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Full-Text Articles in Physical Sciences and Mathematics
Metamorphic Evidence For Tilt Of The Spuzzum Pluton – Diminished Basis For The Baja British-Columbia Concept, E. H. Brown, Russ R. Burmester
Metamorphic Evidence For Tilt Of The Spuzzum Pluton – Diminished Basis For The Baja British-Columbia Concept, E. H. Brown, Russ R. Burmester
Geology Faculty Publications
To address the question of tilt versus translation as the mechanism responsible for discordance between paleomagnetic directions of Cretaceous plutons in the British Columbia Coast Plutonic Complex and the North American reference direction, metamorphic pressures around the margin of the Spuzzum pluton have been determined. Pressures are derived from microprobe analyses and evaluation of exchange equilibria in the assemblage garnet-biotite-plagioclase-aluminum silicate-quartz. Samples studied come from eight localities in the contact aureole around the pluton and encompass the area of a previous paleomagnetic study. The analyzed samples are coarse grained and exhibit textural features indicative of equilibrium crystallization following emplacement of …
Paleomagnetism Of The Patagonian Plateau Basalts, Southern Chile And Argentina, Robert F. Butler, Francisco Herve, Francisco Munizaga, Myrl E. Beck Jr., Russ R. Burmester, Eduardo S. Oviedo
Paleomagnetism Of The Patagonian Plateau Basalts, Southern Chile And Argentina, Robert F. Butler, Francisco Herve, Francisco Munizaga, Myrl E. Beck Jr., Russ R. Burmester, Eduardo S. Oviedo
Geology Faculty Publications
A total of 505 paleomagnetic samples were collected from 65 sites (volcanic flows) of the Patagonian plateau basalts at four locations in southem Chile and Argentina. K/Ar analyses indicate that 38 flows from two locations form a Late Cretaceous group (64-79 Ma), while the remaining 27 flows are Eocene in age (42-56 Ma). Progressive demagnetization indicates that a characteristic remanent magnetization (ChRM) has been successfully isolated from 59 flows. Rock-magnetic properties and analysis of ChRM directions within and between sites allow the secure inference that the ChRM is a thermoremanent magnetization acquired during original cooling. The Eocene flows yield 15 …