Neogene

The Neogene is a section of the earth's history. According to the present definition, the era of the Cenozoic is geochronological divided into three sections: in the Paleogene, Neogene and the Quaternary. In the Neogene chronostratigraphy, making it the second highest system.

• Geological Time: Cenozoic System: Quaternary ( 2.588 to 0 mya )
• System: the Neogene ( 23.03 to 2.588 mya )
• System: Paleogene ( 66 to 23.03 mya )

The Neogene is characterized by the development of birds and mammals. Between the continents of North and South America, a land bridge formed, a faunal exchange began. There was a slow climatic cooling through to the Pleistocene ice age.

Subdivision

The Neogene is divided into two series:

• System: the Neogene ( 23.03 to 2.588 mya ) Series: Pliocene ( 5.333 to 2.588 mya ) Level: Piacenzium ( 3.6 to 2.588 mya )
• Level: Zancleum ( 5.333 to 3.6 mya )

• Level: Messinian ( 7.246 to 5.333 mya )
• Level: Tortonian ( 11.62 to 7.246 mya )
• Level: Serravallium ( 13.82 to 11.62 mya )
• Level: Langhium ( 15.97 to 13.82 mya )
• Level: Burdigalium ( 20.44 to 15.97 mya )
• Level: Aquitanian ( 23.03 to 20.44 mya )

Climate

The Neogene brought a period of increased cooling until the beginning of the first glaciations in the Gelasian, the lowest level of the Quaternary.

In the Miocene, at the beginning of the Neogene, the climate can be considered still in the North Atlantic- Scandinavian area as moderate. This is evident from the study of the composition of the fossil marine fauna.

In the lower Pliocene, there was a strong first cooling phase in the region of the poles, which again was followed by a longer heating. A varying but relatively rapid drop of the temperature curves followed during the Pliocene.

At the end of the Pliocene it came to the icing of the polar ice caps. On the continent, Antarctica ice sheets were deposited and thus removed from the water cycle. This led to a first lowering of the sea level.

The Pleistocene is referred to as the actual ice age, with changing Vergletscherungsphasen the northern parts of Eurasia and North America.

Conceptual history

Formation and transformation of the concept of

The term Neogene goes back to the Austrian geologists and paleontologists Moriz Hoernes who used him already in the middle of the 19th century for the classification of the deposits in the Vienna Basin. He divided the layers of the geological age of the Cenozoic era into two periods, an older, Paleogene, and a younger, which Neogene. The Neogene also ranged already up to the upper layers, so to the present day.

The Neogene was later used for a better description of the Tertiary, since its beginning before 23.03 million years, the incision between the Oligocene (part of the Paleogene ) and the Miocene ( part of the Neogene to ) marked. However, the Neogene has been reduced to the Miocene epochs and Pliocene and ended with the Tertiary on the border of the Quaternary ( 1.8 million years ago ).

To set the final of the Neogene there is a conflict between the International Stratigraphic Commission ( ICS ) and the International Union for Quaternary Research ( INQUA ) was born. After a claim brought together in the INQUA Quaternary geologists the Neogene should not extend into the present. Instead, it should end with the end of the Pliocene about 2.6 million years ago and are already starting the system at the beginning of the Quaternary Gelasiums.

Change in the geological time scale 2004

The terms Tertiary and Quaternary in the geological time scale were abolished in 2004 and replaced by Paleogene and Neogene. Already in 1978 was supported by a sub-committee of the International Commission on Stratigraphy (ICS ), the Cenozoic is divided into two periods, the Paleogene and Neogene, as suggested by Hoernes 150 years ago. In 2004 was presented as a result of the discussions of the past decades the new Geological Time Scale ( Geologic Time Scale 2004). In 2008, it should be mandatory for all international geologists. However, at the same time redefining and re-introduction of the Quaternary was promised.

Many Quaternary geologists saw the deletion of the Quaternary especially critical since the specifics of the Earth's development during the ice age, which differ significantly from the previous Pliocene, in the new time scale, not came to bear. Your review has meant that the Quaternary was resumed in the time scale and redefined. The period, which included 1.8 million years earlier, was extended to 2.6 million years and now includes all the glacial sediments. This proposal was adopted in June 2009. The Quaternary starts since then with the Gelasian.