Distribution and Origin of Natural Gas Leakage Features on Block 2 of the Orange Basin as Interpreted from 2D Seismic Reflection Data Off-shore the South African Margin.

We have interpreted more than 300 2D seismic-reflection profiles located across the Orange Basin, offshore the western South Africa margin. The dataset covers an area of aprox. 18750 km2 which comprises the exploration Block 2. The main goal of this work was to analyse the occurrence of natural gases within the sedimentary column and the distribution of gas leakage features in relation to tectonic and sedimentary structures, in order to assess quantitatively the hydrocarbon generation, migration and seepage dynamics through geologic time in the basin. A long term aim is to integrate the results into climate change models as thermogenic methane is a strong greenhouse gas and such natural emissions may play a role in controlling climate evolution.