Petrological reconstruction of Triassic seamounts/oceanic islands within the Palaeotethys: Geochemical implications from the Karakaya subduction/accretion Complex, Northern Turkey

2010-10-01
Subduction/accretion complexes provide unique insight into the tectonic assembly of continental margins and oceanic basins, as they record the tectonic stacking and juxtaposition of materials derived from distinct tectonic environments. The Karakaya Complex, exposed throughout northern Turkey, is a good example of an ancient subduction/accretion complex that includes a number of pre-Liassic units that characterize the closure of Palaeotethys. Defining the components of this complex is of crucial importance to understanding the geodynamic evolution of Palaeotethys in the Eastern Mediterranean region. In this study, we explore the geochemistry of metabasic rocks within the Karakaya Complex, redefining and evaluating one of its main constituents, known as "the Nilufer Unit". New geochemical results combined with previously published data suggest that the Nilufer Unit is dominated by oceanic-island basalt (OIB)- and enriched mid-ocean ridge basalt (E-MORB)-type metabasic rocks which are variably enriched in the most highly incompatible elements relative to normal MORB (N-MORB). Associated alkaline OIB-type basalts are characterized by highly fractionated and variable rare earth element (REE) patterns ([La/Yb](N)=4.8-16.2), suggesting melting across the garnet spinel transition, derivation from a heterogeneous mantle source, and/or dynamic melting of a homogeneous source. Similar Nb/Y-Zr/Y systematics of spatially associated OIB- and E-MORB-type samples may indicate involvement of a shared enriched mantle source(s). Combining both geological and geochemical evidence, we suggest that the OIB- and E-MORB-type assemblages defining the Nilufer Unit represent seamounts and oceanic islands formed on Palaeotethyan oceanic crust, which was finally incorporated into a forearc accretionary prism during latest Triassic and became a component of the Karakaya Complex.

Suggestions

Petrology of the Eocene volcanism in the central anataolia: implication for the early tertiary evolution of the Central Anatolian crystalline complex
Geneli, Fatma; Güncüoğlu, M. Cemal; Kuşcu, Gonca; Department of Geological Engineering (2011)
In the Central Anatolian Crystalline Complex (CACC) the Late Cretaceous post-collisional granitic magmatism is followed by Eocene extension, resulting in formation of roughly E-W trending transtensional basins. Formation of these basins was accompanied by calc- alkaline- mildly alkaline volcanism. The volcanic rocks, mainly subaques lava flows and subareal domes are concentrated along these basins and associated with Middle Eocene (Bartonian) Mucur Formation. They are basic to intermediate and are classifie...
Hydrothermal energy transfer and organic carbon production at the deep seafloor
LE BRİS, Nadine; Yücel, Mustafa; DAS, Anindita; Sievert, Stefan M.; LokaBharathi, PonnaPakkam; Girguis, Peter R. (2019-01-18)
In just four decades, hundreds of hydrothermal vent fields have been discovered, widely distributed along tectonic plate boundaries on the ocean floor. Vent invertebrate biomass reaching up to tens of kilograms per square meter has attracted attention as a potential contributor to the organic carbon pool available in the resource-limited deep sea. But the rate of chemosynthetic production of organic carbon at deep-sea hydrothermal vents is highly variable and still poorly constrained. Despite the advent of ...
Trace element and Sr-Nd-Hf-Pb isotopic constraints on the composition and evolution of eastern Anatolian sub-lithospheric mantle
Aktag, Alican; Sayıt, Kaan; Peters, Bradley J.; Furman, Tanya; Rickli, Jorg (2022-11-01)
Quaternary Elazig mafic alkaline volcanism is part of the anorogenic volcanic system of the circum-Mediterranean region, and it provides crucial insights into the chemical nature of the mantle source domains beneath eastern Turkey. Elemental and isotope geochemistry reveals that these mafic lithologies are mainly free of crustal contamination, reflecting geochemical signatures inherited from partial melting of their mantle sources. The trace element and Sr-Nd-Hf-Pb isotope systematics of the most primitive ...
Tectonic history of basins sited along the western section of the North Anatolian Fault System, Turkey
SARP, Gülcan; Gurboga, Sule; Toprak, Vedat; Duzgun, Sebnem (2014-01-01)
Geological and geomorphological features of basins along the western half of the North Anatolian Fault System (NAFS) are used to constrain the formation of these basins by localization of deformation and the total displacement, and to determine the timing of basin development. In this study, tectonic influence direction of the NAFS on tectonic and hydrologic basins Bolu, Yenicaga, Dortdivan, Cerkes, Ilgaz and Tosya has been investigated to deduce information about the formation stages and interaction betwee...
Basement structure and architecture of the Black Sea Basin
Kaymakcı, Nuretdin; Horn, Brian (null; 2018-01-28)
Black Sea consists of two separate back arc basins which opened at different times during the Cretaceous in response to northward subduction of the Neo-Tethys Ocean. The paucity of well data, complex geometries and seismic imaging challenges mean that questions remain regarding the basement architecture though most authors accept that, at least in part, both these basins are floored by oceanic crust, even though there are no magnetic stripes. Interpretation of deep, long offset seismic data (imaging to more...
Citation Formats
K. Sayıt and M. C. Göncüoğlu, “Petrological reconstruction of Triassic seamounts/oceanic islands within the Palaeotethys: Geochemical implications from the Karakaya subduction/accretion Complex, Northern Turkey,” LITHOS, pp. 501–511, 2010, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30290.