Middle Triassic back-arc basalts from the blocks in the Mersin Melange, southern Turkey: Implications for the geodynamic evolution of the Northern Neotethys

2017-01-01
The Mersin Melange is a tectonostratigraphic unit within the allochthonous Mersin Ophiolitic Complex in the Taurides, southern Turkey. This chaotic structure consists of blocks and tectonic slices of diverse origins and ages set in a clastic matrix of Upper Cretaceous age. In this study, we examine two blocks at two different sections characterized by basaltic lava flows alternating with radiolarian-bearing pelagic sediments. The radiolarian assemblage extracted from the mudstone-chert alternation overlying the lavas yields an upper Anisian age (Middle Triassic). The immobile element geochemistry suggests that the lava flows are predominantly characterized by sub-alkaline basalts. All lavas display pronounced negative Nb anomalies largely coupled with normal mid ocean basalt (N-MORB)-like high field strength element (HFSE) patterns. On the basis of geochemical modelling, the basalts appear to have dominantly derived from spinel-peridotite and pre-depleted spinel-peridotite sources, while some enriched compositions can be explained by contribution of garnet-facies melts from enriched domains. The overall geochemical characteristics suggest generation of these Middle Triassic lavas at an intra-oceanic back-arc basin within the northern branch of Neotethys. This finding is of significant importance, since these rocks may represent the presence of the oldest subduction zone found thus far from the Neotethyan branches. This, in turn, suggests that the rupturing of the Gondwanan lithosphere responsible for the opening of the northern branch of Neotethys should have occurred during the Lower Triassic or earlier.

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Upper Cretaceous Radiolarian ages from an arc-back-arc within the Yuksekova Complex in the southern Neotethys melange, SE Turkey
TEKİN, UĞUR KAĞAN; Ural, Melek; Göncüoğlu, Mehmet Cemal; ARSLAN, MEHMET; KÜRÜM, SEVCAN (2015-02-01)
The Yuksekova complex in SE Turkey is a part of a continuous belt of ophiolites and subduction-accretion complexes that stretches from Troodos in the west to Oman in the east, representing the remnants of the Southern Branch of Neotethys. This complex mainly comprises a tectonically chaotic assemblage of basaltic dykes and pillow lavas associated with radiolarian cherts, shales and pelagic limestones. Detailed petrological work on submarine basaltic lavas from Elazig-Malatya area in SE Turkey revealed the p...
Geochemistry, tectono-magmatic discrimination and radiolarian ages of basic extrusives within the Izmir-Ankara Suture Belt (NW Turkey): Time constraints for the neotethyan evolution
Göncüoğlu, Mehmet Cemal; Tekin, U. Kagan (2006-06-01)
The Dagkuplu Melange in the Central Sakarya Valley represents the northernmost outcrops of the Izmir-Ankara Suture Belt in northwest Anatolia. In addition to blocks and slivers of serpentinite, gabbro, blueschist, neritic and pelagic limestones, it includes blocks of basic volcanic rocks associated with radiolarian cherts, pelagic carbonates and mudstones.
Middle Carnian Arc-Type Basalts from the Lycian Nappes, Southwestern Anatolia: Early Late Triassic Subduction in the Northern Branch of Neotethys
Sayıt, Kaan; Göncüoğlu, Mehmet Cemal (2015-11-01)
The Turunc Unit, which represents one of the tectonic slices within the Lycian Nappes in southwestern Anatolia, preserves the remnants derived from the northern branch of Neotethys. The unit includes basalts intercalated with pelagic limestones of middle Carnian age (early Late Triassic) based on the characteristic radiolarian assemblage of the Tetraporobrachia haeckeli Zone. The Turunc lavas reflect trace element signatures resembling those from subduction zones, displaying selective enrichment of Th and l...
Metamorphic evolution of the Karakaya Complex in northern Turkey based on phyllosilicate mineralogy
TETİKER, SEMA; YALÇIN, HÜSEYİN; BOZKAYA, ÖMER; Göncüoğlu, Mehmet Cemal (2015-04-01)
The Triassic Karakaya Complex (KC) of the Sakarya Composite Terrane in northern Turkey is traditionally subdivided into two units. The Lower Karakaya Complex (LKC) consists of a tectonic m,lange with blocks of metabasic rocks, metacarbonates, meta-arenites and metapelites that have been affected by high pressure/low temperature metamorphism. It is followed by a low pressure/low temperature metamorphic overprint; the latter is the only metamorphic event in some tectonic slivers of the LKC. The Upper Karakaya...
Middle-Late Triassic radiolarian cherts from the Arkotdag m lange in northern Turkey: implications for the life span of the northern Neotethyan branch
TEKİN, UĞUR KAĞAN; Göncüoğlu, Mehmet Cemal; Pandolfi, Luca; Marroni, Michele (2012-09-01)
Moderately to well-preserved, relatively diverse Middle and Late Triassic radiolarian assemblages have been obtained from the chert slide-blocks within the Late Cretaceous melange of the IntraPontide Suture Zone at the Pelitoren village to the NE of Kastamonu-Arac in northern Central Anatolia. In this locality, chert slide-blocks are tectonically overlain by metamorphic sole of the serpentinized peridotites belonging to the IntraPontide ophiolites. The oldest radiolarian assemblages, with the middle Late An...
Citation Formats
K. Sayıt, U. K. TEKİN, and M. C. Göncüoğlu, “Middle Triassic back-arc basalts from the blocks in the Mersin Melange, southern Turkey: Implications for the geodynamic evolution of the Northern Neotethys,” LITHOS, pp. 102–113, 2017, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/30353.