40Ar/39Ar dating of Quaternary lavas in northwest Iran: constraints on the landscape evolution and incision rates of the Turkish-Iranian plateau

Allen, M.B., Mark, D.F. , Kheirkhah, M., Barfod, D. , Emami, M.H. and Saville, C. (2011) 40Ar/39Ar dating of Quaternary lavas in northwest Iran: constraints on the landscape evolution and incision rates of the Turkish-Iranian plateau. Geophysical Journal International, 185(3), pp. 1175-1188. (doi: 10.1111/j.1365-246X.2011.05022.x)

Abstract

We report five new ⁴⁰Ar/³⁹Ar ages for basaltic lavas in the Maku region of northwest Iran, between ca. 1.87 and 0.40 Ma, which help constrain the tectonic and landscape evolution of this part of the Turkish–Iranian plateau. Flows originated from the composite volcanoes Ararat (Agri Dagi), Tendürek and Yigit Dagi, in eastern Turkey (Anatolia). These volcanoes are within the Turkish–Iranian plateau, which is a consequence of the Arabia–Eurasia collision, but has a poorly constrained evolution and surface uplift history. Current plateau elevations are typically 1.5–2 km, and relief between non-volcanic summits and basins is typically on the scale of ∼1 km. Samples are from flows that passed along pre-existing river valleys. Gorges were cut by re-established rivers after the eruptions, but the great majority of the local relief (∼95 per cent) lies above the sampled flows and so most likely pre-dates the volcanism. Gorge depths and lava ages allow local Quaternary fluvial incision rates to be calculated, which are ∼0.01 to 0.05 mm yr−1. These rates imply slow surface uplift of this part of the Turkish–Iranian plateau during the Quaternary. We therefore constrain the generation of the great majority of relief in the study area to be pre-Quaternary, and caused by the tectonic construction of the plateau, rather than a subcrustal origin related to the Quaternary magmatism.

• Item Type: Articles
• Additional Information: The definitive version is available at www.blackwell-synergy.com
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Mark, Professor Darren and Barfod, Dr Dan
• Authors: Allen, M.B., Mark, D.F., Kheirkhah, M., Barfod, D., Emami, M.H., and Saville, C.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Geophysical Journal International
• ISSN: 0956-540X
• ISSN (Online): 1365-246X
• Published Online: 15 April 2011
• Copyright Holders: Copyright © 2011 The Authors, Geophysical Journal International, Copyright © 2011 Royal Astronomical Society
• First Published: First published in Geophysical Journal International 2011 185(3):1175-1188
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher