scholarly journals Interpretation of gravity and magnetic data and development of two-dimensional cross-sectional models for the Border Ranges fault system, south-central Alaska

Geosphere ◽  
2013 ◽  
Vol 9 (2) ◽  
pp. 242-259 ◽  
Author(s):  
Niti Mankhemthong ◽  
Diane I. Doser ◽  
Terry L. Pavlis
Keyword(s):  
Fault System ◽  
Magnetic Data ◽  
Two Dimensional ◽  
Cross Sectional ◽  
South Central ◽  
Gravity And Magnetic ◽  
Gravity And Magnetic Data

Offshore extensions of the Avalon Zone of Newfoundland

1985 ◽  
Vol 22 (8) ◽  
pp. 1163-1170 ◽  
Author(s):  
H. G. Miller ◽  
A. K. Goodacre ◽  
R. V. Cooper ◽  
D. Halliday
Keyword(s):  
Strong Correlation ◽  
Sedimentary Basin ◽  
Magnetic Data ◽  
Two Dimensional ◽  
Gravity And Magnetic ◽  
Magnetic Modelling ◽  
Dimensional Gravity ◽  
Gravity And Magnetic Data ◽  
Avalon Peninsula ◽  
Block Faulting

Gravity and magnetic data from the nearshore region of the Avalon Zone of Newfoundland provide evidence of the nature of a sedimentary basin immediately east of the Avalon Peninsula. The data also suggest a strong correlation between the arcuate magnetic patterns of the offshore portion of the Avalon Zone and the Precambrian mafic volcanics mapped onshore. The offshore basin is interpreted to have been formed by Precambrian block faulting and subsequently filled by sediments derived from surrounding paleotopographic highs. Two-dimensional gravity and magnetic modelling results suggest the presence of mafic material beneath the modelled 9+ km of sediment in the basin.

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.

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