Tertiary

The Tertiary was an Earth age in the rank of a system (or period) that comprised the older and much longer section of the Cenozoic (the Earth's New Era). It began at the end of the Cretaceous period 66 million years ago and lasted until the beginning of the Quaternary period 2.6 million years ago. Earth's climate during the Tertiary was much warmer than it is today. After the mass extinction of the large dinosaurs and many other animal species at the end of the Cretaceous period, it was mainly during the Tertiary period that the animal and plant world as we know it today developed.

The term Tertiary should no longer be used within the official geological time scale. However, it is still often used in practice (including in teaching). The current convention divides the Tertiary into two ages and uses the terms Palaeogene for the older (66 to 23.03 mya) and Neogene for the younger (23.03 to 2.588 mya).

Climate

The climate of the Tertiary differed from that of the Quaternary by the mostly significantly higher average global temperatures. At the beginning of the Eocene, about 50 million years ago, the global temperature rose to the highest values (about 30 °C) in the entire Cenozoic ("early Eocene climate optimum"). A distinct warm climate prevailed and the polar regions were ice-free. However, in the further course of the Eocene, the plate-tectonically induced migration of the continents ('continental drift'), especially the increasing isolation of the continent Antarctica, which had drifted into the southern polar region, from the other southern continents (cf. → Gondwana), altered the global heat transport (cf. → global conveyor belt). This led to a cooling of the global climate at the end of the Eocene, and from the Oligocene, circa 35 million years ago, the glaciation of Antarctica began. In the early Miocene, about 20 million years ago, Antarctica was finally completely covered by an ice sheet. Only a few million years later, the glaciation of the Arctic began.

Mountain Formation

About 50 million years ago, the Indian continent collided with Asia, creating the Himalayan Mountains and the highlands of Tibet. In addition, the formation or the main phases of the formation of the Alps, the Apennines, the Carpathians, the Pyrenees and the Caucasus in Europe and the Andes in South America and the Rocky Mountains in North America took place during the Tertiary period. Mountain building in Eurasia was accompanied by the extensive closure of the Tethys Ocean. The central areas of the eastern Mediterranean and the Black Sea are small remnants of this former ocean basin.