Linking sediment source-sink pathways, provenance and composition to predict siliciclastic reservoir quality in the Black Sea

Siliciclastic reservoir presence and quality are key exploration risks in the Black Sea. These risks can be minimised by understanding the geological framework and evolution of the region and the source to sink pathways that developed within it. The Black Sea region is an amalgam of arcs and continental fragments that accreted to the southern margin of Laurussia / Laurasia / Eurasia. Plate margin processes resulted in multiple episodes of collision and upper plate extension. Collisional events generated and rejuvenated sediment source areas, including the inversion of earlier extensional basins, and formed flexural successor basins. Extension resulted in basin formation, including the western and eastern Black Sea basins, and the generation of localised areas of footwall uplift and erosion. Identifying and tracking first- and multiple-cycle sediments through these tectonic cycles is highly complex and requires the use of multiple provenance tools.

In this presentation we shall link siliciclastic packages within the Black Sea via their sediment input points to potential source areas onshore. Where the composition of the upstream, onshore, components of these depositional systems are known, direct predictions of downstream, subsurface reservoir quality can be made. Where these sediments are no longer exposed onshore, inferences can be gained from modern sand compositions and knowledge of the nature and history of the source areas themselves. Summarizing the regional CASP petrographic database, we shall rank the various sectors of the Black Sea in terms of their likely post-rift siliciclastic reservoir quality. Ultimately, however, the hypotheses presented in this talk can only be tested through the analysis of well material from the basin itself.