High Resolution Chemostratigraphic Correlation of Devonian-Carboniferous Sequences from Berkine Basin, Eastern Algeria

Tim J. Pearce¹, Teresa Batrina², and Antonio Alaminos Martinez^2
1Chemostrat Ltd, Powys, United Kingdom
²CEPSA, Madrid, Spain

Devonian to Carboniferous sequences of the RKF Field from the Berkine Basin of eastern Algeria consist of progradational cycles of shoreface to shallow marine sandstones and estuarine deposits capped by offshore marine mudstones. Correlation is hampered by complex lateral facies distributions and a lack of a well-constrained sedimentological model. A four well, c.250 sample ICP-OES and ICP-MS based chemostratigraphy study has refined and improved stratigraphic resolution within these sequences. Compared with sandstones, silty claystones tend to be more laterally extensive and have a higher correlation potential. Variations in Al, K, Rb, Cs, Ga, Sc, Fe, Mg, Zr, U, Th, Nb, Ta, Ti, Cr, U, Ni, V and Cu concentrations within silty claystones are used to model stratigraphic changes in feldspars, clay minerals, heavy minerals and organics and thereby construct a robust hierarchical chemostratigraphy framework. Five Chemostratigraphic packages (CP1) are defined, where CP1 is equivalent to the Struntian, CP2-CP3 the Tournaisian and CP4-CP5 to the Visean. These packages are further subdivided into a series of units and subunits that provide a means to refine and enhance the biostratigraphic and sequence stratigraphic models that exist within a field and on a subregional scale.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece