Published January 2010

Climatic conditions and character of forming vegetable cover of Caucasus in early Pliocene

Y.N.Taghiyeva

On the basis of generalization palenological and carpological data on flora of Caucasus the basic climatic parameters of early Pliocene (Balakhany, Cimmerian), appropriate to a damp subtropical climatic zone are restored. The reasons and distinctions in formation of a vegetative cover of Western and East Caucasus are revealed. Accumulation of minerals occurs only at determined paleogeography conditions. It is especially important for petroleum and natural gas, collect not in petroleum and gas parent material and in “traps” - breeds of the certain structure and structure. Formation and migration of these deposits depends on climatic conditions of time of their accumulation. Oil-bearing thickness of pool of Caspian sea, named by productive thickness was formed in an interval of time 5,1-3,4 million years back. Simultaneously in the Western Caucasus, were formed one-age Cimmerian adjournment. In article are restored the paleogeography conditions early Pliocene Caucasus Productive thickness and Cimmerian circle on the basis of the analysis of mineral flora. During accumulation of adjournment of productive thickness there was a strengthening of tectonic activity of all area of Caucasus. Plains occupied a significant part of modern shoaliness of Caspian Sea. Absolute heights of mountains did not exceed 2000 m. In the Black and Caspian seas regress is marked. Caspian Sea in the beginning Pliocene has turned to a chain of small lake reservoirs, greatest of which had a level 500-600 м and settled down within the limits of modern Southern Caspian sea. In second half Productive thickness centuries there is gradual expansion Productive thickness of pool and under waters there is all territory of modern Caspian Sea. Vital forms of plants early Pliocene the birch and the laurels testifying to existence at this time well expressed vertical zoning is characterized by the big specific variety and various to ecological conditions, as, for example. In this interval of time such vegetative groupings, as coniferous, mixed coniferous-broad-leaved forest, deciduous, boggy and streamside woods, light forests, savanna type, steppe took place. The quantity indicators of a climate restored on spore and pollen spectra from chinks of the Baku archipelago for first half Productive thickness of century have made: January 4-6 оC, July 24-26 оC, mid-annual 14-16 оC, 1100 mm are not lower than deposits. Paleoenvironmental reconstructions for flat territories of Azerbaijan early Pliocene have shown temperatures: January 5-11 оC, July 24-27 оC, mid-annual 15-19 оC, mid-annual amount of deposits of 1100-1600 mm. These parameters on the average on 1-1,5 оC were higher than those in first half early Pliocene. Comparison of these data to modern parameters of a climate shows, that in an examined interval of time in arid region of Caucasus, summer temperatures exceeded modern on 2-3 оС, temperatures of January - on 5-8 оC, mid-annual - on 4-5 оC, Presence at flora early Pliocene representatives of family Taxodiaceae with high insistence to a moisture, speaks, that the annual amount of deposits exceeded modern more than three times. At the end of early Pliocene there was an increase of a level and expansion of the area of the Caspian and Black seas, humidity has increased, winter temperatures have increased. Second half early Pliocene (4,5-3,4 million years) answers a climatic optimum Pliocene. Thus, adjournment of productive thickness collected not in conditions of a hot and dry climate as believe, proceeding from deep regress of a level of Caspian Sea, and at a warm and damp climate.