An algorithm to calculate the gravity anomaly of sedimentary basins with exponential density‐depth relationships

We derive wavenumber domain expressions to calculate the gravity anomaly of a body with irregular bounding surfaces and an exponential density-depth relationship. We apply the method to sedimentary basins, which commonly have this type of geometry and density distribution. The mathematical formulation also allows the exponential density-depth relationship to be measured from an arbitrary irregular surface rather than the top surface. Using this arrangement, the gravity anomaly of exhumed sedimentary basins can be predicted if the amount of eroded section can be estimated. The corresponding inverse algorithms are also derived. Examples of the use of the forward algorithms, from the Galicia Interior Basin and the Central Irish Sea Basin, are used to illustrate these methods.

[1]  M. Hubbert,et al.  ROLE OF FLUID PRESSURE IN MECHANICS OF OVERTHRUST FAULTING A REPLY , 1959 .

[2]  A. Mauffret,et al.  Structure and evolution of the Galicia Interior Basin (Atlantic western Iberian continental margin) , 1990 .

[3]  A. Racey,et al.  Fault distribution and timing in the Central Irish Sea Basin , 2001, Geological Society, London, Special Publications.

[4]  R. Bray,et al.  The influence of thermal history on hydrocarbon prospectivity in the Central Irish Sea Basin , 2001, Geological Society, London, Special Publications.

[5]  M. Bott The use of Rapid Digital Computing Methods for Direct Gravity Interpretation of Sedimentary Basins , 1960 .

[6]  M. Hubbert,et al.  ROLE OF FLUID PRESSURE IN MECHANICS OF OVERTHRUST FAULTING II. OVERTHRUST BELT IN GEOSYNCLINAL AREA OF WESTERN WYOMING IN LIGHT OF FLUID-PRESSURE HYPOTHESIS , 1959 .

[7]  P. Cowie,et al.  Gravity effect of sediment compaction: examples from the North Sea and the Rhine Graben , 1990 .

[8]  L. Frazer,et al.  Prediction of sediment thickness in the Norwegian-Greenland Sea from gravity inversion , 2006 .

[9]  John G. Sclater,et al.  Continental stretching: An explanation of the Post-Mid-Cretaceous subsidence of the central North Sea Basin , 1980 .

[10]  H. Granser THREE-DIMENSIONAL INTERPRETATION OF GRAVITY DATA FROM SEDIMENTARY BASINS USING AN EXPONENTIAL DENSITY-DEPTH FUNCTION* , 1987 .

[11]  D. Oldenburg The inversion and interpretation of gravity anomalies , 1974 .

[12]  Robert L. Parker,et al.  The Rapid Calculation of Potential Anomalies , 1973 .

[13]  C. Ranero,et al.  Mechanisms of extension at nonvolcanic margins: Evidence from the Galicia interior basin, west of Iberia , 2003 .

[14]  Lindrith Cordell,et al.  Gravity analysis using an exponential density-depth function; San Jacinto Graben, California , 1973 .

[15]  J. Turner,et al.  Inversion and exhumation of the St. George's Channel basin, offshore Wales, UK , 2005, Journal of the Geological Society.