0000000000676557
AUTHOR
Osman Candan
Geology of the Bozdag area, central Menderes massif, SW Turkey: Pan-African basement and Alpine deformation
The Menderes massif consists of a Precambrian Core Series that preserves evidence for a polymetamorphic history and a Paleozoic/Mesozoic Cover Series that experienced only the Alpine tectonometamorphic evolution. Structural, petrographic, and geochronologic investigations in the central Menderes massif demonstrate that (a) part of the metamorphic and structural evolution of the Precambrian basement is older than the undeformed 551+/-1.4-Ma-old Birgi metagranite, and (b) inferred Alpine fabrics overprinting the Cover Series largely have the same attitudes as the old structures in the much older Core Series. The inferred Alpine fabrics include both contractional and extensional structures. Co…
U-Pb Zircon Geochronology Of The Paleogene - Neogene Volcanism In The Nw Anatolia: Its Implications For The Late Mesozoic-Cenozoic Geodynamic Evolution Of The Aegean
The northern Aegean region was shaped by subduction, obduction, collision, and post-collisional extension processes. Two areas in this region, the Rhodope-Thrace-Biga Peninsula to the west and Armutlu-Almacik- Nallihan (the Central Sakarya) to the east, are characterized by extensive Eocene to Miocene post-collisional magmatic associations. We suggest that comparison of the Cenozoic magmatic events of these two regions may provide insights into the Late Mesozoic to Cenozoic tectonic evolution of the Aegean. With this aim, we present an improved Cenozoic stratigraphy of the Biga Peninsula derived from a new comprehensive set of U-Pb zircon age data obtained from the Eocene to Miocene volcani…
Eclogites within the Menderes Massif / western Turkey
Metagabbros in the core series of the Menderes Massif, for some time considered as post orogenic Miocene intrusives, revealed a strong poly-metamorphic history. The metagabbro bodies exhibit a pronounced zonation. Within their cores, igneous minerals are still preserved. Coronitic textures are interpreted as results of a high temperature, possibly granulitic overprint. The outer parts of the metagabbro bodies mostly consist of strongly to completely retrograded gamet-amphibo-lites, but occasionally contain relies of eclogites. Petrologic investigations confirmed a high pressure overprint and allowed preliminary P, T estimates (650 degrees C, equal to or greater than 1.3 GPa). The intensity …
Revision of "Leptite-gneisses" in the Menderes Massif: a supracrustal metasedimentary origin
The Pan-African basement of the Menderes Massif comprises a regular lithological succession that reaches a thickness of 8 km, the oldest units of which are, in ascending order, so-called leptite-gneisses, a quartzite-sequence transition zone and mica schists. New findings suggest that the protoliths for the leptite-gneisses, proposed to be of volcanic origin in previous studies, were predominantly elastic sediments of litharenitic composition, Geochemical data indicate that the protoliths for the leptite-gneisses were of cratonic provenance. Because they have undergone Pan-African polymetamorphism and are intruded by approximately 550 Ma gneisses of granitic origin, it is believed that the …
Pan-African high-pressure metamorphism in the Precambrian basement of the Menderes Massif, western Anatolia, Turkey
The Menderes Massif is made up of Pan-African basement and a Paleozoic to Early Tertiary cover sequence imbricated by Late Alpine deformation. The Precambrian basement comprises primarily medium- to high-grade schists, paragneisses, migmatites, orthogneisses, metagranites, charnockites, and metagabbros. High-pressure relies in the Pan-African basement are divided into two groups: eclogites and eclogitic metagabbros. The mineral assemblage in the eclogites is omphacite (Jd 44)-garnet-clinozoisite-rutile. The eclogites occur as pods and boudinaged layers in the basement schists and paragneisses. Inclusions found in the cores of the garnets indicate a medium-pressure protolith. The eclogitic m…
Carboniferous granites on the northern margin of Gondwana, Anatolide-Tauride Block, Turkey - Evidence for southward subduction of Paleotethys
Carboniferous metagranites with U-Pb zircon crystallization ages of 331-315 Ma crop out in the Afyon zone in the northern margin of the Anatolide-Tauride Block, which is commonly regarded as part of Gondwana during the Late Palaeozoic. They are peraluminous, calc-alkaline and are characterized by increase in Rb and Ba, decrease in Nb-Ta, and enrichment in Sr and high LILE/HFSE ratios compatible with a continental arc setting. The metagranites intrude a metasedimentary sequence of phyllite, metaquartzite and marble; both the Carboniferous metagranites and metasedimentary rocks are overlain unconformably by Lower Triassic metaconglomerates, metavolcanics and Upper Triassic to Cretaceous recry…