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| Titel |
Estimation of the total magnetization direction of approximately spherical bodies |
| VerfasserIn |
V. C. Oliveira, D. P. Sales, V. C. F. Barbosa, L. Uieda |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2198-5634
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| Digitales Dokument |
URL |
| Erschienen |
In: Nonlinear Processes in Geophysics Discussions ; 1, no. 2 ; Nr. 1, no. 2 (2014-09-05), S.1465-1507 |
| Datensatznummer |
250115124
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| Publikation (Nr.) |
 copernicus.org/npgd-1-1465-2014.pdf |
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| Zusammenfassung |
| We have developed a fast total-field anomaly inversion to estimate
the magnetization direction of multiple sources with approximately
spherical shape and known centres. Our method can be applied to
interpret multiple sources with different magnetization
directions. It neither requires the prior computation of any
transformation like reduction to the pole nor the use of regularly
spaced data on a horizontal grid. The method contains flexibility to
be implemented as a linear or non-linear inverse problem, which
results, respectively, in a least-squares or robust estimate of the
components of the magnetization vector of the sources. Applications
to synthetic data show the robustness of our method against
interfering anomalies and errors in the location of the sources'
centre. Besides, we show the feasibility of applying the upward
continuation to interpret non-spherical sources. Applications to
field data over the Goiás Alkaline Province (GAP), Brazil, show
the good performance of our method in estimating geological
meaningful magnetization directions. The results obtained for
a region of the GAP, near from the alkaline complex of Diorama,
suggest the presence of non-outcropping sources marked by strong
remanent magnetization with inclination and declination close to
-70.35° and -19.81°, respectively. This
estimated magnetization direction leads to predominantly positive
reduced-to-the-pole anomalies, even for other region of the GAP, in
the alkaline complex of Montes Claros de Goiás. These results
show that the non-outcropping sources near from the alkaline complex
of Diorama have almost the same magnetization direction of that ones
in the alkaline complex of Montes Claros de Goiás, strongly
suggesting that these sources have emplaced the crust almost within
the same geological time interval. |
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