427.4 ± 0.5 – 425.6 ± 0.9 Ma
Geology of Asia 425Ma.jpg
Paleogeography of the late Gorstian, 425 Ma
Name formalityFormal
Name ratified1980[4]
Usage information
Celestial bodyEarth
Regional usageGlobal (ICS)
Time scale(s) usedICS Time Scale
Chronological unitAge
Stratigraphic unitStage
Time span formalityFormal
Lower boundary definitionFAD of the graptolite Saetograptus (Colonograptus) varians
Lower boundary GSSPPitch Coppice, Ludlow, U.K.
52°21′33″N 2°46′38″W / 52.3592°N 2.7772°W / 52.3592; -2.7772
GSSP ratified1980[4]
Upper boundary definitionImprecise. Near FAD of the graptolite Saetograptus leintwardinensis
Upper boundary definition candidatesNone
Upper boundary GSSP candidate section(s)None
Upper boundary GSSPSunnyhill, Ludlow, England
52°21′33″N 2°46′38″W / 52.3592°N 2.7772°W / 52.3592; -2.7772
GSSP ratified1980[4]

In the geologic timescale, the Gorstian is an age of the Ludlow Epoch of the Silurian Period of the Paleozoic Era of the Phanerozoic Eon that is comprehended between 427.4 ± 0.5 Ma and 425.6 ± 0.9 Ma (million years ago), approximately. The Gorstian Age succeeds the Homerian Age and precedes the Ludfordian Age.[5] The age is named after Gorsty village southwest of Ludlow. The base of the age is marked by Graptolites tumescens and Graptolites incipiens. The type section is located in a quarry in the Elton Formation at Pitch Coppice, Shropshire, United Kingdom.[6]


  1. ^ Jeppsson, L.; Calner, M. (2007). "The Silurian Mulde Event and a scenario for secundo—secundo events". Earth and Environmental Science Transactions of the Royal Society of Edinburgh. 93 (02): 135–154. doi:10.1017/S0263593300000377.
  2. ^ Munnecke, A.; Samtleben, C.; Bickert, T. (2003). "The Ireviken Event in the lower Silurian of Gotland, Sweden-relation to similar Palaeozoic and Proterozoic events". Palaeogeography, Palaeoclimatology, Palaeoecology. 195 (1): 99–124. doi:10.1016/S0031-0182(03)00304-3.
  3. ^ "Chart/Time Scale". www.stratigraphy.org. International Commission on Stratigraphy.
  4. ^ a b c Holland, C. (1982). "The State of Silurian Stratigraphy" (PDF). Episodes. 1982: 21–23. Retrieved 11 December 2020.
  5. ^ Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. (2004). A Geologic Time Scale 2004. ISBN 9780521786737.
  6. ^ Silurian System