Bitumen - The Archaeology and History of Black Goo

The Ancient Uses of Asphalt - 40,000 Years of Bitumen

Asphalt (Bitumen) Deposits at La Brea Tar Pits
Asphalt (Bitumen) Deposits at La Brea Tar Pits. Stephen Mihalcik

Bitumen (also known as asphaltum or tar) is a black, oily, viscous material that is petroleum, a naturally-occurring organic byproduct of decomposed organic materials. It is also waterproof, and this remarkable natural stuff has been used by humans for a wide variety of tasks and tools for at least the past 40,000 years.

What is Bitumen?

Bitumen is the thickest form of petroleum there is, made up of 83% carbon, 10% hydrogen and lesser amounts of oxygen, nitrogen, sulphur, and other elements.

It is a natural polymer of low molecular weight: at lower temperatures it is rigid and brittle, at room temperature it is flexible, at higher temperatures it flows.

Bitumen deposits occur naturally throughout the world but vary widely in chemical composition and consistency. In some places, bitumen extrudes naturally from terrestrial sources, in others it appears in liquid pools which can harden into mounds, and in still others it oozes from underwater seeps, washing up as tarballs along sandy beaches and rocky shorelines.

Early Uses

The earliest known use of bitumen was by Middle Paleolithic Neanderthals, some 40,000 years ago. Bitumen was found adhering to stone tools used by Neanderthals at sites such as Gura Cheii Cave (Romania) and Hummal and Umm El Tlel in Syria. There where it was used to fasten a wooden or ivory haft to the sharp edged tools.

In Mesopotamia, during the late Uruk and Chalcolithic periods at sites such as Hacinebi Tepe in Syria, bitumen was used for construction of buildings and water-proofing of reed boats, with among other uses.

Processing Bitumen

But, bitumen is used for a huge number of things: as a sealant or adhesive, as building mortar, as incense, and as decorative application on pots, buildings or human skin. The material was also useful in waterproofing canoes and other water transport, and in the mummification process toward the end of the New Kingdom of ancient Egypt.

It is also flammable. And, thanks to recent scholarship, this gooey stuff is also identifiable to source.

The method of processing bitumen was nearly universal: heat the goo until the substance condenses the gases within and liquifies, then add tempers to tweak the consistency. Minerals such as ochre make it thicker,; grasses and other vegetable matter adds stability; waxy/oily elements such as pine resin or beeswax makes it more viscous.

Sourcing

Beginning in Mesopotamia, bitumen was part of the trade stuff that was carried on throughout the Mediterranean and Red seas. Specific chemical analysis of the various samples can illuminate where the stuff originated from. Much of the bitumen in Bronze age Syrian sites has been found to have originated from the Hit seepage on the Euphrates River in southern Mesopotamia.

The earliest reed boat discovered to date was coated with bitumen, at the site of H3 at As-Sabiyah in Kuwait, dated about 5000 BC; its bitumen was found to have come from Ubaid Mesopotamia period 2/3. Asphaltum samples from the slightly later site of Dosariyah in Saudi Arabia, was found to have been from bitumen seepages in Iraq, part of the wider Mesopotamian trade networks of Ubaid Period 3.

Bitumen trade in the region continued well after the end of the Bronze Age: several samples including numerous large jars recovered from the Roman era port of Dibba in the United Area Emirates, and other objects. Sources seem to be Hit in Iraq or unidentified Iranian sources.

Egypt and Mesoamerica

The use of bitumen in Egyptian mummies was important beginning at the end of the New Kingdom (after 1100 BC)--in fact the word from which mummy is derived 'mumiyyah' means bitumen in Arabic. Bitumen was a major constituent for Third Intermediate period and Roman period Egyptian embalming techniques, in addition to traditional blends of pine resins, animal fats, and beeswax.

Recent studies in pre-Classic and post-classic period Mesoamerica have found bitumen was used to stain human remains, perhaps as a ritual pigment as red ochre is.

But more likely, say researchers Argáez and associates, the staining may have resulted from using heated bitumen applied to stone tools which were used to dismember those bodies.

The Chumash of California

In California's Channel Islands, indigenous groups such as the Chumash used bitumen as body paint during curing, mourning and burial ceremonies. They also used it to attach shell beads onto objects such as mortars and pestles and steatite pipes; they used it for hafting projectile points to shafts and fishhooks to cordage.

Asphaltum was also used for waterproofing basketry and caulking sea-going canoes.

The earliest identified asphalum in the Channel Islandss so far is in deposits dated between 10,000-7,000 cal BP at Cave of the Chimneys on San Miguel island. The presence of asphaltum increases during the Middle Holocene (7000-3500 cal BP, and basketry impressions and tarring pebble clusters show up as early as 5,000 years ago. Bitumen's florescence may be associated with the invention of the plank canoe (tomol) in the late Holocene (3500-200 cal BP).

Native Californians traded asphaltum in liquid form and hand-shaped pads wraped in grass and rabbit skin to keep it from sticking. Terrestrial sources for seeps were believed to produce a better quality adhesive and caulking for the tomol canoe, while tarballs were considered inferior.

Sources

This glossary entry is a part of the About.com guide to Raw Materials, and the Dictionary of Archaeology.

A wonderful source on bitumen is the paper by Krishnan and Rajagopal cited below, which has an extensive summary of bitumen used throughout history, and a long discussion about the mechanical properties and locations of the material throughout the world, as well as a 500+ entry bibliography on the subject.

Argáez C, Batta E, Mansilla J, Pijoan C, and Bosch P. 2011. The origin of black pigmentation in a sample of Mexican prehispanic human bones. Journal of Archaeological Science 38(11):2979-2988.

Brown KM. 2016. Asphaltum (bitumen) production in everyday life on the California Channel Islands. Journal of Anthropological Archaeology 41:74-87.

Brown KM, Connan J, Poister NW, Vellanoweth RL, Zumberge J, and Engel MH. 2014. Sourcing archaeological asphaltum (bitumen) from the California Channel Islands to submarine seeps. Journal of Archaeological Science 43:66-76.

Cârciumaru M, Ion R-M, Nitu E-C, and Stefanescu R. 2012. New evidence of adhesive as hafting material on Middle and Upper Palaeolithic artefacts from Gura Cheii-Râsnov Cave (Romania). Journal of Archaeological Science 39(7):1942-1950.

Connan J. 1999. Use and trade of bitumen in antiquity and prehistory: molecular archaeology reveals secrets of past civilizations. Philosophical Transactions of the Royal Society of London 354:33-50.

Connan J, Carter R, Crawford H, Tobey M, Charrié-Duhaut A, Jarvie D, Albrecht P, and Norman K. 2005. A comparative geochemical study of bituminous boat remains from H3, As-Sabiyah (Kuwait), and RJ-2, Ra's al-Jinz (Oman). Arabian Archaeology and Epigraphy 16(1):21-66.

Connan J, and Van de Velde T. 2010. An overview of bitumen trade in the Near East from the Neolithic (c.8000 BC) to the early Islamic period. Arabian Archaeology and Epigraphy 21(1):1-19.

El Diasty WS, Mostafa AR, El Beialy SY, El Adl HA, and Edwards KJ. 2015. Organic geochemical characteristics of the Upper Cretaceous–Early Paleogene source rock and correlation with some Egyptian mummy bitumen and oil from the southern Gulf of Suez, Egypt.

Arabian Journal of Geosciences 8(11):9193-9204.

Fauvelle M, Smith EM, Brown SH, and Des Lauriers MR. 2012. Asphaltum hafting and projectile point durability: an experimental comparison of three hafting methods. Journal of Archaeological Science 39(8):2802-2809.

Jasim S, and Yousif E. 2014. Dibba: an ancient port on the Gulf of Oman in the early Roman era. Arabian Archaeology and Epigraphy 25(1):50-79.

Krishnan JM, and Rajagopal KR. 2003. Review of the uses and modeling of bitumen from ancient to modern times. American Society of Mechanical Engineers, Applied Mechanics Reviews 56(2):149-214.

Rawcliffe C, Aston M, Lowings A, Sharp MC, and Watkins KG. 2005. Laser Engraving Gulf Pearl Shell--Aiding the Reconstruction of the Lyre of Ur. Lacona VI.

Schwartz M, and Hollander D. 2008. Bulk stable carbon and deuterium isotope analyses of bitumen artifacts from Hacinebi Tepe, Turkey: reconstructing broad economic patterns of the Uruk expansion.

Journal of Archaeological Science 35(12):3144-3158.

Van de Velde T, De Vrieze M, Surmont P, Bodé S, and Drechsler P. 2015. A geochemical study on the bitumen from Dosariyah (Saudi-Arabia): tracking Neolithic-period bitumen in the Persian Gulf. Journal of Archaeological Science 57:248-256.

Wendt CJ, and Cyphers A. 2008. How the Olmec used bitumen in ancient Mesoamerica. Journal of Anthropological Archaeology 27(2):175-191.

Wendt CJ, and Lu S-T. 2006. Sourcing archaeological bitumen in the Olmec region. Journal of Archaeological Science 33(1):89-97.