Serravallian

The Serravallian is in the geologic timescale an age or a stage in the middle Miocene epoch/series, that spans the time between 13.82 Ma and 11.63 Ma (million years ago). The Serravallian follows the Langhian and is followed by the Tortonian.[6]

Serravallian
13.82 – 11.63 Ma
Chronology
Neogene Graphical Timeline
-24 —
-22 —
-20 —
-18 —
-16 —
-14 —
-12 —
-10 —
-8 —
-6 —
-4 —
-2 —
North American prairie expands[2]
Subdivision of the Neogene according to the ICS, as of 2021.[3]
Vertical axis: millions of years ago.
Formerly part ofTertiary Period/System
Etymology
Geochronological nameFormal
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Definition
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionMi3b Oxygen-isotopic event (Global cooling episode)
Lower boundary GSSPRas il Pellegrin section, Fomm ir-Riħ Bay, Malta
35°54′50″N 14°20′10″E / 35.9139°N 14.3361°E / 35.9139; 14.3361
GSSP ratified2007[4]
Upper boundary definitionLAD of the Haptophyte Discoaster kugleri
Upper boundary GSSPMonte dei Corvi Beach section, Ancona, Italy
43°35′12″N 13°34′10″E / 43.5867°N 13.5694°E / 43.5867; 13.5694
GSSP ratified2003[5]

It overlaps with the middle of the Astaracian European Land Mammal Mega Zone, the upper Barstovian and lower Clarendonian North American Land Mammal Ages and the Laventan and lower Mayoan South American Land Mammal Ages. It is also coeval with the Sarmatian and upper Badenian stages of the Paratethys time scale of Central and eastern Europe.

DefinitionEdit

The Serravallian stage was introduced in stratigraphy by the Italian geologist Lorenzo Pareto in 1865.[7] It was named after the town of Serravalle Scrivia in northern Italy.

The base of the Serravallian is at the first occurrence of fossils of the nanoplankton species Sphenolithus heteromorphus and is located in the chronozone C5ABr. The official Global Boundary Stratotype Section and Point (GSSP) for the Serravallian is in the 'Ras il-Pellegrin' section, located at the 'Ras il-Pellegrin' headland in the vicinity of 'Fomm ir-Rih' Bay, SW Malta.The base of the Serravallian is represented in the field as the formation boundary between the Globigerina Limestone formation and the Blue Clay formation.[8] The base of the Serravallian is related to the Mi3b oxygen isotope excursion marking the onset of the Middle Miocene Cooling step.

The top of the Serravallian (the base of the Tortonian stage) is at the last common appearance of calcareous nannoplanktons Discoaster kugleri and planktonic foram Globigerinoides subquadratus. It is also associated with the short normal-polarized chronozone C5r.2n.

ReferencesEdit

NotesEdit

  1. ^ Krijgsman, W.; Garcés, M.; Langereis, C. G.; Daams, R.; Van Dam, J.; Van Der Meulen, A. J.; Agustí, J.; Cabrera, L. (1996). "A new chronology for the middle to late Miocene continental record in Spain". Earth and Planetary Science Letters. 142 (3–4): 367–380. Bibcode:1996E&PSL.142..367K. doi:10.1016/0012-821X(96)00109-4.
  2. ^ Retallack, G. J. (1997). "Neogene Expansion of the North American Prairie". PALAIOS. 12 (4): 380–390. doi:10.2307/3515337. JSTOR 3515337. Retrieved 2008-02-11.
  3. ^ "ICS Timescale Chart" (PDF). www.stratigraphy.org.
  4. ^ Hilgen, F. J.; H. A. Abels; S. Iaccarino; W. Krijgsman; I. Raffi; R. Sprovieri; E. Turco; W. J. Zachariasse (2009). "The Global Stratotype Section and Point (GSSP) of the Serravallian Stage (Middle Miocene)" (PDF). Episodes. 32 (3): 152–166. doi:10.18814/epiiugs/2009/v32i3/002. Retrieved 26 December 2020.
  5. ^ Hilgen, F. J.; Hayfaa Abdul Aziz; Bice, David; Iaccarino, Silvia; Krijgsman, Wout; Kuiper, Klaudia; Montanari, Alessandro; Raffi, Isabella; Turco, Elena; Willem-Jan Zachariasse (2005). "The Global boundary Stratotype Section and Point (GSSP) of the Tortonian Stage (Upper Miocene) at Monte Dei Corvi" (PDF). Episodes. 28 (1): 6–17. doi:10.18814/epiiugs/2005/v28i1/001. Retrieved 26 December 2020.
  6. ^ Gradstein et al. (2004)
  7. ^ Lorenzo Pareto, Note sur les subdivisions que l'on pourrait établir dans les terrains tertaires de l'Apennin septentrional In Bulletin de la Société Géologique de France, volume 22, série 2, pp. 210-277
  8. ^ <http://www.stratigraphy.org/gssp/>

LiteratureEdit

  • Gradstein, F.M.; Ogg, J.G. & Smith, A.G.; 2004: A Geologic Time Scale 2004, Cambridge University Press.
  • Pareto, L.; 1865: Note sur la subdivision que l'on pourrait etablir dans les terrains de l'Apennin septentrional, Bulletin de la Société Géologique de France 2(22), p. 210-277. (in French)

External linksEdit