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Abstract

Summary

We present the inversion results for airborne gravity gradient data of the Karasjok Greenstone Belt. The airborne gravity gradient data had been previously used to construct a structural model in conjunction with surface geological observations and bedrock properties. Forward calculation of this structural model fits the long-wavelength signal of the airborne gravity gradient data but poorly explains the observed short-wavelength signal. This can be explained by resolution of the model and the use of constant densities for each lithology. To refine density distribution of the model, we apply stochastic inversion in a Bayesian inversion framework. The inversion is applied to measured components and various combination of the constructed components. It is shown that the inversion of five or six tensor components does not necessarily improve the model resolution and provide better information. That implies that an inversion of the two measured or a subset of the constructed components can equally serve the purpose of interpretation with significantly reduced computation time. The results show a bent area with high-densities (>0.4g/m3) that can be associated with mineralisation at the flanks of the greenstone belt. These areas are more clearly seen in the inverse results than from the geological 3D model alone.

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/content/papers/10.3997/2214-4609.201801460
2018-06-11
2024-04-25

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http://instance.metastore.ingenta.com/content/papers/10.3997/2214-4609.201801460
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3D Stochastic Inversion of Airborne Gravity Gradient Data - Case Example over the Karasjok Greenstone Belt
Conference Proceedings 2018, 1 (2018); https://doi.org/10.3997/2214-4609.201801460
/content/papers/10.3997/2214-4609.201801460
/content/papers/10.3997/2214-4609.201801460
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