Bog mummies are naturally preserved bodies predominantly found in peat bogs and other wetland regions in northern Europe, and because of their impressive state of preservation, many have been mistaken by recent missing persons or murder victims, and even reported to the police. Nearly 2000 of them have been uncovered through Europe - Over 500 Iron Age specimens dating to between 800 B.C. and A.D. 200 were found in Denmark alone -, in countries like Germany, the Netherlands, the United Kingdom, Ireland and Russia, but there are reports of Native American bog burials in Windover, Florida, USA. To date, one of the oldest bog bodies ever discovered is Denmark's Koelbjerg Man, a Mesolithic individual dating to about 8000 BC, and a great amount of those mummies were discovered by peat harvesters.
The mummification process bog bodies go through is entirely related to the environment. The bogs in which they're found usually have large deposits of dead moss and lychens, a humidity that can be due to precipitation or underground water sources, cold climate (excluding the Florida bodies), and high levels of acidity. Most of them also contain Sphagnum moss, that grows upwards and "encases" objects that fall into it, and in its decomposition, this kind of moss can be turned to peat, a substance used as fuel.
The dark, deep and still pockets of water that hold the bodies can become an anaerobic (devoid of oxygen) environment, thus hindering the material's decomposition by bacteria, insects and scavengers, while the cold keeps the integrity of the soft tissues, and the presence of tannic acid in the waters leads to a "tanning" process, of sorts, that hardens the body and further preserves it. Because of this acid, bog mummies usually have very dark skin and orange-red hair, but besides those minor changes, a spectacular amount of tissue is usually preserved intact. Many have even been found with their brains in a significant state of integrity, seeing as this organ takes longer to decay while underwater, being one of the first to do so in normal circumstances. Skeletons, however, aren't as well preserved, because the high acidity of the bogs can dissolve the innorganic matter of their bones.
Due to their well-preserved conditions, many different studies have been conducted on Bog Bodies. Karin Margarita Frei, a specialist from the National Museum of Denmark, for example, investigated the body of Huldremose Woman, a mummy discovered in 1879 wearing a checkered skirt and scarf, both made of sheep's wool, and two leather capes, to understand if some of the bog bodies' clothing could have been dissolved over the centuries. Through microscopy, she noted the presence of organic fibers stuck to the specimen's skin, most likely made of flax, that could've possibly been a form of undergarment that had indeed dissolved due to the bog's acidity.
Following this discovery, Frei performed a first-of-its-kind analysis of the strontium isotope contained in the flax and other materials from the bog woman's clothing, results of which indicated that the textiles and pelts came from terrains with a geologically older profile than those of Denmark, suggesting that Huldremose Woman may have come from somewhere else entirely, according to research published in 2009 in the Journal of Archaeological Science.
Lots of simpler studies are performed on those bodies, however, like X-Rays, tomographies, carbon datings, genetic profiling (when possible), etc., and the discoveries go from the cause of death and social status of the body to the contents of their stomach, place of origin, physical anomalies and many more. European scientists are very active on bog mummy research, especially in Denmark.
☀ National Geographic, access in October 10th 2021:
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