Eustacy was the dominant factor influencing the Gulf of Martaban Field isolated platform, subdivided in Lower and Upper Martaban Limestones (LML) and (UML). LML was established on top of a faulted accretionary basement that influenced the LML late Oligocene growth. At the Oligocene-Miocene boundary, siliciclastic influx inhibited the carbonate growth, infilled a central trough, and covered the LML platform top, creating a relief on top of which grew the UML platform. This platform first aggraded and backstepped, and then drowned due to early Miocene high rates of sea level rise. The Maldives, because of its bigger size, greater growth potential, and lack of siliciclastic, kept up with those early Miocene rates, while Gulf of Martaban Field drowned.

High-resolution geophysical and geologic data were acquired in western and central Ross Sea, Antarctica, to determine the: (1) maximum extent and configuration of the ice sheet during the Last Glacial Maximum (LGM); (2) conditions and processes at the base of the expanded ice sheet and their role in ice stream activity; and (3) relative retreat history of the ice sheet. This information can provide geologic constraints for modeling of ice-sheet retreat. The research formed the basis for development of a public Web site (http://www.glacier.rice.edu) and for middle-school earth-science instructional materials. Based on identification of isolated grounding-zone wedges and consistency of mega-scale glacial lineations, the LGM ice edge reached the Coulman Island region in western Ross Sea. The maximum extent in central Ross Sea occurred at the continental-shelf edge, based on the presence of mega-scale glacial lineations, glacio-tectonic features, and shelf-edge gullies. Streaming ice, overlying a deforming bed typically <5 m in thickness, filled the troughs. Thinner, divergent, slower moving ice, not underlain by deforming sediment, occupied the bank tops. The ice sheet eroded and conveyed sediment from the inner regions toward the outer shelf, where the material was deposited at the grounding line. No features associated with meltwater occur; water available to the subglacial system probably was incorporated into a deforming unit. The ice sheet may have undergone an initial phase of mass wasting, based the large, arcuate iceberg furrows associated with the grounding zones. Ice retreated first from western Ross Sea, possibly because of a diminished contribution from the East Antarctic Ice Sheet. Ice retreat from central Ross Sea lagged that of western Ross Sea. The banks remained ice covered after ice retreat from the troughs; ice shelves may have covered the troughs. During retreat, the grounded ice reworked the substrate into back-stepping grounding-zone wedges and corrugation moraines. The latter features exhibit a spacing on the order of 40 to 100 m and may record annual retreat. This argues for gradual retreat and negates catastrophic collapse of the ice sheet.

During the Triassic, Siberia was a basin approximately 1800 kilometers wide filled by red beds and the widespread Tunguska basalts. Rifting occurred in the northern part of the basin. The western part of the Siberian basin became the West Siberian basin, which was bounded by rising uplifts both to the east and to the west. The differentiation between the effects of tectonics and eustasy in cratonic basins is simple in that the global eustatic signal is basin-wide and enhanced by regional and local tectonics. Thus the first, second and third order cycles of the Upper Jurassic - Turonian in the West Siberian Basin were primarily influenced by eustasy. The Upper Jurassic - Turonian was deposited during an overall transgression and is subdivided into two second-order and sixteen third-order transgressive-regressive cycles. Fourth-order cycles appear to be controlled by delta shifting. A relative sea-level curve for the Upper Jurassic - Turonian resembles the "global" sea-level chart of Hardenbol, et al. (1998).

Velocity analysis resolves relatively long scales of earth structure, on the order of 1 km. Migration produces images with length scales (wavelengths) on the order of 10's of m. In between these two scale regimes lies another, corresponding roughly to structures between 60 to 300m in extent, in which the resolution of velocity analysis is uncertain and the energy of images is small to non-existent. This thesis aims at assessing the impact on velocity analysis of uncertainty at these intermediate length scales, using ideas on time reversal and imaging in randomly inhomogeneous media developed by Borcea and colleagues, in combination with velocity estimation methods of differential semblance type. The main result of this thesis is that the noise in seismic reflection data associated with the middle scales in velocity heterogeneity does not strongly affect the estimates of the long-scale component of velocity, if these estimates are obtained using a statistically stable formulation of differential semblance optimization. Hence the nonlinear influence of uncertainty in the middle scales does not propagate down the length scale. This is in contrast with the results of Borcea and colleagues, who have shown that prestack images are strongly affected, implying that the uncertainty in the middle scales does certainly propagate up the length scale. Random perturbations associated with the middle scales of velocity heterogeneity yield measurable phase shifts in the reflection data. However, it is known that cross-correlations of neighboring seismic traces are stable against these perturbations, under some circumstances. The main theoretical achievement of this thesis, presented in Chapter 3, is to extend this stability result to laterally homogeneous background velocity models, and to cross-correlations containing slowly-varying weights. Chapter 4 shows that differential semblance functionals, specialized to layered modeling, can be written entirely in terms of weighted cross-correlations, and therefore argues that the velocity analysis algorithm and the associated velocity estimates inherit the statistical stability property. A quantitative verification of the stability claims is provided in Chapter 5.

On the northeastern offshore Venezuela, the pre-Tertiary basement consists of a deeply subducted accretionary complex of a Cretaceous island arc system that formed far to the west of its present location. The internal structure of this basement consists of metamorphic nappes that involve passive margin sequences, as well as oceanic (ophiolitic) elements. The Tertiary evolution of the northeastern Venezuela offshore is dominated by Paleogene (Middle Eocene-Oligocene) extension and Neogene transtension, interrupted by Oligocene to Middle Miocene inversions. The Paleogene extension is mainly an arc-normal extension associated with a retreating subduction boundary. It is limited to the La Tortuga and the La Blanquilla Basins and the southeastern Margarita and Caracolito subbasins. All of these basins are farther north of and not directly tied to the El Pilar fault system. On a reconstruction, these Paleogene extensional systems were located to the north of the present day Maracaibo Basin. By early Miocene the leading edge of the now overall transpressional system had migrated to a position to the north of the Ensenada de Barcelona. This relative to South America eastward migration is responsible for the Margarita strike-slip fault and the major inversions that began during the Oligocene and lasted into the Middle Miocene. The Bocono-El Pilar-Casanay-Warm Springs and the La Tortuga-Coche-North Coast fault systems are exclusively Neogene with major transtension occurring during the Late Miocene to Recent and act independently from the earlier Paleogene extensional system. They are responsible for the large Neogene transtensional basins of the area: the Cariaco trough, the Northern Tuy-Cariaco and the Paria sub-basins, and the Gulf of Paria Basin. This latest phase is characterized by strain-partitioning into strike slip faults, a transtensional northern domain and a transpressional southern domain that is responsible for the decollement tectonics and/or inversions of the Serrania del Interior and its associated Monagas foreland structures. Part of the latest (Middle Miocene to Recent) phase is the formation of a large arch that corresponds to the Margarita-Testigos-Grenada zone which perhaps was subject to mild lithospheric compression during the Plio-Pleistocene.

An integrated model is derived for the sequential development of tectonic events in time among different evolving component structural domains comprising the central Walker Lane, west-central Nevada, based on constraints from data compiled from multiple disciplines. Evidence indicates four major tectonic episodes: (1) between 27 and 22 Ma; (2) 22 to 17, 15 Ma; (3) 17, 15 to 11, 10 Ma, and; (4) post-11, 10 Ma. These can be consistently tied to a temporal clockwise reorientation of the regional extension (from northerly to NW-SE) within the central Walker Lane, and also correspond in time with the occurrence of four distinctive litho-compositional assemblages that are confined within major chrono-stratigraphic boundaries defined by regional unconformities within the Tertiary volcano-sedimentary section representing the last 30 m.y. Incorporation of the many isolated Tertiary sections into a regional chrono-stratigraphic framework based on abundant isotopic age data, provides the universal reference frame in time with which to correlate tectonic events among the component structural domains. In this model, the tectonic evolution of the component structural domains results from decomposition of the regional crustal relative displacement field into normal and trace-parallel components along major faults, within the upper brittle crustal layer. Conservation of net relative displacement fields is provided by the mechanical lamination along one or more mid-crustal low-angle to near-horizontal dislocation surfaces (detachment zones) above which decomposition of the changing displacement field is resolved along structures within adjacent developing structural domains. These changing displacement field decompositions and related extension occur E of a major coherent crustal boundary structure, the Sierra Nevada block, and are considered in terms of its motion relative to stable North America, for the evolution of the Walker Lane as a boundary region between it and the expanding Basin and Range to the east.

Detailed outcrop analysis of the Lower Jurassic Kayenta Formation provides the basis for the formulation of a new sequence stratigraphic model for arid to semi-arid continental deposits and the generation of a comprehensive set of sedimentologic criteria for the recognition of ephemeral stream deposits. Criteria for the recognition of ephemeral deposits in the ancient record were divided into three categories according to the scale of the feature being considered. The first category takes into account sedimentary structures commonly found in the record of ephemeral stream deposits including hyperconcentrated and debris flow deposits, planar parallel bedding, sigmoidal cross-bedding, hummocky cross-bedding, climbing ripple lamination, scour-and-fill structures, convolute bedding, overturned cross-bedding, ball-and-pillow structures, pocket structures, pillars, mud curls, flaser lamination, algal lamination, termite nests, and vertebrate tracks. The second category is concerned with the mesoscale facies architecture of ephemeral stream deposits and includes waning flow successions, bedform climb, downstream accretion, terminal wadi splays, and channel-fill successions indicating catastrophic flooding. At the large-scale facies architecture level, the third category, ephemeral stream deposits are commonly arranged in depositional units characterized by a downstream decrease in grain size and scale of sedimentary structures resulting from deposition in terminal fan systems. Outcrops of the Kayenta Formation and its transition to the Navajo Sandstone along the Vermilion and Echo Cliffs of Northern Arizona indicate that wet/dry climatic cyclicity exerted a major control on regional facies architecture. Two scales of wet/dry climatic cyclicity can be recognized in northern Arizona. Three sequence sets composed of rocks accumulated under predominantly dry or wet conditions are the expression of long-term climatic cyclicity. Short-term climatic cyclicity, on the other hand, is represented by high-frequency sequences composed of eolian or ephemeral fluvial deposits overlain by perennial fluvial sediments. Increased evapotranspiration rates, depressed water tables, and accumulation of eolian or ephemeral fluvial deposits characterize the dry portion of these cycles. The wet part of the cycles is marked by an increase in precipitation and the establishment of perennial fluvial systems and lacustrine basins. This depositional model constitutes a valuable tool for correlation of similar deposits in the subsurface.

Understanding the interaction between continental lithosphere and the convecting mantle is not only important for determining the thermal structure and the role of continental lithosphere in the Earth's heat loss system, but also for determining the deformation response of continental lithosphere. This thesis presents the results from numerical simulations and scaling analyses for two studies that solve for: (1) the thermal structure of stable continental lithosphere within a dynamic mantle and (2) the stability of a chemical layer within a convecting mantle. The thermal structure of stable continental lithosphere is determined by its thermal properties as well as by the input of heat from the convecting mantle. The first study varies the total amount and distribution of crustal heat production, as well as lithospheric thickness, while maintaining a coupled heat loss system between the continental lithosphere and convecting mantle. Doing so confirms that the local thermal structure of stable continental lithosphere and surface heat flow variations strongly depend on the total amount and distribution of crustal heat production. Furthermore, the mantle heat flux remains low and constant for variable heat production values and distributions regardless of the presence of a cratonic root. In addition, the chemical component of the stable continental lithosphere regulates the thickness of the thermal lithosphere, influencing deep thermal structure. The second study focuses on the deformation response of a chemical layer when emplaced in the upper thermal boundary layer of the convecting mantle. The manner in which a chemical layer deforms depends on the tradeoff between its intrinsic properties, such as buoyancy, viscosity and yield strength, and the deforming power of the convecting mantle, these being the parameters varied in the study. Scaling relationships extended the results from the numerical simulations to parameters beyond computation capabilities. This study provides analogs for many geologic processes that are dependent on lithospheric deformation. The second study concluded that as mantle convective vigor increases, the required buoyancy of the chemical lithosphere required for stability decreases, as does the yield stress. The viscosity of the chemical lithosphere required for stability depends on its initial volume and weakly on the mantle's convective vigor.

This dissertation consists of three chapters describing seismic stratigraphic studies in three very different continental margin settings. The first chapter discusses the northwestern Ross Sea, the second discusses the southeastern Weddell Sea and the third discusses the Alabama/west Florida margin. The purpose was to investigate stratigraphic relationships between deposition during glacial periods (i.e., eustatic lowstands) and interglacial periods (i.e., eustatic highstands) on high-latitude and low-latitude margins. The high-latitude Antarctic margin is of particular interest because it is over-deepened and surrounds a continent that is free of melt-water. Because of these factors, the shelf/shelf-edge were not subaerially exposed and fluvially incised during eustatic lowstands. Seismic-stratigraphic analysis of the southeastern Weddell and northwestern Ross Sea margins shows that sediments were sequestered in pre-existing glacial troughs or upper-slope fans, at the mouth of glacial troughs. Locations of trough fans and trough mouth fans were strongly controlled by the location of ice streams. This point-source component of stratal architecture contrasts with the implicit line-source assumption that dominates recent thinking of Antarctic stratal development. Point-sourced trough mouth fans are relatively stable features, but as evidenced in Weddell Sea, they have experienced intermittent large-volume collapse. Upper-slope collapse is predicted to have been related to a dramatic change in over-burden, initiated early in an interglacial period following a long-duration glacial period. Interglacial shedding contrasts with models of low/middle-latitude sedimentation, which suggest that the basin is sediment starved during the interglacial. Seismic stratigraphic analysis of the Alabama/west Florida low-subsidence, middle-latitude continental margin indicates that upper-slope shelf-margin deltas have remained intact throughout the glacial cycle, in spite of widespread subaerial exposure. It is concluded that Pleistocene (?) relative-sea-level fall was insufficiently rapid to initiate major bypass of the upper slope. Therefore, other factors (antecedent topography, salt tectonics and growth faulting) are deemed to be more important initiators of upper-slope canyon formation on the middle-latitude margin.

A seismic and sequence stratigraphic investigation of the Rio Grande system provides information conceming: (1) the distribution of depositional units relative to the last glacio-eustatic cycle (120,000 ybp to present); (2) the spatial and temporal distribution of sand-prone units; and (3) whether the control of eustasy and sediment supply (climate) on deposition can be differentiated. The combination of biostratigraphic data (foraminiferal abundances and extinctions), oxygen isotope stratigraphy, and radiocarbon ages in the Rio Grande area provides the chronologic control for the study. The depositional unit dataset consists of 1850 kilometers of high-resolution seismic reflection profiles, 14 platform boring descriptions, and sediment samples from one platform boring. The study of the Rio Grande system indicates the following: (1) transgressive system tract units are primarily prograding deltas rather than back stepping fine grained units, as predicted by basic sequence stratigraphic theory; (2) fluvial- and wave-dominated delta systems exist simultaneously (geologically-speaking) creating difficulties in the prediction of reservoir distribution and quality; and (3) eustatic and climatic control on unit deposition can be differentiated, and the quantity of sediment supply coincides with the amount of moisture in the drainage area.