Researchers identify ancient volcanic arc in Iran
Rock dating places the system’s activity approximately 101 to 97 million years ago, during the Late Cretaceous.
An international research group has found evidence in northwestern Iran of a volcanic system dating back roughly 100 million years. Led by Istanbul Technical University, the team identified the Azerbaijan Continental Magmatic Arc through analyses of surviving rock formations, according to findings published in Geoscience Frontiers.
The researchers investigated volcanic and plutonic samples from several locations, with particular attention to the Siah Cheshmeh-Khoy-Misho-Tabriz Fault. They established ages using zircon U-Pb dating, investigated material origins through Hf isotopes and measured the rocks’ chemical composition.
The results indicated magma formation associated with a tectonic plate descending beneath another plate along a continental margin. The team reported that later deformation, erosion and sediment accumulation had hidden remnants of the arc. Volcanic activity during the Eocene also helped obscure the older evidence.
The study suggests the fault could mark a major tectonic boundary linked to the ancient Neo-Tethys Ocean’s evolution. Retreat of a descending plate and relocation of volcanic arcs may explain the comparatively short episode of magma production, the researchers said.
