High-Resolution Palynostratigraphy, Northern Arabian Plate – A Correlation Tool for Clastic Sequences

Abstract

Our stratigraphic investigations focus on northern Arabian Plate regions, where thick carbonate and clastic sequences are represented by the Late Palaeozoic (Pennsylvanian, Permian). Here, more or less intensely interrupted depositional cycles and complexes occur, which can extend widely (as far as Saudi Arabia and Oman). Many units provide source rock and reservoir intervals (oil and non-associated gas reservoirs). The age classification and correlation of (isolated) clastic units, however, can be a matter of discussion. Because these questions were discussed for some clastic units and subsurface sections in Iraq, our aim was to produce a reliable palynostratigraphic tool, for dating and correlation, most precise as possible and applicable in the northern Arabian Plate regions. In recent studies, some of us developed the correlation of Permian mixed clastic-carbonate sequences to the international standard stages, with special reference to mid Permian sections in SE Turkey and Iraq. Based on data of these palynologically well-analyzed sections, a total of fifteen stratigraphic markers (eleven newly established taxa) were used for the erection of a new palynostratigraphic model. This model is applicable in regional correlation to distinguish deposits from SE Turkey and Iraq precisely within the time span of the late Wordian, to assign strata to the mid and late Wordian, and to the earliest Capitanian, or even to characterize strata older or younger than late Wordian. Deposits can be placed, in high-resolution, within a time interval of less than a half a million years. The applicability of the palynostratigraphic model within the basal Permian clastic deposits of the Kas Formation in SE Turkey was already proven by several dated and correlated surface and subsurface sections. Other examples in our manuscripts present dated intervals within clastic sections of the 100/B/85, TI9, UB8A wells (W Iraq, upper Ga'ara Fm., middle Wordian), and of the Mityaha-1 and Atshan-1 wells (N Iraq, Chia Zairi Fm., late Wordian/early Capitanian). The application of the high-resolution palynostratigraphic model in southern Arabian Plate areas is discussed and a correlation chart compares the dated northern clastic sections with approximately time-equivalent strata in Oman (e.g. with a mudstone band below the Khuff Fm., Huqf area, mid (late) Wordian).

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014