CIAO

In subduction systems, there is an intermediate mantle zone in the overriding plate, located between the wedge and the neighbouring back arc. This zone is influenced by both subduction-related and ocean spreading processes, resulting in a remarkable geochemical heterogeneity of the mantle sources that ultimately generate a wide variety of melts. They in turn will feed the volcanoes on the surface, most of them highly explosive. Our knowledge of these peculiar geodynamic settings is very limited and ophiolitic complexes provide an almost unique opportunity to investigate their chemical-physical features at large scale.

Within the Central Iran Amphibole Ophiolite (CIAO) project, we study the amphibole-bearing peridotites of Nain ophiolite (Iran). This ophiolite includes magmas from MORB to Boninite and suggest that it was formed in an arc/back arc system. We use this unique opportunity to study the physical-chemical conditions of these peculiar peridotites, measuring major, trace and volatile element concentrations in hydrous and nominally anhydrous minerals. Volatile speciation, water activity and oxygen fugacity will be also measured. This study will improve our knowledge of mantle volatile species and circulation mechanism. It will allow to constrain the mass transfer between the two colliding plates, ultimately leading to a better understanding of the input/output budget of the subduction systems.

Within Earth Sciences, CIAO combine disciplines as diverse as petrology, crystallography and geodynamics. It will employ a variety of state of the art analytical techniques. The applicant will work in a synergetic network of highly motivated experts that will guarantee high-quality output and a significant impact on the perspectives of her career. A better understanding of the petrological features of this geodynamic setting, together with its chemical-physical processes will greatly improve our knowledge of volcano eruptions, hoping to reduce the hazards for thousands of people living around volcanic areas.

This project was funded by the European Commission under the Horizon 2020 IF-2014 action and coordinated by the University of Ferrara, Italy.

Abstracts

  1. Tahmineh Pirnia Naeini, Shoji Arai and Emilio Saccani. Plagioclase-peridotites recording the incipient stage of oceanic basin formation: new constraints from the Nain ophiolites (central Iran). Geophysical Research Abstracts, Vol. 18, EGU-2016-7130-1. 2016.
  2. Tahmineh Pirnia Naeini, Shoji Arai and Emilio Saccani. Petrology of the reaction zone between gabbro and peridotite from Nain melange, Central Iran. Goldschmidt Conference Abstracts. 2016.
  3. Emilio Saccani, Tahmineh Pirnia Naeini and Ghodrat Torabi. Geochemistry of pillow lavas and sheeted dikes from Nain and Ashin ophiolites (Central Iran). EGU General Assembly. 2017.
  4. Tahmineh Pirnia Naeini, Emilio Saccani and Ghodrat Torabi. Geochemistry and tectonic significance of basalts from Central Iran: Evidence from Nain and Ashin ophiolites. Goldschmidt Conference Abstracts. 2017.
  5. Emilio Saccani, Tahmineh Pirnia Naeini and Ghodrat Torabi. Geochemistry and tectono-magmatic significance of volcanic and subvolcanic rocks from Nain and Ashin ophiolites (Central Iran). Congresso congiunto SIMP-SGI-SOGEI-AIV Abstract book. 2017.

Publications

  1. Tahmineh Pirnia Naeini, Emilio Saccani and Shoji Arai. Spinel and plagioclase peridotites of the Nain ophiolite (Central Iran): Evidence for the incipient stage of oceanic basin formation. Lithos. Vol 310-311, 2018.
  2. Tahmineh Pirnia Naeini, Emilio Saccani, Ghodrat Torabi, Marco Chiari, Špela Gorican and Edoardo Barbero. Cretaceous tectonic evolution of the Neo-Tethys in Central Iran: Evidence from petrology and age of the Nain-Ashin ophiolitic basalts. Submitted to Geoscience Frontiers, 2018.