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The Himalayan fold-thrust belt and Tibetan Plateau are the result of the collision between the Indian and Eurasian continents. This dissertation documents the kinematics and tectonic history of the Himalayan fold-thrust belt of western Nepal and the northern Tibetan Plateau. In the Himalayan fold-thrust belt, the Main Central thrust emplaced a hanging wall flat of Greater Himalayan rock over a footwall flat of Lesser Himalayan rock in Early Miocene time. Subsequent growth of the Lesser Himalayan duplex (LHD) uplifted and rotated the Ramgarh thrust sheet, Main Central thrust, and overlying Greater Himalayan rock to the surface. Thus, growth of the LHD is responsible for the northward dips in the Greater Himalaya. New Nd isotopic data from throughout Nepal indicate that Lesser Himalayan rocks consistently have more negative epsilonNd values than Greater and Tibetan Himalayan rocks. Growth of the LHD is documented in the syntectonic sediments of the Neogene Siwalik Group. At ∼10-11 Ma in central and western Nepal, the epsilonNd values of the Siwalik Group shift toward more negative values which indicate detrital input from rocks in the LHD. Regional mapping in western Nepal and three balanced cross sections provide a three-dimensional view of the fold-thrust belt. These cross sections suggest over 900 km of shortening in upper crustal rock from the Indus suture to the Main Frontal thrust. This suggests a corresponding ∼900 km long wedge of lower crustal rock was consumed by the Himalayan-Tibetan orogen. This wedge may have been inserted under the Tibetan Plateau, helping it obtain its anomalously thick crust. If lower crustal rocks have been inserted under the Tibetan Plateau, the Himalayan collision can account for ∼70% of the overthickened crust. This leaves ∼30% to be accounted for by other mechanisms. The Tula uplift documents shortening along the northern edge of the Tibetan Plateau. The lithic composition of its sandstone, deformation, and erosion of strata suggests that significant regional uplift and thickening occurred since Late Jurassic time and is still occurring. These relationships suggest that the northern Tibetan Plateau region was tectonically active, and undergoing shortening, long before the early Tertiary India-Eurasian collision.

The structural link that ties the formation of the central Andean plateau to the evolution of the Andean fold-thrust belt is formation and propagation of basement megathrusts. Balanced cross-sections through a regional west-vergent thrust system in the hinterland of the eastward-verging Andean fold-thrust belt suggest that the Altiplano basin is a crustal-scale, piggy-back basin created as a basement megathrust propagated up and over a half-crustal scale ramp located on the eastern edge of the Altiplano. The backthrust belt, detached above the basement thrust sheet, acted as a crustal-scale, passive-roof duplex building taper after the megathrust overextended the system eastward. Pervasive shortening and vertical elongation seen at the outcrop and regional scales supports the development of the backthrust belt as a taper-building mechanism. The interrelationship of the backthrust belt, basement megathrust, and Andean plateau is shown in a sequential, kinematic model based on balanced cross sections from the volcanic arc to the foreland. The model links the formation of the plateau to east- and west-verging portions of the Andean fold-thrust belt through the eastward propagation of two large basement megathrusts. The megathrusts can explain topographic and structural steps in the Andean fold-thrust belt and accommodate a minimum of 300-330 km of shortening which matches shortening estimates in the tightly folded and faulted cover rocks. To a first approximation, the eastern margin of the central Andean plateau (defined by the 3 km topographic contour) is contiguous with the leading edge of the upper basement megathrust. The relationship between the basement highs and the physiographic boundaries of the Andean plateau suggests that extensive megathrust sheets (involving strong rocks such as crystalline basement or quartzite) play an important role in the formation of the central Andean plateau. Combining the history of foreland basin migration with palinspastically restored regional cross sections across the Bolivian Andes between 18°-20°S argues for an eastward migrating fold-thrust belt/foreland basin system since the late Cretaceous. The longer time span for the Andean orogeny implies greater shortening amounts, a decrease in shortening rates with time and a high (3-4 km) Andean plateau by 20 Ma.

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Thesis (Ph. D.)--University of Washington, 1984. / Vita. Bibliography: leaves [223]-229.

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Thesis (M.S.)--George Mason University, 2007. / Title from PDF t.p. (viewed Jan. 22, 2008). Thesis director: Allan Falconer. Submitted in partial fulfillment of the requirements for the degree of Master of Science in Geographic and Cartographic Sciences. Vita: p. 197. Accompanied by: 1 Microsoft Access file, 1 ArcMap file, 1 GIS file, and multiple JPEF Image files and AUX files in 2 .zip folders. Includes bibliographical references (p. 192-196). Also available in print.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 62-64). Also available via the Internet.