Joint inversion of airborne gravity gradiometry and magnetic data from the Lac de Gras region of the Northwest Territories of Canada

2014 ◽  
Author(s):  
Yue Zhu* ◽  
Martin Cuma ◽  
Michael S. Zhdanov ◽  
Yuri Kinakin
Keyword(s):  
Northwest Territories ◽  
Joint Inversion ◽  
Magnetic Data ◽  
Airborne Gravity ◽  
Gravity Gradiometry ◽  
Airborne Gravity Gradiometry

scholarly journals Interpretation of airborne gravity gradiometry and magnetic data using cross-gradients

2012 ◽  
Vol 2012 (1) ◽  
pp. 1-4
Author(s):  
Carlos Cevallos ◽  
Mark Dransfield ◽  
Jacqueline Hope ◽  
Heather Carey
Keyword(s):  
Magnetic Data ◽  
Airborne Gravity ◽  
Gravity Gradiometry ◽  
Airborne Gravity Gradiometry

3D inversion of airborne gravity gradiometry data for the Budgell Harbour Stock, Newfoundland: A case history using a probabilistic approach

Geophysics ◽  
2019 ◽  
Vol 84 (4) ◽  
pp. B269-B284 ◽  
Author(s):  
Meixia Geng ◽  
J. Kim Welford ◽  
Colin G. Farquharson ◽  
Alexander L. Peace
Keyword(s):  
Joint Inversion ◽  
Probabilistic Approach ◽  
Stable Solution ◽  
Airborne Gravity ◽  
Inversion Method ◽  
Gravity Gradiometry ◽  
3D Inversion ◽  
Long Wavelength ◽  
Text Model ◽  
Airborne Gravity Gradiometry

We have studied the Mesozoic Budgell Harbour Stock, a gabbroic intrusion in north-central Newfoundland, Canada, using 3D inversion of airborne gravity gradiometry data based on a probabilistic inversion method. Significantly, differences were observed between the results when inverting the single [Formula: see text] component and when inverting the 5C combination. We also found that the [Formula: see text] model failed to reproduce the long-wavelength signals from other components, whereas the model recovered from five components accommodated all of the signals from all of the components. To estimate the influence of long-wavelength signals from targets other than the intrusion, such as deeper bodies or large-scale terrain variations, inversion tests are performed on a synthetic model. The inversion results for the synthetic example indicate that the joint inversion of five components is more sensitive to long-wavelength signals, which can generate spurious structures to fit all of the signals from the five components. In contrast, the [Formula: see text] model is less affected by the long-wavelength signals and thus tends to produce a stable solution, despite failing to incorporate all of the long-wavelength signals from the tensor data. We found that gravity gradiometry data could be used to delineate the intrusion within this study area, which is also consistent with the susceptibility model recovered from inversion of aeromagnetic data and with results from a previous geophysical study. Moreover, the differences between the [Formula: see text] model and the 5C model may reflect the long-wavelength signals in the gravity gradiometry data.

scholarly journals Recovering Magnetization of Rock Formations by Jointly Inverting Airborne Gravity Gradiometry and Total Magnetic Intensity Data

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 366
Author(s):  
Michael Jorgensen ◽  
Michael S. Zhdanov
Keyword(s):  
Joint Inversion ◽  
Magnetization Vector ◽  
Mineral Deposit ◽  
Airborne Gravity ◽  
Earth Model ◽  
Magnetic Intensity ◽  
Gravity Gradiometry ◽  
Rock Formations ◽  
Magnetic Inversion ◽  
Airborne Gravity Gradiometry

Conventional 3D magnetic inversion methods are based on the assumption that there is no remanent magnetization, and the inversion is run for magnetic susceptibility only. This approach is well-suited to targeting mineralization; however, it ignores the situation where the direction of magnetization of the rock formations is different from the direction of the induced magnetic field. We present a novel method of recovering a spatial distribution of magnetization vector within the rock formation based on joint inversion of airborne gravity gradiometry (AGG) and total magnetic intensity (TMI) data for a shared earth model. Increasing the number of inversion parameters (the scalar components of magnetization vector) results in a higher degree of non-uniqueness of the inverse problem. This increase of non-uniqueness rate can be remedied by joint inversion based on (1) Gramian constraints or (2) joint focusing stabilizers. The Gramian constraints enforce shared earth structure through a correlation of the model gradients. The joint focusing stabilizers also enforce the structural similarity and are implemented using minimum support or minimum gradient support approaches. Both novel approaches are applied to the interpretation of the airborne data collected over the Thunderbird V-Ti-Fe deposit in Ontario, Canada. By combining the complementary AGG and TMI data, we generate jointly inverted shared earth models that provide a congruent image of the rock formations hosting the mineral deposit.

scholarly journals AIRBORNE GRAVITY GRADIOMETRY SURVEY IN THE SOUTHEASTERN PORTION OF PIMENTA BUENO GRABEN IN PARECIS BASIN: INTEGRATED 2D FORWARD MODELING AND ITS IMPLICATIONS IN DEFINING A NEW STRUCTURAL FRAMEWORK

2015 ◽  
Vol 33 (1) ◽  
pp. 101 ◽  
Author(s):  
Alan De Souza Cunha ◽  
Fábio Andre Perosi ◽  
Luiz Fernando Braga ◽  
Leandro Barros Adriano ◽  
Marlon Cabrera Hidalgo-Gato ◽  
...  
Keyword(s):  
Geophysical Methods ◽  
Forward Modeling ◽  
Magnetic Data ◽  
Airborne Gravity ◽  
Gravity Gradiometry ◽  
Seismic Section ◽  
Technical Data ◽  
Geophysical Surveys ◽  
Well Data ◽  
Airborne Gravity Gradiometry

ABSTRACT. Airborne geophysical surveys are widely used in geological prospecting of hydrocarbon reservoirs. The efficiency and acquisition speed of these methods in covering large areas accredit them as a key tool for any exploration project where there are sparse technical data available to support the exploratory decisions. Among the airborne geophysical methods, potential methods, namely, gravity and magnetics are the most spread in oil & gas projects of this nature. Such methods are used to support the generation of regional geological knowledge and also in detailed approaches, integrated with seismic, geochemical and well data. The objectives of this work were to describe the FalconTM Airborne Gravity Gradiometry System, explaining acquisition and processing steps, and crosscheck the results of its application in the southeastern portion of the Parecis Basin with two proposed models for the structural genesis and evolution proposed by the academy. Throughout the integration of the airborne gravity gradiometry and magnetic data along 2D seismic section it was possible to infer the geometry of the Pimenta Bueno Graben. While many works have mapped basement depth about 7,000 m, the current modeling shows basement deeper than 10,000 m.Keywords: airborne gravity gradiometry, 2D forward modeling, Parecis Basin, FalconTM, tectonic framework.RESUMO. Levantamentos aerogeofísicos são amplamente utilizados na prospecção geológica de reservatórios de hidrocarbonetos. A eficiência e a velocidade de aquisição desses métodos na cobertura de grandes áreas os credenciam como uma ferramenta fundamental para qualquer projeto de exploração onde há poucos dados técnicos disponíveis para apoiar as decisões exploratórias. Dentre os métodos geofísicos aéreos, os potenciais gravimétricos e magnetométricos são os mais utilizados em projetos da natureza de prospecção de óleo e gás. Tais métodos são utilizados para apoiar a geração de conhecimento geológico regional e também em abordagens de detalhe, integrados com seções sísmicas, dados geoquímicos e de poço. Este trabalho pretende apresentar o Sistema FalconTM de Gravimetria Gradiométrica, descrevendo suas etapas de aquisição e processamento, e interpretação dos resultados de sua aplicação na porção sudeste da Bacia do Parecis, em confronto com dois modelos propostos para a gênese e evolução estrutural da Bacia. Através da integração dos dados de gravimetria gradiométrica com dados magnéticos extraídos ao longo da secção sísmica 2D foi possível inferir a geometria detalhada do graben de Pimenta Bueno. Enquanto trabalhos anteriores mapearam a profundidade do embasamento em cerca de 7.000 metros, uma modelagem 2D direta e vinculada mostra que o mesmo pode alcançar, de forma localizada, profundidades maiores que 10.000 metros.Palavras-chave: gravimetria gradiométrica aérea, modelagem direta 2D, Bacia dos Parecis, FalconTM, arcabouc¸o tectônico.

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