*Interpretation Method:There are two approaches to interpretation of the Bouguer anomaly:1- Direct: The original data are analysed.2- Indirect: models are constructed to compute theoretical gravity anomaly.High GravityActual DataTheoretical modelFaultCavityOre

*Gravity Data display in two way:1- As profiles; Has some charecteristic:A- Easley interpreted.B- RapidC- Note more accurate. DistanceBouguer GravityDistanceBouguer Anomaly2- As map; Has some charecteristic:A- Need skill ness to interprete.B- Need more timeC- More accurate. Bouguer gravity mapBouguer Anomaly map

*Ambiguity in gravity interpretation:We have the following ambiguities:1- The B.G or B.A at any station may represent superimposed effect of many mass distribution at various depths. Or we can say the B.G map is never a simple picture of a single isolated anomaly. B.G or B.A is a combination of :1- Sharp anomaly.2- Broad anomaly.SharpBroadFaultOre bodyAnticline

*2- Determining the source from effect (it is more serious) . There are a large number of mass distribution produce the same effect.DistanceBouguer Anomaly1234

*DistanceBouguer AnomalyDistanceBouguer AnomalyCavityAnticlineFaultFaultDeep StructureShallow StructureRegionalResidual

*Regional and Residual Gravity:Regional: It is characterized by:1- It is from large scale structure.2- locate at great depth.3- It is of long wave length.4- Covers large distance.5- It has large magnitude.6- Vary slowly with distance.7- Example: a- Basement b- Regional anticline. c- Petroleum traps. d- Deep seated faults.Regional and Residual Gravity:Residual: It is characterized by:1- It is from small scale structure.2- locate at small depth.3- It is of short wave length.4- Covers small distance.5- It has small magnitude.6- Vary greatly with distance.7- Example: a- Shallow faults. b- small anticline. c- Cavity. d- Groundwater table.

*Bouguer Gravity (500 Mgal)RegionalResidualBouguer AnomalyDistanceBouguer AnomalyA- Smooth contour lines.B- Parallel.C- Space between lines are equalD- Large magnitude (495 Mgal)

A- Complex contour lines.B- Irregular.C- Space between lines are not equalD- Small magnitude (5 Mgal)

*How we distinguish regional and residual:DistanceBouguer AnomalyResidualRegionalProfileMapExample:1- Ore bodyResidualRegional

*Bouguer Anomaly2- FaultResidualRegionalMethod of Separation of Anomaly