Evidence for shear heating, Musgrave Block, central Australia

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dc.contributor.authorCamacho, A
dc.contributor.authorMcDougall, Ian
dc.contributor.authorArmstrong, Richard
dc.contributor.authorBraun, Jean
dc.date.accessioned2015-12-13T23:20:37Z
dc.date.issued2001
dc.date.updated2015-12-12T09:03:53Z
dc.description.abstractThe phenomenon of shear-heating is generally difficult to recognise from petrologic evidence alone. Establishing that shear zones attain higher temperatures than the surrounding country rocks requires independent evidence for temperature gradients. In the Musgrave Block, central Australia, there is a clear spatial association between shear zones and interpreted elevated temperatures. Eclogite facies shear zones that formed at ~ 550 Ma record temperatures of ~650-700°C. Outside the high-pressure shear zones, minerals with low closure temperatures such as biotite (~450°C in the 40Ar-39Ar and Rb-Sr systems), preserve ages >800 Ma, suggesting that these rocks did not experience temperatures greater than about 450°C at ~550 Ma for any extended period. Thus, the shear zones record temperatures that are ~200°C higher than the surrounding country rocks. Simple calculations show that the combination of relatively high shear stresses (~100 MPa) and high strain rates (~10-11 s-1) for short durations (<1 Ma) can account for the observed apparent temperature variations. The evidence indicates that shear heating is the dominant mechanism for localised temperature increases in the shear zones, while the country rock remained at relatively lower temperatures.
dc.identifier.issn0191-8141
dc.identifier.urihttp://hdl.handle.net/1885/90787
dc.publisherPergamon-Elsevier Ltd
dc.sourceJournal of Structural Geology
dc.subjectKeywords: Shear heating; High pressure effects; Petrology; Rocks; Shear stress; Structural geology; heat flow; heat source; isotopic analysis; petrology; Proterozoic; shear zone; Australia
dc.titleEvidence for shear heating, Musgrave Block, central Australia
dc.typeJournal article
local.bibliographicCitation.lastpage1013
local.bibliographicCitation.startpage1007
local.contributor.affiliationCamacho, A, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationMcDougall, Ian, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationArmstrong, Richard, College of Physical and Mathematical Sciences, ANU
local.contributor.affiliationBraun, Jean, College of Physical and Mathematical Sciences, ANU
local.contributor.authoremailu6100426@anu.edu.au
local.contributor.authoruidCamacho, A, u4037786
local.contributor.authoruidMcDougall, Ian, u6100426
local.contributor.authoruidArmstrong, Richard, u4029979
local.contributor.authoruidBraun, Jean, u8901439
local.description.embargo2037-12-31
local.description.notesImported from ARIES
local.description.refereedYes
local.identifier.absfor040303 - Geochronology
local.identifier.absfor040312 - Structural Geology
local.identifier.ariespublicationMigratedxPub21240
local.identifier.citationvolume23
local.identifier.doi10.1016/S0191-8141(00)00172-3
local.identifier.scopusID2-s2.0-0035357988
local.identifier.uidSubmittedByMigrated
local.type.statusPublished Version

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