HR: 1340h
AN: V13A-1454    [Abstracts]
TI: Steam Cooking of the Andes
AU: * Schilling, F R
EM: fsch@gfz-potsdam.de
AF: GFZ Potsdam, Department 4 Telegrafenberg, Potsdam, 14473 Germany
AU: Kukowski, N
AF: GFZ Potsdam, Department 4 Telegrafenberg, Potsdam, 14473 Germany
AU: Gottschalk, M
AF: GFZ Potsdam, Department 4 Telegrafenberg, Potsdam, 14473 Germany
AU: Tiwari, R
AF: GFZ Potsdam, Department 4 Telegrafenberg, Potsdam, 14473 Germany
AU: Ramelow, J
AF: GFZ Potsdam, Department 4 Telegrafenberg, Potsdam, 14473 Germany
AU: Knoll, M
AF: GFZ Potsdam, Department 4 Telegrafenberg, Potsdam, 14473 Germany
AB: Subduction related orogeny at the pacific margin has lead to one of the largest and highest plateaus on Earth - the Central Andes. This high plateau is characterized by geophysical anomalies, such as a high heat flow density exceeding 100 mW/m$^{2}$, a crustal thickness of about 70 km, a high Buguer anomaly, an extreme electrical conductivity anomaly, and low velocity zones. To better understand the underlying processes generating this high plateau, we need to identify and quantify the controlling parameters of the Andean evolution. It has been shown by Springer 1999 that conductive heat transfer alone is not able to explain the observed heat flow density. Babeyko et al. 2002 discuss additional heat flow through an enhanced mantle heat flux in addition to crustal convection. However, a portion of the observed heat flux remains still unresolved. We'll present a simple model to explain the observed heat flux by advective heat of water through the mantle wedge. Part of the high amount of fluids which is subducted with the down-going slab is released beneath the mantle wedge. The ascending water is heated by the hot mantle wedge. The fluid transports heat into the crust leading to an enhanced heat flow density. This steam cooking hypothesis leads to a number of consequences, which allows to explain the triggering of the Central Andean evolution, the high heat flux, partial melting of the crust, and the strong variation from North to South of geological, petrological, and geophysical observations. Babeyko, AY et al. (2002), EPSL, 199, 373-388 Springer M (1999) Tectonophysics, 306, 377-395
DE: 8450 Planetary volcanism (5480)
DE: 8100 TECTONOPHYSICS
DE: 8105 Continental margins and sedimentary basins
DE: 8125 Evolution of the Earth
DE: 3900 MINERAL PHYSICS
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting