Basin modelling of a transform margin setting: structural, thermal and hydrocarbon evolution of the Tano Basin, Ghana

Abstract

This study explores the structural and thermal evolution of the Ghana transform margin. The main objective is to explore how the opening of the Atlantic Ocean and subsequent interaction with the Mid-Atlantic Ridge (MAR) has affected the margin's structural and thermal evolution. Two representative evolution scenarios are described: a reference case that neglects the influence of continental breakup and a second scenario that accounts for a possible heat influx during the passage of the MAR as well as magmatic underplating. These two scenarios have further been analysed for the implications for the hydrocarbon potential of the region.The scenario analysis builds on a suite of 2D realizations performed with TECMOD2D, modelling software for automated basin reconstructions. As the observed stratigraphy is input, the structural and thermal evolution of the basin is automatically reconstructed. This is achieved through the coupling of a lithosphere scale forward model with an inverse algorithm for model parameter optimization.We find that lateral heat transport from the passing MAR in combination with flexure of the lithosphere can explain the observed uplift of the margin. These results were obtained for a broken plate elasticity solution with a relative large value for the effective elastic thickness (Te=15) and necking level (15 km). Lateral heat flow from oceanic lithosphere is clearly visible in elevated basement heat flow values up to 50 km away from the ocean-continent transition (OCT). This influx of heat does not seem to have affected the maturation history along the margin significantly. Only the deepest sediments close to the OCT show slightly elevated vitrinite reflectance in simulations that account for the passage of the MAR. In conclusion, it appears that that lateral heat transport from the oceanic lithosphere is instrumental in shaping the Ghana transform margin but seems to have only limited control on the maturation history.

Southwest Barents Sea rift basin evolution: comparing results from backstripping and time‐forward modelling

“…In contrast to the backstripping approach, TecMod time‐forward modelling stretches the full thickness of the lithosphere and fills the basins with sediments in a kinematically, isostatically and thermally integrated model, described in detail by Rüpke et al . (, ) and Theissen & Rüpke (). Deformation is achieved using only pure shear, so faults are not explicitly restored, but can be approximated with sufficient lateral resolution (Rüpke et al ., ).…”

Transform margins: development, controls and petroleum systems – an introduction

“…Antobreh Rupke et al 2010). In theory, frictional heating along the transform should also contribute to the thermal perturbation (Carslaw & Jaeger 1959;Lachenbruch & Sass 1980;Kanamori 1994;d'Alesio et al 2004) although its effect is rather minimal (Todd & Keen 1989;Saffer et al 2003;Williams et al 2004Williams et al , 2005Zoback et al 2011).…”

Interrelation between rifting, faulting, sedimentation, and mantle serpentinization during continental margin formation—including examples from the Norwegian Sea

“…The technical details can be found in Rüpke et al . []. The two‐dimensional forward model is locally based on pure‐shear kinematics and resolves simultaneously for differential thinning, flexural isostasy, heat transfer, sedimentation, and compaction on a Lagrangian finite‐element mesh.…”