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This presentation focuses on the Bronze Age landscape evolution of Central Crete, which was investigated on the basis of a geoarchaelogical research design. A multi-method approach using geophysics, sedimentological analyses, terrestrial laser scanning, GIS and 3D visualization software was applied. According to the findings, human-environmental interactions such as extensive clearing, soil erosion and climate change led to the complete degradation of the mountains of Crete. Until today, the region was never colonized again due to unfavorable environmental conditions. In contrast to the current conditions, Central Crete experienced an era of bloom during the 2nd millenium BC that allowed people to settle and cultivate this remote landscape. A first-time visualization of the former landscape gives insight into this significant transition, which occurred at the end of the Minoan period around 1200 BC.
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Les Journées des Jeunes Géomorphologues, Avignon, February 2011
Christoph Siart 1, Matthieu Ghilardi 2, Markus Forbriger 1 , Olaf Bubenzer 1
The spatial shift of the Cretan ecumene during the 2nd millennium BC: climate, social upheaval or both?
1 Geographical Institute – University of Heidelberg, Germany2 CEREGE/CNRS – Aix‐en‐Provence, France
Objectives
• reconstructing the Holocene environmental change in Crete• natural impact on ancient cultures?• human impact and landuse? investigation of karst depressions (geoarchives)
Methods• terrestrial laserscanning (TLS), remote sensing & GIS• geophysical prospection (ERT) & percussion drilling• sedimentological analysis & datings• mineralogical provenance (XRD, SEM‐EDX, EPMA etc.)• 3D visualisation
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Case studiesA) Zominthos (~ 1650 BC, Minoan period)
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Zominthos: Electrical resistivity tomography ‐ off‐site studiessubsurface karst relief
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Zominthos: ERT on‐site studiessubsurface archaeological remains
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Zominthos: Subsurface karst relief modeltransferring geophysics into 3D
Data:ER‐ & SR tomographies1.5 m high resolution DEMHydrologic analysis ‐ArcGISQuickbird MS pansharpened
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Zominthos: Sedimentological investigations
AMS 14C datings: palaeosoils ~2900 BCSantorini ash in depths of 10 m b.s (~ 1620 BC)
geomorphodynamic activity only since Late Minoan / Subboreal (1600 BC)
massive erosion and colluviation complete degradation in only a few centuries
OPX
CPX
OPX &
glass
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Climate change in the Eastern Mediterranean
Case studiesB) Lato (~ 1400 / 800 BC, Mycenean / Dorian period)
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
high basal resistivities(limestone bedrock)
superficial high resistivities (colluvium, footslope deposits)
thick fill with loamy sediment (~ 25m), conical subsurface relief with dip towards doline center, bedrock in depths of approx. 20‐25 m
fine‐grained, unconsolidated sediment
transition zone(limestone detritus mixed with loose material)
Lato: ERT off‐site studiessubsurface karst relief
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
fine‐grained, unconsolidated sediment below 2.5 m, nostructures identified
archaeological finds?
heterogeneous surface causedby anthropogenic perturbation
Lato: ERT on‐site studiessubsurface archaeological remains
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
spring
ancient drainage channelor water harvesting system(subsurface structures)
S
R
A
Lato: ERT‐TLS on‐site studiesthe morphological context
recent surface drainage(active gully)
The Cretan mountains todaylandscape degradation and climate alteration
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
The Cretan mountains BC3D visualisation of the ancient landscape
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
• dolines and poljes as favorable sites for land use since Bronze Age (water supply, agriculture, etc.)
• karst depressions as promising palaeoenvironmental archives
• vast colluviation & decameters of infills since Bronze‐Age as a result of land degradation and climatic change
• water supply, the primary settlement determinant, displays profound dependency on climatic conditions and changes
• neo determinism: man‐environment interactions led to spatial shift of the ecumene multi‐causal approach
General conclusions
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
Thank you for your attention,merci beaucoup pour votre attention!
Les Journées des Jeunes Géomorphologues, Avignon, February 2011Siart et al.: The spatial shift of the Cretan ecumene during the 2nd millennium BC
