Wikipedia

GSSP

boundary of a stage on the geologic time scale

A GSSP, more fully a Global Boundary Stratotype Section and Point, is an internationally agreed point which defines the start of a stage on the geologic time scale.

Many GSSPs are marked by golden spikes. This 'golden spike' marks the GSSP for the start of the Ediacaran.

The work is done by the International Commission on Stratigraphy, a part of the International Union of Geological Sciences. As of 2012, 64 of the 101 stages that need a GSSP have been decided.[1]

Rules for GSSP

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A geologic section has to follow the rules to be adapted as a GSSP by the ICS. The list below are the rules:[2][3]

  • A GSSP has to decide the lower boundary (start of a geological period) of a geologic stage.
  • The lower boundary (start of a geological period) has to be decided using a primary (main) marker (usually first appearance datum of a fossil specie).
    • There should also be secondary markers (other fossils, chemical, geomagnetic reversal).
    • The horizon in which the marker appears should have minerals that can be radiometrically dated.
    • The marker has to have regional and global correlation in outcrops of the same age
    • The marker should be independent of facies.
  • The outcrop has to have an acceptable thickness
  • Sedimentation has to be constant without any changes in facies
  • The outcrop should not be affected by tectonic and sedimentary movements, and metamorphism
  • The outcrop has to be accessible to research and free to access.
    • This includes that the outcrop has to be located where it can be visited quickly (International airport and good roads), has to be kept in good condition (Ideally a national reserve), in accessible terrain, extensive enough to allow repeated sampling and open to researchers of all nationalities.

List

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This list shows some of the GSSPs.

Period Epoch Age (mya) Status GSSP location Defining markers Geographic Coordinates References
Phanerozoic
Cainozoic
Quaternary
Holocene 0.117
 
 NGRIP2 ice core,

Greenland

75°06′00″N 42°19′12″W / 75.1000°N 42.3200°W / 75.1000; -42.3200 [4]
Pleistocene 2.588
 
 Monte San Nicola Section,

Sicily, Italy

37°08′49″N 14°12′13″E / 37.1469°N 14.2035°E / 37.1469; 14.2035 [5]
Neogene
Pliocene 5.333
 
 Heraclea Minoa section

Heraclea Minoa, Sicily, Italy

37°23′30″N 13°16′50″E / 37.3917°N 13.2806°E / 37.3917; 13.2806 [6]
Miocene 23.03
 
 Lemme-Carrosio Section,

Carrosio, Italy

44°39′32″N 8°50′11″E / 44.6589°N 8.8364°E / 44.6589; 8.8364 [7]
Palaeogene
Oligocene 33.9
 
 Massignano Section,

Massignano, Ancona, Italy

43°31′58″N 13°36′04″E / 43.5328°N 13.6011°E / 43.5328; 13.6011 [8]
Eocene 56
 
 Dababiya section,

Luxor, Egypt

  • Base of negative Carbon Isotope Excursion (CIE).
 25°30′00″N 32°31′52″E / 25.5000°N 32.5311°E / 25.5000; 32.5311 [9][10]
Palaeocene 66
 
 El Kef Section,

El Kef, Tunisia

36°09′13″N 8°38′55″E / 36.1537°N 8.6486°E / 36.1537; 8.6486 [11]
Mesozoic
Cretaceous
Upper Cretaceous 100.5
 
 Mont Risoux,

Hautes-Alpes, France

44°23′33″N 5°30′43″E / 44.3925°N 5.5119°E / 44.3925; 5.5119 [12]
Lower Cretaceous 145

Candidates:

  • Magnetic—base of Chron M18r
Jurassic
Upper Jurassic 163.5 Candidate sections:
Middle Jurassic 174.1
 
 Fuentelsaz, Spain 41°10′15″N 1°50′00″W / 41.1708°N 1.8333°W / 41.1708; -1.8333 [13]
Lower Jurassic 201.3
 
 Kuhjoch section, Karwendel mountains, Northern Calcareous Alps, Austria 47°29′02″N 11°31′50″E / 47.4839°N 11.5306°E / 47.4839; 11.5306
Triassic
Upper Triassic 235
 
 Prati di Stuores, Dolomites, Italy 46°31′37″N 11°55′49″E / 46.5269°N 11.9303°E / 46.5269; 11.9303 [14]
Middle Triassic 247.2 Candidate sections: 45°04′27″N 28°48′08″E / 45.0742°N 28.8022°E / 45.0742; 28.8022
Lower Triassic 252.2
 
 Meishan, Zhejiang, China 31°04′47″N 119°42′21″E / 31.0798°N 119.7058°E / 31.0798; 119.7058
Palaeozoic
Permian 298.9
 
 Aidaralash, Ural Mountains, Kazakhstan 50°14′45″N 57°53′29″E / 50.2458°N 57.8914°E / 50.2458; 57.8914 [15]
Carboniferous
Pennsylvanian 323.2
 
 Arrow Canyon, Nevada, USA 36°44′00″N 114°46′40″W / 36.7333°N 114.7778°W / 36.7333; -114.7778 [16]
Mississippian 358.9
 
 La Serre, Montagne Noire, France 43°33′20″N 3°21′26″E / 43.5555°N 3.3573°E / 43.5555; 3.3573 [17]
Devonian 419.2
 
 Klonk, Prague, Czech Republic 49°51′18″N 13°47′31″E / 49.8550°N 13.7920°E / 49.8550; 13.7920 [18]
Silurian 443.4
 
 Dob's Linn, Moffat, U.K. 55°26′24″N 3°16′12″W / 55.4400°N 3.2700°W / 55.4400; -3.2700 [19]
Ordovician 485.4
 
 Greenpoint section

Green Point, Newfoundland, Canada

49°40′58″N 57°57′55″W / 49.6829°N 57.9653°W / 49.6829; -57.9653 [20]
Cambrian 541
 
 Fortune head section,

Newfoundland, Canada

47°04′34″N 55°49′52″W / 47.0762°N 55.8310°W / 47.0762; -55.8310 [21]
Era Period Precambrian
Proterozoic
Neoproterozoic
Ediacaran 635
 
 Enorama Creek section

Flinders Ranges, South Australia

  • Worldwide distinct cap carbonates.
  • Beginning of a distinctive pattern of secular changes in carbon isotopes.
 31°19′53″S 138°38′00″E / 31.3314°S 138.6334°E / -31.3314; 138.6334 [22]
Cryogenian 850
 
 Defined chronometrically now. GSSP is in progress. [23]
Tonian 1000
 
 Defined chronometrically [23]
Mesoproterozoic
Stenian 1200
 
 Defined chronometrically [23]
Ectasian 1400
 
 Defined chronometrically [23]
Calymmian 1600
 
 Defined chronometrically [23]
Palaeoproterozoic
Statherian 1800
 
 Defined chronometrically [23]
Orosirian 2050
 
 Defined chronometrically [23]
Rhyacian 2300
 
 Defined chronometrically [23]
Siderian 2500
 
 Defined chronometrically [23]
Archaean & Hadean
Neoarchaean 2800
 
 [23]
Mesoarchaean 3200
 
 [23]
Palaeoarchaean 3600
 
 [23]
Eoarchaean 4000
 
 [23]
Hadean 4567
 
 [23]

Global Standard Stratigraphic Age (GSSAs)

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Because defining a GSSP depends on finding well-preserved geologic sections and identifying key events, this task becomes more harder as one goes farther back in time. Before 640 million years ago, boundaries on the geologic timescale are defined simply by reference to fixed dates, known as "Global Standard Stratigraphic Ages". The oldest GSSP is the one that marks the start of the Ediacaran at 635 million years ago.

References

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  1. ↑ "International Chronostratigraphic Chart 2012" (PDF). ICS. Retrieved 28 November 2012.
  2. ↑ Remane J. et al 1996. "Guidelines for the establishment of global chronostratigraphic standards by the International Commission on Stratigraphy (ICS)". Episodes. 19: 77–81. doi:10.18814/epiiugs/1996/v19i3/007.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  3. ↑ "GSSP Rules". Geologic Timescale Foundation.
  4. ↑ Walker, Mike et al 2009 (2009). "Formal definition and dating of the GSSP (Global Stratotype Section and Point) for the base of the Holocene using the Greenland NGRIP ice core, and selected auxiliary records". Journal of Quaternary Science. 24 (1): 3–17. Bibcode:2009JQS....24....3W. doi:10.1002/jqs.1227. S2CID 40380068.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  5. ↑ Rio, Domenico et al 1998 (1998). "The Gelasian Stage (Upper Pliocene): a new unit of the global standard chronostratigraphic scale". Episodes. 21 (2): 82–87. doi:10.18814/epiiugs/1998/v21i2/002.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  6. ↑ Couvering John A. Van et al 2000 (2000). "The base of the Zanclean Stage and of the Pliocene Series". Episodes. 23 (3): 179–187. doi:10.18814/epiiugs/2000/v23i3/005. S2CID 10836910.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  7. ↑ Steininger, Fritz F. et al 1997 (1997). "The Global Stratotype Section and Point (GSSP) for the base of the Neogene". Episodes. 20 (1): 23–28. doi:10.18814/epiiugs/1997/v20i1/005.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  8. ↑ Silva, Isabella Premoli; Jenkins, D Graham (1993). "Decision on the Eocene-Oligocene boundary stratotype". Episodes. 16 (3): 379–382. doi:10.18814/epiiugs/1993/v16i3/002.
  9. ↑ Dupuis C. et al 2003 (2003). "The Dababiya Quarry section: lithostratigraphy, clay mineralogy, geochemistry and paleontology". Micropaleontology. 49 (1): 41–59. doi:10.2113/49.Suppl_1.41. hdl:1912/5251.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  10. ↑ Aubry, Marie-Pierre et al 2007 (2007). "The Global Standard Stratotype-section and Point (GSSP) for the base of the Eocene Series in the Dababiya section (Egypt)". Episodes. 30 (4): 271–286. doi:10.18814/epiiugs/2007/v30i4/003.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  11. ↑ Molina, Eustoquio 2006; et al. "The Global Boundary Stratotype Section and Point for the base of the Danian Stage (Paleocene, Paleogene, "Tertiary", Cenozoic) at El Kef, Tunisia - Original definition and revision". Episodes. 29 (4): 263–278. doi:10.18814/epiiugs/2006/v29i4/004.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  12. ↑ Kennedy, W.J.; Gale, A.S.; Lees, J.A.; Caron, M. (2004). "The Global Boundary Stratotype Section and Point (GSSP) for the base of the Cenomanian Stage, Mont Risou, Hautes-Alpes, France". Episodes. 27 (1): 21–32. doi:10.18814/epiiugs/2004/v27i1/003.
  13. ↑ Cresta S. et al 2001 (2001). "The Global Boundary Stratotype Section and Point (GSSP) of the Toarcian-Aalenian Boundary (Lower-Middle Jurassic)". Episodes. 24 (3): 166–175. doi:10.18814/epiiugs/2001/v24i3/003.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  14. ↑ Mietto P. et al 2012 (2012). "The Global Boundary Stratotype Section and Point (GSSP) of the Carnian stage (Late Triassic) at Prati di Stuores/Stuores Wiesen section (Southern Alps, NE Italy)". Episodes. 35 (3): 414–430. doi:10.18814/epiiugs/2012/v35i3/003.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  15. ↑ Davydov, Vladimir I. et al 1998 (1998). "Proposal of Aidaralash as Global Stratotype Section and Point (GSSP) for base of the Permian System". Episodes. 21 (1): 11–18. doi:10.18814/epiiugs/1998/v21i1/003.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  16. ↑ Lane, H. Richard et al 1999. (1999). "The IUGS boundary in the middle of the Carboniferous: Arrow Canyon, Nevada, USA". Episodes. 22 (4): 272–283. doi:10.18814/epiiugs/1999/v22i4/003.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  17. ↑ Paproth, Eva et al 1991 (1991). "Decision on the Devonian - Carboniferous boundary stratotype". Episodes. 14 (4): 331–336. doi:10.18814/epiiugs/1991/v14i4/004.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  18. ↑ "Global Boundary Stratotype Section and Point". International Commission of Stratigraphy. Retrieved 14 September 2012.}
  19. ↑ Holland C.H. 1985 (1985). "Series and Stages of the Silurian System". Episodes. 8 (2): 101–103. doi:10.18814/epiiugs/1985/v8i2/005.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  20. ↑ Cooper R.A. et al 2001 (2001). "Global Stratotype Section and Point for base of the Ordovician System". Episodes. 24 (1): 19–28. doi:10.18814/epiiugs/2001/v24i1/005.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  21. ↑ Brasier, Martin; Cowie, John; Taylor, Michael (1994). "Decision on the Precambrian-Cambrian boundary stratotype". Episodes. 17 (1–2): 3–8. doi:10.18814/epiiugs/1994/v17i1.2/002.
  22. ↑ Knoll, Andrew et al 2006 (2006). "The Ediacaran Period: a new addition to the geologic time scale". Lethaia. 39 (1): 13–30. doi:10.1080/00241160500409223.{{cite journal}}: CS1 maint: numeric names: authors list (link)
  23. ↑ 23.00 23.01 23.02 23.03 23.04 23.05 23.06 23.07 23.08 23.09 23.10 23.11 23.12 23.13 Plumb, K. A. (1991). "New Precambrian timescale". Episodes. 14 (2): 139–140. doi:10.18814/epiiugs/1991/v14i2/005.
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