Surface-geology, oil-well, seismic-reflection, and magnetostratigraphic data are
integrated to evaluate structural style and shortening rate at the Himalayan front (Sub-Himalaya) of northwest India. The Sub-Himalaya, between the Main Boundary thrust
and the Himalayan Frontal fault, is the actively deforming front of the Himalaya. At
certain locations, the Himalayan Frontal fault...
At collisional mountain ranges the tectonic history of crustal shortening and
subsequent post-collisional erosion is preserved in the form of the presently observed
gravity anomalies. In this study, models of erosion and isostatic rebound at various stages
of collision illustrate the evolution of crustal structure, topography, and resulting gravity
anomalies....
Elliptical borehole enlargements or "breakouts" caused by systematic spalling of a
borehole wall due to regional maximum horizontal stresses were identified in 18 wells
drilled in the Coast Range and Willamette Valley of western Oregon. The breakouts
generally indicate a NNW to NNE orientation of maximum horizontal compression
(oH[subscript max])...
Two examples of Pacific rim plate boundary deformation are presented. In the first
part of the thesis crustal models are derived for the northwestern part of the Vizcaino
block in California using marine seismic and gravity data collected by the Mendocino
Triple Junction Seismic Experiment. A northwest-southeast trending kink in...
This thesis presents elastic finite difference simulations of two dimensional wavefield propagation for line-9, recorded during the 1993 part of the multi-institutional, multi-year Mendocino Triple Junction (MTJ) Seismic Experiment. Line-9 is a high-resolution, large-aperture seismic profile oriented in north-south direction, extending from the subduction regime north of the MTJ to...
During the Cenozoic, tectonics in the Cuyama basin of the southeastern Salinian block changed from extension to strike-slip faulting to compression and rotation. During the Oligocene-early Miocene, the Cuyama basin was adjacent to the southern Mojave region and part of that extensional tectonic regime. Many present-day reverse faults have an...
Magnetic and gravity modelling was completed along two E-W transects offshore central Oregon. These models indicate that the backstop-forming western edge of the Siletz terrane has a seaward dip of approximately 40° to 49° at 44°48'N, shallowing to ~28° at 44°1 1 'N. This is a well-determined result, given available...