TIME-DEPENDENT CRUSTAL TEMPERATURE MODELING - CENTRAL ALPS

Authors
Citation
V. Cermak et L. Bodri, TIME-DEPENDENT CRUSTAL TEMPERATURE MODELING - CENTRAL ALPS, Tectonophysics, 257(1), 1996, pp. 7-24
Citations number
42
Categorie Soggetti
Geochemitry & Geophysics
Journal title
ISSN journal
00401951
Volume
257
Issue
1
Year of publication
1996
Pages
7 - 24
Database
ISI
SICI code
0040-1951(1996)257:1<7:TCTM-C>2.0.ZU;2-6
Abstract
The conventional modeling of crustal temperatures is based on the stea dy-state approach, which is reliable in tectonically stable regions on ly. The present work focuses on the assessment of the influence of the transient effects on the thermal field at regions of ongoing continen tal collision. In the first part of this study, the thermal effects of most evident processes operating in collision zones (thickening and f laking of the crust, frictional heating on the surfaces of flakes, bul k replacement of mantle lithosphere by hotter rocks, and also uplift a nd erosion) are estimated on the basis of 1-D time-dependent synthetic models. The results show that surface heat flow caused by the most of investigated transient processes may differ from the steady-state one by quantities of the order of magnitude larger than the uncertainties of the heat flow measurements, These differences may exist over tens of millions of years. In the second part, three 2-D time-dependent tem perature sections gradually including the above assessed effects have been calculated for the Central Alps, The results show that time-depen dent models give better agreement of the calculated and measured heat flow patterns than previously developed for the same region steady-sta te model (Cermak et al., 1990). Best agreement is achieved when only t he transient effects of thickening and flaking and increased heat infl ow from the mantle are taken into account. A poorer coherence of the o ther versions with the measured heat flow is probably attributable to uncertain knowledge (and consequently great simplification) of spacing and time dependence of erosion and/or frictional heating.