August 2009 LIP of the Month

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Large Igneous Provinces (LIPs) and Carbonatites

R.E. Ernst (1), K. Bell (2)

(1) Dept. of Earth Sciences, University of Ottawa, Ottawa, CANADA K1N 6N5; Richard.Ernst@ErnstGeosciences.com

(2) Dept. of Earth Sciences, Carleton University, Ottawa, ON, CANADA K1S 5B6; kib@magma.ca

Extracted and modified from Ernst and Bell (2009)

Increasing evidence suggests that many carbonatites (magmatic rocks with >50% carbonate) are plume-related and linked both spatially and temporally with large igneous provinces (LIPs), i.e. high volume, short duration, intraplate-type, magmatic events consisting mainly of flood basalts and their plumbing systems. Because carbonatites are found in all continents, including Antarctica, and range in age from 3.0 Ga to present they make ideal probes for monitoring the secular evolution of the mantle.

Examples of LIP-carbonatite associations (Figs. 1, 2 and 3) include: i. the 66 Ma Deccan flood basalt province associated with the Amba Dongar, Sarnu-Dandali (Barmer), and Mundwara carbonatites and associated alkali rocks, ii. the 130 Ma Paraná-Etendeka (e.g. Jacupiranga, Messum); iii. the 250 Ma Siberian LIP that includes a major alkaline province, Maimecha-Kotui with numerous carbonatites, iv. the ca. 370 Ma Kola Alkaline Province coeval with basaltic magmatism widespread the East European craton (EEC), and v. the 615–555 Ma CIMP (Central Iapetus Magmatic Province) of eastern Laurentia and western Baltica. In the > 2500 Ma Superior craton, Canada, a number of carbonatites are associated with the 1115–1085 Ma Keweenawan LIP and some are coeval with pan-Superior ca. 1870 Ma mafic- ultramafic magmatism. In addition, the Phalaborwa and Shiel carbonatites are spatially and temporally associated with the ca. 2060 Ma Bushveld event of the Kaapvaal craton.

The frequency of this LIP-carbonatite association suggests that LIPs and carbonatites might be considered as different evolutionary ‘pathways’ in a single magmatic process/system involving different degrees of partial melting. The low degrees of partial melting needed to generate low viscosity, carbonated melts, coupled with their rapid migration to the surface, makes them ideal indicators of thermal instablities in the mantle. Carbonatites thus might mark the low temperature, peripheral parts of plume activity whereas higher degress of melting closer to the centre result in flood basalts and associated magmatism. The isotopic mantle components FOZO, HIMU, EM1 but not DMM, along with primitive noble gas signatures in some carbonatites, suggest a sub-lithospheric mantle source for carbonatites, consistent with a plume/asthenospheric upwelling origin proposed for many LIPs.


Figure 1: Generalized location of the LIP events presented in Figure 2 and discussed in the text. Each outlined area encloses flood basalts, dyke swarms, sill provinces, and other mainly mafic magmatism belonging to a LIP. Diamonds schematically mark individual and groups of associated carbonatites. Colours for LIPs and associated carbonatites match, and separate events are set in different colours to distinguish them.

  
  

  
  
Figure 2: Summary of age distribution of carbonatites with respect to main episodes of LIP events (grey bars). Age bars based on best ages compiled in Table 1 of Ernst and Bell (2009). Age bars show range based on given +/−2 sigma uncertainties, or given ranges. In cases in which an uncertainty is not provided, a value of +/−10 Ma is arbitrarily assigned, which is high but appropriately conservative. U-Pb, Ar-Ar and Rb-Sr ages are considered more reliable and are presented as filled rectangles. K-Ar and fission track ages are left as open rectangles. After Figure 2 in Ernst and Bell (2009).


Figure 3: Example of the Keweenawan LIP (grey shading) and associated carbonatites (solid circles) and alkaline complexes (open circles) of the Great Lakes region of south central Canada and north central USA. See Figure 1 for general location. Carbonatites complexes are labelled as follows: BBH = Big Beaver House, SL = Schryburt Lake, SI = Sullivan Island, SeL = Seabrook Lake, VT = Valentine Township (Valentine), FR = Firesand River, PL = Prairie Lake, CL = Chipman Lake. Information on the carbonatites and alkaline complexes compiled from Woolley and Kjarsgaard (2008) and Sage (1991). Red star and circle locate inferred centre and 1000 km radius of underlying mantle plume ~1100 Ma ago. Boundaries of USA states and Canadian Provinces shown. Modified after Figure 9 in Ernst and Bell (2009).

REFERENCE FOR FULL DETAILS:

Ernst, R.E. and Bell, K. (2009) Large Igneous Provinces (LIPs) and carbonatites. Mineralogy and Petrology (in press), doi 10.1007/s00710-009-0074-1

SELECTED CARBONATITE REFERENCES

Bailey, D. (1993) Carbonate magmas: Journal of the Geological Society of London 150: 637-651.

Bell, K. (2001) Carbonatites: Relationships to mantle plume activity. In: Ernst R.E., Buchan, K.L. (eds) Mantle Plumes: Their Identification Through Time. Geological Society of America Special Paper 352, pp.267-290

Bell, K., Rukhlov, A.S. (2004) Carbonatites from the Kola Alkaline Province: Origin, evolution and source characteristics. In: Zaitsev, A., Wall, F., (eds) Phoscorites and Carbonatites from Mantle to Mine: the key example of the Kola Alkaline Province, Mineralogical Society Series 10, London, pp 421-455

Bell, K., Simonetti, A. (1996) Carbonatite magmatism and plume activity: implications from the Nd, Pb and Sr isotope systematics of Oldoinyo Lengai, Journal of Petrology, 37: 1321-1339.

Bell, K., Simonetti, A. (2009) Source of parental melts to carbonatites - critical isotopic constraints. Mineralogy and Petrology, (in press), doi 10.1007/s00710-009-0059-0

Bell, K., Tilton, G.R. (2002) Probing the mantle: the story from carbonatites. EOS, American Geophysical Union, 83:273, 276-277

Gerlach, D.C., Cliff, R.A., Davies, G.R., Norry, M., Hodgson, N. (1988) Magma sources of the Cape Verdes archipelago: isotopic and trace element constraints: Geochimica et Cosmochimica Acta, 52: 2979-2992.

Sage, R.P. (1991) Alkalic rock, carbonatite and kimberlite complexes of Ontario, Superior Province, In: Thurston, P.C., Williams, H.R., Sutcliffe, R.H., Stott GM (eds.) Geology of Ontario, Part 1, Ontario Geological Survey, Special Volume, Part 1, pp. 683-709.

Simonetti, A., Bell, K., Viladkar, S. (1995) Isotopic data from the Amba Dongar carbonatite complex, west-central India: evidence for an enriched mantle source. Chemical Geology (Isotope Geoscience Section), 122: 185-198.

Simonetti, A., Goldstein, S.L., Schmidberger, S.S., Viladkar, S.G. (1998) Geochemical and Nd, Pb, and Sr isotope data from Deccan alkaline complexes-inferences for mantle sources and plume-lithosphere interaction. Journal of Petrology, 39:1847-1864

Stoppa, F. (2007) CO2 magmatism in Italy: from deep carbon to carbonatite volcanism. In: Vladykin NV (ed) Alkaline Magmatism, its sources and plumes, Proceedings of VI International Workshop, Irkutsk and Napoli, pp 109-126

Woolley, A.R., Kjarsgaard, B.A. (2008) Carbonatite occurrences of the world: map and database. Geological Survey of Canada Open File 5796.

SELECTED LIP REFERENCES

Bryan, S.E., Ernst, R.E. (2008). Revised Definition of Large Igneous Provinces (LIPs) . Earth-Science Reviews, 86: 175-202.

Coffin, M.F., Eldholm, O. (1994). Large igneous provinces: crustal structure, dimensions, and external consequences. Reviews of Geophysics, 32: 1-36.

Coffin, M.F., Eldholm, O. (2001). Large igneous provinces: progenitors of some ophiolites? In: Ernst, R.E. and Buchan, K.L. (eds.). Mantle Plumes: Their Classification Through Time Geological Society of America Special Paper 352, pp. 59-70.

Coffin, M.F., Eldholm, O., (2005). Large igneous provinces. In: R.C. Selley, R.C., Cocks, L.R.M., Plimer, I.R. (eds.). Encyclopedia of Geology. Elsevier, Oxford, pp. 315-323.

Courtillot, V.E., Renne, P.R. (2003). On the ages of flood basalt events. C.R. Geoscience, 335: 113-140, doi: 10.1016/S1631-0713(03)00006-3.

Courtillot, V., Jaupart, C., Manighetti, I., Tapponier, P., Besse, J. (1999). On causal links between flood basalts and continental break-up. Earth and Planetary Science Letters, 166: 177-195.

Ernst, R.E., Buchan, K.L., (2001). Large mafic magmatic events through time and links to mantle-plume heads. In: Ernst., R.E., Buchan, K.L. (eds.) Mantle Plumes: Their Identification Through Time. Geological Society of America Special Paper 352, pp. 483- 575.

Ernst, R.E., Buchan, K.L., Campbell, I.H. (2005). Frontiers in Large Igneous Province research. Lithos, 79: 271-297.

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