3D geological modelling of a polyphase deformed pre‐Variscan IOCG mineralization located at the southeastern border of the Ossa Morena Zone, Iberian Massif (Spain)

Abstract

A previously unrecorded group of stratiform and stratabound-type magnetite beds (IOCG) has been found at the southeastern border of the Ossa Morena Zone (Variscan Massif of Spain). These mineralizations, hosted in Upper Precambrian-Lower Cambrian rocks, are located in a transpressive belt, and were strongly deformed by the Variscan Orogeny, thus showing polyphase noncoaxial folding. This folding has been recognized by the interference patterns observed in magnetite beds outcropping in old mine workings. A detailed mapping of several adits shows a Ramsay type 1 'egg box' or dome-and-basin interference pattern which arises when both D 1 (NW-SE trending) and D 2 (NE-SW trending) fold axes and axial planes are orthogonal or at a high angle to each other. An analysis of the magnetitic layers using orthogonal thickness and conic functions has been carried out to characterize fold profiles geometry.Deformation is also accommodated by oblique WNW-ESE trending thrust faults which produce centimetric to metric displacements of the magnetite beds. A 22% shortening in the NE-SW direction and 24% in the NW-SE direction has been estimated. Finally, as polyphase folding and thrust structures in three dimensions have a complex geometry, a 3D geological modelling has been carried out to obtain a better insight into the geometry of mineralized magnetite bodies.

A new 3D geological model and interpretation of structural evolution of the world-class Rio Tinto VMS deposit, Iberian Pyrite Belt (Spain)

“…The use of 3D models facilitate the understanding of surface and subsurface geology is wellestablished by several authors (i. e., Houlding, 1994;Lemon and Jones, 2003;Calcagno et al, 2008;Kaufman and Martin, 2008;Maxelon et al, 2009;Gumiel et al, 2010b;Wang et al, 2013).…”

3D Geological Model of the Touro Cu Deposit, A World-Class Mafic-Siliciclastic VMS Deposit in the NW of the Iberian Peninsula

“…The methodology used in the Touro 3D geological modeling was implemented in a system consisting of a GIS, a spatial database and a 3D modeling software [53][54][55][56]. It involves several different steps for processing data, depending on the ore type (Figure 3A-C Different drilling surveys performed from 1960 to that most recently carried out by Atalaya Mining were used to reconstruct the 3D geometry of the deposits.…”

3D models for hydrothermal copper ore bodies at Sin Quyen deposit, North Vietnam: A case report for ore reserves and prediction of hidden mineral resource potential

“…The 3D models are proposed based on the 2D/3D seismic data [ [15] , [16] , [17] , [18] , [19] ] or data from boreholes [ 20 , 21 ] or geophysical data [ [22] , [23] , [24] , [25] ] or combination of borehole log and geophysical data [ 26 , 27 ]. The 3D model could also be used for integrating comprehensive geological structures for the fluid flow quantitative evaluation involved in the breccia formation in the Uranium ore deposit, Athabasca Basin, Canada [ 28 ] or understanding the surface and subsurface geological characteristics which were widely studied [ 20 , [29] , [30] , [31] , [32] , [33] , [34] ]. Furthermore, these analysis data not only directly prove the accuracy of the features of extracting geology but also can be useful for predicting potential mineral targets and evaluating resources [ 35 ].…”