Geology of Turkey
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The geology of Turkey is the product of a wide variety of
Turkey's varied landscapes are the product of a wide variety of tectonic processes that have shaped Anatolia over millions of years and continue today as evidenced by frequent earthquakes and occasional volcanic eruptions. Except for a relatively small portion of its territory along the Syrian border that is a continuation of the Arabian Platform, Turkey geologically is part of the great
However, many of the rocks exposed in Turkey were formed long before this process began. Turkey contains outcrops of Precambrian rocks, (more than 520 million years old; Bozkurt et al., 2000). The earliest geological history of Turkey is poorly understood, partly because of the problem of reconstructing how the region has been tectonically assembled by plate motions. Turkey can be thought of as a collage of different pieces (possibly terranes) of ancient continental and oceanic lithosphere stuck together by younger igneous, volcanic, and sedimentary rocks.
During the
During the Cenozoic folding, faulting, and uplifting, accompanied by volcanic activity and intrusion of igneous rocks was related to major continental collision between the larger Arabian and Eurasian plates (e.g. Robertson & Dixon, 1984).
Present-day earthquakes range from barely perceptible tremors to major movements measuring five or higher on the open-ended
Turkey's terrain is structurally complex. A central massif composed of uplifted blocks and downfolded troughs, covered by recent deposits and giving the appearance of a plateau with rough terrain, is wedged between two folded mountain ranges that converge in the east. True
Nearly 85% of the land is at an elevation of at least 450 meters; the average and median altitude of the country is 1,332 and 1,128 meters, respectively. In Asiatic Turkey, flat or gently sloping land is rare and largely confined to the deltas of the
More than 80% of the land surface is rough, broken, and mountainous, and therefore is of limited agricultural value (see Agriculture, ch. 3). The terrain's ruggedness is accentuated in the eastern part of the country, where the two mountain ranges converge into a lofty region with a median elevation of more than 1,500 meters, which reaches its highest point along the borders with Armenia, Azerbaijan, and Iran. Turkey's highest peak, Mount Ararat (Ağrı Dağı) — 5,137 meters high — is situated near the point where the boundaries of the four countries meet.
Background
Turkey's terrain is structurally complex. A central massif composed of uplifted blocks and downfolded troughs, covered by recent deposits and giving the appearance of a plateau with rough terrain, is wedged between two folded mountain ranges that converge in the east. True lowland is confined to the plain of the Ergene river in Thrace, extending along rivers that discharge into the Aegean Sea or the Sea of Marmara, and to a few narrow coastal strips along the Black Sea and Mediterranean Sea coasts.[citation needed]
Nearly 85% of the land is at an elevation of at least 450 meters; the median altitude of the country is 1,128 meters. In Asiatic Turkey, flat or gently sloping land is rare and largely confined to the deltas of the
More than 80% of the land surface is rough, broken, and mountainous, and therefore is of limited agricultural value. The terrain's ruggedness is accentuated in the eastern part of the country, where the two mountain ranges converge into a lofty region with a median elevation of more than 1,500 meters, which reaches its highest point along the borders with Armenia, Azerbaijan, and Iran. Turkey's highest peak, Mount Ararat (Ağrı Dağı)—about 5,166 meters high—is situated near the point where the boundaries of the four countries meet.
Geological history
The earliest geological history of Turkey is poorly understood, partly because these oldest rocks in the region are involved into younger deformation phases that hindered their evolution. This created problem of reconstructing how the region has been tectonically assembled by plate motions. Turkey can be thought of as a collage of different continental pieces and remnants of oceanic lithospheric rocks amalgamated together by younger tectonic processes that involve accumulation of igneous (both plutonic and volcanic) and sedimentary rocks.
Plate tectonics
Except for a relatively small portion of its territory along the
The Anatolian Plate, together with the
The
Rocks
Many of the rocks exposed in Turkey were formed long before this process began. Turkey contains outcrops of Precambrian rocks, (more than 540 million years old).[5]
During the
During the Cenozoic (Tertiary about 66 to 1.6 million years) folding, faulting and uplifting, accompanied by volcanic activity and intrusion of igneous rocks was related to major continental collision between the larger Arabian and Eurasian plates.[10]
Earthquakes
Turkey's most severe earthquake in the twentieth century occurred in Erzincan on the night of 1939-12-27; it devastated most of the city and caused an estimated 30,000 deaths. Earthquakes of moderate intensity often continue with sporadic aftershocks over periods of several days or even weeks. Seismicity in Turkey is more likely to happen in the North Anatolian Fault Zone, East Anatolian Fault Zone and in the subduction region of the Aegean Plate between the Anatolian plate.
See also
External links
Notes
References
- Bergougnan, H. (1975) Dispositif des ophiolites nord-est anatoliennes, origine des nappes ophiolitiques et sud-pontiques, jeu de la faille nord-anatolienne. Comptes Rendus de l'Académie des Sciences, Série D: Sciences Naturelles, 281: 107–110.
- Bozkurt, E. and Satir, M. (2000) The southern Menderes Massif (western Turkey); geochronology and exhumation history. Geological Journal, 35: 285–296.
- Kaymakci, N., 2000. Tectono-stratigraphical evolution of the Çankırı basin (Central Anatolia, Turkey) (Vol. 190, pp. 1–247). Utrecht University.
- Kaymakci, N., Inceöz, M., Ertepinar, P. and Koç, A. 2010. Cretaceous to recent kinematics of SE Anatolia (Turkey) In Sosson, M. Kaymakci, N., Stephenson, R., Starostenko, V. and Bergerat, F. (Eds.) Sedimentary basin tectonics from the Black Sea and Caucasus to the Arabian Platform. Geological Society London Special Issue No. 340, 409-435.
- Reilinger, Robert; McClusky, Simon; Vernant, Philippe; Lawrence, Shawn; Ergintav, Semih; Cakmak, Rahsan (May 2006). "GPS constraints on continental deformation in the Africa-Arabia-Eurasia continental collision zone and implications for the dynamics of plate interactions: EASTERN MEDITERRANEAN ACTIVE TECTONICS". Journal of Geophysical Research: Solid Earth. 111 (B5). .
- Robertson, A. and Dixon, J.E.D. (1984) Introduction: aspects of the geological evolution of the Eastern Mediterranean. In: Dixon and Robertson (Editors), The Geological Evolution of the Eastern Mediterranean. Geological Society, London, Special Publications, 17, 1–74.
- Ustaömer, T. and Robertson, A. (1997) Tectonic-sedimentary evolution of the north Tethyan margin in the Central Pontides of northern Turkey. In: A.G. Robinson (Editor), Regional and Petroleum Geology of the Black Sea and Surrounding Region. AAPG Memoir, 68, Tulsa, Oklahoma, 255–290.
- This article incorporates text from this source, which is in the public domain. Country Studies. Federal Research Division.
- This article incorporates public domain material from The World Factbook. CIA.
Further reading
- Brinkmann, Roland, 1976, Geology of Turkey, Elsevier Scientific Pub. Co ISBN 0-444-99833-0
- Higgins, MD and Higgins, RA, 1996,*A Geological Companion to Greece and the Aegean Cornell University Press. ISBN 0-8014-3337-1