Shallow melting of MORB-like mantle under hot continental lithosphere, Central Anatolia

Mary Reid, W. Kirk Schleiffarth, Michael A. Cosca, Jonathan R. Delph, Janne Blichert-Toft, Kari M. Cooper

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Widespread mafic volcanism, elevated crustal temperatures, and plateau-type topography in Central Anatolia, Turkey, could collectively be the result of lithospheric delamination, mantle upwelling, and tectonic escape. We use results from 40Ar/39Ar geochronology, basalt geochemistry, and a passive-source broadband seismic experiment obtained in a collaborative international effort (Continental Dynamics-Central Anatolia Tectonics) to investigate the upper mantle structure and evolution of melting conditions over an ∼2400 km2 area south and west of Hasan volcano. New 40Ar/39Ar dates for the basalts mostly cluster between 0.2 and 0.6 Ma, but some scoria cones are as old as 2.5 Ma. Basalts are dominantly Mg-rich (Mg# = 62–71), moderately alkaline (normative Ne < 5 wt %), and, based on major and trace element signatures, derived from a peridotitic source. Covariations between radiogenic isotope and trace element signatures reveal contributions from a subduction-related component and intraplate-like mantle asthenosphere, as well as from ambient upper mantle. Central Anatolian basalts reflect maximum mantle potential temperatures of <1350°C and an average pressure of melt equilibration of 1.4 GPa, which are cooler and shallower than for basalts from Eastern and Western Anatolia. When considered in light of regionally slow upper mantle shear wave velocities, the mantle lithosphere may be thin and infiltrated by melts, or largely absent. An absence of secular changes in melting conditions suggests little to no lithospheric thinning over the past ∼1 Ma, despite evidence for lithospheric extension. Hasan basalts appear to be generated by decompression melting in response to the rollback of the Cyprean slab.

Original languageEnglish (US)
Pages (from-to)1866-1888
Number of pages23
JournalGeochemistry, Geophysics, Geosystems
Volume18
Issue number5
DOIs
StatePublished - May 1 2017

Fingerprint

continental lithosphere
mid-ocean ridge basalt
lithosphere
Earth mantle
basalt
Melting
melting
mantle
upper mantle
Trace Elements
Tectonics
trace elements
tectonics
trace element
melt
Geochronology
signatures
Volcanoes
Geochemistry
mantle structure

Keywords

  • Ar/Ar basalt geochronology
  • Central Anatolia
  • magma genesis
  • primary basalts
  • shear wave tomography

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

Cite this

Reid, M., Schleiffarth, W. K., Cosca, M. A., Delph, J. R., Blichert-Toft, J., & Cooper, K. M. (2017). Shallow melting of MORB-like mantle under hot continental lithosphere, Central Anatolia. Geochemistry, Geophysics, Geosystems, 18(5), 1866-1888. https://doi.org/10.1002/2016GC006772

Shallow melting of MORB-like mantle under hot continental lithosphere, Central Anatolia. / Reid, Mary; Schleiffarth, W. Kirk; Cosca, Michael A.; Delph, Jonathan R.; Blichert-Toft, Janne; Cooper, Kari M.

In: Geochemistry, Geophysics, Geosystems, Vol. 18, No. 5, 01.05.2017, p. 1866-1888.

Research output: Contribution to journalArticle

Reid, M, Schleiffarth, WK, Cosca, MA, Delph, JR, Blichert-Toft, J & Cooper, KM 2017, 'Shallow melting of MORB-like mantle under hot continental lithosphere, Central Anatolia', Geochemistry, Geophysics, Geosystems, vol. 18, no. 5, pp. 1866-1888. https://doi.org/10.1002/2016GC006772
Reid, Mary ; Schleiffarth, W. Kirk ; Cosca, Michael A. ; Delph, Jonathan R. ; Blichert-Toft, Janne ; Cooper, Kari M. / Shallow melting of MORB-like mantle under hot continental lithosphere, Central Anatolia. In: Geochemistry, Geophysics, Geosystems. 2017 ; Vol. 18, No. 5. pp. 1866-1888.
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