Rapid early-middle Miocene exhumation of the Kazdaǧ Massif (western Anatolia)


Cavazza W., Okay A. , Zattin M.

International Journal of Earth Sciences, vol.98, no.8, pp.1935-1947, 2009 (Journal Indexed in SCI Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 98 Issue: 8
  • Publication Date: 2009
  • Doi Number: 10.1007/s00531-008-0353-9
  • Title of Journal : International Journal of Earth Sciences
  • Page Numbers: pp.1935-1947

Abstract

Apatite fission-track analyses indicate that the Kazdaǧ Massif in northwestern Anatolia was exhumed above the apatite partial annealing zone between 20 and 10 Ma (i.e. early-middle Miocene), with a cluster of ages at 17-14 Ma. The structural analysis of low-angle shear zones, high-angle normal faults and strike-slip faults, as well as stratigraphic analysis of upper-plate sedimentary successions and previous radiometric ages, point to a two-stage structural evolution of the massif. The first stage -encompassing much of the rapid thermal evolution of the massif- comprised late Oligocene-early Miocene low-angle detachment faulting and the associated development of small supradetachment grabens filled with a mixture of epiclastic, volcaniclastic and volcanic rocks (Küçükkuyu Fm.). The second stage (Plio-Quaternary) has been dominated by (i) strike-slip faulting related to the westward propagation of the North Anatolian fault system and (ii) normal faulting associated with present-day extension. This later stage affected the distribution of fission-track ages but did not have a component of vertical (normal) movement large enough to exhume a new partial annealing zone. The thermochronological data presented here support the notion that Neogene extensional tectonism in the northern Aegean region has been episodic, with accelerated pulses in the early-middle Miocene and Plio-Quaternary. © Springer-Verlag 2008.