SEG Honorary Lecture: Building on 3D geological knowledge through gravity and magnetic modeling workflows at regional to local scales

2011 ◽  
Author(s):  
Richard Lane
Keyword(s):  
Magnetic Modeling ◽  
Gravity And Magnetic

Contribution of magnetic modeling to the discovery of a hidden massive sulfide body at Hajar, Morocco

Geophysics ◽  
1991 ◽  
Vol 56 (7) ◽  
pp. 983-991 ◽  
Author(s):  
A. Bellott ◽  
J. Corpel ◽  
R. Millon
Keyword(s):  
Gravity Data ◽  
Massive Sulfide ◽  
Magnetic Survey ◽  
Massive Sulfides ◽  
Magnetic Modeling ◽  
Gravity And Magnetic ◽  
Gravity Response ◽  
Modeling Techniques ◽  
Magnetic Model ◽  
D Model

The Hajar prospect is located in the Guemassa Paleozoic massif, about 30 km southwest of Marrakesh, Morocco. Visean volcano‐sedimentary formations are present in this massif and in the Jebilets massif north of Marrakesh. In these formations, syngenetic massive sulfides occur, and one of these bodies, Kettara in the Jebilets, has been partially mined. Using the Kettara magnetic anomaly to establish the magnetization parameters, we performed a preliminary interpretation of the Hajar anomaly. Our 2.5-D model determined the depth of the structure to be about 150 to 200 m below the surface. This relatively shallow depth was a decisive factor in siting a reconnaissance drillhole, which encountered massive sulfides between 158 and 276 m. After completing a systematic gravity and magnetic survey, 3-D magnetic modeling was attempted, constrained by the results of four drillholes. Now that more than 20 holes have been drilled, this magnetic model still conforms to the newly revealed geology. Unfortunately, it was not possible to extract useful information concerning the orebody from modeling and interpreting the gravity data. The gravity response is masked by disturbances such as faults and variations in depth and nature of the Visean basement. The discovery of the Hajar deposit shows that magnetic investigations, improved by pertinent modeling techniques, can be used at various stages of exploration to help recognize and define massive sulfide bodies.

Gravity and Magnetic Modeling of Central Italy: Insights Into the Depth Extent of the Seismogenic Layer

2019 ◽  
Vol 20 (4) ◽  
pp. 2157-2172 ◽  
Author(s):  
P. Mancinelli ◽  
M. Porreca ◽  
C. Pauselli ◽  
G. Minelli ◽  
M.R. Barchi ◽  
...  
Keyword(s):  
Central Italy ◽  
Seismogenic Layer ◽  
Magnetic Modeling ◽  
Gravity And Magnetic ◽  
Depth Extent
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