The Central Atlantic Magmatic Province (CAMP) is defined by tholeiitic basalts that crop out in once-contiguous parts of North America, Europe, Africa, and South America and is associated with the breakup of Pangea. ⁴⁰ Ar/ ³⁹ Ar and paleomagnetic data indicate that CAMP magmatism extended over an area of 2.5 million square kilometers in north and central Brazil, and the total aerial extent of the magmatism exceeded 7 million square kilometers in a few million years, with peak activity at 200 million years ago. The magmatism coincided closely in time with a major mass extinction at the Triassic-Jurassic boundary.

The evolution of life on Earth is marked by catastrophic extinction events, one of which occurred ca. 200 Ma at the transition from the Triassic Period to the Jurassic Period (Tr-J boundary), apparently contemporaneous with the eruption of the world's largest known continental igneous province, the Central Atlantic magmatic province. The temporal relationship of the Tr-J boundary and the province's volcanism is clarified by new multi-disciplinary (stratigraphic, palynologic, geochronologic, paleomagnetic, geochemical) data that demonstrate that development of the Central Atlantic magmatic province straddled the Tr-J boundary and thus may have had a causal relationship with the climatic crisis and biotic turnover demarcating the boundary

The end-Triassic extinction is one of the Phanerozoic’s largest mass extinctions. This extinction is typically attributed to climate change associated with degassing of basalt flows from the central Atlantic magmatic province (CAMP). However, recent work suggests that the earliest known CAMP basalts occur above the extinction horizon and that climatic and biotic changes began before the earliest known CAMP eruptions. Here we present new high-precision U-Pb ages from CAMP mafic intrusive units, showing that magmatic activity was occurring ∼100 Kyr ago before the earliest known eruptions. We correlate the early magmatic activity with the onset of changes to the climatic and biotic records. We also report ages from sills in an organic rich sedimentary basin in Brazil that intrude synchronously with the extinction suggesting that degassing of these organics contributed to the climate change which drove the extinction. Our results indicate that the intrusive record from large igneous provinces may be more important for linking to mass extinctions than the eruptive record.

The volcanic activity of Mts Bambouto and Oku (Western Highlands) and of the Ngaoundere Plateau, in the continental sector of the Cameroon Volcanic Line, Equatorial West Africa, ranges in age from Oligocene to Recent. It is characterized by basanitic, alkali basaltic and transitional basaltic series. Mineral chemistry, major and trace element bulk-rock compositions, and geochemical modelling suggest that the magmatic series evolved mainly at low pressure (2–4 kbar) through fractional crystallization of clinopyroxene and olivine ± magnetite, at moderately hydrated (H₂O = 0·5–1 wt %) and QFM (quartz–fayalite–magnetite) to QFM + 1 fO₂ conditions. Basalts from Ngaoundere (Miocene to Quaternary) and from the early activity (31–14 Ma) of the Western Highlands have incompatible trace element and Sr–Nd isotopic compositions similar to those of oceanic Cameroon Line basalts, pointing to a similar asthenospheric mantle source. By contrast, the late (15–4 Ma) Western Highlands basanites and alkali basalts have anomalously high concentrations of Sr, Ba and P, and low concentrations of Zr, which are exclusive features of continental Cameroon basalts. The genesis of these latter magmas is consistent with derivation from an incompatible element enriched, amphibole-bearing lithospheric mantle source. Western Highlands basalts show a continuous spectrum from high to low Sr–Ba–P compositions, and may result from variable amounts of mixing between melts derived from an anhydrous lherzolite source (asthenospheric component) and melts from an amphibole-bearing peridotite source (lithospheric HSr component). New ⁴⁰Ar/³⁹Ar ages for Mts Oku and Bambouto basalts, combined with previous ⁴⁰Ar/³⁹Ar and K/Ar ages of basaltic and silicic volcanics, and with volcanic stratigraphy, suggest a NE–SW younging of the peak magmatic activity in the Western Highlands. This SW younging trend, extending from the Oligocene volcanism in northern Cameroon (e.g. Mt Oku) to the still active Mt Cameroon, suggests that the African plate is moving above a deep-seated mantle thermal anomaly. However, the age and location of the Ngaoundere volcanism does not conform to the NE–SW younging trend, implying that the continental sector of the Cameroon Volcanic Line cannot be easily interpreted as the surface expression of a single hotspot system.

The roots of modern-style ecosystems go back to the Carnian (ca. 233 Ma), a time of global climate change and extinction.