Did magmatism of the Central Atlantic Magmatic Province (CAMP) extend to the proto-Cameroon Line in the Gulf of Guinea (West/Central Africa)?

Abstract Pre-Gondwana breakup configurations suggest that the Borborema Province of Northeast Brazil and the areas of present-day Gulf of Guinea in West/Central Africa formed a conjugate fit in the West Gondwana supercontinent. Pangea breakup was associated with extensive magmatism, e.g., emplacement of the Central Atlantic Magmatic Province (CAMP). CAMP manifested as dykes, sills, and flows in areas of present-day West Africa, South America, east coast of North America (USA and Canada), and in Europe. While the Borborema Province of Northeast Brazil was widely affected by pre-, syn-, and post-Pangea breakup magmatism (including CAMP), it is not clear why whole-time equivalents, i.e., similar magmatism, have not yet been reported in areas of present-day Jos Plateau, Benue Trough, and the Cameroon Line in the Gulf of Guinea. We gathered 467, 444, and 125 radioisotope age data, respectively, for the Gulf of Guinea, Northeast Brazil, and global CAMP systems. In addition to confirming the Hettangian (201.43 ± 0.15 Ma) global CAMP peak activity, the assembled data confirm a later ‘tailing’ CAMP in Guinea, Northeast Brazil (Maranhão) and Canada, that occurred at ~ 192.5 ± 0.5 Ma. Very few mafic dykes in the Gulf of Guinea have been dated. The assembled data show that one of them at Kendem on the Cameroon Line gave a 40 Ar– 39 Ar plateau age that falls within the tailing CAMP window. When compared to 1100 and 490 geochemical data collected for the Gulf of Guinea and global CAMP, respectively, this Lower Jurassic Cameroon Line dyke closely resembles CAMP in Northeast Brazil. We use the radioisotope age and geochemical similarity between the Cameroon Line dyke from Gulf of Guinea and CAMP from Northeast Brazil to argue for the need to investigate a more eastward extension of CAMP than is presently known. Currently available radioisotope age data on the Cameroon Line suggest that the onset of magmatism on different centers of the line may have a space–time relationship. This has implications for deep mantle involvement in the magmatism of the volcanic chain and therefore needs further investigation. Graphical Abstract