Palynological correlation of the Arqov and Saad formations of the Negev, Israel, with the Umm Irna Formation of the eastern Dead Sea, Jordan

Palynological study of the Arqov and Saad formations of the Negev, Israel, in Avdat-1 borehole has allowed comparison with the assemblages of the Umm Irna Formation of the Dead Sea, Jordan. Core 7 of Avdat-1 (Saad Formation) contains common Hamiapollenites dettmannae and Distriatites insolitus indicating that it correlates with the Arabian Peninsula OSPZ5 Biozone and therefore has a likely Roadian–Wordian age, rather than a Westphalian age as previously suggested. Core 6 contains Indotriradites mundus, whose first appearance indicates the base of OSPZ6 (Wordian, extending into the Capitanian), but also contains common Protohaploxypinus uttingii, Pretricolpipollenites bharadwajii and Thymospora spp. As such, the assemblages of Core 6 are most similar to those of the Umm Irna Formation, while those of Core 7 are older, as implied by the correlation of Core 7 with OSPZ5. An interesting difference between typical OSPZ6 assemblages and those of Avdat-1 Core 6 is the common presence of Falcisporites stabilis in the latter. This pollen was produced by the corystosperm plant Dicroidium and its presence in Core 6 further indirectly confirms previous suggestions that Dicroidium (once considered confined to the Triassic) existed in the pre-Triassic in the Middle East. The difference in thickness in Permian sediments between Avdat-1, eastern Negev boreholes, and the Umm Irna Formation may be due to greater accommodation space provided by a southwestward extension of the Palmyrid depocenter, or perhaps subsidence related to a fault in a similar position to the present Dead Sea Fault, or a fault ancestral to the Dead Sea Fault.