Forward modeling of self-potential fields in mineral exploration

2007 ◽  
Author(s):  
Carlos A Mendonça
Keyword(s):  
Mineral Exploration ◽  
Forward Modeling ◽  
Potential Fields ◽  
Self Potential

Marine self-potential gradient exploration of the continental margin

Geophysics ◽  
2005 ◽  
Vol 70 (5) ◽  
pp. G109-G118 ◽  
Author(s):  
Graham Heinson ◽  
Antony White ◽  
David Robinson ◽  
Nader Fathianpour
Keyword(s):  
Mineral Exploration ◽  
South Australia ◽  
Potential Gradient ◽  
Ocean Waves ◽  
Horizontal Gradient ◽  
Reconstruction Method ◽  
Source Regions ◽  
Image Reconstruction Method ◽  
Numerical Finite Element ◽  
Self Potential

The self-potential (SP) method for mineral exploration is seldom used on land, primarily because of electrode noise problems and nonunique interpretations. Marine measurements of the horizontal gradient of the SP field, on the other hand, are relatively simple to make with an array of electrodes towed behind a ship. With low ship speeds of 5 to 10 km/hour, dense spatial sampling (∼1 m) can be obtained with resolution of better than 1 μV/m. In this paper we report on gradient SP data recorded on the continental shelf of South Australia by a horizontal array of towed electrodes approximately 20 m above the seafloor. Ocean waves and swells with periods of 5 to 15 s yielded large amplitude signals ±20 μV/m, but subseafloor mineralization produced SP gradient anomalies of ±50 μV/m and widths of 2 km or more in a number of parallel traverses. Integrating the observed SP gradients along each line delineated SP anomalies of amplitude up to −100 mV. Self-potential and magnetic anomaly data show limited spatial correlation and have different wavelengths, suggesting that SP sources are probably nonferrous minerals, such as graphite, and are deeper than the magnetic sources. The source of the SP signal is probably reduction-oxidation (redox) potential ([Formula: see text]) variations across a conducting body below the seafloor. We approximate the source as being two dimensional and find the most probable locations of line sources by an image reconstruction method. Numerical finite-element modeling of more realistic source regions suggests shallow, easterly dipping (∼15°) conductors of 1 Ω.m in the uppermost 2 km.

2.5D self-potential forward modeling by natural-infinite element coupling method

2020 ◽  
Vol 179 ◽  
pp. 104077
Author(s):  
Jing Xie ◽  
Yi-an Cui ◽  
Youjun Guo ◽  
Lijuan Zhang ◽  
Meryem Fanidi ◽  
...  
Keyword(s):  
Forward Modeling ◽  
Coupling Method ◽  
Infinite Element ◽  
Self Potential

High-precision Fourier forward modeling of potential fields

Geophysics ◽  
2014 ◽  
Vol 79 (5) ◽  
pp. G59-G68 ◽  
Author(s):  
Leyuan Wu ◽  
Gang Tian
Keyword(s):  
High Precision ◽  
Forward Modeling ◽  
Potential Fields

Ensemble Kalman Inversion for Determining Model Parameter of Self-potential Data in the Mineral Exploration

2021 ◽  
pp. 179-202
Author(s):  
Sungkono ◽  
Erna Apriliani ◽  
Saifuddin ◽  
Fajriani ◽  
Wahyu Srigutomo
Keyword(s):  
Mineral Exploration ◽  
Model Parameter ◽  
Self Potential

3D Forward Modeling of Seepage Self-potential Using Finite-infinite Element Coupling Method

2020 ◽  
Vol 25 (3) ◽  
pp. 381-390
Author(s):  
Jing Xie ◽  
Yi-an Cui ◽  
Lijuan Zhang ◽  
Changying Ma ◽  
Bing Yang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Streaming Potential ◽  
Forward Modeling ◽  
The Self ◽  
Coupling Method ◽  
Infinite Element ◽  
Coupled Method ◽  
Complex Models ◽  
Self Potential

The streaming potential in porous media is one of the main constituents of the self-potential. It has attracted special attention in environmental and engineering geophysics. Forward modeling of streaming potentials could be the foundation of corresponding data inversion and interpretation, and improving the application effect of the self-potential method. The traditional finite element method has a large subdivision area and computational quantity, and the artificial boundary condition is not suitable for complex models. The Helmholtz-Smoluchowski equation is introduced for evaluating the streaming potential. Then three new shape functions of the multidirectional mapping infinite elements are proposed and the finite-infinite element coupling method is deduced for reducing the subdivision scale and improving both the calculation efficiency and accuracy. The correctness and validity of the new coupled method are verified by a resistive model in homogeneous half-space. Besides, a seepage model with complex terrain and a landfill model with dynamic leakages are modeled using the improved coupled method. The results show that the accuracy of the improved coupled method is superior to the unimproved coupled method, and is better than the finite element method. Also, the coupled method has better adaptability to complex models and is suitable for the accurate simulation of dynamic multi-source seepage models.

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