Paleogene geology

geological signature, usually a thin band of rock, marking the transition from the end of the Cretaceous Period and the beginning of the Paleogene Period, dated with radiometric methods, at the age of 66.043 ± 0.011 Ma

oceanic tectonic plate under the northern Pacific Ocean which has been subducted under the North American Plate

ancient tectonic plate that existed during the mid-Cretaceous through early Cenozoic time; the remainder of the plate is now located east of the Drake Passage/Shackleton Fracture Zone