Archaeoseismology and Palaeoseismology in the Alpine ... - Tierra

(e.g. Mula, 1999 or Bullas 2002), showing a potentially
seismic activity in the region.
SEDIMENTARY AND ARCHAEOLOGICAL RECORD
The general stratigraphic succession of the site consists of
a fining‐upward cycle, basically beginning with gravels
and/or sands of a meandering channel and concluding
with flood‐plain lutites (Figs. 2 and 3). The cycle consists
of three intervals, which correspond to fluvial
subenvironments determined by sedimentological
analysis. From bottom to top the facies association are: 1)
channel filling, 2) channel abandonment and 3) flood
plain. This vertical succession of lithofacies with upward
decreasing energy characterizes sedimentation in a
typical meandering‐dominated flood plain.
The particular sedimentary conditions occurred here have
preserved very well seven anthropogenic layers
intercalated with the fluvial deposits (Fig. 3). Each one
was covered by a fluvial flow that has preserved the
archaeological record, separating one anthropogenic level
from other and avoiding the alteration of the remnants by
human activity during the next period.
Human habitat appears controlled by fluvial
environmental evolution: it was sporadic during the
channel work (facies association A and B, fig 3) and more
intense when rock shelter floor topography was
homogenized at the level of the flood plain of the main
channel (facies C).
Fig.2: Main archaeological trench showing the habitat levels
(dark) and a bed with outsized clasts (MRC, massive rock
collapse). Sedimentological interpretation is showed in Fig. 3.
A bed with outsized clasts (MRC level, Figs. 2 and 3)
appears intercalated in fine sands and lutites of the facies
association C, overlying the N2 anthropogenic layer (5820
+/‐ 50 BP). The bed consists of very angular and scattered
cobbles and boulders of sandy dolostones lacking internal
organization. The grain size and the textural maturity of
the clasts are genetically independent of the facies
association C, deposited at lower regime flow in a flood‐
plain where the bed intercalates. Thus, the MRC level is
unconnected with purely fluvial processes. This level
directly overlays the N2 level, sealing fire and bone‐food
remnants. Scarce artefacts have been found among the
stones of the MRC. The MRC level and the scarce
anthropogenic remains are completely covered by the
next flood sand level, and the next occupation level (Ch,
Fig. 2; 3710 +/‐ 40 BP).
1 st INQUA‐IGCP‐567 International Workshop on Earthquake Archaeology and Palaeoseismology)
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Fig.3: Detailed stratigraphic column from the archaeological site,
with indication of the lithofacies and facies associations.
The fluvial sediments studied present rounded particles
with an average maximum size of coarse‐grained gravel.
Thus, the MRC level with pebble‐ and cobble‐sized blocks
represents an exceptionally coarse‐grained layer. It is
made up of fragmented sandy dolomites from the walls
and roof of the rock shelter. Larger fragments are
fractured, though they preserve most of the original joints