I think you want to know maximum depth of magnetic anomaly source. Theoretical using down ward method, but this method is unstable. It is better you use from Model Vision software for inversion modelling. The Geosoft is for  data processing, not modeling. Of course, Geosoft has application for  basement Depth Estimation and modeling. Also there are many inversion method or numerical method for final depth estimation.

Good luck

Subhendu Hello

Theoretically, you can recognize any magnetic source with magnetization (or magnetic inclination) differenig from the host media and occuring over the Curie surface (~ 580-600 oC).

For inverse problem solution different methods can be applied. Some of these methods developed especially for complex environments (oblique magnetization, rugged relief and unknown level of the normal field) you can find in the following publications presented in the RG DataBase:

Eppelbaum, L.V., Khesin, B.E. and Itkis, S.E., 2001. Prompt magnetic investigations of archaeological remains in areas of infrastructure development: Israeli experience. Archaeological Prospection, 8, No.3, 163-185.

Eppelbaum, L.V., 2011. Study of magnetic anomalies over archaeological targets in urban conditions. Physics and Chemistry of the Earth, 36, No. 16, 1318-1330.

Eppelbaum, L.V., 2015. Quantitative interpretation of magnetic anomalies from thick bed, horizontal plate and intermediate models under complex physical-geological environments in archaeological prospection. Archaeological Prospection, 23, No. 2, 255-268.

Eppelbaum, L.V., 2015. Quantitative interpretation of magnetic anomalies from bodies approximated by thick bed models in complex environments.  Environmental Earth Sciences, 74, 5971-5988.

Best regards

Lev Eppelbaum

Eppelbaum, L.V. and Mishne, A.R., 2011. Unmanned Airborne Magnetic and VLF investigations: Effective Geophysical Methodology of the Near Future. Positioning, 2, No. 3, 112-133.

The robustness of Geosoft software is its flexibility in enhancing and or providing information of interest and de-emphasize or surppress the other . Thus to obtain magnetic anomalies at different depths, I suggest you use depth continuation process subroutine of GEOSOFT software which discriminate against wavelengths (long and short). Based thereon depth continuation process is of 2 kinds namely upward and downward continuation. Whilst upward continuation process will provide magnetic anomalies at different depths due to deep magnetic sources by enhancing long wavelength and surpressing the short wavelength; reverse is the case for downward continuation. However, obtaining exact depth might be difficult due to non-uniqueness. It is therefore imperative the depths obtained are validated using Source Parameter Imaging (SPI) and perhaps ground-truthing.

Dear all , Thanks for your guidance and i want one more specific guidance in this case.

I have to prepare different anomaly maps (gravity & magnetic) in different depths like 1000m 1500m and i have to investigate the changes so ..in this case downward continuation will be best or any other methods are there?

Hi

Downward continuation is unstable. For real potential data befor using downward must apply a smooting filter. You can the upward continuation for weaken short wavelength related to small and shallow sources. The downward or upward continuatoin are used for qualitative interpretation. It is better to use of numerical methods such as Euler or modeling methods.

Dear Ata Sir

                               Thanks for your guidance. In geosoft Euler will give different depths anomaly map? IS there any tool or option for that?

Euler give some rang  of different depth. If you select the Euler entrance parameters in Geosoft correctly, the solutions are exact. You also can use from the power spectrum  or AN-EUL in Geosoft.. Also you can apply the proposed  methods in the authentic articles for depth estimation. Of course, it needs that  you write a code for desired method. 

I wish my comments be useful

Ata

Thanks Yunus and Ana for your kind guidance....I will tell result  after doing some more research on it....

You can also try Matched Filter Analysis, https://pubs.usgs.gov/of/2007/1355/pdf/of07-1355.pdf.

I have some published research using this, you can find in my profile.

Well if you are using Geosoft, try VOXI (3D inversion) with or without constraints (geology, well data, ...) as a first step. Having a good data is also important. How big is your grid? There are also many filters such as power spectrum where you can see your data. Good Luck.

Dear Sarita

I hope these referenseces be useful.

Ata

http://www.geosoft.com/media/uploads/resources/technical-notes/montaj_depthtobasement_technote.pdf

http://www.geosoft.com/media/uploads/resources/brochures/OM_GM_fs_2009_10_web.pdf

Depth estimation is the ultimate goal of exploration geophysics. There are many traditional ways to estimate depths of 2D anomalies (like 3D Euler filter mentioned above), however, the best way is to run 3D inversion. I suggest to use Magnetization Vector Inversion (MVI) to estimate the Magnetization Vectors in 3D. The magnitude of the vectors gives you the susceptibility distribution. Although, unconstrained inversion gives you a rough view about target depths. To increase your 3D model certainty, you can probably use drill-core constrained inversion methods, or cooperative/joint inversion methods.

Hi everyone, I have a similar problem. I've been working with Euler Deconvolution of Geosoft but the depth results become more urcentain when depth increases more than 2 km, the problem is that I'm interested on deep upper crust features. I tried on increasing the grid cell size of the original grid but I didn't have good results, what happens with upward continuations, are the depths correct or need to be modified? I'm working with gravitmetric and magnetic data by the way.

All suggestions will be much appreciated.

What problem you are getting exactly ? how many number of solution and what is the statistics of yours solution? what is the depth tolerance and window cell size and total how many number of data points ? which is ur expected result? is it ground data or model data? please let us know ...clear the problem Claudia Peredo

Subhendu, thanks for your response. I'm working on identifying fault systems in a regional area (around 450 square kilometers) using satellite gravity and aeromagnetic data with special interest on the deepest structures. For my gravity data I'm working with Complete Bouguer Anomaly, the grid cell size is 880 meters and for my window I choosed 20x20 (wich is equivalent to 17600 meters) ando also tried with 15x15 window. My SI is 0 with a depth tolerance of 15. For this parameters I obteined 7006 solutions were I applied a restriction of a dxy tolerance of 40%. The problem is that when I graphic the solutions by depth I realize the solutions related to depths more than 2km are clustered and doesn't represent alignements like in more shallow depths. For the 15 x 15 window the response seem to improve for shallow features but still the same for the deepest structures.

Dear Claudia Peredo , as you have told that you are interested in deeper structure and you are working with Bouguer anomaly which is a summed of residual and regional, so here in your case residual is noise as you are finding deeper structure so you have to eliminate residual part and try to work with regional part for that you can use upward continuation and for this you can follow some publications to understand the mechanism of upward continuation, and then apply Euler solutions with different set of SI and window size and try it then let me know ..best wishes.....Sub..

References

Jacobsen, B. H., 1987. A case for upward continuation as a standard separation filter for potential field maps.Geophys-ics, 52(8), 1138-1148.

Keating, P., N. Pinet, and M. Pilkington, 2011b. Comparison of some commonly used regional residual separation techniques: Proceedings of International Workshop on Gravity, Electrical & Magnetic Methods.

Actually, Downward Continuation is what you need, but its results are very non-unique. There are some research articles about handling the non-uniqueness of Downward Continuation to get the most stable results, but you can't do that inside Geosoft yet and you need some coding practice.

Article A stable iterative downward continuation of potential field data

https://academic.oup.com/gji/article/151/1/146/622474

Article An improved and stable downward continuation of potential fi...

If you wish to model physical properties (susceptibility/density/resistivity/chargeability) that lead to the observed geophysical signals, you should use VOXI Earth Modeling module inside the Oasis Montaj.