Download Full Text (146.6 MB)
Christos Pennos Ph.D. Thesis Submitted at the Aristole University of Thessaloniki School of Geology Department of Physical Enviromental Geography Examination Date: July 2014Abstract: The present study examines the landscape evolution of the Menikio Mountain based on morphological features that are evident inside the caves. The various evolutionary stages of the Mountain's landscape development are dated. In addition, a paleoclimatic reconstruction for the broader area is attempted. For this approach two stalagmites have been selected from the Mikro and Megalo Eptamilon caves. U - series dating techniques were used in order to determine the exact time spam of the records and in order to obtain the paleoclimatic signal, measurements of δ18O and δ13C were performed along the growth axis of the stalagmites. The project employs a range of approaches, using extensive fieldwork inside the caves alongside with laboratory chemical procedures in order to define the paleoenviromental conditions. Also, geographic information systems and remote sensing techniques together with electric resistivity tomographies and borehole data were used in order to define old buried landforms and reconstruct the paleo-landscape of the broader area. For this study and for cave entrances to be defined, G.I.S. applications in combination with ground truth verification were used. High accuracy orthophotomaps (www.ktimatologio.gr) were used in order to identify cave entrances at the vast barren landscape of Menikio Mountain. After the ground truth verification of the caves, extended exploration using alpine caving techniques took place. In the same time or in some cases following the exploration the survey of the caves was conducted using the distox cave survey system. For the reconstruction of the speleogenetic phases the meso and microforms from each cave were mapped and categorized. From this analysis it was clear which of the studied caves represent the position of the old aquifer and in combination with speleothem dating techniques they provide insights on the landscape evolution of the study area. Following the methodology proposed by Hellstrom (2003), uranium-thorium disequilibrium dating has been applied on 48 samples extracted from 7 stalagmites and calcite deposits from different caves. The results from these datings were imported at the ModAge software (Hercman and Pawlak, 2012), in order to reconstruct the chronostratigraphic model of stalagmite development. Stable Isotope measurements on two stalagmites were performed at the laboratories of Hertelendi Laboratory of Environmental studies, Institute for Nuclear Research Hungarian Academy of Sciences in Hungary and at the Institute of Geological Sciences of the Polish Academy of Sciences at the Warsaw Research Centre. The stalagmites are covering a time spam from 14.67ka B.P. to 8.25ka B.P. for the MegaloSP3 stalagmite and from 55.446ka B.P. to 6.379ka B.P. for the MikroSP6. The results showed that MegaloSP3 stalagmite was not in isotopically equilibrium conditions. Examining the Hendy test (Hendy, 1971) results from MegaloSP3 one may suggest that they indicate evaporation, since a consistent enrichment in δ18O with distance from its vertical axis is evident. The paleoclimatological study of these two stalagmites and their comparison with other records revealed a rapid and sensitive climate and ecosystem response to the North Atlantic climatic oscillations showing that the region of North Aegean and the East Meditarranean was climatically influenced by the ocean circulation and ocean heat transport of the North Atlantic. The landscape analysis with the use of remote sensing techniques revealed that the dolines of the highest part (1000m) of the Menikio Mountain that more than the half population (490) of the dolines are found at the altitudinal zone between 1500m- 1700m. a.m.s.l. Almost, 160 dolines are located at the highest altitudes between 1800m-1963m a.m.s.l. and 150 are lying at the lower elevations between 1200m and 1400m a.m.s.l. The existence of the Kior Delik that lays at 1643m a.ms.l., in combination with the results of the landscape analysis, are suggesting the existence of a paneplain at the same altitudinal zone. The Electric Resistivity Tomographies (E.R.T.) that were applied at the Kallipoli's polje revealed the presence of a buried paleo karstic surface that is covered from fine-grained sediments of almost 250m of thickness. The presence of this buried surface is correlating with the Tsifliki cave. Tsifliki cave presents clearly epiphreatic features that in combination with the paleo-karstic surface suggesting an old base level found approximately at 750m a.ms.l. Two vibracores were drilled at the polje, in order to study the magnetic signal of the fine-grained sediments and extract paleoclimatic informations on the polje creation. Unfortunatelly, although the variation with depth of the magnetic properties of the sediments is very prominent, no datable material was found and therefore the determination of the time spam that these changes occurred couldn't be determined. Finally, by dating a speleothem deposit covering the floor of the Megalo Eptamilon cave and correlating its absolute altimetric position with the springs of Agios Ioannis, found at the bottom of the valley, it was possible to date the base level drop rate. The base level drop rate was found to be equal to 0.45mmyr-1 at least for the last 76.5ka. This rate comes in agreement with the uplift rate that was proposed by Tranos and Mountrakis (2004), who studied the tectonic uplift of the Menikio Mountain and they calculated a value equal to 0.5mmyr-1. Using linear correlation it was possible to estimate the youngest possible age for the standstills on which Tsifliki Cave and Kior Delik Cave occur. These dates are estimated to 468ka B.P. and 941.5ka B.P. respectively. Open Access - Permission by Author(s) See Extended description for more information.
1 online resource
"Landscape evolution of Menikio mountain (Macedonia, Greece) based on morphological and sedimentological analyses of caves" (2014). KIP Articles. 2982.