscape. Spruce Hills Works     click on image to enlarge The Spruce Hill Works site was described as early as 1811 as a stone-walled fortification ringing the brow of a prominent hill overlooking the Paint Creek valley southwest of Chillicothe (Figure 5). Later investigations at other hilltop enclosures in southern Ohio such as Fort Ancient, Fort Hill, and the Pollack Works have determined that many of these were built during the Hopewell period for ceremonial rather than defensive purposes. In 1987, the National Park Service began to consider whether the Spruce Hill Works might be significant enough to warrant protection and preservation, either as a unit of Hopewell Culture NHP or perhaps by some other means.   Figure 5. A map of the Spruce Hill Works made by Squier and Davis in 1847. One of the gateway features at the south end of the site was test excavated in 1995. However, virtually no systematic scientific investigations had been conducted at the site, and some questioned whether the "stone walls" were man-made at all. Legislation enacted in 1992 directed the National Park Service to conduct further studies of the site to answer these questions and to explore options for preservation, if warranted. During the fall of 1995, personnel from Hopewell Culture NHP surveyed the site and conducted limited test excavations near one of four opening or gateways at the southern end of the site. The encircling band of loose sandstone blocks was found to be in much the same condition and configuration as described and mapped by the earliest observers. The stratigraphic position of the gateway features above bedrock exposures confirms their anthropogenic origin, though much of the remainder of the "wall" is coincident with a natural sandstone outcrop and may in fact be natural. Test excavations recovered fragments of a single plain, grit-tempered ceramic vessel and a diagnostic Hopewell bladelet manufactured from Vanport (Flint Ridge) flint in association with one of the southern gateway openings. These results suggest that the Spruce Hill Works site does, in fact, represent one of several Hopewellian hilltop enclosures in southern Ohio. Additional excavations were conducted during 1996. An excavation trench placed across one of the gateways along the southern margin of the site produced conclusive evidence for a Hopewellian authorship. The stones making up the gateway were stratigraphically separated from the underlying sandstone bedrock by more than 3 m of Wisconsin-age loess deposits. Furthermore, the size and distribution of the stones used to construct the gateway provide evidence of intentional design: the bulk of the feature is constructed of small, rubble-sized stones while the outer surfaces are faced with large tabular blocks, perhaps to stabilize the structure or modify its outward appearance. A diagnostic Hopewell bladelet of Vanport flint was found embedded approximately 40 cm deep within the structure. All of the early accounts of the Spruce Hill Works attest to the occurrence of considerable quantities of burned, fused, or glazed sandstones and vitrified soils at several locations along the enclosure wall. The temperatures needed to produce these effects (in excess of 1100° C) have led many to speculate that these may relate to some high temperature technology such as iron ore extraction. There is no evidence that prehistoric Native Americans ever experimented with these technologies. However, 18th and 19th century Euroamericans are known to have constructed simple iron furnaces in southern Ohio and elsewhere. During the present investigations, test excavations at three locations documented vast quantities of these burned materials. In all three cases, the materials appear to be in secondary, redeposited contexts. The nature, origin, age, and affiliation of these materials remain uncertain. Thanks: A special note of appreciation is due to Edward and Mary Emily Steel, the present stewards of the Spruce Hill Works, for their friendship, hospitality, and efforts to protect and preserve the Spruce Hill Works for future generations.