Rift Transection, Inversion and Punctuated Subsidence - Tectonic Development of the North Falkland Basin

Interpretation of 2D and 3D seismic data enabled a holistic basin-wide model for the prospective North Falkland Basin (NFB) that helps to better understand the area’s inherent structural and stratigraphic complexity and petroleum system.

The NFB is an excellent example of two transecting rift basins in which their post-rift phase of subsidence is punctuated by structural inversion of the basin axis prior to hydrocarbon maturation and migration. There is an older Late Jurassic Southern Rift Basin with major NW–SE-striking normal faults, and a younger Early Cretaceous Northern Rift Basin with major N–S-striking normal faults that initiated prior to South Atlantic rifting.

The Northern Rift Basin developed in a fluvial and later lacustrine environment before becoming marine in the Tertiary. A prograding delta system filled the basin from the north in response to uplift in northern areas close to the site of South Atlantic rifting. Contemporaneously, sediment was shed off the segmented basin-bounding fault via long-established feeder drainage systems through breached relay ramps. The resultant sediment dispersal led to deposition of numerous clastic lacustrine turbidites that created the Sea Lion fans play fairway, the location of which has been controlled by compaction and infill of the syn-rift sub-basins below.