Lower Cretaceous fossils from central Niger document the succession of sauropod dinosaurs on Africa as it drifted into geographic isolation. A new broad-toothed genus of Neocomian age ( approximately 135 million years ago) shows few of the specializations of other Cretaceous sauropods. A new small-bodied sauropod of Aptian-Albian age ( approximately 110 million years ago), in contrast, reveals ...

Abstract The age of the beginning magnetic polarity Chron M0r, a proposed marker for base Aptian Stage, is disputed due to divergence published radioisotopic dates and ambiguities in stratigraphic correlation sections. Our magnetostratigraphy core DH1 from Svalbard, Norway, calibrates bentonite bed, dated by U-Pb methods 123.1 ± 0.3 Ma, uppermost part magnetozone M1r, which ∼1.9 m.y. before M0r...

Integrated organic petrographic and geochemical analyses were made on organic-rich marine carbonate mixed clastic-carbonate rocks of Middle–Late Jurassic Early Cretaceous age from the Shushan Basin, Egypt to evaluate their hydrocarbon potential. Analyses allowed identification depositional settings, paleoclimate, three third order genetic stratigraphic sequences (SQ) with deposits assigned high...

Abstract Widespread oceanic anoxia, biological crises, and volcanic activity are associated with the onset of Early Aptian (ca. 120 Ma) Oceanic Anoxic Event 1a (OAE1a). Reconstructions deoxygenation its links to broadly contemporaneous volcanism, however, remain poorly resolved. We use geochemical data, including δ53Cr ratios rare Earth element abundances, define timing tempo submarine volcanis...

Identification of processes driving carbonate diagenesis requires an accurate chronology, particularly along volcanic margins where complex mineral parageneses develop. The Cretaceous “Pre-Salt” carbonates formed in the proto-South Atlantic and are now extensive hydrocarbon reservoirs offshore Brazil Angola. Primary diagenetic textures strongly affect reservoir properties, but timings depositio...

The purpose of this paper is to characterize the configuration northern Tunisia’s basin during Cretaceous on basis abundant slump folds and frequent synsedimentary faults. are studied determine slumps transport vergence submarine paleoslope. local regional stress field used syn-sedimentary deformation. During Valanginian–Aptian times, characterized by southward slope. From Albian Santonian anal...