scholarly journals Geophysical-Structural Framework in a Mineralized Region of Northwesternmost Camaquã Basin, Southern Brazil

2021 ◽  
Vol 60 (2) ◽  
pp. 101-123
Author(s):  
Henrique Garcia Pereira
Keyword(s):  
Potential Field ◽  
Depth Estimation ◽  
Southern Brazil ◽  
Potential Field Data ◽  
Structural Framework ◽  
Geological Features ◽  
Different Depths ◽  
Ground Magnetic ◽  
Deep Sources ◽  
Ground Potential

Airborne and ground magnetic and gravimetric maps provide important information about the spatial distribution of causative sources in the geological substrate. These sources normally have different physical and geometric properties and are located at different depths, making it difficult to identify the geological features that correspond to the sources. Filtering and enhancement techniques can be used to highlight features in potential field anomalies (such as center and edges of sources). Also, these techniques remove associated noise, isolate shallow from deep sources, and estimate depths. We applied enhancement and depth estimation techniques in airborne and ground potential field data to delineate a subsurface structural framework of two copper occurrences (Victor Teixeira and Capão Grande) in the northwestern border of Camaquã Basin with the Sul-Riograndense Shield. Our results confirmed previously recognized structures and revealed an interconnected structural framework, which has an estimated depth of 170 m by Euler solutions. This configuration suggests a possible connection between the two mineralization outcrops, which are separated by a distance of 2,300 m.

scholarly journals Geological features of the northeastern Canadian Arctic margin revealed from analysis of potential field data

2016 ◽  
Vol 691 ◽  
pp. 48-64 ◽  
Author(s):  
Goodluck K. Anudu ◽  
Randell A. Stephenson ◽  
David I.M. Macdonald ◽  
Gordon N. Oakey
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Canadian Arctic ◽  
Potential Field Data ◽  
Geological Features

scholarly journals Space-frequency analysis and reduction of potential field ambiguity

1997 ◽  
Vol 40 (5) ◽  
Author(s):  
M. Fedi ◽  
A. Rapolla
Keyword(s):  
Potential Field ◽  
Phase Plane ◽  
Gravity Data ◽  
Depth Resolution ◽  
Depth Estimation ◽  
Vertical Axis ◽  
Local Power ◽  
Potential Field Data ◽  
Space Frequency ◽  
Inherent Ambiguity

Ambiguity of depth estimation of magnetic sources via spectral analysis can be reduced representing its field via a set of space-frequency atoms. This is obtained throughout a continuous wavelet transform using a Morlet analyzing wavelet. In the phase-plane representation even a weak contribution related to deep-seated sources is clearly distinguished with respect a more intense effect of a shallow source, also in the presence of a strong noise. Furthermore, a new concept of local power spectrum allows the depth to both the sources to be correctly interpreted. Neither result can be provided by standard Fourier analysis. Another method is proposed to reduce ambiguity by inversion of potential field data lying along the vertical axis. This method allows a depth resolution to gravity or the magnetic methods and below some conditions helps to reduce their inherent ambiguity. Unlike the case of monopoles, inversion of a vertical profile of gravity data above a cubic source gives correct results for the cube side and density.

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.

Sign in / Sign up

Export Citation Format

Share Document