MULTI-PHASE HORMUZ SALT DIAPIRISM IN THE SOUTHERN ZAGROS, SW IRAN

H. Motamedi*¹, M. Sepehr*², S. Sherkati* and M. Pourkermani**

* National Iranian Oil Company, Exploration Directorate, Tehran, Iran.

** Earth Science Faculty, Shahid Beheshti University, Tehran, Iran.

¹ author for correspondence, email: h.motamedi@niocexp.ir

² deceased.

In the Zagros orogenic belt in SW Iran, a 14 km thick sedimentary succession is decoupled from crystalline basement by the thick Infracambrian Hormuz complex. The complex consists of evaporites (“Hormuz salt”) together with marls, sandstones, carbonates and volcanic rocks and is known from emergent salt diapirs in the Fars and High Zagros areas. In this paper, we document discrete pulses of halokinetic activity using seismic profiles, well data and recent field studies. The earliest phase of mobilization of the Hormuz salt occurred in the pre-Silurian. Later pulses of salt movement took place during opening of Neo-Tethys in Permo-Triassic times and during ophiolite obduction onto the NE Arabian plate margin in the Late Cretaceous. Halokinesis was intense during the Neogene Zagros orogeny when some salt plugs breached the surface.

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