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Full-Text Articles in Physical Sciences and Mathematics
Deformation Of Continental Crust Along A Transform Boundary, Coast Mountains, British Columbia, Scott Bogue, Margaret Rusmore, Karen Dodson, Kenneth Farley, Glenn Woodsworth
Deformation Of Continental Crust Along A Transform Boundary, Coast Mountains, British Columbia, Scott Bogue, Margaret Rusmore, Karen Dodson, Kenneth Farley, Glenn Woodsworth
Scott Bogue
New structural, paleomagnetic, and apatite (U-Th)/He results from the continental margin inboard of the Queen Charlotte fault (∼54°N) delineate patterns of brittle faulting linked to transform development since ∼50 Ma. In the core of the orogen, ∼250 km from the transform, north striking, dip-slip brittle faults and vertical axis rotation of large crustal domains occurred after ∼50 Ma and before intrusion of mafic dikes at 20 Ma. By 20 Ma, dextral faulting was active in the core of the orogen, but extension had migrated toward the transform, continuing there until <9 Ma. Local tilting in the core of the orogen …
Very Rapid Geomagnetic Field Change Recorded By The Partial Remagnetization Of A Lava Flow, Scott Bogue, Jonathan Glen
Very Rapid Geomagnetic Field Change Recorded By The Partial Remagnetization Of A Lava Flow, Scott Bogue, Jonathan Glen
Scott Bogue
A new paleomagnetic result from a lava flow with a distinctive, two-part remanence reinforces the controversial hypothesis that geomagnetic change during a polarity reversal can be much faster than normal. The 3.9-m-thick lava (“Flow 20”) is exposed in the Sheep Creek Range (north central Nevada) and was erupted during a reverse-to-normal (R-N) geomagnetic polarity switch at 15.6 Ma. Flow 20 began to acquire a primary thermoremanence while the field was pointing east and down but was soon buried, reheated, and partially-remagnetized in a north-down direction by the 8.2-m-thick flow that succeeded it. A simple conductive cooling calculation shows that the …