HR: 13:55h
AN: V33G-02    [Abstracts]
TI: The North Atlantic Igneous Province: Computer Modeling of Hot Spots for the Icelandic Convective System
AU: * Rakhmenkoulova, I F
EM: iraida0205@yahoo.com
AF: Institute of Geology, Koptyug Pr.3, Novosibirsk, 630090 Russian Federation
AU: * Rakhmenkoulova, I F
EM: iraida0205@yahoo.com
AF: Novosibirsk State University, Pyrogova,2, Novosibirsk, 630090 Russian Federation
AU: Perepechko, Y V
AF: Institute of Geology, Koptyug Pr.3, Novosibirsk, 630090 Russian Federation
AU: Sharapov, V N
AF: Institute of Geology, Koptyug Pr.3, Novosibirsk, 630090 Russian Federation
AU: Sharapov, V N
AF: Novosibirsk State University, Pyrogova,2, Novosibirsk, 630090 Russian Federation
AU: Perepechko, L N
AF: Institute of Thermophysics, Pr. Lavrentyeva, 1, Novosibirsk, 630090 Russian Federation
AB: North Atlantic Igneous Province can be regarded as unique natural laboratory. Besides, it is a one of the most studied regions. The paper deals with the dynamics of rock melting in the upper mantle under Iceland, when a mantle plume develops above a hot spot. Our 2D convection codes `Maix2D' allow us to simulate the evolution of magmatic system. Mathematical model is based on the extended Boussinesq approximation. Four solid-state phase transitions have been taken into account in the equation of state. This allowed us to give a realistic description for the ashenosphere development and further evolution of the magmatic system. For the Icelandic Convective System heat-mass transfer processes of the magmatic system and the data of the melting zone have been computed. Temperature distribution with depth in the upper mantle was taken in such a way, that convection was developing without melting in the absence of a hot spot. For the lowest degree of melting the temperature inside the hot spot was taken $1850-1900 {\deg}C$. Several numerical experiments for various temperatures and sizes of hot spots as well as the lithosphere thicknesses have been computed. The results show that in the presence of a hot spot a zone of melting (asthenosphere) develops. The existence time for this zone is about $10-25 Ma$ (depending on the initial conditions), which is in agreement with the observed data for the Icelandic Convective System. The codes allowed us to compute the degree of melting, the location, size and geometry, the chemical composition, and the existence time of the asthenosphere. This work was supported by the RFBR (Grant No. 04-05-64107), the Ministry of Science of Russian Federation (the State Contract No. 43.043.1.1.1601), the Presidium of SB RAS (grant No. 106), the President Grants (NSh-2118.2003.5, NSh-1573.2003.5).
DE: 3210 Modeling
DE: 3230 Numerical solutions
DE: 1749 Volcanology, geochemistry, and petrology
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting