Chadronian
Encyclopedia
The Chadronian age within the North American Land Mammal Ages
chronology is the North American faunal stage
typically set from 38,000,000 to 33,900,000 years BP
, a period of . It is usually considered to fall within the Eocene
epoch. The Chadronian is preceded by the Duchesnean
and followed by the Orellan
NALMA stages.
The Chadronian can be further divided into the substages of:
through Rupelian
of the Late Eocene through Early Oligocene in the geologic time scale
.
North American Land Mammal Ages
The North American Mammal Ages establishes a geologic timescale for prehistoric North American fauna beginning 66.5 Ma during the Paleocene and continuing through to the Late Pleistocene...
chronology is the North American faunal stage
Faunal stage
In chronostratigraphy, a stage is a succession of rock strata laid down in a single age on the geologic timescale, which usually represents millions of years of deposition. A given stage of rock and the corresponding age of time will by convention have the same name, and the same boundaries.Rock...
typically set from 38,000,000 to 33,900,000 years BP
Before Present
Before Present years is a time scale used in archaeology, geology, and other scientific disciplines to specify when events in the past occurred. Because the "present" time changes, standard practice is to use AD 1950 as the origin of the age scale, reflecting the fact that radiocarbon...
, a period of . It is usually considered to fall within the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
epoch. The Chadronian is preceded by the Duchesnean
Duchesnean
The Duchesnean North American Stage on the geologic timescale is a North American Land Mammal Age , with an age from 42 to 38 million years BP, representing . It falls within the Eocene epoch. The Duchesnean is preceded by the Uintan and followed by the Chadronian NALMA.The Duchesnean falls within...
and followed by the Orellan
Orellan
The Orellan North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology , typically set from 33,900,000 to 33,300,000 years BP, a period of . It is usually considered to fall within the Early Oligocene...
NALMA stages.
The Chadronian can be further divided into the substages of:
- Late/Upper Chadronian (shares upper boundary). Lower boundary source of the base of the PriabonianPriabonianThe Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene epoch or series. It spans the time between and...
(approximate) - Middle Chadronian. Lower boundary source and base of the Priabonian (approximate). Upper boundary source of the base of the Orellan (approximate).
- Early/Lower Chadronian (shares lower boundary). Upper boundary source: base of Orellan (approximate).
Geological time
The Chadronian maintains a period of time within the PriabonianPriabonian
The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene epoch or series. It spans the time between and...
through Rupelian
Rupelian
The Rupelian is, in the geologic timescale, the older of two ages or the lower of two stages of the Oligocene epoch/series. It spans the time between and . It is preceded by the Priabonian stage and is followed by the Chattian stage....
of the Late Eocene through Early Oligocene in the geologic time scale
Geologic time scale
The geologic time scale provides a system of chronologic measurement relating stratigraphy to time that is used by geologists, paleontologists and other earth scientists to describe the timing and relationships between events that have occurred during the history of the Earth...
.