Euler Deconvolution Applied to Potential Field Data from the Parnaíba Basin, Brazil

2003 ◽  
Author(s):  
Telma Aisengart Santos
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Euler Deconvolution ◽  
Potential Field Data ◽  
Parnaíba Basin

scholarly journals Geophysical tutorial: Euler deconvolution of potential-field data

2014 ◽  
Vol 33 (4) ◽  
pp. 448-450 ◽  
Author(s):  
Leonardo Uieda ◽  
Vanderlei C. Oliveira ◽  
Valéria C. F. Barbosa
Keyword(s):  
Open Source ◽  
Potential Field ◽  
Field Data ◽  
Synthetic Data ◽  
Euler Deconvolution ◽  
Potential Field Data ◽  
Python Package

In this tutorial, we will talk about a widely used method of interpretation for potential-field data called Euler de-convolution. Our goal is to demonstrate its usefulness and, most important, to call attention to some pitfalls encountered in interpretation of the results. The code and synthetic data required to reproduce our results and figures can be found in the accompanying IPython notebooks ( ipython.org/notebook ) at dx.doi.org/10.6084/m9.figshare.923450 or github.com/pinga-lab/paper-tle-euler-tutorial . The note-books also expand the analysis presented here. We encourage you to download the data and try them on your software of choice. For this tutorial, we will use the implementation in the open-source Python package Fatiando a Terra ( fatiando.org ).

scholarly journals GRAVITY AND MAGNETIC SIGNATURE OF THE TRANSBRASILIANO LINEAMENT IN THE EAST-CENTRAL PORTION OF THE PARNAÍBA BASIN, NORTHEASTERN BRAZIL

2017 ◽  
Vol 35 (1) ◽  
Author(s):  
Thuany Patrícia Costa de Lima ◽  
Emanuel Ferraz Jardim de Sá ◽  
Fernando Antonio Pessoa Lira Lins ◽  
Alex Francisco Antunes ◽  
José Antônio De Morais Moreira
Keyword(s):  
Shear Zone ◽  
Potential Field ◽  
Field Data ◽  
Magnetic Anomalies ◽  
Northeastern Brazil ◽  
Central Portion ◽  
East Central ◽  
Potential Field Data ◽  
Gravity And Magnetic ◽  
Parnaíba Basin

ABSTRACT. The Transbrasiliano Lineament (TBL) corresponds to a NE-trending mega shear zone of late Neoproterozoic age with an extensive segment underneath the Parnaíba Basin (northeastern Brazil); the Eopaleozoic to Mesozoic section of the basin evidence the lineament’s brittle reactivation events. This paper presents a case study of TBL in the east-central portion of Parnaíba Basin with a special concern to the characterization of pre-Silurian grabens in the basement. The approach involves the interpretation of potential field data and seismic reflection line based on a plastic dextral transcurrent mega shear zone model. The gravity anomaly belts display a curvilinear shape joining the NE trend of the TBL, in accordance to a dextral S-C pair. A retrogressive stage with narrower ductile-brittle dextral structures controlled the opening of pull-apart grabens. Magnetic anomalies seem to be related to these late structures. The integration of the map analyses, seismic interpretation and 2D gravity modeling led to the conclusion that the sources causing the gravity and magnetic anomalies in the basin result from mass variations related to anisotropies of the crystalline basement and crustal heterogeneities, such as granite plutons, metasedimentary belts, shear zones and pre-Silurian grabens. The delimitation of grabens underneath the Parnaíba Basin suffers severe restrictions when solely interpreted based on potential field data. Keywords: gravity forward modeling, Transbrasiliano Lineament, magnetic anomaly. RESUMO. O Lineamento Transbrasiliano (LTB) corresponde a uma megazona de cisalhamento com direção NE, de idade Neoproterozoica, com um extenso segmento subjacente à Bacia do Parnaíba; a seção Eopaleozoica a Mesozoica da bacia evidencia seus eventos de reativação. Este trabalho aborda o LTB na porção centro-leste da Bacia do Parnaíba, com especial atenção à caracterização de grabens pré-Silurianos do embasamento. A abordagem envolve interpretações de dados de métodos potenciais e de linha sísmica de reflexão baseadas em um modelo de megazona de cisalhamento plástica transcorrente dextral. As faixas de anomalias gravimétricas exibem uma geometria curvilínea, aproximando-se em direção ao trend NE do Lineamento Transbrasiliano, em consonância a um par S-C dextral. Um estágio retrogressivo com estruturas dúcteis-frágeis mais estreitas controlaram a abertura de grabens pull-apart. As anomalias magnéticas imageam essas estruturas tardias. A integração da análise de mapas de anomalia, interpretação sísmica e modelagem gravimétrica 2D permite concluir que as fontes causadoras das anomalias gravimétricas e magnéticas na bacia resultam de variações de massa relacionadas a heterogeneidades crustais e às anisotropias do embasamento cristalino, tais como plútons graníticos, faixas de metassedimentos e zonas de cisalhamento, com contribuição subordinada dos grabens pré-Silurianos. A delimitação desses grabens subjacentes à Bacia do Parnaíba sofre severas restrições quando interpretadas unicamente com base nos dados de métodos potenciais. Palavras-chave: modelagem gravimétrica direta, Lineamento Transbrasiliano, anomalia magnética.

An improved approach for detecting the locations of the maxima in interpreting potential field data

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Luan Thanh Pham ◽  
Ozkan Kafadar ◽  
Erdinc Oksum ◽  
Ahmed M. Eldosouky
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Potential Field Data

Adaptive sampling of potential-field data: A direct approach to compressive inversion

Geophysics ◽  
2014 ◽  
Vol 79 (1) ◽  
pp. IM1-IM9 ◽  
Author(s):  
Nathan Leon Foks ◽  
Richard Krahenbuhl ◽  
Yaoguo Li
Keyword(s):  
Potential Field ◽  
Adaptive Sampling ◽  
Field Data ◽  
Computational Cost ◽  
Large Field ◽  
Magnetic Data ◽  
Data Sampling ◽  
Data Types ◽  
Data Set ◽  
Potential Field Data

Compressive inversion uses computational algorithms that decrease the time and storage needs of a traditional inverse problem. Most compression approaches focus on the model domain, and very few, other than traditional downsampling focus on the data domain for potential-field applications. To further the compression in the data domain, a direct and practical approach to the adaptive downsampling of potential-field data for large inversion problems has been developed. The approach is formulated to significantly reduce the quantity of data in relatively smooth or quiet regions of the data set, while preserving the signal anomalies that contain the relevant target information. Two major benefits arise from this form of compressive inversion. First, because the approach compresses the problem in the data domain, it can be applied immediately without the addition of, or modification to, existing inversion software. Second, as most industry software use some form of model or sensitivity compression, the addition of this adaptive data sampling creates a complete compressive inversion methodology whereby the reduction of computational cost is achieved simultaneously in the model and data domains. We applied the method to a synthetic magnetic data set and two large field magnetic data sets; however, the method is also applicable to other data types. Our results showed that the relevant model information is maintained after inversion despite using 1%–5% of the data.

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