Selandian
Encyclopedia
The Selandian is in the geologic timescale an age or stage in the Paleocene
. It spans the time between and . It is preceded by the Danian
and followed by the Thanetian
. Sometimes the Paleocene is subdivided in subepochs, in which the Selandian forms the "Middle Paleocene".
island of Zealand (Danish
: Sjælland).
The base of the Selandian is close to the boundary between biozone
s NP4 and NP5. It is slighltly after the first appearances of many new species of the calcareous nannoplankton genus
Fasciculithus (F. ulii, F. billii, F. janii, F. involutus, F. tympaniformis and F. pileatus) and close to the first appearance of calcareous nannoplankton species Neochiastozygus perfectus. At the original type location
in Denmark the base of the Selandian is an unconformity
. The official GSSP was established in the Zumaia
section (43° 18'N, 2° 16'W) at the beach of Itzurun, Pais Vasco, northern Spain
.
The top of the Selandian (the base of the Thanetian) is laid at the base of magnetic chronozone C26n.
The Selandian stage overlaps with the lower part of the Tiffanian
North American Land Mammal Age, the Peligran
, Tiupampan
and lower Itaboraian
South American Land Mammal Ages and part of the Nongshanian Asian Land Mammal Age. It is coeval with the lower part of the Wangerripian stage from the Australia
n regional timescale.
.; 1920: En ny københavnsk Lokalitet for forsteningsførende Paleocæn, Meddelelser fra Dansk Geologisk Forening 5, pp. 1–10 (published March 1921). ; 1924: De københavnske Grønsandslag og deres Placering i den danske Lagrække. Meddelelser fra Dansk Geologisk Forening 6, pp. 1–39.
Paleocene
The Paleocene or Palaeocene, the "early recent", is a geologic epoch that lasted from about . It is the first epoch of the Palaeogene Period in the modern Cenozoic Era...
. It spans the time between and . It is preceded by the Danian
Danian
The Danian is the oldest age or lowermost stage of the Paleocene epoch or series, the Paleogene period or system and the Cenozoic era or erathem. The beginning of the Danian age is at the Cretaceous-Tertiary extinction event...
and followed by the Thanetian
Thanetian
The Thanetian is, in the ICS' Geologic timescale, the latest age or uppermost stratigraphic stage of the Paleocene Epoch or series. It spans the time between and . The Thanetian is preceded by the Selandian age and followed by the Ypresian age...
. Sometimes the Paleocene is subdivided in subepochs, in which the Selandian forms the "Middle Paleocene".
Stratigraphic definition
The Selandian was introduced in scientific literature by Alfred Rosenkrantz in 1924. It is named after the DanishDenmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
island of Zealand (Danish
Danish language
Danish is a North Germanic language spoken by around six million people, principally in the country of Denmark. It is also spoken by 50,000 Germans of Danish ethnicity in the northern parts of Schleswig-Holstein, Germany, where it holds the status of minority language...
: Sjælland).
The base of the Selandian is close to the boundary between biozone
Biozone
Biostratigraphic units or Biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa....
s NP4 and NP5. It is slighltly after the first appearances of many new species of the calcareous nannoplankton genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Fasciculithus (F. ulii, F. billii, F. janii, F. involutus, F. tympaniformis and F. pileatus) and close to the first appearance of calcareous nannoplankton species Neochiastozygus perfectus. At the original type location
Type locality (geology)
Type locality , also called type area or type locale, is the where a particular rock type, stratigraphic unit, fossil or mineral species is first identified....
in Denmark the base of the Selandian is an unconformity
Unconformity
An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...
. The official GSSP was established in the Zumaia
Zumaia
Zumaia is a small town in the north of Spain in the Basque Country. The Mayor is Iñaki Agirrezabala, member of Eusko Alkartasuna and Gazte Abertzaleak....
section (43° 18'N, 2° 16'W) at the beach of Itzurun, Pais Vasco, northern Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
.
The top of the Selandian (the base of the Thanetian) is laid at the base of magnetic chronozone C26n.
The Selandian stage overlaps with the lower part of the Tiffanian
Tiffanian
The Tiffanian 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 60,200,000 to 56,800,000 years BP lasting . It is usually considered to overlap the Selandian and Thanetian within the...
North American Land Mammal Age, the Peligran
Peligran
The Peligran age is a period of geologic time within the Paleocene epoch of the Paleogene used more specifically with South American Land Mammal Ages. It follows the Tiupampan and precedes the Itaboraian age....
, Tiupampan
Tiupampan
The Tiupampan age is a period of geologic time within the Paleocene epoch of the Paleogene used more specifically with South American Land Mammal Ages. It precedes the Peligran age....
and lower Itaboraian
Itaboraian
The Itaboraian age is a period of geologic time within the Paleocene epoch of the Paleogene used more specifically with South American Land Mammal Ages. It follows the Peligran and precedes the Riochican age....
South American Land Mammal Ages and part of the Nongshanian Asian Land Mammal Age. It is coeval with the lower part of the Wangerripian stage from the Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n regional timescale.
Literature
; 2008: Foraminiferal and δ13C isotopic event-stratigraphy across the Danian-Selandian transition at Zumaya (northern Spain): chronostratigraphic implications, Terra Nova 20: pp 38-44., 2009: New high resolution calcareous nannofossil analysis across the Danian-Selandian transition at the Zumaia section: comparisons with South Tethys and Danish sections, Geologica Acta 7(1-2), pp 79-92.; 2004: A Geologic Time Scale 2004, Cambridge University PressCambridge University Press
Cambridge University Press is the publishing business of the University of Cambridge. Granted letters patent by Henry VIII in 1534, it is the world's oldest publishing house, and the second largest university press in the world...
.; 1920: En ny københavnsk Lokalitet for forsteningsførende Paleocæn, Meddelelser fra Dansk Geologisk Forening 5, pp. 1–10 (published March 1921). ; 1924: De københavnske Grønsandslag og deres Placering i den danske Lagrække. Meddelelser fra Dansk Geologisk Forening 6, pp. 1–39.
External links
- GeoWhen Database - Selandian
- Paleogene timescale, at the website of the subcommission for stratigraphic information of the ICS
- Stratigraphic chart of the Paleogene, at the website of Norges Network of offshore records of geology and stratigraphy