Second Horizontal Derivatives of Ground Magnetic Data Applied to Gold Exploration in thE Yilgarn Craton of Western Australia

1997 ◽  
Vol 28 (1-2) ◽  
pp. 232-234 ◽  
Author(s):  
N. R. Gyngell
Keyword(s):  
Western Australia ◽  
Magnetic Data ◽  
Yilgarn Craton ◽  
Gold Exploration ◽  
Ground Magnetic ◽  
Derivatives Of

Interpretation of ground magnetic data in Suyoc, Mankayan Mineral District, Philippines

2021 ◽  
Author(s):  
Creszyl Joy J. Arellano ◽  
Leo T. Armada ◽  
Carla B. Dimalanta ◽  
Karlo L. Queaño ◽  
Eric S. Andal ◽  
...  
Keyword(s):  
Magnetic Data ◽  
Ground Magnetic ◽  
Mineral District

Optical filtering of airborne and ground magnetic data

1976 ◽  
Vol 114 (4) ◽  
pp. 663-683 ◽  
Author(s):  
M. K. Seguin ◽  
H. H. Arsenault
Keyword(s):  
Magnetic Data ◽  
Optical Filtering ◽  
Ground Magnetic

Automatic 3-D interpretation of potential field data using analytic signal derivatives

Geophysics ◽  
1997 ◽  
Vol 62 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Nicole Debeglia ◽  
Jacques Corpel
Keyword(s):  
Signal Amplitude ◽  
Vertical Gradient ◽  
Analytic Signal ◽  
Magnetic Data ◽  
Practical Implementation ◽  
Potential Field Data ◽  
Gravity And Magnetic ◽  
Second Derivatives ◽  
Gravity And Magnetic Data ◽  
Derivatives Of

A new method has been developed for the automatic and general interpretation of gravity and magnetic data. This technique, based on the analysis of 3-D analytic signal derivatives, involves as few assumptions as possible on the magnetization or density properties and on the geometry of the structures. It is therefore particularly well suited to preliminary interpretation and model initialization. Processing the derivatives of the analytic signal amplitude, instead of the original analytic signal amplitude, gives a more efficient separation of anomalies caused by close structures. Moreover, gravity and magnetic data can be taken into account by the same procedure merely through using the gravity vertical gradient. The main advantage of derivatives, however, is that any source geometry can be considered as the sum of only two types of model: contact and thin‐dike models. In a first step, depths are estimated using a double interpretation of the analytic signal amplitude function for these two basic models. Second, the most suitable solution is defined at each estimation location through analysis of the vertical and horizontal gradients. Practical implementation of the method involves accurate frequency‐domain algorithms for computing derivatives with an automatic control of noise effects by appropriate filtering and upward continuation operations. Tests on theoretical magnetic fields give good depth evaluations for derivative orders ranging from 0 to 3. For actual magnetic data with borehole controls, the first and second derivatives seem to provide the most satisfactory depth estimations.

Resolving Optimum Magnetic Signatures for Drill-Hole Targeting in Gold Exploration – A Case Study for Mbudzane in Gwanda, Zimbabwe

2013 ◽  
Vol 3 (1) ◽  
pp. 9-29
Author(s):  
Dumisani John Hlatywayo ◽  
Emmanuel Sakala
Keyword(s):  
Drill Hole ◽  
Magnetic Survey ◽  
Gold Exploration ◽  
Rock Formations ◽  
Induced Polarisation ◽  
Line Spacing ◽  
Magnetic Signatures ◽  
Ground Magnetic ◽  
Tilt Derivative ◽  
Resistivity Image

Optimum magnetic signatures for drill-hole targeting in gold exploration in Mbudzane were resolved from induced polarisation-resistivity and magnetic anomalies. Total magnetic field and a gold-in-soil map showed the area is magnetically quiet with high anomalous values along old gold workings. Induced polarisation was carried out along a grid for lines of 500m length, 50m separation and a baseline oriented at 330˚. The survey comprised a gradient array and three real sections. The magnetic survey was conducted over the same grid as the induced polarisation. Stations were set at 5m intervals for a line spacing of 50m. The results show intense anomalies that suggest different degrees of magnetic alteration and a set of conjugate lineaments and faults that possibly control the mineralisation in Mbudzane. The tilt derivative of the reduced-to-pole image resolves the separation between anomalies, giving information on the faulting. High chargeability is confined to the sheared and silicified mafic schist. The gradient resistivity image revealed contact between rock formations. Real section IP shows coincident low chargeability – low resistivity anomalies close to the surface. Chargeability intensity increases with depth, suggesting incipient development of disseminated sulphide replacement zones. A strong correlation between ground magnetic inferred contacts and apparent resistivity-chargeability anomalies forms the basis for suggesting a new drill-hole targeting. They dictate both the depth and angle at which drilling should be carried out. These results should be applicable to any region where drill-hole targeting in gold exploration may be required.

Proterozoic deformation in the northwest of the Archean Yilgarn Craton, Western Australia

2008 ◽  
Vol 162 (3-4) ◽  
pp. 354-384 ◽  
Author(s):  
Catherine V. Spaggiari ◽  
Jo-Anne Wartho ◽  
Simon A. Wilde
Keyword(s):  
Western Australia ◽  
Yilgarn Craton

scholarly journals Performance of Two Different Flight Configurations for Drone-Borne Magnetic Data

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5736
Author(s):  
Filippo Accomando ◽  
Andrea Vitale ◽  
Antonello Bonfante ◽  
Maurizio Buonanno ◽  
Giovanni Florio
Keyword(s):  
Electromagnetic Interference ◽  
Source Parameters ◽  
Spectral Characteristics ◽  
Magnetic Data ◽  
Prototype System ◽  
Control Dataset ◽  
Periodic Data ◽  
Ground Magnetic ◽  
The Stability ◽  
Careful Processing

The compensation of magnetic and electromagnetic interference generated by drones is one of the main problems related to drone-borne magnetometry. The simplest solution is to suspend the magnetometer at a certain distance from the drone. However, this choice may compromise the flight stability or introduce periodic data variations generated by the oscillations of the magnetometer. We studied this problem by conducting two drone-borne magnetic surveys using a prototype system based on a cesium-vapor magnetometer with a 1000 Hz sampling frequency. First, the magnetometer was fixed to the drone landing-sled (at 0.5 m from the rotors), and then it was suspended 3 m below the drone. These two configurations illustrate endmembers of the possible solutions, favoring the stability of the system during flight or the minimization of the mobile platform noise. Drone-generated noise was filtered according to a CWT analysis, and both the spectral characteristics and the modelled source parameters resulted analogously to that of a ground magnetic dataset in the same area, which were here taken as a control dataset. This study demonstrates that careful processing can return high quality drone-borne data using both flight configurations. The optimal flight solution can be chosen depending on the survey target and flight conditions.

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