Waterlogging (archeology)

In archaeology, waterlogging refers to the long-term exclusion of air by groundwater, which creates an anaerobic environment that can preserve artifacts perfectly. Such waterlogging preserves perishable artifacts. Thus, in a site which has been waterlogged since the archaeological horizon was deposited, exceptional insight may be obtained by study of artifacts made of leather, wood, textile or similar materials. 75-90% of the archaeological remains at wetland sites are found to be organic material. Tree rings found from logs that have been preserved allow archaeologists to accurately date sites. Wetland sites include all those found in lakes, swamps, marshes, fens, and peat bogs.

Peat bogs, nearly all of which occur in northern latitudes, are some of the most important environments for wetland archaeology. Peat bogs have likewise preserved many wooden trackways, including the world's oldest road, which is a 6,000-year-old one-mile stretch of track.

Bog bodies are the best-known finds from the peat bogs of northwest Europe, with most of them dating from the Iron Age. Most corpses that were found were individuals that met a violent death and were probably either executed as criminals or killed as a sacrifice before thrown into the bog. For example, the Old Croghan Man was stabbed, decapitated, mutilated, and tied down to the bottom of a bog pool. His body is an amazing display of how splendidly waterlogging can preserve a body, as his hands, skin, fingernails, and stomach were amazingly intact. Another example of a waterlogging artifact or mummy was Ötzi, found by two tourists near the border of Austria and Italy. Ötzi is now displayed in Bolzano, Italy, in the South Tyrol Museum of Archaeology.

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