Investigations of Intraplate Volcanism: Caribbean Large Igneous Province, Galapagos Plume-Ridge Interaction and Eastern North Atlantic Volcanism
Final Report Abstract
The studies focused on intraplate volcanism and included carbonatitic volcanism in High Atlas, Hf isotopic composition of volcanism in the eastern North Atlantic, origin and evolution of the Manihiki and Hikurangi Plateaus in the SW Pacific, plume-ridge interaction at the Galapagos Spreading Center and along the southern Mid-Atlantic Ridge and interaction of the Galapagos Hotspot tracks with the Central America subduction zone. Some of the major results of these projects include: 1) relationship between carbonatite volcanism in the High Atlas and the Canary Island hotspot, 2) evidence for a common “C” type component in eastern North Atlantic intraplate volcanism, 3) similarity in age (c. 117- 125 Ma) and chemical composition (FOZO-EM1 mixture) of the Hikurangi and Manihiki to the Ontong Java plateaus, suggesting that they were also part of the Greater Ontong Java Event and that this massive event covered ~1% of the Earth’s surface with volcanism, 4) derivation of the “Greater Ontong Java Event from a stalled plume head at the transition zone between the upper and lower mantle, 5) distinct HIMU-type chemical composition of later (c. 86-99 Ma) seamount volcanism on the Hikurangi Plateau, 6) similar age and composition of Hikurangi seamount volcanism to Cretaceous mafic volcanism on New Zealand, consistent with a HIMU-plume event (<100 Ma) having triggered the last phase of break-up of Gondwana (separation of Antarctica and Zealandia fragments), 7) new constraints on the interaction of the zoned Galapagos plume with the Cocos-Nazca (Galpagos) spreading center, 8) model for the origin of alkalic and adakitic volcanism in Panama, Costa Rica and the Nicaraguan backarc, znd 9) new evidence for complex chemical heterogeneities along the Southern Mid-Atlantic Ridge between 7-12°S.
Publications
- (2010) Age and Geochemistry of Volcanic Rocks from the Hikurangi and Manihiki Oceanic Plateaus. Geochimica et Cosmochimica Acta 74: 7196-7219
Hoernle K, Hauff F, van den Bogaard P, Werner R, Mortimer N, Geldmacher J, Garbe- Schönberg D, Davy B
(See online at https://doi.org/10.1016/j.gca.2010.09.030) - (2011) Hafnium isotopic variations in East Atlantic intraplate volcanism. Contrib. Mineral. Petrol.
Geldmacher J, Hoernle K, Hanan BB, Blichert-Toft J, Hauff F, Gill JB, Schmincke H- U
(See online at https://doi.org/10.1007/s00410-010-0580-5)
