Lithostratigraphical nomenclature of the English Palaeogene succession

Daley, Brian; Edwards, Nicholas P.; Insole, Allan N.

doi:10.1017/s0016756800042035

Cited by 5 publications

(2 citation statements)

References 3 publications

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“…Seismic data was acquired within the west Solent (Figure 9) over an area known to contain dipping and faulted limestones and mudstones (Daley et al, 1979). An area 80 m wide by 600 m long was surveyed using repeated lines.…”

Section: Testing and Initial Results From The 3d Chirp Systemmentioning

confidence: 99%

Design of a 3D Chirp Sub-bottom Imaging System

et al. 2005

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Chirp sub-bottom profilers are marine acoustic devices that use a known and repeatable source signature (1 -24 kHz) to produce decimetre vertical resolution cross-sections of the subseabed. Here the design and development of the first true 3D Chirp system is described. When developing the design, critical factors that had to be considered included spatial aliasing, and precise positioning of sources and receivers. Full 3D numerical modelling of the combined source and receiver directivity was completed to determine optimal source and receiver geometries. The design incorporates 4 source transducers (1.5 -13 kHz) that can be arranged into different configurations, including Maltese Cross, a square and two separated pairs. The receive array comprises 240 hydrophones in 60 groups whose group-centres are separated by 25 cm in both horizontal directions, with each hydrophone group containing four individual elements and a pre-amplifier.After careful consideration, it was concluded that the only way to determine with sufficient accuracy the source-receiver geometry, was to fix the sources and receivers within a rigid array.Positional information for the array is given by a Real Time Kinematic GPS and attitude system incorporating four antennas to give position, heading, pitch and roll. It is shown that this system offers vertical positioning accuracy with a root-mean-square (rms) error less than 2.6 cm, while the horizontal positioning rms error was less than 2.0 cm. The system is configured so that the chirp source signature can be chosen by software aboard the acquisition vessel. The complete system is described and initial navigational and seismic data results are presented. These data demonstrate that the approach of using a fixed source-receiver geometry combined with RTK navigation will provide complete 3D imaging of the sub-surface.3

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Section: Testing and Initial Results From The 3d Chirp Systemmentioning

confidence: 99%

Design of a 3D Chirp Sub-bottom Imaging System

et al. 2005

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“…The stratigraphic nomenclature of the Eocene strata of the Hampshire Basin is in a state of some confusion. T h i s stems largely from the use of both lithostratigraphic and biostratigraphic criteria to define stratigraphic units (Daley, Edwards & Insole 1979). An example particularly relevant to the work presented here involves the stratigraphic definition of the Bracklesham Group.…”

Section: Stratigraphic Nomenclaturementioning

confidence: 99%

A. G. Plint

1988

Basin Research

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Recent improvements in biostratigraphic and magnetostratigraphic control in the Eocene sediments of the Hampshire Basin prompted direct comparison of depositional sequences in outcrop with those predicted by the latest and most detailed Exxon coastal onlap chart. This study focused on the upper two cycles of the London Clay Formation, the Bracklesham Group and the Barton Formation, comprising nine depositional sequences, each a few 10s of metres thick. The sediments were divided into three basic facies associations: marine, estuarine and alluvial. Depositional sequences invariably rest on a regional erosion surface cut during sea‐level lowstand. The lower part of each sequence consists typically of ‘estuarine’ sediments (including tidal channel, lagoon, tidal flat and marsh deposits), laid down under brackish conditions during the early stages of sea‐level rise. Estuarine deposits are typically erosively overlain by marine shoreface or shelf deposits; the eroded, pebble‐strewn contact marks the passage of the marine shoreface. Marine deposits may be erosively overlain by alluvial sediments that record coastal progradation in response to stable or slowly falling sea level. Magnetostratigraphy, in the form of truncated or absent magnetozones provides supporting evidence for significant erosion during periods of lowstand. Every sequence can be matched to the Exxon coastal onlap chart, with one exception, which, on biostratigraphic and magnetostratigraphic evidence has been shown to be absent from the Hampshire Basin. The Exxon chart suggests that in this exceptional instance, coastal onlap was insufficient to effect marine deposition in the Hampshire Basin.

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Dennis Curry: a bibliography

Whittaker

2002

Proceedings of the Geologists' Association

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Lithostratigraphical nomenclature of the English Palaeogene succession

Cited by 5 publications

References 3 publications

Design of a 3D Chirp Sub-bottom Imaging System

Design of a 3D Chirp Sub-bottom Imaging System

A. G. Plint

Dennis Curry: a bibliography

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