Show simple item record

dc.contributor.authorWhyte, A. J.
dc.contributor.authorWeller, O. M.
dc.contributor.authorCopley, A. C.
dc.contributor.authorSt‐Onge, M. R.
dc.date.accessioned2021-10-30T09:15:15Z
dc.date.available2021-10-30T09:15:15Z
dc.date.issued2021-10-30
dc.date.submitted2021-06-22
dc.identifier.citationGeochemistry, Geophysics, Geosystems, volume 22, issue 11, page e2021GC009988
dc.identifier.issn1525-2027
dc.identifier.otherggge22662
dc.identifier.other2021gc009988
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/330109
dc.description.abstractAbstract: The distribution of rheologically strong cratons, and their weakening by metamorphic hydration reactions, is of fundamental importance for understanding first‐order strength contrasts within the crust and the resulting controls on the tectonic evolution of the continents. In this study, the Douglas Harbor structural window within the Paleoproterozoic Trans‐Hudson orogen of Canada is used to study the hydration of the footwall Archean Superior craton basement by water released from the overlying Paleoproterozoic Cape Smith thrust‐fold belt. Phase equilibria modeling is applied to quantify the Archean and Paleoproterozoic metamorphic conditions, and to determine the effect of hydration on basement mineralogy. The amount of structurally bound water within the basement is calculated and shown to decrease as a function of distance below the basal décollement of the thrust‐fold belt. Applying a reactive fluid transport model to these results, the rate coefficient for fluid‐rock reaction is constrained to be 10 − 19 m o l − 1 m 3 s − 1 , and the diffusivity of water through the grain boundary network to be 10 − 9 m 2 s − 1 at the ambient metamorphic conditions of 570 ° C and 7.5 kbar. This newly documented rate of water diffusion is three orders of magnitude slower than thermal diffusion, implying that hydration by diffusion may be the rate‐limiting factor in the weakening of cratons, and therefore plays an important role in their geological persistence. This conclusion is consistent with field observations that Paleoproterozoic strain in the Douglas Harbor structural window is restricted to hydrated portions of the Archean Superior craton basement.
dc.languageen
dc.subjectGEOCHEMISTRY
dc.subjectReactions and phase equilibria
dc.subjectMINERALOGY AND PETROLOGY
dc.subjectFluid flow
dc.subjectMetamorphic petrology
dc.subjectSTRUCTURAL GEOLOGY
dc.subjectRheology: crust and lithosphere
dc.subjectTECTONOPHYSICS
dc.subjectContinental margins: convergent
dc.subjectVOLCANOLOGY
dc.subjectResearch Article
dc.subjectmetamorphism
dc.subjecttectonics
dc.subjectreaction rates
dc.subjectfluid diffusion
dc.subjectrheology
dc.titleQuantifying Water Diffusivity and Metamorphic Reaction Rates Within Mountain Belts, and Their Implications for the Rheology of Cratons
dc.typeArticle
dc.date.updated2021-10-30T09:15:14Z
dc.identifier.doi10.17863/CAM.77553
dcterms.dateAccepted2021-10-09
rioxxterms.versionofrecord10.1029/2021gc009988
rioxxterms.versionAO
rioxxterms.versionVoR
rioxxterms.licenseref.urihttp://creativecommons.org/licenses/by/4.0/
dc.contributor.orcidCopley, A. C. [0000-0003-0362-0494]
pubs.funder-project-idNERC C‐Clear DTP (NE/S007164/1)


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record