Search results
Results From The WOW.Com Content Network
The Eocene–Oligocene extinction event, also called the Eocene-Oligocene transition (EOT) or Grande Coupure (French for "great cut"), is the transition between the end of the Eocene and the beginning of the Oligocene, an extinction event and faunal turnover occurring between 33.9 and 33.4 million years ago. [1]
The Eocene-Oligocene transition was a major cooling event and reorganization of the biosphere, [33] [34] being part of a broader trend of global cooling lasting from the Bartonian to the Rupelian. [ 35 ] [ 36 ] The transition is marked by the Oi1 event, an oxygen isotope excursion occurring approximately 33.55 million years ago, [ 37 ] during ...
An example of a switch between two equilibria in the AMOC is the Eocene-Oligocene transition (EOT) 34 MA ago, where proxies of the deep circulation suggest the onset of the AMOC. This caused a major shift in the global climate towards colder and drier conditions.
The Eocene-Oligocene Boundary 33.9 million years ago was the transition from the last greenhouse period to the present icehouse climate. [17] [18] [10] At this point, when ~25% more of Antarctica's surface was above sea level and able to support land-based ice sheets relative to today, [19] CO 2 levels had dropped to 750 ppm. [20]
Following the maximum was a descent into an icehouse climate from the Eocene Optimum to the Eocene–Oligocene transition at 34 Ma. During this decrease, ice began to reappear at the poles, and the Eocene–Oligocene transition is the period of time when the Antarctic ice sheet began to rapidly expand. [52]
A brief marine incursion marks the early Oligocene in Europe. There appears to have been a land bridge in the early Oligocene between North America and Europe since the faunas of the two regions are very similar. During the Oligocene, South America was finally detached from Antarctica and drifted north toward North America.
The late Eocene Epoch saw the rebirth of seasons, which caused the expansion of savanna-like areas with the earliest substantial grasslands. [57] [58] At the transition between the Eocene and Oligocene epochs there was a significant extinction event, the cause of which is debated. The Oligocene Epoch spans from 34 million to 23 million years ago.
According to them the formation spans approximately 8 million years, with its oldest localities situated in latest Eocene strata. Locality BQ-2 has been estimated to be 37 million years old (early Priabonian), while L-41 falls into an age range of 34.8–33.7 million years old, a timespan that includes the Eocene-Oligocene Boundary. Although an ...