Late Miocene K-rich volcanism in the Eslamieh Peninsula (Saray), NW Iran: Implications for geodynamic evolution of the Turkish–Iranian High Plateau

Abstract

a b s t r a c tKeywords: High-K lavas Geochemistry, Sr-Nd-Pb isotopes, Post-collisional magmatism Iran Post-collisional volcanism in northwestern Iran is represented by the Saray high-K rocks including leucite-bearing under-saturated and leucite-free silica saturated rocks. We report Ar-Ar age data which constrain the age as ca. 11Ma (late Miocene). Most of clinopyroxene phenocrysts from the volcanic rocks have complex oscillatory zoning, with high Ti and Al cores, low Ti and high Al mantled clinopyroxenes, grading into low Ti and Al outer rims. All the rocks are highly enriched in incompatible trace elements and have identical Sr-Nd-Pb isotopes. Enrichment in incompatible elements and other geochemical features for the Saray lavas suggest a metasomatized sub-continental lithospheric mantle (SCLM) as the magma source. The negative Nb- Ta Pb isotopic values of the Saray lavas imply the involvement of slab terrigenous sediments and/or a continental lithosphere. Isotopically, the volcanic rocks define a binary trend, representing 5-8% mixing between the primary mantle and sediment melts. Our melting models suggest residual garnet in the source and are incompatible with partial melting of amphibole and/or phlogopite bearing lherzolites, although the complex geochemical features might indicate the result of mixing between melts produced by different sources or a homogenous melt passing through a compositionally-zoned mantle during multiple stages of partial melting and melt migration. The geochronological, geochemical and isotopic data for the Saray rocks suggest that these Late Miocene magmas were derived from a small degree of partial melting of subduction-metasomatized (subcontinental) lithospheric mantle source in a post-collisional setting.

Petrogenesis and geochemical characteristics of Plio-Quaternary alkali basalts from the Qorveh–Bijar volcanic belt, Kurdistan Province, NW Iran

“…(a) AFC modelling for the QBB rocks (gneissic xenoliths of Kord, 2012); (b) 143 Nd/ 144 Nd vs Sr (Moghadam et al . 2014); (c) 87 Sr/ 86 Sr vs Th (ppm) (Ersoy et al . 2012) with modelled assimilation – fractional crystallization pathways (AFC; r = 0.4 curve); (d) Ba/La vs Ce/Pb and (e) Th/Yb vs Ba/La plots to assess the effects of subducted slab materials on the mantle source of QBBs. …”

Generation of collision-induced Early to Middle Miocene adakitic magmas in Pertek (Tunceli) area from Eastern Anatolia postsubductional setting, Turkey

“…Overall samples demonstrate weak Eu anomalies (Eu/Eu*=0.81-0.89) (Figure 7b). Observed trace element compositions (see Figure 7a) (e.g., with depletion in Nb-Ta and Ti and high concentrations of LILE) can be attributed to metasomatized mantle wedges (Kheirkhah et al 2009(Kheirkhah et al , 2013Moghadam et al, 2014;Lechmannn et al, 2018).…”

The Van Microplate: A New Microcontinent at the Junction of Iran, Turkey, and Armenia

“…We have compiled whole-rock, chemical data on 900 volcanic rocks (Agostini et al, 2007;Jahangiri, 2007;Azizi and Jahangiri, 2008;Haghnazar and Malakotian, 2009;Mazhari et al, 2009Mazhari et al, , 2011Ahmadzadeh et al, 2010;Dilek et al, 2010;Ranin et al, 2010;Aghazadeh et al, 2011;Aghazadeh et al, 2015;Ansari et al, 2011;Dabiri et al, 2011;Hajialioghli et al, 2011;Mahmoudi et al, 2011;Asiabanha and Foden, 2012;Alishah et al, 2013;Ansari, 2013;Castro et al, 2013;Ghaffari et al, 2013;Kheirkhah et al, 2013;Moghadam et al, 2014;Neill et al, 2015;Doroozi et al, 2016;Haghnazar et al, 2016;Moritz et al, 2016;Sahakyan et al, 2017;Taki, 2017;Ashrafi et al, 2018;Haghighi Bardineh et al, 2018;Jafari Sough et al, 2018;Lechmann et al, 2018;Shafaii Moghadam et al, 2018;Zhang et al, 2018;Ghalamghash et al, 2019;Temizel et al, 2019) from Cretaceous to Quaternary magmatism in northwestern Iran, southern Armenia, and eastern Turkey (Supplementary S2). The sample locations and references for each area are shown in Figures 4A-E.…”

“…We plotted 203 sample data points (Supplementary S2) in the 87 Sr/ 86 Sr vs. 143 Nd/ 144 Nd diagram collected from published works (Alpaslan et al, 2004;Agostini et al, 2007;Haghnazar and Malakotian, 2009;Mazhari et al, 2009, Mazhari et al, 2011Aghazadeh et al, 2011, Aghazadeh et al, 2015Dabiri et al, 2011;Allen et al, 2013a, Allen et al, 2013bGhaffari et al, 2013;Moghadam et al, 2014;Neill et al, 2015;Sahakyan et al, 2017;Haghighi Bardineh et al, 2018;Lechmann et al, 2018;Shafaii Moghadam et al, 2018;. Most samples plot near the mantle array with some variation for the Cretaceous and Eocene igneous rocks.…”