Thanks to Annique van der Boon for this great post about her trip this month to Iran.

Iran is a fascinating country for geologists. Most of the country has a semi-arid to desert climate, so there is quite little vegetation, which means there is a lot of outcrop. Iran is ideally suited to study the disappearance of the Tethys ocean since the breakup of Pangea, as it is the place where the effects of the subduction of the Neo-Tethys oceanic crust, and the subsequent collision of Arabia and Eurasia during the Alpine orogeny can be observed. The country is incredibly big and the geology is very diverse and relatively unexplored. Our trip took us to the IASBS in Zanjan, in the northwest of Iran, where we met the geologists with whom we cooperate. From Zanjan we went on a 5-day fieldtrip in the Talesh mountains. These mountains are located in the north of Iran, bordering the Caspian Sea. The Talesh is located within the active collision zone between Arabia and Eurasia, and continues towards the north into the Talysh mountains of Azerbaijan, and towards the east into the Alborz mountains. These all together make up part of the Alpine-Himalayan mountain chain. The region is still tectonically active, with many earthquakes, as well as some recent (Holocene) volcanoes.

My interest lies in older volcanic rocks, of Eocene age. During the Eocene, large amounts of volcanics were deposited in Iran. The tectonic setting is at present not very clear for all volcanics. Part of them were most likely formed as a volcanic arc that was related to the subduction of Arabia beneath Eurasia, called the Urumieh-Dokhtar magmatic arc (or UDMA). But in the northwest of Iran, the UDMA seems to merge with the Alborz mountains, and it is unclear what their exact relationship is.

I went together with one of my supervisors, professor CorLangereis, and a postdoc of our group, Daniel Pastor Galán. Daniel is doing research on the oroclinal bending of the Talysh-Alborz mountain belt.

Although December is not the best time to go to the Alborz/Talesh mountains, we decided to try it anyway. This resulted in a beautiful field trip with conditions that I never worked in before (with lots of snow and cold temperatures).

Agard, P., Omrani, J., Jolivet, L., Whitechurch, H., Vrielynck, B., Spakman, W., Monié, P., Meyer, B., Wortel, R., 2011. Zagros orogeny: a subduction-dominated process. Geological Magazine 148, 692–725.