 |
| Titel |
Magnetic and paleomagnetic investigation of sediments of the Kostenki section |
| VerfasserIn |
D. K. Nurgaliev, P. Yassonov, D. Gilmanova, A. Sinitsyn, F. Heller |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250029211
|
|
|
|
|
|
| Zusammenfassung |
| The Kostenki sites (Voronezh region) are considered as key position in the Paleolithic
archeology and the Quaternary geology of Eastern Europe. Together with the Molodova sites
in the western Ukraine, they provide the most important stratigraphic sequences for this part
of the world and hence the chronological framework for most Paleolithic sites of the vast
region between the Carpathian and the Ural Mountains.
The most significant challenge to the traditional point of view has emerged from dating
and numerical chronology of the Chronological Group I at Kostenki. The cultural layers of
this group underlie a volcanic ash horizon. Data from the following two chrono-stratigraphic
markers, which are of particular importance for the dating of these layers, will be
presented:
1. A volcanic ash horizon has been identified at seven Kostenki–Borshchevo sites and at
other localities in the region and which was caused by the Campanian Ignimbrite eruption
from the Phlegrean volcanic fields in southern Italy about 40,000 calendar years ago. The ash
horizon is situated within the interval of the so-called Middle to Upper Paleolithic
“transition”. Its position can be precisely correlated with a number of other environmental
events, such as for instance the Heinrich Event 4 (HE4), the Laschamp geomagnetic field
excursion, and a particular cosmogenic nuclide peak (Fedele, Giaccio & Hajdas
2008). Samples from different stratigraphic levels containing tephra have been
investigated with thermomagnetic methods and coercive force measurements; the
latter were performed with a coercivity spectrometer. The magnetic mineralogy
is dominated by titano-magnetites which were altered during transportation and
reworking.
2. A paleomagnetic excursion was identified in the sediments and the fossil soils between
the cultural layers IVa and IVb and represents the second chronological marker. The natural
remanent magnetization direction shows a complicated behavior during thermal and
alternating field demagnetisation. Apparently, primary remanence directions are partly
overprinted by secondary magnetization directions resulting from recent water infiltration or
by physical weathering causing sediment re-deposition. Nevertheless, a detailed image of this
excursion was reconstructed using data from another outcrop with less distorted NRM
directions. The obtained virtually geomagnetic pole (VGP) latitude data was then compared
with known VGP records of Laschamp excursion. The latter has been dated to 40-43 ka
(Weninger & Jöris 2008). |
|
|
|
|
|
|