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. © 2006 Elsevier Ltd. All rights reserved.