Geology and geochemical evaluation of Taftan Volcano, Sistan and Baluchestan Province, southeast of Iran

Abstract

At a glance of its stratighraphy, the Taftan Volcano can be classified as three groups: pre-, syn-and post-volcanic deposits. The pre-volcanic deposits consist mostly of flysch facies and colored mélange complex. The syn-volcanic deposits are mainly the product of the Taftan Volcano which is mostly composed of pyroclastic and lava flows from the main body of this volcano. The post-volcanic deposits are mostly epiclastic and reworked materials from the Taftan Volcano due to its erosion and weathering. Major and trace elements, and Sr/Rb isotopic compositions determined on whole-rock samples from the Taftan Volcano showed that the volcano was formed at the continental margin. The whole-rock isotopic composition of the Taftan Volcano showed a feature of strong enrichment with 87 Sr/ 86 Sr=0.705326-0.705921. Geochronological samples of the Taftan Volcano determined by the 40 K/ 40 Ar method gave an age range of 6.95±0.72 to 0.71±0.03 Ma. The rare-earth element patterns are characterized by high LREE and nearly strongly linear patterns for MREE to HREE, suggesting that distinctive minerals such as olivine and pyroxene crystallized in the early magmatic stage and then were involved in reaction between the lower crust and residual magma. The integrated isotope and trace element systematics and tectonic structure beneath the Taftan Volcano suggested the lower-crust assimilation by the primary magma. The primary magma had generated from a heterogeneous mantle source and a secondary petrogenetical process. This magma could have been affected by the subduction of the Oman Sea underneath the continental Eurasia plate.

On the magmatic record of the Makran arc, southeastern Iran: Insights from zircon U‐Pb geochronology and bulk‐rock geochemistry

“…All samples show consistent primitive mantle‐normalized trace element patterns characterized by an orogenic signature like the Mirabad samples (Figure b). In addition, the trace element data are in good agreement with those published by Biabangard and Moradian [] for the Taftan volcanic rocks. Most Taftan samples are characterized by high 87 Sr/ 86 Sr (0.7063–0.7068) and low 143 Nd/ 144 Nd (0.5124–0.5125) relative to the Bulk Silicate Earth, except sample 10–31 that has depleted Sr‐Nd isotopic compositions ( 87 Sr/ 86 Sr = 0.7044, 143 Nd/ 144 Nd = 0.5128; Figure and Table ).…”

“…FeO* denotes the amount of total iron oxides assuming Fe 2 O 3 /FeO = 1:9. Reference fields for Neogene‐Quaternary magmatic rocks at Bazman (Iran), Taftan (Iran), and Koh‐i‐Sultan (Pakistan) are drawn after published data by Biabangard and Moradian [], Saadat and Stern [], and Richards et al . [].…”

“…Published data are after Conrad et al . [] (K/Ar; Bazman), Biabangard and Moradian [] (K/Ar; Taftan), Perelló [] (K/Ar and 39 Ar/ 40 Ar; Ting‐Dargun), and Richards et al . [] ( 39 Ar/ 40 Ar; Koh‐i‐Sultan and Reko Diq‐Saindak).…”

“…The Taftan volcano is located in the southern Sistan suture zone and its summit is ∼4050 m in height. Biabangard and Moradian [] obtained K/Ar ages of ∼7.0 Ma for a basalt sample, and ∼6.0 and ∼0.7 Ma for two andesite samples. The Bazman volcano is situated on the southern part of the Lut block with a maximum elevation of ∼3500 m. Conrad et al .…”

Iranshahr blueschist: subduction of the inner Makran oceanic crust

“…). They have calcalkaline affinities and consist of basalt to andesite, tuff and ignimbrite (Berberian et al ., ; Biabangard & Moradian, ; Saadat & Stern, ).…”