Banca de DEFESA: ELIZANGELA SOARES AMARAL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
DISCENTE : ELIZANGELA SOARES AMARAL
DATA : 23/10/2018
HORA: 09:00
LOCAL: Auditório do Departamento de Geofísica
TÍTULO:

Can Euler's Deconvolution delineate interfaces of magnetic bodies?

PALAVRAS-CHAVES:

Magnetometry; Euler deconvolution; magnetic modeling

PÁGINAS: 77
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Geociências
RESUMO:

Methodological researches have pointed out severe limitations of Euler deconvolution (ED) to outline source shape. However ED has been extensively employed on field data to outline interfaces and estimate dips of faults and shear zones, evidencing a disagreement between theoretical and practical results of the tool. To reconcile this disagreement, we show that ED might help to infer useful information about source volume and dip, when it is applied to the reduced-to-the-pole anomalies caused by two types of body. In the first, the body might have uniform magnetization contrast but rough interfaces. The dip can then be grossly estimated from the solution cluster. In the second type, the body interfaces might be smooth but it has internal magnetization contrasts. Now, besides dip, one can delimit approximately the source volume from the solution cluster envelope. ED was also applied to field anomalies, which are caused by a curved-shape thrust zone and by a banded iron formation. These two field cases were considered as examples of anomalies caused by the described first and second types of bodies, being the ED results similar for each body type: for the thrust zone, the solution cluster follows its known geologic shape and allows to estimate dip variation whilst, for the banded iron formation, the solution cluster spreads out occupying a volume. For the latter case, a trial-anderror 3D modeling of the field anomaly was also performed to estimate the magnetization distribution and ED was applied to the fitting synthetic anomaly. The resulting solution cluster is similar to the one obtained with the field anomaly, showing the consistency of the ED results. From the obtained results, it can be conclude that ED does not really outlines source shape but that useful information about dip and volume might be indeed inferred.

MEMBROS DA BANCA:
Interno - 1315614 - DAVID LOPES DE CASTRO
Externo à Instituição - ROBERTA MARY VIDOTTI - UnB
Presidente - 349684 - WALTER EUGENIO DE MEDEIROS