Field of Science

The Iceman story

"I remembered the effect that the view of the tremendous and ever-moving glacier had produced upon my mind when I first saw it. It had then filled me with a sublime ecstasy that gave wings to the soul, and allowed it to soar from the obscure world to light and joy. The sight of the awful and majestic in nature had indeed always the effect of solemnising my mind, and causing me to forget the passing cares of life. I determined to go without a guide, for I was well acquainted with the path, and the presence of another would destroy the solitary grandeur of the scene."
Mary W. Shelley "Frankenstein" (1813)

It was a fast and lonesome death, wounded by an arrow in the back, the man bleed to death within minutes. The body was left on the site of the murder, maybe the aggressors assumed that scavengers and time would erase all of the evidences, but in the cold and dry climate the body begun to desiccate and large scavengers didn't venture in this desolate realm, only some flies were able to deposits their eggs on the body but they weren't able to destroy it.
During the next winter snow accumulated in the gully where the body laid and in the next decades and centuries the snow transformed slowly into ice, protecting and preserving the mortal remains.


Fig.1. The small snowfield on the middle of this photography is covering again the gully in which the body of "Ötzi" was discovered.

Time passed, then in the late summer of 1991 - exact 20 years ago- two German tourists, Helmut and Erika Simon, accidentally discovered the body emerging from the ice
, the marked ablation during the summer (helped by sunny weather and the deposition of Saharan dust on the glacier ice, that absorbed much solar radiation) of the small glacier near the Similaun Hut, in the Ötztaler Tyrolean Alps, brought the corpse back to the surface.
The prehistoric mummified corpse - soon known worldwide as "Ötzi" the Iceman - together with its unique set of artefacts, provided a unique opportunity for the research of th
e cultural development of a bronze-age culture, this corpse is the highest prehistoric find (ca. 3.280m a.s.l.) in the Alps.

But the body and artefacts provided also insights on the glacier dimensions during the little known phases of the warmest parts of the Holocene in Europe. This phase is pract
ically undocumented by glacial sediments, eroded by later glacial advances, and is only recognizable by proxy data like changes in pollen diagrams or dating organic materials, over- or underlying glacial or proglacial deposits.

During the last glacial maximum some 18.000 years ago the entire area was completely ice-covered, only narrow and steep arêtes and horns protruded from the ice. In the area of the Similaun Hut sharp trim lines in a height varying from 3.060m to 3.400m divide the uppermost frost-shattered crests from the lower slopes, smoothed by glacial erosion. The trim line can also recognized locally as marked weathering line that separates different oxidized surfaces (the bed rock consists of Fe-rich gneiss and schist).
A second trim line is marked by an abrupt change in lichen diameter (from 100mm above to 40mm below) and density. The dating by lichenometry attributes this glaciers to the Little Ice Age (LIA, ca. 1.600-1.850), which generally corresponds to the maximum Holocene glacier expansion.
The mummy itself was dated by radiocarbon dating to 4.500+-30
and 4.580+-30 yr B.P., which corresponds to a calibrated age of 5.300-5.050 yr B.P. The relatively sudden burial of the corpse in a more or less permanent snow and ice cover indicates a significant climatic change that induced glacier expansion at the beginning of the Neoglaciation in the second half of the Holocene.
This supposed change of the glaciers was supported also by some soil horizons found in depression between 3.000 and 3.215m a.s.l. and dated to 5.615+-55 yr B.P. (6.450-6.300 cal yr B.P.) and 3.885+-60 yr B.P. (4.416-4.158 cal yr B.P.). Similar recent so
ils needed at least 5 to 12 centuries for its development, suggesting that the climatic conditions on the site were for a long time relative favourable for biological and chemical activity.

The Iceman and his site so reveal that between 9.000 and 5.000 yr B.P. the mountain glaciers were smaller than in the second half of the Holocene. About 6.400 cal yr B.P. and for several centuries after, an ice-free peripheral belt allowed the accumulation of organic
matter and developments of relatively thick soils. Between 5.300 to 5.050 cal yr B.P. ago a rapid climatic change took place, producing a persistent snow cover and the expansion of glaciers, which conserved the body until again the glaciers begun to retreat.
And the recent retreat of the glaciers still continues, in 1970 the glacier that revealed the mummy was part of the much greater Niederjoch Glacier, a composite alpine glacier that descends northward in the Nieder-Valley, but only in the last 5 years the Nied
erjoch-glacier lost 60-100m length.

Fig.2. The "Similaun" as highest peak (3.597m a.s.l.) with his two main glaciers, the "Similaun" in foreground, and the "Niederjoch" in background. Until ca. 1970 the glaciers flowed together, but the glacier retreat in the last years was notable.

Fig.3. Location (black circle) of the site of the bronze-age mummy in the Ötztaler Alps. Blue areas represents the glacier extends in 2003, the red line the glacier extends during the Little Ice Age (ca. 1600-1850), blue, green and yellow the main glacier-stages during the Pleistocene-Holocene transition.

The environment in which the Iceman lived was characterised by a rich biodiversity, he could use and in fact used an astonishing variety of plants found in his living space.
Both the axe shaft and the long bow were found in the vicinity of the corpse and were made of yew (Taxus baccata), a resistant and elastic wood typ. The quiver for the arrows was made of caprine skin and was stiffened with the elastic wood of the hazel tree (Corylus avellana). The 14 arrows were made of the hard wood of the wayfaring tree (Viburnum lantana). One is repaired, the front end being restored with dogwood (Cornus). The dagger handle is also made by hard wood from a piece of ash (Fraxinus excelsior). Its sheath was knotted from the bark of basswood (Tilia).
He carried also two containers made of birch (Betula) bark, in one were found charcoal pieces wrapped in Norway maple (Acer platanoides) leaves.
Several wood species could be identified from the charcoal remains, probably spruce (Picea/Larix-type), pine (Pinus mugo-type), green alder (Alnus viridis), some Pomoideae which were probably Juneberry (cf. Amelanchier ovalis), dwarf willow (Salix reticulata-type) and elm (Ulmus).
A sort of backpack was constructed from a thick branch of hazel (Corylus avellana) bent into a U-shape, together with two coarsely-worked laths of larch (Larix decidua).


The majority of wood species found with the Iceman grow in the montane regions (valley bottoms to 1.800 m), although some subalpine (1.800-2.500 m) and alpine (above 2.500 m) conifer species are also represented. Their ecological requirements point to the transition zone between thermophilic mixed-oak forest communities (Quercetalia pubescenti-petreae) and the montane spruce forest (Piceetum montanum). Norwegian maple (A. platanoides), European yew (T. baccata), ash (Fraxinus sp.), lime (Tilia sp.) and elm (Ulmus sp.) allow to infer a humid habitat with a mineral rich, free-draining soil and a mild winter climate.
All that is similar to the present-day conditions in the woodlands found on the slopes and in gorges in the lower Schnalstal and Vinschgau in South Tyrol, where it is assumed he lived.

So the botanical evidence seems to confirm a climate comparable to modern conditions, and implies a glacial extent similar, if not slightly minor to the present. This has very important influence on the reconstruction of past, and modern climatic and glacial development, and at last the actual discussion about climatic change.

Bibliography:


BARONI, C. & OROMBELLI, G. (1996): Short paper - the alpine "Iceman" and Holocene Climatic Change. Quaternary Research 46: 78-83

MAGNY, M. & HAAS, J.N. (2004): Rapid Communication - A major widespread climatic change around 5300 cal. yr BP at the time of the Alpine Iceman. Journal of Quaternary Science 19(5): 423-430

OEGGL, K. (2009): The significance of the Tyrolean Iceman for the archaeobotany of Central Europe. Veget. Hist. Archaeobot. 18:1-11

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