Language:

Brittle faults are weak, yet the ductile middle crust is strong: Implications for lithospheric mechanics

Geophysical research letters, 2014-11, Vol.41 (22), p.8067-8075 [Peer Reviewed Journal]

2014. American Geophysical Union. All Rights Reserved. ;ISSN: 0094-8276 ;EISSN: 1944-8007 ;DOI: 10.1002/2014GL061349

Full text available

Citations Cited by

Actions
1. Add to My Research
2. Remove from My Research
3. E-mail
4. Print
5. Permalink
6. Citation
7. EasyBib
8. EndNote
9. RefWorks
10. Delicious
11. Export RIS
12. Export BibTeX

Title:
Brittle faults are weak, yet the ductile middle crust is strong: Implications for lithospheric mechanics
Author: Behr, Whitney M. ; Platt, John P.
Subjects: Bearing ; Boreholes ; Brittleness ; Continental crust ; crustal rheology ; Crustal stress ; Crusts ; Deformation ; Ductile brittle transition ; Estimates ; Failure ; fault friction ; Fault lines ; Fault location ; fault strength ; Fault zones ; Faults ; Fracture mechanics ; Friction ; Geological faults ; Lithosphere ; lithospheric strength ; Load bearing elements ; Mechanical stimuli ; Mechanics ; mylonites ; paleopiezometry ; Plate tectonics ; Rock ; Rocks ; Seismic phenomena ; Seismology ; Shear ; Shear stress ; Sliding friction ; Slip ; Slumping ; Strength ; Stresses ; Strike-slip faults ; Temperature ; Temperature effects ; Thrust
Is Part Of: Geophysical research letters, 2014-11, Vol.41 (22), p.8067-8075
Description: A global compilation of shear stress magnitude from mylonites developed along major fault zones suggests that maximum shear stresses between 80 and 120 MPa are reached at temperatures between 300 and 350°C on normal, thrust, and strike‐slip faults. These shear stresses are consistent with estimates of brittle rock strengths based on sliding friction (e.g., Byerlee's law), and with in situ measurements of crustal stress measured in boreholes. This confirms previous suggestions that in some areas at least, the continental crust is stressed close to failure down to the brittle‐ductile transition. Many major active faults in all tectonic regimes are considered to be relatively weak, however; peak static shear stresses for brittle faults estimated by a variety of techniques lie in the range of 1–50 MPa. The sharp contrast between static shear stresses estimated on the seismogenic parts of major faults and those estimated from steady‐state microstructures in ductile rocks immediately below the seismogenic zone suggests that there is an abrupt downward termination, probably controlled by temperature, of the weakening processes that govern fault behavior in the upper crust. These data also imply that seismogenic parts of major fault zones contribute little to lithospheric strength, and are unlikely to have much influence on either the slip rate or the location of the faults. Conversely, ductile middle crust immediately below the brittle‐ductile transition deforms at high stresses, and forms a significant load‐bearing element within the lithosphere. Key Points Stresses on major brittle faults are low but are high in the middle crustSeismogenic parts of major fault zones do not influence lithospheric strengthMiddle crust below the BDT forms a load‐bearing element within the lithosphere
Publisher: Washington: Blackwell Publishing Ltd
Language: English
Identifier: ISSN: 0094-8276
EISSN: 1944-8007
DOI: 10.1002/2014GL061349
Source: Wiley Blackwell AGU Digital Archive
Alma/SFX Local Collection

Back to results list


INSPIRE LIBRARY - TON DUC THANG UNIVERSITY	(84-028) 37 755 057	Feedback
19 Nguyen Huu Tho St. Dist.7, HCM	thuvien@tdtu.edu.vn	Feedback

Brittle faults are weak, yet the ductile middle crust is strong: Implications for lithospheric mechanics

2014. American Geophysical Union. All Rights Reserved. ;ISSN: 0094-8276 ;EISSN: 1944-8007 ;DOI: 10.1002/2014GL061349

Searching Remote Databases, Please Wait