Abstract

Platform sediments of Iran span the Late Ediacaran and extend into the Palaeozoic. They are primarily clastic and carbonaceous in nature, deposited in coastal and lagoonal settings. They crop out in the Takab area, as the Soltanieh Formation (Late Proterozoic to Atdabanian), the Barut Formation (Early Bottomian), the Zaigun Formation (Middle Bottomian), the Lalun Formation (Late Bottomian) and the Mila Formation (Middle Cambrian to Early Ordovician). A Precambrian–Cambrian assemblage has been identified at the base of Member 3 and the top of Member 2 in the Soltanieh Formation. The Soltanieh Formation consists of shallow marine sediments. Vertical microfacies variation reflects two regressive sequences, the earliest Cambrian System being a regressive cycle. The presence of Chuaria and Vendotaenia in the Soltanieh Formation allows correlation of Iranian sequences to those elsewhere in the world, indicating a late Neoproterozoic age. Detailed facies analyses of the Soltanieh, Barut, Zaigun, Lalun, and Mila formations allow refined palaeoenvironmental reconstructions to be made for the Ediacaran–Cambrian/Ordovician in Iran.