The effect of liquid chromatographic separation on matrix-related signal suppression in electrospray ionization mass spectrometry (LC-ESI-MS) was investigated. A method incorporating on-line two-dimensional liquid chromatography mass spectrometry (LC/LC-MS) was developed to compensate for matrix effects and signal suppression in qualitative and quantitative analysis. The LC/LC-MS(MS) approach was successfully applied for single-component and multicomponent analysis in a variety of complex matrixes. It was demonstrated that matrix-related signal suppression could be induced solely by (i) column overload, (ii) matrix component-analyte coelution, or a combination of each. Application of on-line orthogonal LC/LC separations can be effective in reducing both causes of matrix-related signal suppression effects i.e., column overload and matrix-analyte coelution for a variety of LCn/MSn applications.

The southern termination of the Nordland Ridge, mid-Norway exhibits variations in extensional style which can be attributed to differing degrees of coupling between pre-salt 'basement' and postsalt 'cover' strata. South of the Nordland Ridge, Jurassic and Cretaceous extension is distributed relatively uniformly over the 80 km wide Halten Terrace. Further to the north the zone of extension narrows to less than 40 km and the majority of the extension is taken up on the Revfallet Fault, which separates the Donna Terrace from the Nordland Ridge. Displacement on the Revfallet Fault, at basement level, increases progressively from its zero displacement tip to a maximum of 7 km, 60 km to the north. At low displacements, extension in the cover is decoupled from the basement extension and vertical level changes are accommodated by monoclinal flexure. As displacement on the Revfallet Fault increases, the degree of basement-cover coupling increases and a much closer spatial link between deformation in the basement and in the cover is evident. This progressive increase in degree of coupling is characterized by increased footwall uplift and decreased extension in the cover away from the master fault. The degree of basementcover coupling can also be shown to vary not only with displacement but also with time, in response to variable strain rates. Initial extension during the Jurassic was predominantly decoupled and occurred over 50 Ma period. After 40-50 Ma of relative quiescence, the major extensional episode occurred within a comparatively short 10 Ma period in the mid-Cretaceous. This later period of rapid extension requires strain rates at least an order of magnitude greater than those of the Jurassic. The results of this study have led to significant changes in the regional tectono-stratigraphic model.

The Revfallet Fault system, Heidrun area, offshore mid-Norway, illustrates considerable variation in structural style along strike which is attributed to variation in coupling between basement and cover (separated by Triassic salt), due to the variable displacement along the fault system and to distinct phases of shallow level as well as basement-involved extension. Deformation in the southern part of the fault is partitioned over a number of cover-graben and associated with the development of a monoclinal flexure above the basement fault system. With an increase in displacement northwards, cover-graben become grounded on the pre-salt basement resulting in the rotation and breaching of the extensional drape fold and, eventually, partial and full coupling between basement and cover fault systems.Analogue models were designed to simulate the 3D evolution of cover deformation above a variable displacement extensional fault separated from the cover by a ductile basal unit and to validate the structural interpretations and evolutionary models for the Revfallet Fault system. Analogue model results reveal the changing geometry along strike from a gentle extensional drape fold with minimal brittle deformation at low extension, to a breached drape fold system with significant rotation and collapse of the cover across the basement fault as displacement increases. Models conducted with a two-phase history -shallow extension (orthogonal and oblique) followed by basement-involved extension illustrate variable reactivation of covergraben along strike during the basement-involved event, and collapse and rotation of the extensional footwall to the basement fault as displacement increases to a maximum. Coupling between cover faults and the basement fault only occurred where an oblique, precursor cover-graben cuts across the basement fault from hanging wall to footwall. Closer examination of the structural and stratigraphic relationships reveals major discrepancies between throw on cover and basement fault segments. The analogue model results compare favourably to seismic data from the Revfallet Fault system and validate the structural model for this fault system.

The Mesozoic Gulf of Mexico Basin is considered in this discussion as the set of contiguous, Triassic and Jurassic sub-basins directly involved in the counterclockwise rotation of the Yucatan Block from North America in the Late Jurassic. The rifting and seafloor spreading history of the basin is less well understood than analogous salt basins of the Atlantic margins, largely because the base salt surface is significantly deeper and has hereto widely been considered acoustic basement. In 2012, 17,000 km of 2D PSDM reflection seismic data (SuperCache) were acquired across the deep water of the U.S. Gulf of Mexico. The unique acquisition configuration of long-offset, powerful source, and deep-tow of both source and receivers was designed to optimize the imaging of the presalt architecture of the basin to a depth of 40 km. On these seismic data, the base of the salt and its correlative unconformity, continental and oceanic basement, and the Moho are evident. In combination with vintage, reflection seismic data, shipboard and regional gravity data, and regional refraction profiles, a crustal interpretation has been extended to the greater Gulf of Mexico Basin. The continental crustal architecture is described in terms of crustal thinning: from low (<30%) to transitional (>70%). Synkinematic sequences are recognized within the Late Triassic to the Middle Oxfordian (~70 my). The final break-up phase occurred within 15 my, ending with a basin-wide open marine transgression and initial emplacement of oceanic crust at 160±1 Ma; continued extension may have occurred in the eastern part of the basin in the latest Jurassic. The basin margins are considered to be intermediate between magmapoor and volcanic end-members. The ocean crust tapers from a maximum width of 700 km in the west, where it is anomalously thin, to anomalously thick as it approaches the pole of rotation in the Straits of Florida. The architecture of extinct spreading valleys and fracture zones is analogous to the modern, slow spreading mid-Atlantic ocean, suggesting that spreading continued until the latest Jurassic (~142 Ma), possibly as late as within the early Cretaceous (~132 Ma).