Central Atlantic Magmatic Province
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The Central Atlantic magmatic province (CAMP) was formed during the breakup of Pangaea during the Mesozoic Era. The initial breakup of Pangaea in early Jurassic time provided a legacy of basaltic dikes, sills, and lavas over a vast area around the present central North Atlantic Ocean.
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[edit] Connected magma flows
Although some connections among these basalts had long been recognized, in 1988 they were linked as constituting a single major flood basalt province(Rampino and Stothers). The basaltic sills of similar age (near 200 Ma, or earliest Jurassic) and composition (intermediate-Ti quartz tholeiite) which occur across the vast Amazon River basin of Brazil were linked to the province in 1999(Marzoli et al.).
[edit] Geographical extent
The province has been described as extending within Pangaea from present-day central Brazil northeastward about 5000 km across western Africa, Iberia, and northwestern France, and from the interior of western Africa westward for 2500 km through eastern and southern North America(McHone).
If not the largest Province by volume, the CAMP certainly encompasses the greatest area known, roughly 11 million km², of any continental large igneous province.
Nearly all CAMP rocks are tholeiitic in composition, with widely separated areas where basalt flows are preserved, as well as large groups of diabase (dolerite) sills or sheets, small lopoliths, and dikes throughout the province.
Dikes occur in very large individual swarms with particular compositions and orientations. CAMP activity is apparently related to the rifting and breakup of Pangaea during the Late Triassic through Early Jurassic periods, and the enormous province size, varieties of basalt, and brief time span of CAMP magmatism invite speculation about mantle processes that could produce such a magmatic event as well as rift a supercontinent(Wilson; McHone).
[edit] References
Articles and Research Papers
- Marzoli, A., P.R. Renne, E.M. Piccirillo, M. Ernesto, G. Bellieni, and A. De Min, 1999, Extensive 200 million-year-old continental flood basalts of the central Atlantic magmatic province: Science, v. 284, p. 616-618.
- McHone J.G., 2000, Non-plume magmatism and rifting during the opening of the Central Atlantic Ocean: Tectonophysics, v. 316, p. 287-296.
- Rampino, M.R., and R.B. Stothers, R.B., 1988, Flood basalt volcanism during the past 250 million years: Science, v. 241, p. 663-668.
- Wilson, M., 1997, Thermal evolution of the Central Atlantic passive margins: Continental break-up above a Mesozoic super-plume: J. Geol. Soc. London, v. 154, p. 491-495.
- Hames, W.E., McHone, J.G., Ruppel, C., and Renne, P., eds., 2003, The Central Atlantic Magmatic Province: American Geophysical Union Monograph 136, 267 p.
