How Are Bog Bodies Different From Desert Mummies?

Bogs are created through the slow buildup of plant matter over long stretches of time. These wetland areas have an extraordinary ability to preserve items buried within them.

Numerous artifacts, including human remains, have been uncovered in bogs, preserved for millennia. Some bog bodies are so intact that scientists can examine the contents of their stomachs, revealing their final meals and providing a glimpse into ancient diets.

These preserved ancient human remains have fascinating stories to tell, and today we'll explore the strange science that makes their preservation possible.

What Exactly Are Bogs?

Found in cool, damp regions, bogs are waterlogged areas that develop when decomposing plant matter, or peat, builds up in low-lying zones.

Bogs are typically located in cooler climates and are often found in lake basins formed by ice age glaciers that no longer receive consistent river or stream water. Over time, mosses blanket the surface, with the moss layer primarily made up of sphagnum moss in most cases.

Sphagnum moss has the ability to drastically change its environment. When water or soil gets trapped underneath it, they lose access to the oxygen typically supplied by the air. The peat formed by sphagnum can also absorb calcium and magnesium, making the surrounding soil and water mildly acidic.

Since bacteria and fungi struggle to thrive in these harsh conditions, the decomposition of dead plant matter occurs at an incredibly slow pace. Rather than breaking down immediately, it lingers, gradually accumulating over time. The buildup of this plant waste eventually transforms into peat, a damp, mud-colored material.

Peat serves as animal bedding and can also be used as a fossil fuel, which makes it a valuable resource in regions like the Irish midlands. However, for archaeologists, peat holds less significance compared to the ancient remains of Homo sapiens that can sometimes be found within it.

Bog Bodies Uncovered

Bog bodies, often referred to as bog people, are human remains that have been preserved naturally through the mummification process in a peat bog. While many of these bodies date back to the Iron Age (around 1300 B.C.E. to 800 C.E., depending on the region), some are even older.

The title of the "oldest known bog body" is attributed to the Koelbjerg Man, whose remains are believed to date from around 8000 B.C.E., making it the earliest known bog body from the Mesolithic era.

Various regions of Northern Europe, such as Denmark, Germany, the Netherlands, the British Isles, and Ireland, have yielded the discovery of these bodies. The unique conditions of bogs, including cold temperatures, acidic waters, and oxygen scarcity, hinder the typical decomposition process after death, allowing for the preservation of soft tissues for millennia.

These bog mummies are predominantly discovered in raised bogs, which are dome-shaped structures that form in cooler temperate zones. The specific environment of the bog allows for extraordinary preservation of skin, hair, and even clothing.

However, the acidic bog water often leads to the demineralization of the bones, weakening them. The skin that remains preserved frequently adopts a dark or tanned hue due to the tannins present in the bog's waters.

Iron Age CSI

Bogs have captivated human interest for centuries, not just due to their fossil fuels. The spongy terrain, which is prone to burning, has piqued curiosity since the Bronze Age. Many individuals either perished in these bogs or were placed there posthumously. These preserved bodies have been discovered globally.

The wetlands of northwestern Europe are known as a hotspot for bog bodies, with numerous corpses found across Germany, England, the Netherlands, and surrounding countries. In 2011, workers extracting peat in Ireland's Cúl na Móna Bog accidentally struck a Bronze Age body with a milling machine.

The remains were identified as those of an adult male, later named the "Cashel Man", who likely died in his 20s.

His body exhibited several injuries, including a broken arm and a severe gash on his back. These wounds could have resulted from the immense weight of the bog moss above him or the milling machine's blades. Still, archaeologists speculate that Cashel Man was a victim of ritualized sacrifice.

(Other European bog bodies have shown signs of stab wounds, slit throats, and evidence of torture. Historians believe these local wetlands were once notorious for ritual human sacrifice and other brutal deaths.)

Carbon dating reveals that Cashel Man died approximately 4,000 years ago, seven centuries before King Tut was born. He holds the title of the oldest European bog body discovered with intact skin, a corpse whose skin has remained preserved for millennia.

This isn't just a coincidence. Many bog bodies maintain some or all of their original skin. For instance, the Tollund Man, a corpse from 2,300 years ago discovered in a Danish peat bog in 1950, has hands that have mostly turned to bone, but much of his skin remains so well-preserved that fine details, like the lines on his forehead, are still visible.

Skincare Secrets

While the Tollund Man's skin didn't completely decay, the process of mummification altered its texture and appearance. Much like the Cashel Man, the Haraldskjaer Woman, and other bog bodies, his skin developed a noticeable tan.

Bog mummies typically have dark brown, leathery skin. Some even retain hair that has turned red after death. This phenomenon is likely due to sphagnan, a recently discovered polymer that seeps from decaying sphagnum moss.

Leather is created through a process that strengthens the natural fibers in animal hides. Sphagnan, as a tanning agent, has a similar effect on human skin, making it tough and giving it a tea-colored hue.

Sphagnan also interacts with nitrogen, an element essential for bacteria to survive. By removing nitrogen from the environment, sphagnan helps prevent the growth of microorganisms that would otherwise decompose human and animal remains. Additionally, sphagnan, in its acidic form, draws calcium out of dead bodies, weakening bones in the process.

While sphagnan is effective at preserving skin, its removal of calcium isn’t beneficial for skeletons. Mummies from certain bogs have been found with soft, brittle bones that are as fragile as cardboard and have been misshaped by the heavy peat.

However, this assumes the decalcification process doesn’t entirely destroy the bones. Some bog bodies have been discovered missing bones, and in some cases, the mummies are completely boneless. These are essentially human-shaped bags of leathery skin, wrapped around preserved organs.

Bog Skeletons

However, not all bogs are equally destructive to bones. The water's acidity varies between bogs, and this influences how well corpses are preserved. In highly acidic peat bogs, the preserved mummies tend to have abundant skin and soft tissue but often lack strong or even any bones.

There are also bogs with relatively alkaline, or "basic," water. These places have the opposite effect on bodies, with the environment causing a different type of preservation. A prime example is the Windover Archaeological Site, a peat-bottomed pond in Florida, where dozens of Indigenous Americans were laid to rest between 6,990 and 8,120 years ago.

Remains from 168 individuals have been uncovered in the peat. The pond’s water is enriched with magnesium and calcium carbonates, which come from a large deposit of crushed snail shells beneath the pond. These minerals make the water more alkaline, partially neutralizing the sphagnan.

Rather than mummified skin bags, the bog is filled with bare bones and skeletons. Despite their exposed state, the ancient remains surprised scientists with an unexpected discovery: Brain tissue was found in over 90 of the skulls recovered from Windover pond.

World's Largest Peat Bog

The West Siberian Plain, covering an area of over 1.2 million square kilometers (463,323 square miles) in Russia, holds the title of the largest peat bog on Earth. Situated between the Ural Mountains and the Yenisei River, this expansive region features a blend of forests, swamps, and thick peat layers, some of which extend up to 33 feet (10 meters) deep.

These vast peatlands play a vital role as carbon sinks, capturing enormous quantities of carbon over millennia. As the organic matter remains undecomposed, it traps carbon, preventing it from being released into the atmosphere.

This function is critical in combating climate change. Yet, human activities such as draining the bogs for agriculture and forestry threaten this balance by releasing the stored carbon as greenhouse gases. Furthermore, rising global temperatures pose the danger of releasing potent methane from these peatlands.

In addition to its climate impact, the West Siberian Plain is home to a diverse range of plant and animal species, making its preservation crucial for both ecological health and climate stability.