Depicting the 3D geometry of ore bodies using implicit lithological modeling: An example from the Horto-Baratinha iron deposit, Guanhães block, MG

Abstract

The definition of geological domains is essential for mineral exploration and is traditionally done manually, section by section, in a laborious, time consuming and subjective process, to construct a 3D model. The technique referred to as implicit modeling is an option to model deposits in a fast and practical manner. This article presents the lithological model of the Horto-Baratinha iron deposit, located in the Antônio Dias municipality, central-eastern part of Minas Gerais state, constructed using the Leapfrog Geo ® software. The deposit is situated at the Guanhães tectonic block that is a basement domain of the Neoproterozoic Araçuaí Orogenic Belt. The deposit is comprised of itabirite-hosted high-grade iron bodies (>60 wt.% Fe) associated with polydeformed mica schists, amphibole schist with a Statherian maximum deposition age, enclosed by Statherian granitoids of the Borrachudos Suite and crosscut by undeformed pegmatite dikes crystallized during Late Ediacaran-Cambrian. The sequence was affected by progressive multiple deformation phases, associated with the collisional stage of the Brasiliano Orogeny (630-560 Ma), generating a dome and basin mesoscale refolding shape. The model points the proximity between highgrade bodies and pegmatite indicating the possibility that the intrusions contribute to the iron mineralization.

Three-dimensional geological modelling of igneous intrusions in LoopStructural v1.5.10

“…The geometries of intrusions have been characterised using different datasets, such as field observations of the intrusion's top, base, and lateral contacts; drilling data; and interpretation of gravity and seismic surveys (e.g. Braga et al, 2019;Cervantes, 2019;Eshaghi et al, 2016;Rawling et al, 2011;Grocott et al, 2009;Leaman, 1976Leaman, , 2002Paterson et al, 1996). There is a general agreement that intrusions develop tabular geometries in the coarse scale, with their horizontal dimensions being greater than their vertical dimension (e.g.…”