Dear Mr. Fauzi,

a 2-D composite color plot like that will not give you an answer to your question. See:

DILL, H.G. (2015) The Hagendorf-Pleystein Province: The center of pegmatites in an ensialic orogen.- Modern Approaches in Solid Earth Sciences,

Springer, Dortrecht, Heidelberg, London, New York, ISBN-978-3-319-18805-8, 475 pp.

Section 3.3

Geophysical suveys in the pegmatite-aplite areas of the NE Bavarian Basement

p. 163 - 172

You need cross sections and 3-D diagrams. It is only the contrast between the felsic mobilizates granite, pegmatite and aplite and the more basic country rocks that counts. Moreover I prefer a combination of gravimetry, seismics, geomagnetics and geoelectric measurements. Each method has its strong and weak points.

With kind regards

H.G.Dill

Hi Fakhruddin, I can only see a northwestern structural trend in these data. However, gravity data are not a very useful tool to interpret structures due to their poor resolution. Better try to conduct a ground magnetic survey across your prospect. It will give you a much clearer picture!

Dear Fakhruddin Fauzi

Gravity anomalies over granite bodies are often of negative polarity and can be represented as rounded polygons. These characteristics were used to trial a method to map possible locations of subsurface granite bodies.

Two approaches were used to outline the geometry of rounded gravity anomalies:

1· Contouring of the residual Bouguer gravity field after removal of a regional field; and

2· Detection of edges in the residual Bouguer gravity field.

The resulting polygons are coloured according to proximity to known granite, whether outcropping or found in wells. Three categories of polygon are identified: known granite falling within the gravity polygon, near such outcrop, or not proximal to outcrop.

The processing was done using software developed by the author in the Perl programming language and stored in the Energy Division software repository. The processing was organised to run in batch mode on any system on which Perl is installed: MS-Windows, Unix, Linux or NCI systems.

i send some articles about your question that i hope it will be useful for you.

sincerely yours.