Petrology of the shoshonitic Çambaşı pluton in NE Turkey and implications for the closure of the Neo-Tethys Ocean: Insights from geochemistry, geochronology and Sr–Nd isotopes

Abstract

Abstract The Eastern Pontide Orogenic Belt (EPOB) is one of the well-preserved continental magmatic arcs in the Alpine–Himalayan Belt and consists of Paleozoic to Miocene plutonic bodies. This paper presents new geological, bulk-rock major and trace element analyses, biotite Ar–Ar ages and Sr–Nd isotope data on representative samples from the Cambasi granitic body exposed in the northwestern part of the EPOB. Although the majority of the plutons in the EPOB show calc-alkaline affinity and I-type character, the Cambasi pluton has a shoshonitic affinity and an I-type, metaluminous signature. The pluton is composed of mainly monzonite, quartz monzonite and granite bodies including monzo-dioritic mafic microgranular enclaves (MMEs). Excluding the MMEs, these rocks have 57.7–70.2 wt.% SiO2, 13.1–17.5 wt.% Al2O3, 3.06–3.64 wt.% Na2O, 3.66–5.92 wt.% K2O, 0.33–3.3 wt.% MgO and Mg#