Additional references not referenced in the text Ander, M E., Govro, J., Shi, J., and Aliod, D., 1999b, Deep Penetration Density: A new borehole gravity meter: SEG Expanded Abstracts, 18, 39-392 Cowan, D.R., and Cowan, S., 1993, Separation filtering applied to aeromagnetic data: Exploration Geophysics24, 429-436 Longman, I.M., 1959, Formulas for computing the tidal accelerations due to the moon and the sun: J Geoph Res., 64, 2351-2355 Marson, I and Klingele, E E., 1993, Advantages of using the vertical gradient of gravity for 3-D interpretation : Geophysics, 58, 1588-1595 Sandwell, D.T., 1991, Geophysical applications of satellite altimetry: Rev Geophys Suppl., 29, 132-137 Verduzco, B., Fairhead, J.D., Green, C.M., and MacKenzie, C., 2004, New insights into magnetic derivatives for structural mapping: The Leading Edge, 23, 116-119 Vine, F J and D H Matthews, 1963, Magnetic anomalies over oceanic ridges, Nature, 199, 947-949 Figure captions Figure Satellite-derived marine free-air gravity field, merged with terrestrial gravity field, published by Sandwell and Smith (2001), courtesy of the NOAA-NGDC 75 Figure Perspective view of a 3D model representing the base of aquifer sediments in the Albuquerque and neighboring basins Gravity modeling, which focused on separating the effects of the aquifer thickness from the underlying sedimentary package plus Precambrian basement, used the iterative technique of Jachens and Moring (1990) constrained by drill hole information The model was combined with faults synthesized from geophysical interpretations and geologic mapping to give a 3D surface that ultimately served as the lower limit of a regional ground-water flow model for the entire basin area From Grauch et al (2002) Figure Gzz, the partial derivative with respect to the Z axis, of the vertical force of gravity Left: Gzz derived from conventional Bouguer gravity Center: Gzz as measured with FTG survey Right: “Best estimate” of Gzz where all tensor components have been incorporated in data enhancement procedures Figure Prestack depth-migration profile along line B through K-2 Field Top: Kirchhoff migration Center: Kirchhoff migration with base of salt horizon shown in yellow, as determined by FTG inversion Bottom: Wave-equation prestack depth-migration which also shows the presence of a salt keel Yellow horizon shows the FTG inversion result Figure Vertical gravity gradient, Gzz, from the Ekati survey The image below shows an enlarged section of a south-east part of the image above Two dykes separated at just over 300 m are resolved on the lower image, in which the white bar has a horizontal dimension of 300 m Figure Vertical gravity, Gz, from the Ekati survey 76 Figure 77 Figure 78 Figure 79 Figure 80 Figure 81 Figure 82 ... partial derivative with respect to the Z axis, of the vertical force of gravity Left: Gzz derived from conventional Bouguer gravity Center: Gzz as measured with FTG survey Right: “Best estimate”... a 3D model representing the base of aquifer sediments in the Albuquerque and neighboring basins Gravity modeling, which focused on separating the effects of the aquifer thickness from the underlying... shows the presence of a salt keel Yellow horizon shows the FTG inversion result Figure Vertical gravity gradient, Gzz, from the Ekati survey The image below shows an enlarged section of a south-east