Abstract:
This paper presents a review of various gravity anomalies and their uses in passive margin studies. It has been shown that simple modelling of gravity anomalies on regional scale can provide a subsurface picture, and from this process of interpretation the following can be established: The extent to which isostatic equilibrium exists in the subsurface. Passive margins on regional scale appear to be in isostatic equilibrium, but differences in the Airy derived theoretical Mobo and the Mobo deduced from the modelling have been observed. Such deviations could be attributed to a variety of reasons. For example, strict theoretical considerations of the Airy hypothesis may produce artifacts which are geologically not plausible. Slight isostatic imbalance across the margin may exist. Minor variability in crustal and upper mantle densities may be present across the margin, and two-dimensional modelling of the three dimensional subsurface anomalies. The horizontal extent over which the complete transition in crustal thinning occurs across the margin can be estimated. It has been observed that on starved continental margins, such as Bay of Biscay and Goban Spur, most of the crustal attenuation occurs on the continental side of the continent ocean transition (COT). The characteristic signature in the isostatic anomaly has been found useful in locating continent ocean transition (COT), which can be further supported by the presence of a characteristics signature of magnetic anomaly profile.
Page(s):
9-20
DOI:
DOI not available
Published:
Journal: Pakistan Journal of Petroleum Technology, Volume: 1, Issue: , Year: 1992