The plate tectonic history of Oregon is but one piece of a worldwide jigsaw puzzle encompassing much of geologic time. With the splitting of Pangaea in Mesozoic times, Oregon has occupied the leading edge of the North American Plate as it has impinged upon the ancestral oceanic East Pacific Plate....
Extensive new trackline coverage of the Chile Trench between 23°S and 34°S, including more than 60 bathymetric and seismic reflection profiles across the trench axis, allows a much more detailed study of the tectonics and sedimentation of this feature than previously possible. Sediment distribution along the axis shows a remarkable...
The geology of Oregon has become a jigsaw puzzle of moving parts set on a foundation of changing conditions as the crust and mantle undergo successively different manners of deformation through time. As more megahypotheses arise from increasingly sophisticated views of plate tectonics and from more detailed analyses of synoptic...
Anomaly timescales for the last 90 million years, derived from
marine magnetic profiles and published prior to mid-1979, are summarized,
illustrated for comparison, and critically reviewed. A revised timescale
is constructed using calibration points which fix the ages of anomalies
2.3', 5.5, 24, and 29. An equation is presented for...
The Nanga Parbat-Haramosh massif (NPHM) is a north-south trending
structural and topographic high, which interrupts the east-west trend
of the Himalaya in northern Pakistan. Previously, the massif was
thought to be bounded by the Main Mantle thrust (MMT), a north-dipping
thrust along which the Kohistan-Ladakh arc was thrust south over...
The collision of the Indian subcontinent with Asia beginning 40 million years ago
produced the Himalayan orogenic belt, the largest continental collision belt active today. The foreland fold-and-thrust belt in northern Pakistan consists of the Salt Range-Potwar Plateau area. In this region the distance from the Main Boundary Thrust(MBT) to...
Gravity data along a N-S profile from Kohistan to the Punjab plain of Pakistan
have been incorporated into recent interpretation of the gross structure of the foreland
fold and thrust belt of the Himalaya. In northern Pakistan large deviations from Airy
Isostatic equilibrium are observed. An excess of mass characterizes...