The Cenozoic history of the retreating Hellenic subduction system in eastern Mediterranean involves subduction, accretion, arc magmatism, exhumation, normal faulting, and large-scale continental extension from ∼60 Mya until Recent. Ages for high-pressure metamorphism central Aegean Sea region range ∼53 Ma north (the Cyclades islands) to ∼25−20 south (Crete). Younging reflects southward retreat zone. shape pressure-temperature-time paths rocks is remarkably similar across all tectonic units,...

Structural investigations in the central part of Menderes Massif (Ödemiº-Kiraz submas-sif) reveal presence a large-scale, low-angle extensional shear zone with top-to-the-N-NE sense. Regional ductile deformation was accompanied by intrusion two syntectonic granodiorites that have been dated 40 Ar/ 39 Ar method. One hornblende isochron age 19.5 ± 1.4 Ma and biotite plateau ages 13.1 0.2 12.2 0.4 Ma, respectively, constrain extension already active early Miocene. Successive tectonic denudation...

Research Article| July 01, 2001 An active bivergent rolling-hinge detachment system: Central Menderes metamorphic core complex in western Turkey Klaus Gessner; Gessner 1Institut für Geowissenschaften, Johannes Gutenberg-Universität, 55099 Mainz, Germany Search for other works by this author on: GSW Google Scholar Uwe Ring; Ring Christopher Johnson; Johnson 2T.H. Huxley School of Environment, Earth Science and Engineering, Imperial College, London SW7 2BP, UK Ralf Hetzel; Hetzel...

Research Article| May 01, 1995 Bivergent extension in orogenic belts: The Menderes massif (southwestern Turkey) Ralf Hetzel; Hetzel 1Institut für Geowissenschaften, Johannes Gutenberg-Universität, 55099 Mainz, Germany Search for other works by this author on: GSW Google Scholar Cees W. Passchier; Passchier Uwe Ring; Ring Özcan O. Dora 2Department of Geological Engineering, Dokuz Eylül University, 35100 Bornova/Izmir, Turkey Author and Article Information Publisher: Society America First...

We report 40 Ar/ 39 Ar ages from various tectonic units in the Aegean and westernmost Turkey. On basis of published geochronologic data our we propose that is made up several high‐pressure units, which were successively underplated Late Cretaceous until Miocene. Ages for metamorphism range 80–83 Ma parts Vardar‐Izmir‐Ankara suture zone north to 21–24 Basal unit Cyclades external belt on Crete south. Published seismic suggest currently occurring underneath Crete. Younging a southerly...

This paper analyzes the importance of preexisting structure for evolution Cenozoic Malawi rift, which constitutes southernmost part western branch East African rift system. Kinematic analyses demonstrate that regional extension direction rotated clockwise from ENE to SE during rifting. faults (of dip‐, oblique‐, and strike‐slip character) rejuvenated crustal structures whenever those were properly oriented with respect directions. Depending on these boundary conditions attempts find easiest...

Abstract Direct dating of brittle structures is challenging, especially absolute diagenesis followed by a series superimposed deformation events. We report 22 calcite U-Pb ages from tectonites and carbonate host rocks that date 3 diagenetic 6 Results show fibers these compatible with overprinting relationships. Ages indicate occurred between 147 ± Ma 103 34 Ma, was top-to-the-south, layer-parallel shearing due to ophiolite obduction at 84 5 (2σ errors). Sheared top-to-the-northeast, veins...

Structural, metamorphic, and geochronologic work shows that the Ampelos/Dilek nappe of Cycladic blueschist unit in eastern Aegean constitutes a wedge high‐pressure rocks extruded during early stages orogeny. The extrusion formed incipient collision Anatolian microcontinent with Eurasia when subduction deep underthrusting ceased was thrust southward over greenschist‐facies Menderes nappes along its lower tectonic contact, Cycladic‐Menderes thrust, effectively cutting out ∼30‐ to 40‐km‐thick...

We report fault slip data from exhumed surfaces along the NNE trending Alpenrhein valley and its intersection with WNW striking Bodensee Graben near Alpine thrust front of Central Alps in Swiss-Austrian-German border region. This conjugated graben system straddles boundary between foreland allows comparing kinematics formation two different tectonic domains. Our show sinistral transtension dextral Graben. Both transtensional systems resulted same kinematic regime NW directed shortening NE...

Abstract Uplift of the Al Hajar Mountains in Oman has been related to either Late Cretaceous ophiolite obduction or Neogene Zagros collision. To test these hypotheses, cooling central is constrained by 10 apatite (U‐Th)/He (AHe), 15 fission track (AFT), and four zircon (ZHe) sample ages. These data show differential between two major structural culminations mountains. In 3 km high Jabal Akhdar culmination AHe single‐grain ages range 39 ± 2 Ma 1 (2 σ errors), AFT from 51 8 32 4 Ma, ZHe 62 Ma....

The Samail Ophiolite in the Oman Mountains formed at a Cretaceous subduction zone that was part of wider Neo-Tethys plate-boundary system. original configuration and evolution this system is hidden structurally metamorphically complex nappe stack below Ophiolite. Previous work provided evidence for high-temperature metamorphism high pile (in metamorphic sole Ophiolite), high-pressure deepest (Saih Hatat window), possibly reflecting downward younging, progressive accretion history zone....

Thermochronological data reveal that the Late Cretaceous–Tertiary nappe pile of Anatolide belt western Turkey displays a two-stage cooling history. Three crustal segments differing in structure and history have been identified. The Central Menderes metamorphic core complex represents an ‘inner’ axial segment exposes lowest structural levels pile, whereas two ‘outer’ submassifs, Gördes submassif to north Çine south, represent higher pile. A regionally significant phase Oligocene Early Miocene...

Abstract Deep-seated metamorphic rocks are commonly found in the interior of many divergent and convergent orogens. Plate tectonics can account for high-pressure metamorphism by subduction crustal thickening, but return these metamorphosed back to surface is a more complicated problem. In particular, we seek know how various processes, such as normal faulting, ductile thinning, erosion, contribute exhumation rocks, what evidence be used distinguish between different processes. this paper,...

Based on lithostratigraphic comparisons the Menderes Massif has been correlated with Cycladic Massif, thereby implying that eastern Mediterranean consists of a narrow pre-Alpine basement belt which is laterally continuous over long distance and experienced similar Alpine orogenic history. Our work indicates architecture, age tectonometamorphic history both massifs differ fundamentally from each other. The remnants overly an exotic unit, nappes. Both do not represent lateral continuations...

Radiometrie (K‐Ar and 40 Ar/ 39 Ar) age determinations of volcanic volcaniclastic rocks, combined with structural, gravity, seismic reflection data, are used to constrain the sedimentary strata contained within seismically volcanically active northern Malawi (Nyasa) rift characterize changes in basin flank morphologies time. Faulting volcanism Tukuyu‐Karonga began at approximately 8.6 Ma, when sediments were deposited a broad, initially asymmetric lake bounded on its northeastern side by...

Research Article| May 01, 2001 Miocene high-pressure metamorphism in the Cyclades and Crete, Aegean Sea, Greece: Evidence for large-magnitude displacement on Cretan detachment Uwe Ring; Ring 1Institut für Geowissenschaften, Johannes Gutenberg-Universität, 55099 Mainz, Germany Search other works by this author on: GSW Google Scholar Paul W. Layer; Layer 2Department of Geology Geophysics, University Alaska, Fairbanks, Alaska 99775, USA Thomas Reischmann 3Institut Author Article Information...

Ion microprobe U–Pb dating of granitoid rocks from key structural outcrops the Menderes Massif in western Turkey provides an important constraint to thermal and deformational history a structurally complex metamorphic belt within Alpine chain. Crystallization ages two granite protoliths, derived weighted means rim homogeneous prismatic zircon grains, are 541 ± 14 Ma 566 9 Ma, whereas cores zoned pyramidal short-prismatic grains range Palaeoproterozoic Neoproterozoic age. These indicate that...

Secondary ion mass spectrometry (SIMS) U–Th–Pb dating of magmatic zircon from the synkinematic Eğrigöz and Koyunoba granites a leucogranite dyke dates core-complex formation in northern Anatolide belt western Turkey at 24–19 Ma. The intrude into footwall Simav detachment are strongly elongated NNE direction parallel to tectonic transport on detachment. Although large parts undeformed, localized mylonitic ultramylonitic deformation occurs directly beneath preserves evidence progressive...

Research Article| November 01, 1992 Normal vs. strike-slip faulting during rift development in East Africa: The Malawi Uwe Ring; Ring 1Institut für Geowissenschaften, Universität Mainz, Saarstrasse 21, D-6500 Germany Search for other works by this author on: GSW Google Scholar Christian Betzler; Betzler 2Geologisches Institut, Frankfurt, Senckenberganlage 32-34, D6000 Frankfurt am Main, Damian Delvaux 3Musée Royal de l'Afrique Centrale, Leuvensesteenweg 13, B-3080 Tervuren, Belgium Geology...

To better understand the driving mechanisms behind transition from collision to extension in a convergent orogen, data multiple low‐temperature thermochronometers were obtained Simav detachment fault (SDF), earliest developed major extensional structure recognized western Anatolide orogen of Turkey. Twenty‐two zircon fission track (FT), 26 apatite FT, 12 (U‐Th)/He ages, and FT length analyses are presented. The establish that SDF was active between ∼25 ∼19 Ma. coincidence timing magmatism...