Breccia Beds in the Khuff (Permian–Triassic) in Ras Al Khaimah, United Arab Emirates: Collapse or Transgressive in Origin?

The laterally extensive, so-called mid-Bih breccia beds occur in carbonate successions of the Upper Permian–Lower Triassic Khuff-equivalent Bih Formation in Ras Al Khaimah, United Arab Emirates (UAE). These carbonates have been deposited on a stable platform setting at the passive margin of the Neo-Tethys Ocean. The breccia beds have previously been interpreted to be formed by dissolution of sulphate beds by groundwater followed by collapse of overlying carbonate beds (Strohmenger et al., 2002; Fontana et al., 2010). Contrary to this earlier interpretation, we present several lines of field, petrographic, isotopic and fluid inclusion evidence suggesting that the “breccias” are intraformational conglomerates representing a major marine transgressive surface.