Karoo-Ferrar
{{short description|Two large igneous provinces in Southern Africa and Antarctica respectively}}
The Karoo and Ferrar large igneous provinces (LIPs), in Southern Africa and Antarctica respectively, collectively known as the Karoo-Ferrar, Gondwana,E.g. {{Harvnb|Elliot|Fleming|Foland|Zhang|2001}} or Southeast African LIP,E.g. {{Harvnb|Gohl|Uenzelmann-Neben|Grobys|2011}} are associated with the initial break-up of the Gondwana supercontinent at {{Circa}} {{Ma|183|{{Abbr|Ma|Million year ago}}}}.
Its flood basalt mostly covers South Africa and Antarctica, but portions extend further into southern Africa and into South America, India, Australia and New Zealand.{{Harvnb|Segev|2002|loc=Fig. 5, p. 176}}
Karoo-Ferrar formed just prior to the breakup of Gondwana in the Lower Jurassic epoch, about 183 million years ago;{{Cite journal|url=https://pubs.geoscienceworld.org/gsa/geology/article-abstract/24/6/535/190811/Synchronous-emplacement-of-Ferrar-and-Karoo?redirectedFrom=fulltext|title=Synchronous emplacement of Ferrar and Karoo dolerites and the early breakup of Gondwana|first1=John|last1=Encarnación|first2=Thomas H.|last2=Fleming|first3=David H.|last3=Elliot|first4=Hugh V.|last4=Eales|date=June 1, 1996|journal=Geology|volume=24|issue=6|pages=535–538|via=Silverchair|doi=10.1130/0091-7613(1996)024<0535:SEOFAK>2.3.CO;2}} this timing corresponds to the early Toarcian anoxic event and the Pliensbachian-Toarcian extinction.{{Harvnb|Jourdan|Féraud|Bertrand|Kampunzu|2005|loc=Relation with mass extinction, p. 748}} It covered about 3 x 106 km2.{{Harvnb|Jourdan|Féraud|Bertrand|Kampunzu|2005|loc=Geological setting, p. 745}} The total original volume of the flow, which extends over a distance in excess of 6000 km (4000 km in Antarctica alone), was in excess of 2.5 x 106 km3 (2.5 million cubic kilometres).{{Harvnb|Courtillot|Renne|2003|loc=The Karoo and Farrar provinces, p. 124}}
The Ferrar LIP is notable for long-distance transport and the Karoo LIP for its large volume and chemical diversity.
The igneous activity of the Karoo LIP began {{Circa}} {{Ma|204|Ma}} at the northern margin of the province. The long-lasting Chon-Aike Province in Patagonia, the Antarctic Peninsula, and Ellsworth Land was activated {{Circa}} {{Ma|190|Ma}} in an unstable tectonic environment in which both extension and subduction occurred. Chon-Aike had a peak between {{Ma|183|173|Ma}} but produced continued magmatism between {{Ma|168|141|Ma}}. By {{Ma|184|175|Ma}} the Karoo magmatism had spread to Namibia, Lesotho, Lebombo, and the Ferrar province in Antarctica. The Karoo LIP ended {{Ma|145|Ma}} with peripheral eruptions in Patagonia, the Antarctica Peninsula, northern South Africa, Kerala in India, and southeast Australia. The Karoo Province uplifted southern Africa c. {{Convert|1.5|km|abbr=on}} and broke East Gondwana (India, Antarctica, and Australia) away from West Gondwana (South America and Africa) beginning in the opening of the Weddell Sea.{{Harvnb|Segev|2002|loc=The first tectonomagmatic period in southern Gondwana – the Karoo province, pp. 175–176}}
In the Cretaceous, some 15 million years after the last Karoo eruption, renewed magmatism was initiated between Mary Byrd Land in Antarctica and New Zealand from where it spread along Gondwana's southern margin, from eastern Australia to the Antarctic Peninsula. Isotopic dating suggests a series of igneous events at 133–131, 124–119, and 113–107 Ma in Australia; 110–99 Ma in Mary Byrd Land; 114-109 and 82 Ma in New Zealand; and 141 and 127 Ma in the Antarctic Peninsula. This phase of magmatism resulted in extension and rift between Australia and Antarctica, Australia and Lord Howe Rise, and Mary Byrd Land and New Zealand.{{Harvnb|Segev|2002|loc=The Cretaceous Marie Byrd Land – Eastern Australia province, pp. 176–178}}
Ferrar Supergroup
According to Robert John Pankhurst, "The Ferrar Supergroup is well known as being representative of a Middle Jurassic (and partly later), Gondwana-wide continental flood basalts event which includes Tasmanian dolerites, the Karoo Supergroup of southern Africa and the Serra Geral basalts of central South America." These continental tholeiites are indicative of a large-scale extensional rift system and associated Middle Jurassic magmatic activity linked to the break-up of Gondwana 25 m.y. later, when East Antarctica separated from Africa, and the Mozambique Basin opened. Included in the supergroup are the Ferrar Dolerite sills and dykes, the Kirkpatrick Basalts, and the volcanogenic Carapace Sandstone and Mawson Formation.{{cite book |last1=Pankhurst |first1=R.J. |last2=Storey |first2=B.C. |last3=Millar |first3=I.L. |editor1-last=Thomson |editor1-first=M.R.A. |editor2-last=Crame |editor2-first=J.A. |editor3-last=Thomson |editor3-first=J.W. |title=Magmatism related to the break-up of Gondwana, in Geological Evolution of Antarctica |date=1991 |publisher=Cambridge University Press |location=Cambridge |isbn=9780521372664 |pages=577–578}}{{cite book |last1=Tingey |first1=R.J. |editor1-last=Tingey |editor1-first=Robert |title=Mesozoic tholeiitic igneous rocks in Antarctica: the Ferrar (Super) Group and related rocks, in The Geology of Antarctica |date=1991 |publisher=Clarendon Press |location=Oxford |isbn=0198544677 |pages=153–174}}{{cite journal |last1=Riley |first1=Teal |last2=Flowerdew |first2=Michael |last3=Pankhurst |first3=Robert |last4=Curtis |first4=Mike |last5=Millar |first5=Ian |last6=Fanning |first6=C. Mark |last7=Whitehouse |first7=Martin |title=Early Jurassic magmatism on the Antarctic Peninsula and potential correlation with the Subcordilleran plutonic belt of Patagonia |journal=Journal of the Geological Society |date=2017 |volume=174 |issue=2 |pages=365–376 |doi=10.1144/jgs2016-053 |bibcode=2017JGSoc.174..365R |s2cid=132402764 |url=https://www.bas.ac.uk/data/our-data/publication/early-jurassic-magmatism-on-the-antarctic-peninsula-and-potential-correlation/ |access-date=17 December 2019}}{{cite book |last1=Barrett |first1=P.J. |editor1-last=Tingey |editor1-first=Robert |title=The Devonian to Jurassic Beacon Supergroup of the Transantarctic Mountains and correlatives in other parts of Antarctica, in The Geology of Antarctica |date=1991 |publisher=Clarendon Press |location=Oxford |isbn=0198544677 |pages=122–123, 129, 145}}
See also
- {{annotated link|Discovery Seamounts}}
- Chon Aike Formation
References
; Notes
{{Reflist}}
; Sources
{{Refbegin}}
- {{Cite journal
| last1 = Courtillot | first1 = V. E.
| last2 = Renne | first2 = P. R.
| title = On the ages of flood basalt events (Sur l'âge des trapps basaltiques)
| year = 2003 | journal = Comptes Rendus Geoscience | volume = 335 | issue = 1 | pages = 113–140
| url = http://www.mantleplumes.org/WebDocuments/CourtRenne2003.pdf | access-date = 8 August 2015
| doi = 10.1016/S1631-0713(03)00006-3 | bibcode = 2003CRGeo.335..113C| citeseerx = 10.1.1.461.3338
}}
- {{Cite conference
| last1 = Elliot | first1 = D. H.
| last2 = Fleming | first2 = T. H.
| last3 = Foland | first3 = I. C. A.
| last4 = Zhang | first4 = X.
| title = Establishing contemporaneity and duration of magmatism in the Jurassic Gondwana Large Igneous Province
| year = 2001 | conference = Earth System Processes – Global Meeting | location = Edinburgh
| url = https://gsa.confex.com/gsa/2001ESP/finalprogram/abstract_7930.htm | access-date = 13 January 2018
}}
- {{Cite journal
| last1 = Gohl | first1 = K.
| last2 = Uenzelmann-Neben | first2 = G.
| last3 = Grobys | first3 = N.
| title = Growth and dispersal of a southeast African large igneous province
| year = 2011 | journal = South African Journal of Geology | volume = 114 | issue = 3–4 | pages = 379–386
| url = http://epic.awi.de/23393/1/Gohl-etal_Mozambique-Ridge_SAJG_2011.pdf | access-date = 13 January 2018
| doi = 10.2113/gssajg.114.3-4.379 | bibcode = 2011SAJG..114..379G
}}
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| last1 = Jourdan | first1 = F.
| last2 = Féraud | first2 = G.
| last3 = Bertrand | first3 = H.
| last4 = Kampunzu | first4 = A. B.
| last5 = Tshoso | first5 = G.
| last6 = Watkeys | first6 = M. K.
| last7 = Le Gall | first7 = B.
| title = Karoo large igneous province: Brevity, origin, and relation to mass extinction questioned by new 40Ar/39Ar age data
| year = 2005 | journal = Geology | volume = 33 | issue = 9 | pages = 745–748
| url = http://www.colby.edu/academics_cs/courses/GE127/upload/JourdanEtAl2005_KarooIgneous.pdf | access-date = 11 January 2018
| doi = 10.1130/G21632.1 | bibcode = 2005Geo....33..745J}}
- {{Cite journal
| last = Segev | first = A.
| title = Flood basalts, continental breakup and the dispersal of Gondwana: evidence for periodic migration of upwelling mantle flows (plumes)
| year = 2002 | journal = European Geosciences Union. Stephan Mueller Special Publication Series, 2 | volume = 2
| pages = 171–191
| doi = 10.5194/smsps-2-171-2002
| url = http://www.stephan-mueller-spec-publ-ser.net/2/171/2002/smsps-2-171-2002.pdf | access-date =8 August 2015
| bibcode = 2002SMSPS...2..171S | doi-access = free
}}
{{Refend}}
{{coord missing|South Africa}}
{{Large igneous provinces}}
Category:Large igneous provinces
Category:Volcanism of Antarctica
Category:Volcanism of Australia (continent)
Category:Volcanism of South Africa