Aptian–Maastrichtian palynomorphs from the offshore Tano Basin, western Ghana

Abstract

Cretaceous dinoflagellate cysts and miospores have been recovered from the Tano 1-1 and 1S-3AX wells, offshore of western Ghana. Based on marker palynomorphs ( Afropollis jardinus, Elaterosporites klaszii, Elaterocolpites castelainii, Sofreipites legouxae, Reyrea polymorphus, Cyclonephelium vannophorum) an Aptian-early Cenomanian age has been assigned to sediments from the well Tano 1-1. The taxa Auriculiidites reticulatus, Spinizonotriletes echinatus, Buttinia andreevi, Longapertites spp., Echitriporites trianguliformis, Dinogymnium spp., Trichodinium castanea, Andalusiella spp., which are elements typical of Campanian–Maastrichtian sediments have been recognized in the sediments from 1S-3AX. Palaeoenvironmental interpretation based on identified palynomorphs in the light of their ecological preferences and also on the relative proportions of palynomorph groups, indicate that the Aptian-lower Cenomanian sediments were deposited in a marginal marine environment with vegetation on wetlands, under a relatively dry climate. The Campanian–Maastrichtian sediments suggest a fluctuation between marginal to open marine (inner shelf) conditions. The sediments have characteristic elements indicative of the Albian–Cenomanian “Elaterate Province”, and the late Cretaceous “Senonian Palmae Province”, which supports a warm tropical climate.