Stratigraphic palynology of Devonian boreholes from northern Saudi Arabia

Abstract

This extended abstract describes well-preserved palynomorph assemblages recovered from Devonian strata in five shallow boreholes in the northern part of Saudi Arabia. These fully cored holes overlap stratigraphically to form a 1,640 ft composite section spanning the upper Tawil, Jauf and lower Jubah formations. Only the Jauf and lower Jubah, represented by 188 samples taken over a 1,300 ft stratigraphic interval, are addressed here as the sandy Tawil lithologies are unsuitable for palynological analysis. The 900 feet of alternating of siliciclastic and carbonate units, that together comprise the five members of the Jauf Formation, were sampled comprehensively. However, the Jubah Formation, like the Tawil Formation, is mostly sandstone and is productive palynologically at only two levels separated by a 300 ft barren interval. The age of the sampled succession is assessed using index species from the established Euramerican Devonian palynozonations of Richardson & McGregor (1986) and Streel et alii (1987), and is shown to span the late Early and Middle Devonian.