Cretaceous period

Cretaceous period. The Cretaceous period, which spanned from approximately 145 to 65 million years ago, is a significant geological period that is characterized by the break-up of the Supercontinent Pangaea into several smaller continents, including North America, South America, Africa, Europe, Asia, and Australia. This period is marked by the formation of several major mountain ranges, including the Rocky Mountains and the Himalayan Mountains, as a result of the movement of the Indian Plate and the Eurasian Plate. The Cretaceous period is also notable for the presence of numerous Volcanic arcs, including the Andes Mountain range, which was formed as a result of the subduction of the Nazca Plate under the South American Plate.

Introduction

The Cretaceous period is divided into two epochs: the Early Cretaceous and the Late Cretaceous. The Early Cretaceous epoch, which lasted from approximately 145 to 100 million years ago, is characterized by the formation of several major Sedimentary basins, including the Paris Basin and the London Basin. The Late Cretaceous epoch, which lasted from approximately 100 to 65 million years ago, is marked by the deposition of several thick sequences of Chalk and Limestone in the Western Interior Seaway of North America and the English Channel region of Europe. This period is also notable for the presence of numerous Fossil species, including Ammonites, Belemnites, and Rudists, which are found in the Solnhofen Limestone and the Pierre Shale formations.

Geology

The geology of the Cretaceous period is characterized by the formation of several major Mountain ranges, including the Sierra Nevada and the Cascade Range. The movement of the Pacific Plate and the North American Plate resulted in the formation of several major Fault lines, including the San Andreas Fault and the Cascadia Subduction Zone. The Cretaceous period is also notable for the presence of numerous Volcanic fields, including the Deccan Traps and the Siberian Traps, which were formed as a result of the eruption of large amounts of Basaltic lava. The Geological Survey of Canada and the United States Geological Survey have conducted extensive research on the geology of the Cretaceous period in North America.

Paleogeography

The paleogeography of the Cretaceous period is characterized by the break-up of the Supercontinent Pangaea into several smaller continents. The movement of the African Plate and the South American Plate resulted in the formation of the Atlantic Ocean and the South Atlantic Ocean. The Cretaceous period is also notable for the presence of several major Seaways, including the Tethys Sea and the Western Interior Seaway, which connected the Gulf of Mexico to the Arctic Ocean. The National Oceanic and Atmospheric Administration and the European Space Agency have conducted extensive research on the paleogeography of the Cretaceous period using Satellite imagery and Geographic information systems.

Climate

The climate of the Cretaceous period is characterized by a warm and humid environment, with no Polar ice caps present at the North Pole or the South Pole. The Cretaceous period is notable for the presence of several major Deserts, including the Sahara Desert and the Gobi Desert, which were formed as a result of the movement of the African Plate and the Eurasian Plate. The Intergovernmental Panel on Climate Change and the National Aeronautics and Space Administration have conducted extensive research on the climate of the Cretaceous period using Climate models and Paleoclimatology.

Life Forms

The Cretaceous period is characterized by the presence of numerous Flowering plants, including Magnolias and Oak trees, which are found in the Hell Creek Formation and the Lance Formation. The Cretaceous period is also notable for the presence of several major Animal groups, including Dinosaurs, Pterosaurs, and Marine reptiles, which are found in the Solnhofen Limestone and the Pierre Shale formations. The American Museum of Natural History and the Natural History Museum, London have conducted extensive research on the life forms of the Cretaceous period using Fossil records and Phylogenetics.

Extinction Events

The Cretaceous period is notable for the presence of several major Extinction events, including the K-Pg extinction event, which occurred at the end of the Cretaceous period and resulted in the extinction of approximately 75% of all species on Earth, including the Non-avian dinosaurs. The Chicxulub asteroid impact and the Deccan Traps are believed to have contributed to the K-Pg extinction event. The University of California, Berkeley and the University of Chicago have conducted extensive research on the extinction events of the Cretaceous period using Geochronology and Paleontology. The Society of Vertebrate Paleontology and the Paleontological Society have also conducted research on the extinction events of the Cretaceous period. Category:Geologic periods