Cretaceous - Wikipedia The Cretaceous was named for the extensive chalk deposits of this age in Europe, but in many parts of the world, the deposits from the Cretaceous are of marine limestone, a rock type that is formed under warm, shallow marine conditions
Cretaceous Period | Definition, Climate, Dinosaurs, Map - Britannica Cretaceous Period, in geologic time, the last of the three periods of the Mesozoic Era It began 145 million years ago and ended 66 million years ago and featured the extinction of the dinosaurs at the end of the period
The Cretaceous Period: What was Earth like before dinosaurs went . . . The Cretaceous Period lasted for nearly 80 million years Discover what the climate was like in this geological period, where the continents were and what animals and plants lived on them Find out how an asteroid ended the age of dinosaurs
Cretaceous Period—145. 0 to 66. 0 MYA - U. S. National Park Service In 1882 a Belgian geologist, Omalius d’Halloy, proposed the term “Cretaceous” for strata encircling the Paris Basin in France The term derives from the Latin word for chalk (“creta”) and describes thick deposits of calcium carbonate (CaCO 3) ooze and chert (SiO 2)
Cretaceous - New World Encyclopedia The Cretaceous period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic period, from about 146 to 136 million years ago (Ma) to the beginning of the Paleocene epoch of the Paleogene period, or Tertiary sub-era (about 65 5 to 64 Ma)
Cretaceous Period Facts and Information | National Geographic During this period, oceans formed as land shifted and broke out of one big supercontinent into smaller ones Continents were on the move in the Cretaceous, busy remodeling the shape and tone of
The Cretaceous Period The Cretaceous is defined as the period between 145 5 and 65 5 million years ago,* the last period of the Mesozoic Era, following the Jurassic and ending with the extinction of the dinosaurs (except birds)
Cretaceous Period - Mesozoic, Paleogene, Cenozoic | Britannica The Cretaceous System is divided into two rock series, Lower and Upper, which correspond to units of time known as the Early Cretaceous Epoch (145 million to 100 5 million years ago) and the Late Cretaceous Epoch (100 5 million to 66 million years ago)
Cretaceous Period | Natural History Museum Ocean basin volumes diminished and the seas reached their highest levels during the Cretaceous Period, resulting in vast shallow continental seas Huge deposits of chalk left from the skeletal remains of marine organisms, give the period its name