New Publication December 2020 "Geochronology of volcanically associated hydrocarbon charge in the pre-salt carbonates of the Namine Basin, Angola

Rochelle-Bates, N.; Roberts, N.M.W.; Sharp, I.; Freitag, U.; Verwer, K.; Halton, Alison; Fiordalisi, E.; van Dongen, B.E.; Swart, R.; Ferreira, C.H.; Dixon, R. and Schroder, S. (2020). Geochronology of volcanically associated hydrocarbon charge in the pre-salt carbonates of the Namibe Basin, Angola. Geology (Early Access).

This new publication, online in Geology uses Ar/Ar dating of basalt and insitu carbonate U/Pb dating to look at the timings of hydrocarbon charge in the volcanic rifted margin of the South Atlantic. To test if fluid flow was synchronous with known volcanic pulses, from a near by volcanic complex produced an 40Ar/39Ar age of 89.9 ± 1.8 Ma, which overlaps that of the dated calcite veins yielded a pooled U-Pb age of 86.2 ± 2.4 Ma. The overlapping dates and the localized bitumen occurrence around the dated volcanic center show a clear genetic relationship between Late Cretaceous igneous activity and hydrocarbon charge. The dolomite was dated at 56.8 ± 4.8 Ma, revealing a previously unknown Paleocene/Eocene fluid-flow phase in the basin.