A sequence stratigraphic analysis of the nearshore West Cameron and East Cameron blocks, central Gulf of Mexico, was developed for Lower Miocene age strata. Interpretation of each depositional sequence included delineation of paleoshelf/slope breaks, isopach, seismic facies, and paleogeography maps. Sequence development and sedimentation patterns were influenced by two prominent structural styles, growth faulting and salt/shale deformation. Two depositional sequences A and B, were identified and interpreted to consist of depositional environments ranging from submarine fan to coastal and shallow marine deltaics. Sequence A is the oldest Lower Miocene sequence and is divided into two depositional packages, a lowstand portion and a condensed interval. Because the paleo-shelf break was landward of our study area, there is an absence of well-developed shelfal facies in this sequence, and the condensed interval represents the distal transgressive and highstand portion of the sequence. The lowstand portion suggests a north to northwest source direction and has a maximum thickness of 2200 feet. The axis of maximum thickness, derived from isochron mapping, integrated with paleogeographic interpretation, indicates that the thickness or aggradation is related to mass-wasting processes and channel systems characteristic of submarine fan environments. The influence of pre-existing topography and basin configuration on sequence development and stratal architecture is evident where the axes of maximum thickness are separated by thin intervals of little to no deposition, related to a paleostructural high. Sequence B is better developed than Sequence A because of its location within the axis of the depocenter and can be subdivided into the following depositional environments: well-developed prograding submarine fan and slope deposits (associated primarily with falling sea-level) that are capped updip by an erosional surface associated with a marine transgression; an overall transgressive unit composed of localized regressive deltaic deposits; and aggradational fluvial/deltaic and shallow marine sediments associated with a continued rise in sea-level. Sequence B has a maximum thickness of 3200 feet and, like Sequence A, this aggradation within the basin is attributed to mass-wasting and channel development within a slope envronment. The variation in location of thickness trends, combined with evidence of erosional channels from different source directions, indicates the migration of sediment supply through time from a more westerly to a more northerly direction.

No abstract

No abstract

No abstract

This paper describes the development of several wayside detectors for use in assessing the “dynamic” performance and general condition of freight car and locomotive trucks operating in revenue service. The objective is to improve safety of operations via automated wayside performance-based inspection systems and the development of performance-based criteria to improve and supplement existing maintenance policies and procedures.