Cretaceous-Tertiary geodynamics: a North Atlantic exercise

Diagenesis of Lower Cretaceous Pelagic Carbonates, North Atlantic: Paleoceanographic Signals Obscured

The stable isotope and minor element geochemistry of Neocomian (Lower Cretaceous) pelagic carbonates of the North Atlantic Basin (Deep Sea Drilling Project Sites 105, 367, 387, 391, and 603) was examined to develop a diagenetic model for pelagic limestones. In particular, we hoped to test the fidelity of whole-rock geochemical records as paleoceanographic indicators for pelagic deposits of pre-...

Extraterrestrial cause for the cretaceous-tertiary extinction.

Platinum metals are depleted in the earth's crust relative to their cosmic abundance; concentrations of these elements in deep-sea sediments may thus indicate influxes of extraterrestrial material. Deep-sea limestones exposed in Italy, Denmark, and New Zealand show iridium increases of about 30, 160, and 20 times, respectively, above the background level at precisely the time of the Cretaceous-...

Fungal proliferation at the Cretaceous-Tertiary boundary.

The evolution of life on Earth has been interrupted by several mass extinction events. The Cretaceous-Tertiary (K-T) extinction [65 million years ago (Ma)] is associated with the impact of a large bolide (1). On the basis of extensive data (2–4), the K-T boundary is characterized by a palynological extinction horizon coincident with a geochemical marker bed commonly succeeded by a bed rich in f...

North Atlantic Treaty Organisation

North Atlantic Treaty Organization