A microstructural investigation of the deformational conditions and kinematics of flow in peridotite tectonites from the North Arm Mountain massif, Bay of Islands ophiolite complex, Newfoundland

dc.contributor.advisorCasey, John
dc.contributor.committeeMemberElthon, Donald
dc.contributor.committeeMemberGardner, Gerald H. F.
dc.creatorBrink, Ronald Steven
dc.date.accessioned2023-10-17T18:47:18Z
dc.date.available2023-10-17T18:47:18Z
dc.date.copyright1990-09-13
dc.date.issued1987
dc.description.abstractMicrostructural and petrofabric investigations of cumulate and residual peridotite rocks from the North Arm Mt. massif, Bay of Islands ophiolite, Newfoundland suggest that the two units share a similar deformational history. Comparable stresses (350-425 bars from olivine neoblast and subgrain paleo- piezometry), strain rates (about 1 x 10 -14 sec), deformational temperatures (950[degrees]C+ from slip systems inferred through olivine petrofabric and kink band studies), mineral shape anisotropies, olivine petrofabrics and metamorphic textures (porphyroclastic-equigranular) are found in rocks from both sides of the cumulate-residual boundary. A low-temperature, high-strain, high-stress, high-strain rate deformation with NW (subduction direction) peridotite flow (from olivine Z-axis and spinel Iineation trends) characterizes the lowermost three km of North Arm massif rock. Stresses, strains and strain rates decline in magnitude up section while some flow directions above the three km level are found to trend NE (the sea floor spreading direction inferred from sheeted dike orientations). Basal North Arm massif rocks are considered to have undergone a subduction-related deformation that overprints original mantle upwelling- derived microstructures. Deformation is heterogenous in upper North Armmassif peridotites, with subduction-related strain partitioned into discrete shear zones.
dc.description.departmentEarth and Atmospheric Sciences, Department of
dc.format.digitalOriginreformatted digital
dc.format.mimetypeapplication/pdf
dc.identifier.other21538199
dc.identifier.urihttps://hdl.handle.net/10657/15326
dc.language.isoen
dc.rightsThis item is protected by copyright but is made available here under a claim of fair use (17 U.S.C. Section 107) for non-profit research and educational purposes. Users of this work assume the responsibility for determining copyright status prior to reusing, publishing, or reproducing this item for purposes other than what is allowed by fair use or other copyright exemptions. Any reuse of this item in excess of fair use or other copyright exemptions requires express permission of the copyright holder.
dc.subjectOphiolites--Newfoundland and Labrador
dc.subjectGeology--Newfoundland and Labrador
dc.subjectPeridotite
dc.titleA microstructural investigation of the deformational conditions and kinematics of flow in peridotite tectonites from the North Arm Mountain massif, Bay of Islands ophiolite complex, Newfoundland
dc.type.dcmiText
dc.type.genreThesis
dcterms.accessRightsThe full text of this item is not available at this time because it contains documents that are presumed to be under copyright and are accessible only to users who have an active CougarNet ID. This item will continue to be made available through interlibrary loan.
thesis.degree.collegeCollege of Natural Sciences and Mathematics
thesis.degree.departmentGeosciences, Department of
thesis.degree.disciplineGeosciences
thesis.degree.grantorUniversity of Houston
thesis.degree.levelMasters
thesis.degree.nameMaster of Science

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