III.—The Fauna of the Lower Oligocene Tertiary Beds of Helmstadt, near Brunswick. By Dr. A. v. Koenen - [Die Fauna der unter-oligocänen Tertiärschichten von Helmstädt bet Braunschweig. von DrA. V. Koenen. Zeitschrift der deutschen geologischen Gesellschaft. Jahrg, 1865, pp. 459–533. 2 plates. ]

1866 ◽  
Vol 3 (21) ◽  
pp. 127-128
Keyword(s):  
Lower Oligocene

Palaeogene warping in the Isle of Wight

1971 ◽  
Vol 108 (5) ◽  
pp. 399-405 ◽  
Author(s):  
B. Daley ◽  
N. Edwards
Keyword(s):  
Western Europe ◽  
Isle Of Wight ◽  
Southern England ◽  
Lower Oligocene ◽  
North Western

SummaryGentle folding or warping, of Lower Oligocene age, pre-dating the main post-Hamstead Beds folding, is indicated where the Bembridge Marls rest unconformably on eroded Bembridge Limestone. The folding appears to have been along generally NW–SE trending axes. This trend is compatible with penecontemporaneous and even earlier folding in Southern England and adjacent parts of north-western Europe. In Southern England, the main folding may have been earlier than the Miocene age generally accepted.

Herpetofauna of the Calf Creek Local Fauna (Lower Oligocene: Cypress Hills Formation) of Saskatchewan

1972 ◽  
Vol 9 (12) ◽  
pp. 1612-1631 ◽  
Author(s):  
J. Alan Holman
Keyword(s):  
Middle Eocene ◽  
Tropical Climate ◽  
Local Fauna ◽  
Lower Oligocene ◽  
Bridger Formation

A Lower Oligocene deposit, the Calf Creek local fauna of the Cypress Hills Formation, near Eastend, Saskatchewan, yielded the remains of one salamander, three anurans, three turtles, a crocodilian, six lizards, and three snakes. All of the 13 herpetological families identified are extant. The four amphibian genera identified are extant, but only two of nine reptilian genera identified are living today. One genus and species and one species of iguanid lizard, one species of xantusiid lizard, and one species of small boid snake are described as new. The Calf Creek local fauna herpetofauna indicates a subtropical or tropical climate. The herpetofauna of the Calf Creek local fauna shows several differences from the herpetofauna of the Middle Eocene Tabernacle Butte local fauna of the Bridger Formation of Wyoming.

scholarly journals The architecture of the Kattendijk Formation and the implications on the early Pliocene depositional evolution of the southern margin of the North Sea Basin

2020 ◽  
Vol 23 (3-4) ◽  
Author(s):  
Jef DECKERS ◽  
Stephen LOUWYE
Keyword(s):  
Cone Penetration ◽  
Early Pliocene ◽  
Cone Penetration Tests ◽  
The North ◽  
Lower Oligocene ◽  
Deep Incision ◽  
The North Sea ◽  
Depositional Evolution ◽  
Penetration Tests ◽  
East West

An east-west correlation profile through the upper Neogene succession north of Antwerp, based on cone penetration tests, reveals the architecture of the lower Pliocene Kattendijk Formation. It shows a basal incision of the Kattendijk Formation down to 20 m in Miocene sands and locally even Lower Oligocene clays. The incision is part of a much larger gully system in the region at the base of the Kattendijk Formation. The strongest gully incision is observed along the western profile, and coincides with increases in the thickness of the Kattendijk Formation from its typical four to six meters thickness in the east towards a maximum of 15 m in the west. Correlations show that this additional thickness represents a separate sequence of the Kattendijk Formation that first filled the deepest part of the gully prior to being transgressed and covered by the second sequence deposited in a larger gully system. Both sequences of the Kattendijk Formation have basal transgressive layers, and are lithologically identical. Initial, deep incision at the base of the Kattendijk Formation might have been the result of the constriction of early Pliocene tidal currents that invaded and expanded fluvial or estuarine gullies that had developed during the latest Miocene sea-level low. A similar mechanism had been proposed for the development of late Miocene gully system at the base of the Diest Formation further southeast in northern Belgium. As the wider area was transgressed and covered by the second sequence of the Kattendijk Formation, flow constriction ended, currents weakened and gully incisions were reduced in size.

An Early Oligocene age for the oldest known monkeys and rodents of South America

2021 ◽  
Vol 118 (37) ◽  
pp. e2105956118
Author(s):  
Kenneth E. Campbell ◽  
Paul B. O’Sullivan ◽  
John G. Fleagle ◽  
Dorien de Vries ◽  
Erik R. Seiffert
Keyword(s):  
South America ◽  
Amazon Basin ◽  
Middle Eocene ◽  
Detrital Zircons ◽  
Age Difference ◽  
Early Oligocene ◽  
Lower Oligocene ◽  
Upper Oligocene ◽  
Caviomorph Rodents ◽  
Age Estimates

The Santa Rosa fossil locality in eastern Perú produced the first Paleogene vertebrate fauna from the Amazon Basin, including the oldest known monkeys from South America. This diverse paleofauna was originally assigned an Eocene age based largely on the stage of evolution of the site’s caviomorph rodents and marsupials. Here, we present detrital zircon dates that indicate that the maximum composite age of Santa Rosa is 29.6 ± 0.08 Ma (Lower Oligocene), although several zircons from Santa Rosa date to the Upper Oligocene. The first appearance datum for Caviomorpha in South America is purported to be the CTA-27 site in the Contamana region of Perú, which is hypothesized to be ∼41 Ma (Middle Eocene) in age. However, the presence of the same caviomorph species and/or genera at both CTA-27 and at Santa Rosa is now difficult to reconcile with a >11-My age difference. To further test the Middle Eocene age estimate for CTA-27, we ran multiple Bayesian tip-dating analyses of Caviomorpha, treating the ages of all Paleogene species from Perú as unknown. These analyses produced mean age estimates for Santa Rosa that closely approximate the maximum 29.6 ± 0.08 Ma composite date provided by detrital zircons, but predict that CTA-27 is much younger than currently thought (∼30 Ma). We conclude that the ∼41 Ma age proposed for CTA-27 is incorrect, and that there are currently no compelling Eocene records of either rodents or primates in the known fossil record of South America.

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