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Full-Text Articles in Physical Sciences and Mathematics
Contractional Tectonics : The Himalayan Orogen And Perdido Fold-Thrust Belt, Dian He
Contractional Tectonics : The Himalayan Orogen And Perdido Fold-Thrust Belt, Dian He
LSU Doctoral Dissertations
This dissertation focuses on the kinematic evolution of two major categories of contractional tectonics: collisional orogenic belts and toe structures of passive margins, which are characterized by fold-thrust belts that are hundreds of kilometer-scale and tens of kilometer-scale, respectively. The Himalayan orogen is an excellent example of collisional orogenic belts along convergent plate boundaries. It is commonly structurally defined as three stacked units separated by two fault systems: the Main Central thrust (MCT) and South Tibet detachment (STD). The development and emplacement of the middle unit, the Himalayan crystalline core, has long been debated within the extrusion framework, a process …
Effects Of Stress And Water Saturation On Seismic Velocity And Attenuation In Near Surface Sediments, James Michael Crane
Effects Of Stress And Water Saturation On Seismic Velocity And Attenuation In Near Surface Sediments, James Michael Crane
LSU Doctoral Dissertations
Seismic investigation in the near-surface is complicated by highly attenuating media, large interparticle stresses, and variable water saturation, so new tools and methodology are necessary to understand the relationships between velocity, attenuation, and physical properties of the propagating media. A new shear wave source is developed for investigation of gas-charged, organic-rich sediments because compressional waves are highly attenuated and currently available sources are inadequate. The new source compares favorably to a traditional hammer impact source, producing a signal with a broader-band of frequencies (30-100Hz cf. 30-60Hz) and signal-to-noise ratios (SNR) equivalent to ~3 stacked hammer blows to the hammer impact …