Thermal models of core-complex evolution in Arizona and New Guinea: Implications for ancient cooling paths and present-day heat flow

Tectonics ◽  
1996 ◽  
Vol 15 (5) ◽  
pp. 933-951 ◽  
Author(s):  
Richard A. Ketcham
2004 ◽  
Vol 44 (3) ◽  
pp. 381-396 ◽  
Author(s):  
Ming-C. Cheng ◽  
Feixia Yu ◽  
Lin Jun ◽  
Min Shen ◽  
Goodarz Ahmadi

2009 ◽  
Vol 27 (6) ◽  
pp. 405-422 ◽  
Author(s):  
N. R. DACZKO ◽  
P. CAFFI ◽  
J. A. HALPIN ◽  
P. MANN

2018 ◽  
Vol 115 (46) ◽  
pp. 11706-11711 ◽  
Author(s):  
Matthew J. Kohn ◽  
Adrian E. Castro ◽  
Buchanan C. Kerswell ◽  
César R. Ranero ◽  
Frank S. Spear

Some commonly referenced thermal-mechanical models of current subduction zones imply temperatures that are 100–500 °C colder at 30–80-km depth than pressure–temperature conditions determined thermobarometrically from exhumed metamorphic rocks. Accurately inferring subduction zone thermal structure, whether from models or rocks, is crucial for predicting metamorphic reactions and associated fluid release, subarc melting conditions, rheologies, and fault-slip phenomena. Here, we compile surface heat flow data from subduction zones worldwide and show that values are higher than can be explained for a frictionless subduction interface often assumed for modeling. An additional heat source––likely shear heating––is required to explain these forearc heat flow values. A friction coefficient of at least 0.03 and possibly as high as 0.1 in some cases explains these data, and we recommend a provisional average value of 0.05 ± 0.015 for modeling. Even small coefficients of friction can contribute several hundred degrees of heating at depths of 30–80 km. Adding such shear stresses to thermal models quantitatively reproduces the pressure–temperature conditions recorded by exhumed metamorphic rocks. Comparatively higher temperatures generally drive rock dehydration and densification, so, at a given depth, hotter rocks are denser than colder rocks, and harder to exhume through buoyancy mechanisms. Consequently––conversely to previous proposals––exhumed metamorphic rocks might overrepresent old-cold subduction where rocks at the slab interface are wetter and more buoyant than in young-hot subduction zones.


1982 ◽  
Vol 87 (B8) ◽  
pp. 6711-6723 ◽  
Author(s):  
R. P. Von Herzen ◽  
R. S. Detrick ◽  
S. T. Crough ◽  
D. Epp ◽  
U. Fehn

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