![]() ![]() ![]() Palaeobotanical studies of leaf and pollen floras show that the vegetation changed several times from forested to steppic phases in response to the climate oscillations of the Lower Pleistocene. At 53.68 ka (MIS 3), 12.6 ka, 10.78 ka and 4.14 ka (MIS 1), the development of travertines on some slopes and in some valleys highlights temperate and humid climatic phases. During Marine Isotopic Stages 12, 6 and 4, glaciers and fluvio-glacial deposits were probably present overall the principal uplands and valleys of southern Armenia. From 993 ka, volcanic eruptions produced lava flows that covered the fluvio-lacustrine accumulations. Before 1.21 Ma, tectonic movements (antecedents of the lower part of the Vorotan valley) generated extensive lake formations with diatomaceous deposits. ![]() The chronology of morphogenetic events has been determined by 17 radiometric dates (K/Ar, Ar/Ar, U/Th), palaeomagnetic investigations and is placed in a spatial context by a detailed geomorphological map and a 24-km geological transect of the Vorotan valley, the main area studied. The Pleistocene diatomaceous deposits studied contain leaf impressions and pollen, allowing local palaeoclimatic reconstructions. Fluvio-lacustrine environments, indicated by diatomaceous deposits, prevailed in the Syunik region of southern Armenia during the Pliocene and Pleistocene. The morphogenetic evolution of the Lesser Caucasus has been strongly influenced by Plio-Quaternary volcanic and tectonic events and Pleistocene glaciations. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |