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IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy (S) - IASPEI - International Association of Seismology and Physics of the Earth's Interior JSS013 Poster presentation 2235 Petrology and geochemistry of Kuhe - Dom Volcanic Rocks in Ardestan, central Iran Mrs. Neda Baranpourian geology Petrology IAGA Mohammad Hossain Razavi, Mohammad Hashem Emami The Eocene volcano - sedimentary Rocks of Kuhe - Dom are located in Urmiyeh - Dokhtar magmatic belt in the northeast of Ardestan district, central Iran. The stratigraphic sequence is composed of lower Eocene Gorgab and Middle Eocene sahlab formations. The volcanic Rocks are olivine basalt, basaltic andesite, trachy basalt, trachy andesite andesite, dacite, rhyodacite and rhyolite. The pyroclastics rocks are less common in this area and consist of various types of crystal lithic tuffs and bereccias, in which crystals are essentially plagioclases and lithic fragments mainly basaltic-andesites and trachy-basaltandesites. On the basis of trace and REE element diagrams, the Kuhe Dom rocks show characteristics of calcalkaline series. Petrological and geochemical investigations indicate that the Kuhe - Dom Volcanic Rocks are high k, Meta aluminous and are consistent to continental arc setting. Keywords: magmaticbelt, geochemistry, petrology

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy (S) - IASPEI - International Association of Seismology and Physics of the Earth's Interior JSS013 Poster presentation 2236 Modeling of the thermal structure of continental lithosphere Prof. Victor Kronrod Russian Academy of Sciences Vernadsky Institute of Geochemistry Tatiana Kronrod In this paper, a method is proposed for the calculation of the thermal regime of the crust and continental lithosphere (the temperature, heat flows, and heat generation). A specific feature of the method developed for solving the inverse thermophysical problem is the incorporation of constraints obtained from the seismic data inversion for the reconstruction of temperature. The input data are seismic velocities, surface heat flows, and the petrologic models of depleted garnet peridotites and fertile matter of the primitive mantle. We consider a region that comprises the crust (consisting of a few layers) and the lithosphere (where heat transfer is governed by the conductive mechanism). The thermal boundary of the lithosphere is defined by the intersection of the calculated temperature profile in the conductive region with the potential adiabat. The solution is divided into two stages. At the first stage, the temperature profile (T) is determined from absolute P and/or S wave velocities. The T profile is then adjusted to a thermophysical model of conductive transfer in the crust and mantle. Also at the second stage, the surface heat flow and the T profile are used to determine heat generation, the thicknesses of the crustal layers, and the heat flow components in the crust and lithosphere. The inverse problem of thermal conduction in a multilayer medium uses results of the temperature reconstruction by seismic data inversion. This allowed us to determine the analytical depth dependence of the temperature, the intensity of radiogenic heat sources in the crust, and the heat flow components in the crust and mantle. The procedure of converting seismic profiles into thermal ones is based on the equations of state of mantle material taking into account phase transformations and anharmonicity and anelasticity effects. To calculate the anelastic effects, a dimensionless coefficient is introduced into the standard procedure of calculating the Q factor; the value of this coefficient depends on the depth and is determined from the condition of minimization of a functional that characterizes the misfits between the temperature profile derived from the IASP91 model and the "average" geotherm for continents. We illustrate the application of our approach with the example of the lithosphere of the Archean Kaapvaal craton and the Earth's normal mantle (an "averaged" contemporary continental mantle). As a reference model, we take the model IASP91. In reconstructing the thermal regime and the thickness of the cratonic lithosphere, we use the BPI1A regional model. Our modeling results show good agreement with modem geothermal models. This work was supported by the Russian Foundation for Basic Research, project 06-05-64151. Keywords: temperature, lithosphere, seismic velocity

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