Deformation of the Lower Cambrian Sequence in the Sandikli Region (Afyon), central Turkey

The Lower Cambrian Kocayayla Group forms the stratigraphically lowermost part of the relative autochthonous Geyikdagj unit of the Taurus Range in the Sandikh (Afyon) region. It is represented by the Celiloglu Formation, Gogebakan Formation, Kestel Cayi volcanics and the Tasoluk Formation in the ascending order. The Celiloglu Formation consists of quartzites with intercalations of metapelites. The Gogebakan Formation overlies the Celiloglu Formation along a gradational boundary, and is composed of metapelites with malic volcanic intercalations. The Gogebakan Formation grades laterally and vertically into the Kestel Cayi volcanics (Sandikh porphyroids) consisting of rhyolites with volcanosedimentary intercalations. The Tasoluk Formation is composed of yellow quartzites and it is the uppermost unit of the Kocayayla Group gradationally overlaying Kestel Cayi volcanics. ne Kocayayla Group is overlain by the Sandikh unit and there is a pronounced unconformity between them. The Sandikh unit consists of white quartzites, brown dolomites, trilobite-bearing limestones and mudstones of the Middle-Upper Cambrian age. The Lower Jurassic Ilyash Formation unconformably covers both the Kocayayla Group and Sandikh unit. The flat-laying Neogene volcanosedimentary rocks are the youngest succesion unconformably covering the all older rock units. ne Kocayayla Group was deformed and underwent a low-grade metamorphism marked by sericite-chlorite-biotite/stilpnomelane-quartz paragenesis in the metapelites; of the Gogebakan and Tasoluk formations and chlorite-epidote-albite-quartz and opaque assemblage in the mafic volcanic intercalations in the Gogebakan Formation, before the deposition of the trilobite-bearing Middle-Upper Cambrian succession. The Gogebakan and Tasoluk formations and the Kestel Cayi volcanics show a single penetrative foliation which mostly obliterated the primary structures whereas beds, trace fossils and cross-stratifications are partly preserved in the quarzite beds of the Celiloglu Formation. The Gogebakan Formation has rough foliation while the Kestel Cayi volcanics displays anastomizing and continuous foliation with a prominent stretching lineation. The attitude of the stretching lineation concentrates at 25/45 and 280/43 in the Kocayayla area, and sigma-clasts, s/c fabrics and quartz sigmoids indicate top-NNE and ESE shear sense. This difference in shear direction is related to the post-Liassic rotation in the core of southwest-verging asymmetric anticline. After removing this younger folding it is determined that, the linear fabrics has a concentration of 280/43 with top-ESE shear sense. In the Tasoluk area, the linear fabrics clusters at 320/43 with top-NW shear sense. The difference in orientation of foliation, linear fabric and shear sense in the Lower Cambrian Kocayayla Group indicate regional scale Alpine fold event(s) that rotated the earlier deformation fabrics in the Geyikdagi unit. (c) 2006 Lavoisier SAS. All rights reserved

Kinematics of the Central Taurides during Neotethys closure and collision, the nappes in the Sultan Mountains, Turkey

In the Central Taurides, the Sultan Mountains comprise in ascending order the Cimendere unit and the AkAYehir, Doganhisar, Cay nappes composed of metasedimentary sequences deposited from Cambrian to Tertiary. The overthrust of the Cay nappe on the Lutetian CeleptaAY formation representing the uppermost stratigraphic position in the Cimendere unit indicates that the latest nappe emplacement occurred during the Middle Eocene. The Oligocene and Miocene rocks are in post-tectonic facies in the west Central Taurides. The kinematic data from these nappes related to closure of the Neotethys reveal a top-NE shear sense in the northwest part and a top-SE shear sense in the southeast part of the Sultan Mountains. The Sultan Mountains are located in the north part of the Isparta Angle which was tectonically assembled by the Lycian, Hoyran-BeyAYehir-Hadim and Antalya allochthons on the Bey DaglarA +/- and Anamas-Akseki autochthons from the Latest Cretaceous to the Late Pliocene. The previous paleomagnetic data showed that the west and east subsections of the Isparta Angle were subjected to post-Eocene 30A degrees-40A degrees anticlockwise and clockwise rotations, respectively. In consideration of these paleomagnetic data, the kinematic data measured in the Sultan Mountains might be restored into approximately E-W-trending linear fabric associated with a top-E shear sense. These new kinematic data from the nappes in the Sultan Mountains disagree with the existing tectonic models that suggest N-S nappe translation over the Central Taurides during the latest Cretaceous-Middle Eocene. The alternative tectonic model for the Antalya nappes in the core of the Isparta Angle related to east-west compression suggests westward and eastward nappe emplacements on the surrounding autochthons. However, the new kinematic data presented here point consistently to a top-E shear sense in all tectonostratigraphic units in the Sultan Mountains currently located in the north part of the Anamas-Akseki autochthon

Emplacement age and direction of the Lycian nappes in the Söke-Selu̧k region, Western Turkey

In the Söke-Selçuk region, western Turkey, the northernmost exposures of the Lycian nappes are found as tectonic slices on the Menderes Massif. The Menderes Massif is represented by a continuous platform sequence and a blocky unit. The lower parts of the Menderes platform sequence is composed of Triassic-Jurassic marbles and an alternation of calcschists and micaschists; however, the upper parts are composed of emery- and rudist-bearing massive marbles. Along a gradational boundary, a blocky unit is found on top of the platform sequence, and it comprises blocks of metaophiolite and emery-bearing marble set in garnet-micaschists matrix. Along a low-angle fault marked by thin slices of red-green phyllites, tectonic slices of the Lycian nappes overlay garnet-micaschists of the massif. The Lycian nappes are represented mainly by a carbonate sequence which consists of dolomites, oncoidal limestones, intraformational limestone conglomerates, and cherty limestones. In the carbonate sequence of the Lycian nappes, undeformed primary structures are clearly observed just several meters above the sole fault, indicating a metamorphic break between the Lycian nappes and the Menderes Massif. The linear fabric in red-green phyllites at the sole of the Lycian nappes trends NNE-SSW, gently plunges to SSW and NNE, and is parallel to the linear fabric of the neotectonic period in the western Turkey. S/C relation suggests top-to-the SSW sense of shear in red-green phyllites. The deformation localized along the sole of the tectonic slices indicates that the red-green phyllites acted as a decollement surface. The deformational features, stratigraphic relations, orientation of linear fabric and metamorphic break reveal that Lycian nappes were emplaced on the Menderes Massif along a low-angle normal fault, after the Early to Middle Eocene Main Menderes metamorphism and prior to the deposition of the Middle Miocene sedimentary cover

Emplacement age and direction of the Lycian nappes in the Soke-Selcuk region, western Turkey

In the Soke-Selcuk region, western Turkey, the northernmost exposures of the Lycian nappes are found as tectonic slices on the Menderes Massif. The Menderes Massif is represented by a continuous platform sequence and a blocky unit. The lower parts of the Menderes platform sequence is composed of Triassic-Jurassic marbles and an alternation of calcschists and micaschists: however, the upper parts are composed of emery- and rudist-bearing massive marbles. Along a gradational boundary, a blocky unit is found on top of the platform sequence, and it comprises blocks of metaophiolite and emery-bearing marble set in garnet-micaschists matrix. Along a low-angle fault marked by thin slices of red-green phyllites, tectonic slices of the Lycian nappes overlay garnet-micaschists of the massif. The Lycian nappes are represented mainly by a carbonate sequence which consists of dolomites, oncoidal limestones. intraformational limestone conglomerates, and cherty limestones. In the carbonate sequence of the Lycian nappes, undeformed primary structures are clearly observed just several meters above the sole fault, indicating a metamorphic break between the Lycian nappes and the Menderes Massif. The linear fabric in red-green phyllites at the sole of the Lycian nappes trends NNE-SSW, gently plunges to SSW and NNE, and is parallel to the linear fabric of the neotectonic period in the western Turkey. S/C relation suggests top-to-the SSW sense of shear in red-green phyllites. The deformation localized along the sole of the tectonic slices indicates that the red-green phyllites acted as a decollement surface. The deformational features, stratigraphic relations, orientation of linear fabric and metamorphic break reveal that Lycian nappes were emplaced on the Menderes Massif along a low-angle normal fault, after the Early to Middle Eocene Main Menderes metamorphism and prior to the deposition of the Middle Miocene sedimentary cover

Tectonic significance of mafic volcanic rocks in a Mesozoic sequence of the Menderes Massif, West Turkey

The Mesozoic platform sequence of the Menderes Massif consists of thick succession of detrital and carbonate rocks. In this sequence there are mafic metavolcanic rocks at two different levels. The first level of mafic metavolcanic intercalations is in the Late Triassic detrital-rich series located in the Caltasi Formation, which is the lowermost unit of the Mesozoic platform. The second level of the mafic metavolcanic rocks is located in the Late Cretaceous-(?)Paleocene Selcuk Formation laying on top of the platform sequence. The Caltasi Formation, which is composed of mica-schists, thinly-bedded cherts, calc-schist and mafic volcanic intercalations unconformably overlie the Bayindir Formation, which consists of mica-schists, phyllites, and white quartzites of Palaeozoic or probably older age. The mafic volcanic rocks in the Caltasi Formation are alkaline basalts with within plate characteristics and are formed during an intraplate extension. The Caltasi Formation is conformably overlain by the Kayaalti Formation represented by calc-schists, dolomitic marbles, and rudist- and emery-bearing massive marbles in ascending order. The Selcuk Formation overlies the Kayaalti Formation and consists of a mica-schist matrix with allochthonous blocks of mafic volcanic rocks, metaperidotites, metagabbros and massive marbles. The mafic volcanic rocks in the Selcuk Formation are tholeiitic basalts and are petrologically similar to mid-oceanic basalts. The geological and geochemical characteristics of the mafic metavolcanic rocks in the Caltasi Formation indicate that during the Late Triassic, the Menderes platform was segmented, probably by the opening of a branch of the Neotethyan Ocean. Between the Late Triassic and the Late Cretaceous, the Menderes carbonate platform was built up. During the Latest Cretaceous-Early Paleocene, a slab of oceanic crust obducted on this platform and provided slices of mafic metavolcanic rocks into the Selcuk Formation