Adze: Part of an Ancient Woodworking Toolkit

Iron Adze
Adze for cutting and shaping wood. Getty Images / Oliver Strewe / Lonely Planet Images

An adze (or adz) is a woodworking tool, one of several tools used in ancient times to perform carpentry tasks. Archaeological evidence suggests that the first Neolithic farmers used adzes for everything from felling trees to shaping and assembling wooden architecture such as roof timbers, as well as constructing furniture, boxes for two- and four-wheeled vehicles, and walls for subterranean wells. 

Other essential tools for the ancient and modern carpenter include axes, chisels, saws, gouges, and rasps. Woodworking toolkits vary widely from culture to culture and time to time: the earliest adzes date from the Middle Stone Age period of about 70,000 years ago, and were part of a generalized hunting toolkit. 

Adzes can be made of a wide variety of materials: ground or polished stone, flaked stone, shell, animal bone, and metal (typically copper, bronze, iron). 

Defining Adzes

Adzes are generally defined in the archaeological literature as distinct from axes on several bases. Axes are for hewing trees; adzes for shaping wood. Axes are set in a handle such that the working edge is parallel to the handle; the working edge of an adze is set to be perpendicular to the handle. 

Adzes are bifacial tools with a pronounced asymmetry: they are plano-convex in cross-section. Adzes have a domed upper side and a flat bottom, often with a distinct bevel towards the cutting edge. In contrast, axes are generally symmetrical, with biconvex cross sections. The working edges on both flaked stone types are wider than one inch (2 centimeters).  

Similar tools with working edges of less than an inch are generally classified as chisels, which can have varied cross sections (lenticular, plano-convex, triangular).

Identifying Adzes Archaeologically

Without the handle, and despite the literature defining adzes as plano-convex in shape, it can be difficult to distinguish adzes from axes, because in the real world, the artifacts are not bought in a Home Depot but made for a specific purpose and perhaps sharpened or used for another purpose. A series of techniques have been created to ameliorate, but as yet not resolve, this issue. These techniques include: 

  • Use-wear: the examination by macroscopic and microscopic techniques of the working edges of a tool to identify striations and nicks that have accumulated over its use-life and may be compared to experimental examples. 
  • Plant residue analysis: the recovery of microscopic organic leavings including pollen, phytoliths, and stable isotopes from whatever plant was being worked. 
  • Traceology: the examination by macroscopic and microscopic techniques of well-preserved pieces of wood to identify marks left behind by the woodworking process. 

All of these methods rely on experimental archaeology, reproducing stone tools and using them to work wood to identify a pattern which might be expected on ancient relics. 

Earliest Adzes

Adzes are among the earliest type of stone tool identified in the archaeological record and recorded regularly in Middle Stone Age Howiesons Poort sites such as Boomplaas Cave, and Early Upper Paleolithic sites throughout Europe and Asia. Some scholars argue for the presence of proto-adzes in some Lower Paleolithic site—that is, invented by our hominid ancestors Homo erectus.

Upper Paleolithic 

In the Upper Paleolithic of the Japanese islands, adzes are part of a "trapezoid" technology, and the make up a fairly small portion of the assemblages at such sites as the Douteue site in Shizuoka prefecture. Japanese archaeologist Takuya Yamoaka reported on obsidian adzes as part of hunting toolkits on sites dated approximately 30,000 years ago (BP). The Douteue site stone trapezoid assemblages as a whole were basally hafted and heavily used, before being left behind broken and discarded.

Flaked and groundstone adzes are also regularly recovered from Upper Paleolithic sites in Siberia and other places in the Russian Far East (13,850–11,500 cal BP), according to archaeologists Ian Buvit and Terry Karisa. They make up small but important parts of hunter-gatherer toolkits. 

Dalton Adzes 

Dalton adzes are flaked stone tools from Early Archaic Dalton (10,500–10,000 BP/12,000-11,500 cal BP) sites in the central United States. An experimental study on them by U.S. archaeologists Richard Yerkes and Brad Koldehoff found that the Dalton adzes were a new tool form introduced by Dalton. They are very common on Dalton sites, and usewear studies show they were heavily used, made, hafted, resharpened, and recycled in a similar fashion by several groups. 

Yerkes and Koldehoff suggest that at the transition period between the Pleistocene and Holocene, changes in climate, particularly in hydrology and landscape, created a need and desire for river travel. Although neither Dalton wooden tools or dugout canoes from this period have survived, the heavy use of the adzes identified in the technological and microwear analysis indicates they were used for felling trees and likely manufacturing canoes. 

Neolithic Evidence for Adzes 

While wood-working—specifically making wooden tools—is clearly very old, the processes of clearing woods, building structures, and making furniture and dugout canoes are part of the European Neolithic set of skills that were required for the successful migration from hunting and gathering to sedentary agriculture. 

A series of Neolithic wooden-walled wells dated to the Linearbandkeramik period of central Europe have been found and intensively studied. Wells are particularly useful for the study of traceology, because water-logging is known to preserve wood. 

In 2012, German archaeologists Willy Tegel and colleagues reported evidence for a sophisticated level of carpentry at Neolithic sites. Four very well-preserved eastern German wooden well walls dated between 5469–5098 BCE provided Tegel and colleagues an opportunity to identify refined carpentry skills by scanning high-resolution images and producing computer models. They found that early Neolithic carpenters built sophisticated corner joins and log constructions, using a series of stone adzes to cut and trim the timber.

Bronze Age Adzes

A 2015 study on Bronze Age use of a copper ore deposit called Mitterberg in Austria used a very detailed traceology study to reconstruct woodworking tools. Austrian archaeologists Kristóf Kovács and Klaus Hanke used a combination of laser scanning and photogrammetric documentation on a well-preserved sluice box found at Mitterberg, dated to the 14th century BCE by dendrochronology

The photo-realistic images of the 31 wooden objects that made up the sluice box were then scanned for tool mark recognition, and the researchers used a workflow segmentation process combined with experimental archaeology to determine that the box was created using four different hand tools: two adzes, an axe, and a chisel to complete the joining. 

Adzes Takeaways

  • An adze is one of several woodworking tools used in prehistoric times to fell trees and construct furniture, boxes for two- and four-wheeled vehicles, and walls for subterranean wells. 
  • Adzes were made of a variety of materials, shell, bone, stone and metal, but typically have a domed upper side and a flat bottom, often with a distinct bevel towards the cutting edge.
  • The earliest adzes in the world date to the Middle Stone Age period in South Africa, but they became much more important in the Old World at the time of the emergence of agriculture; and in Eastern North America, to respond to climate change at the end of the Pleistocene. 

Sources 

Bentley, R. Alexander, et al. "Community Differentiation and Kinship among Europe's First Farmers." Proceedings of the National Academy of Sciences 109.24 (2012): 9326–30. Print.

Bláha, J. "Historic Traceology as a Complex Tool for the Discovery of Lost Construction Skills and Techniques." WIT Transactions on The Built Environment 131 (2013): 3–13. Print.

Buvit, Ian, and Karisa Terry. "The Twilight of Paleolithic Siberia: Humans and Their Environments East of Lake Baikal at the Late-Glacial/Holocene Transition." Quaternary International 242.2 (2011): 379–400. Print.

Elburg, Rengert, et al. "Field Trials in Neolithic Woodworking – (Re)Learning to Use Early Neolithic Stone Adzes." Experimental Archaeology 2015.2 (2015). Print.

Kovács, Kristóf, and Klaus Hanke. "Recovering Prehistoric Woodworking Skills Using Spatial Analysis Techniques " 25th International CIPA Symposium. ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2015. Print.

Tegel, Willy, et al. "Early Neolithic Water Wells Reveal the World's Oldest Wood Architecture." PLOS ONE 7.12 (2012): e51374. Print.

Yamaoka, Takuya. "Use and Maintenance of Trapezoids in the Initial Early Upper Paleolithic of the Japanese Islands." Quaternary International 248.0 (2012): 32–42. Print.

Yerkes, Richard W., and Brad H. Koldehoff. "New Tools, New Human Niches: The Significance of the Dalton Adze and the Origin of Heavy-Duty Woodworking in the Middle Mississippi Valley of North America." Journal of Anthropological Archaeology 50 (2018): 69–84. Print.