3D Gravity and Aeromagnetic Inversion for Mvt Lead-Zinc Exploration at Pillara, Western Australia

Short Note: Early seismic refraction and gravity exploration over the Blendvale MVT lead-zinc deposit, Western Australia

“…Figure 1 shows the interpreted seismic refraction and gravity sections over the main part of Line AA with the Bouguer gravity profile that was also shown in Figure 4 of Isles et al (1987). The interpreted gravity section was obtained using a density contrast between the shales and siltstones and the limestone of 0.35 t.m -3 , which is close to the 0.30 t.m -3 obtained by Fullagar et al (2004) using extensive borehole data. On this profile, the gravity high over the reef has an amplitude of about 5.5 milliGal (0.55 gu), and the anomaly is asymmetric due mainly to the proximity of the granitic basement on the eastern side (Fullagar et al, 2004, Figure 1).…”

“…The refraction line was 9.0 km in length and extended onto the shale/ siltstone sequence at its margins. The Blendvale deposit, itself, is shown on Figure 2 of Fullagar et al (2004), approximately at (7 972 200 N, 793 000 E).…”

“…However, the relatively high cost of this approach for deeper exploration prompted extensive testing and application of various geophysical methods over an extended period (Scott et al, 1994). Recently, Fullagar et al (2004) presented a 3D gravity interpretation of the upper surface of the dolomitic limestone containing the Blendvale deposit. Accurate location of this interface is important to exploration of this ancient reef complex.…”

“…This gravity interpretation exploited the large density contrast between the overlying shales and siltstones and the limestone, and was constrained by 561 boreholes that intersected the upper limestone surface. Fullagar et al (2004) recognised that seismic methods are applicable to the problem of mapping this surface, but no seismic interpretations over this deposit were presented or discussed.…”

Three-dimensional potential field modelling of the subsurface morphology of complex maar volcanoes - Examples from the Newer Volcanics Province, Western Victoria

“…The 3D models were built within Gocad and used as a reference model for homogenous, heterogeneous and geometry inversions of the gravity data performed within VPmg (Fullagar et al 2000;Fullagar et al 2004;Fullagar & Pears 2007). Inversions were applied to minimise the misfit between the observed and calculated data and to understand the 3D structures and density distribution within the volcanoes underlying vent systems.…”