March Madness Aside, This Month We’re Fired up for Fire clay!

In western and northcentral Pennsylvania and eastern Ohio, fire clay deposits are found underlying coal seams and date to the Carboniferous age. Fire clays have historically been an important economic resource for the Commonwealth, most notably during the industrial boom of the mid-19th and early 20^th century. The archaeological record also demonstrates Pennsylvania fire clays were a natural resource exploited by Pre-Contact Native Americans as early as 6000 years ago, although direct evidence of prehistoric quarry activities is lacking. Future trace element studies from probable sources as compared with artifacts have potential to shed further light on the movement of people, and the trade and exchange of goods and ideas in the Upper Ohio drainage basin, Middle Atlantic and Northeast. 

                          Map of Clay Sources in Northern Appalachia, (Ries 1903)

Fire clay samples from Cambria, Clearfield and Fayette counties

Fire clay is the common term  for clays of high aluminum content, valued since the industrial revolution and prior for their refractory properties, or resistance to high temperatures. Objects made from fire clay will remain structurally stable up to or above 3,000 ˚F. “Fire bricks” manufactured from these clays are used in metal, ceramic and glass industries for lining furnaces and kilns. Refractory clays are also used to create tools and utilitarian vessels also subjected to high heat in metallurgy, pottery and glass-works, such as crucibles and saggers.

Harmony Brick Works furnace, Leetsdale (36AL480), (Sewell 2004)

By the mid-1800s in Pennsylvania, plastic forms of fireclay and non-plastic deposits, known as flint clays, were mined to produce refractory materials for the iron, coal, ceramic and glass industries, and were a key product that in tandem with the associated coal sources of the region facilitated the burgeoning steel industry in Pittsburgh. 

Fire brick, manufactured by S. Barnes Company of Pittsburgh to line furnaces and kilns at  the Harmony Brick Works, a common brick manufacturer, Leetsdale (36AL480), (Sewell 2004).

 Fire brick manufacture was the second leading clay production industry in Pennsylvania at the turn of the 20^th century. Combined 1901 and 1902 profits from fire brick manufacture grossed over $9.3 million, just under the $9.9 million income from common brick production. Pennsylvania manufacturers, using local fire clay sources, supplied nearly half of the refractory brick used in the nation, and were only surpassed in production by Ohio refractories (Ries, 1903). 

                                 Table courtesy of (Ries 1903)

Long before the steel boom greatly increased the demand for commercial-industrial refractory products, Native Americans were exploiting fire clay deposits for their unique plastic, yet stone-like properties. Raw sourced fire clays are easily hand polished to a high luster. For this reason, it was a valued material used by a variety of prehistoric cultural groups to make specialized ground stone tools such as bannerstones or atlatl weights, smoking pipes, gorgets, pendants and other personal adornments.

Gorget fragment and polished fire clay spalls surface collected from the Buffington site (36In15), Veigh collection

Fire clay artifacts have been found in archaeological contexts that range from the Late Archaic to Contact Period, yet the most distinct and diagnostic artifact almost exclusively made from fire clays are blocked-end tubular pipes. These pipes were produced and widely traded in the Adena and to a lesser extent, the Middlesex/Meadowood interaction spheres during the Early Woodland throughout the Ohio Valley, Middle Atlantic and Northeast.

Blocked-End Tubular fire clay pipes from the Haldeman O’Connor Cache, Shelly Island (36Yo3)

Rafferty (2004: 16) argues that the uniformity of blocked-end tubular smoking pipes suggests they were traded widely from specific and limited number of workshops. In contrast, the variability found in conical and open-ended tube pipes, also widely dispersed during the Early Woodland, were more likely products of local regional developments. While the well documented fire clay sources, such as those found in Portsmouth, Ohio are closer to the heartland of Adena culture in the Upper Ohio Valley, McConaughy hypothesizes that trace element source studies may demonstrate bordering Cresap phase communities of West Virginia and Pennsylvania, whose mortuary practices and aspects of material culture show a vested interaction in Adena trade and exchange networks, were potential suppliers of blocked-end tubular pipes. Pipes found in various stages of early production in Warren, Forest, Elk and Clarion counties may further indicate local fire clay quarry activities. It is possible that local Cresap phase communities would have  controlled access to these upper Allegheny Valley fire clay sources, and the production and trade of this pipe variety facilitated their interactions in these greater regional exchange networks (Mayer-Oakes 1955; McConanghy in press). Smith (1979) also notes that outcrops in Clearfield County believed to be “used extensively for pipe and pendant-making by the later Susquehannock inhabitants of the West Branch” of the Susquehanna River as potential quarry sources in the Early Woodland. 

Fire clay pipes and preforms (Mayer-Oakes 1955)

Blocked-end tubular pipe distribution in the Susquehanna River Valley (Smith 1979)

However, prehistoric fire clay quarries have yet to be recorded in the Pennsylvania Archaeological Site Survey (PASS). This may be largely due to the extensive mining of these resources in the 19^th and 20^th centuries that have likely destroyed most archaeological evidence of pre-industrial quarry use. Furthermore, fire clay trace element sourcing studies have yet to be a priority in regional archaeology research. Comprehensive comparative sourcing studies would be a possible avenue for future study, (McConaughy in press), and provide direct evidence that western and north central fire clay sources were also mined in prehistory.

We hope you’ve enjoyed our overview of fire clay use through time. Mark your calendars for the 49^th Annual Middle Atlantic Archaeology Conference, March 21-24, 2019 in Ocean City, Maryland. It is still possible to register online to attend through March 8^th.

References

Ries, Heinrich

1903       The Clays of the United States East of the Mississippi River. Department of the Interior, United States Geological Survey, Professional Paper No. 11.

Mayer-Oakes, William J.

1955    Prehistory of the Upper Ohio Valley; An Introductory Archaeological Study. Anthropological Series, No 2. Annuals of Carnegie Museum 34, Pittsburgh.

McConaughy, Mark A.

In press Chapter 7, Early and Middle Woodland in the Upper Ohio Drainage Basin. The Archaeology of Native Americans in Pennsylvania Volume 1. University of Pennsylvania Press, Philadelphia.

Rafferty, Sean M.

2004       “They Pass Their Lives in Smoke, and at Death Fall into the Fire”: Smoking Pipes and Mortuary Ritual during the Early Woodland Period. The Archaeology of Tobacco Pipes in Eastern North America: Smoking and Culture. The University of Tennesee Press, Knoxville.  

Sewell, Andrew R.

2004       Chapter 5 Phase III Archaeology Data Recovery at the Historic Brickworks Component of 36AL480 in Leetsdale, Allegheny County, Pennsylvania ER# 1999-2661-003-E. Submitted by Hardlines Design Company, 4608 Indianola Avenue, Columbus, Ohio 43214. On file at The State Museum of Pennsylvania, Section of Archaeology.

Smith, Ira F. III

1979       Early Smoking Pipes in the Susquehanna River Valley. Pennsylvania Archaeologist 49(4):9-23

Stewart, R. Michael

1989       Trade and Exchange in Mid-Atlantic Prehistory. Archaeology of Eastern North America 17:47-78

For more information, visit PAarchaeology.state.pa.us or the Hall of Anthropology and Archaeology at The State Museum of Pennsylvania .