Neogene anticlockwise rotation of central Anatolia (Turkey): preliminary palaeomagnetic and geochronological results


Platzman E., Tapirdamaz C., Sanver M.

TECTONOPHYSICS, vol.299, pp.175-189, 1998 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 299
  • Publication Date: 1998
  • Doi Number: 10.1016/s0040-1951(98)00204-2
  • Title of Journal : TECTONOPHYSICS
  • Page Numbers: pp.175-189

Abstract

A palaeomagnetic and geochronological study was carried out on fifty sites from the Neogene volcanic province of central Anatolia. Results from this analysis show that there has been a progressive anticlockwise rotation of this region over the period spanning at least the last 10-12 Ma. We interpret this rotation as having resulted from the collision of Arabia with Anatolia along the Bitlis suture. If we assume a constant rate of rotation we obtain a rate of 2.4 degrees/Ma. This value is significantly higher than the present-day rotation rate obtained from GPS (1.3 +/- 0.1 degrees/Ma) and also implies that these rocks have been rotating at their present rate since well before collision occurred along the Bitlis suture (similar to 12 Ma): a geologically unreasonable conclusion. If, however, we combine these data with data from other palaeomagnetic studies with good age control the resultant curve seems to show three distinct linear segments: (1) 0-5 Ma with a very slow rate of rotation (1.2 degrees/Ma); (2) 5-12 Ma where we observe a rapid increase of rotation rate to 6.5 degrees/Ma; and (3) > 12 Ma, when the rotation rate is again essentially zero (-0.041 degrees/Ma). These results are generally consistent with a model calling for Middle Miocene collision along the Bitlis suture and Late Plio-Pleistocene initiation of motion along the North and East Anatolian fault zones. (C) 1998 Elsevier Science B.V. All rights reserved.