TY - JOUR
T1 - Role of horizontal thermal conduction and finite time thrust emplacement in simulation of pressure-temperature-time paths
AU - Ruppel, C.
AU - Hodges, K. V.
N1 - Funding Information:
Steve Lucas' review of a related manuscript provided the impetus for this study, and we thank K. Furlong for a number of reviews which have encouraged us to examine the 2D problem thoroughly over the years. We thank M. Kohn, N. Sleep, A. Macfarlane, G. Jaroslaw and D. Walker for comments which improved the paper. L. Roy-den first suggested to us the importance of simultaneous thrusting and erosion and pointed out the importance of the ratio of thermal gradients in the vicinity of the fault. Partial salary support for C.R. was provided by a Woods Hole Oceanographic Institution postdoctoral fellowship. This is WHOI contribution 8639.
Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1994/5
Y1 - 1994/5
N2 - Comparison of metamorphic thermal histories produced by (1) one- vs. two-dimensional conductive models and (2) instantaneous vs. finite emplacement time thrusting indicates that the simple 1D or instantaneous models applied by many petrologists generally produce pressure-temperature (PT) paths with topologies similiar to those generated by 2D, time-transitive models. However, maximum temperatures attained by footwall rocks are significantly lower in 1D than in 2D conductive models, leading us to recommend that 2D thermal effects be incorporated into models whenever possible. PT paths produced by instantaneous and finite-duration thrust emplacement differ significantly during the synthrusting period, but the peak metamorphic conditions (TMAX and pressure at TMAX) eventually attained by footwall rocks during erosional unroofing are the same within minimum analytical uncertainties ( ± 50 K, ± 100 MPa) on geothermobarometric data. Thus, if erosion begins only after the end of the thrusting event, instantaneous thrusting is a reasonable simplifying assumption that introduces relatively little inaccuracy into PT models devised to examine peak metamorphic conditions.
AB - Comparison of metamorphic thermal histories produced by (1) one- vs. two-dimensional conductive models and (2) instantaneous vs. finite emplacement time thrusting indicates that the simple 1D or instantaneous models applied by many petrologists generally produce pressure-temperature (PT) paths with topologies similiar to those generated by 2D, time-transitive models. However, maximum temperatures attained by footwall rocks are significantly lower in 1D than in 2D conductive models, leading us to recommend that 2D thermal effects be incorporated into models whenever possible. PT paths produced by instantaneous and finite-duration thrust emplacement differ significantly during the synthrusting period, but the peak metamorphic conditions (TMAX and pressure at TMAX) eventually attained by footwall rocks during erosional unroofing are the same within minimum analytical uncertainties ( ± 50 K, ± 100 MPa) on geothermobarometric data. Thus, if erosion begins only after the end of the thrusting event, instantaneous thrusting is a reasonable simplifying assumption that introduces relatively little inaccuracy into PT models devised to examine peak metamorphic conditions.
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U2 - 10.1016/0012-821X(94)90256-9
DO - 10.1016/0012-821X(94)90256-9
M3 - Article
AN - SCOPUS:0028193790
SN - 0012-821X
VL - 123
SP - 49
EP - 60
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
IS - 1-3
ER -