Cairn - A Stacked Heap of Rocks with a Multitude of Uses

Cairns are Found Everywhere and Have Multiple Purposes and Meanings

Rock Cairn near Eigergletscher Station, Switzerland
Rock Cairn near Eigergletscher Station, Switzerland. thisisbossi

A cairn is a catchall term used by archaeologists to refer to a stone structure of various complexity and purpose. At its most simple, a cairn is a deliberately stacked heap of rocks. Such constructed heaps are found throughout the world, and extant ones can range in size from 2-20 meters (6.5-65 feet) in diameter. They are in various states of disarray, and sometimes the original pattern is difficult to discern, if there was one at all.

Suggested purposes for simple stacked heaps of stones include property markers, grave markers, shrines or route signs along a path or roadway.

However, the word "cairn" is also a category of undefined feature identified on an archaeological field survey--when they are more closely investigated cairns may represent any number of structures, varying widely in shape, construction method and materials.

Cairn Categories

You'll never find a definitive, "official" list of cairn types in any archaeological text, probably because the categories are rather ad hoc, that is say, eccentric to the archaeologist or region. Nevertheless, I have listed here some categories that show up regularly in the scientific literature and have generally accepted meanings.

  • A clearance cairn is a pile of rocks that resulted from clearing stones from a field prior to cultivation. Clearance cairns have been found around the world, the earliest of which date to the creation of the first agricultural fields, but are probably associated with the repetitive use of fields and longer cultivation periods between fallow in slash and burn farming.
  • A summit cairn is one placed prominently in an upland location: often a string of them are placed on the tops of mountains or hills and often within sight of one another and when associated with hearths may be part of a prehistoric long-distance communication network. See Peak Sanctuary.
  • A clitter cairn is a circular or longitudinal strip of stones which was created without the efforts of humans at all, by frost-heave cycles, the movement of glacial ice, or other natural weathering processes. Clitter cairns are always interesting to geologists, and become interesting to archaeologists when they show evidence of having been enhanced by humans or used for various purposes.
  • A ring cairn is an open central area enclosed by a bank of stone, sometimes with a single entrance, that may cover a standard cremation burial.
  • A kerbed cairn is a ring cairn incorporating a row of upright kerbing stones at its base which may have supported a roof.
  • A chambered cairn is a type of passage grave, an above-ground tomb found throughout the world. The earliest of these are prehistoric structures built by Neolithic farmers who used them to inter remains of their dead. Chambered cairns consist of one or more linked chambers, and may include low passages or antechambers. The largest examples could allow several people to move about freely under a high domed roof.

Mapping and Dating Cairns

In some places, such as Leskernick in Cornwall, cairns have been found arranged in large numbers, hundreds of them as part of a landscape that can also include buildings, hearths, pits, field enclosures (stone walls), whole villages, burials and other features. Mapping a cairn field is far easier now that archaeologists can use GPS/GIS strategies and the relatively new method of terrestrial laser scanning (TLS), which allows quick mapping of the cairn itself. That does allow for identifying patterns of stones across a landscape, but still hasn't resolved identifying the purpose or dating of this most universal of stone structure.

Cairns rarely contain artifacts or organic remains, which makes them maddeningly difficult to date. The most successful attempts have used pollen analysis, radiocarbon dating or optically-stimulated-lumimescence (OSL) dating techinques on the soils found within the cairn.

Sources

This article is a part of the About.com guide to the Temples and Shrines, and the Dictionary of Archaeology.

Baran J, Murray AS, and Häggström L. 2003. Estimating the age of stone structures using OSL: the potential of entrapped sediment. Quaternary Science Reviews 22(10–13):1265-1271.

Davidson DA, and Green CM. 1989. An analysis of site catchment areas for chambered cairns on the island of Arran. Journal of Archaeological Science 16(4):419-426.

Fraser JA, and Price DM. 2013. A thermoluminescence (TL) analysis of ceramics from cairns in Jordan: Using TL to integrate off-site features into regional chronologies. Applied Clay Science 82:24-30.

Hakonen A, Kuusela J-M, and Okkonen J. 2015. Assessing the application of laser scanning and 3D inspection in the study of prehistoric cairn sites: The case study of Tahkokangas, Northern Finland. Journal of Archaeological Science: Reports 2:227-234.

Hamilton S, Harrison S, and Bender B. 2008. Conflicting imaginations: Archaeology, anthropology and geomorphology on Leskernick Hill, Bodmin Moor, southwest Britain. Geoforum 39(2):602-615.

Henshall AS, and Ritchie JNG. 1995. The Chambered Cairns of Sutherland: An Inventory of the Structures and Their Contents. Edinburgh: Edinburgh University Press.

Lagerås P, and Bartholin T. 2003. Fire and stone clearance in Iron Age agriculture: new insights inferred from the analysis of terrestrial macroscopic charcoal in clearance cairns in Hamneda, southern Sweden. Vegetation History and Archaeobotany 12(2):83-92.

Lynch F. 1979. Ring Cairns in Britain and Ireland: Their Design and Purpose (the Oliver Davies Lecture for 1979). Ulster Journal of Archaeology 42:1-19.

McIntyre-Tamwoy S, Greer S, and Henry R. 2015. Last days on Pabaju: A stone arrangement on Albany Island Cape York Peninsula, Queensland, Australia. Quaternary International 385:79-87.

O'Sullivan M, and Downey L. 2011. Summit cairns. Archaeology Ireland 25(3):20-23.

Overland A, and Hjelle KL. 2013. Pollen analysis in the context of clearance cairns from boreal forests – a reflection of past cultivation and pastoral farming. Journal of Archaeological Science 40(2):1029-1041.