Gravity exploration must account for the horizontal and vertical differences in density which occur in subsurface geologic features. Gravity anomalies require lateral density discontinuities such as stratigraphic or structural changes in the subsurface. Vertical density differences in the subsurface will change the bias or overall amplitude level of a gravity map or profile but will not produce gravity anomalies.
After completing this module, you will have an understanding of:
- gravitational attraction.
- rock density.
- different sources for density information.
- density contrast.
- the importance of density contrasts to interpretation.
- why a layer-cake geologic section without local structure or stratigraphic changes will not produce local gravity anomalies.
- the reference Tables of Typical Density Values