Potential Field, Geoelectrical and Reflection Seismic Investigations for Massive Sulphide Exploration in the Skellefte Mining District, Northern Sweden

Abstract

Multi-scale geophysical studies were conducted in the central Skellefte district (CSD) in order to delineate the geometry of the upper crust (down to maximum ~ 4.5 km depth) for prospecting volcanic massive sulphide (VMS) mineralization. These geophysical investigations include potential field, resistivity/induced polarization (IP), reflection seismic and magnetotelluric (MT) data which were collected between 2009 and 2010. The interpretations were divided in two scales: (i) shallow (~ 1.5 km) and (ii) deep (~ 4.5 km). Physical properties of the rocks, including density, magnetic susceptibility, resistivity and chargeability, were also used to improve interpretations. The study result delineates the geometry of the upper crust in the CSD and new models were suggested based on new and joint geophysical interpretation which can benefit VMS prospecting in the area. The result also indicates that a strongly conductive zone detected by resistivity/IP data may have been missed using other geophysical data.

2.5D geophysical model of the Gällivare mining area: An integrated study to model the top 4 km of the subsurface and guide for future exploration activities

“…The International Geomagnetic Reference Field (IGRF) correction was applied on the magnetic data with a total field intensity of 52,824, 76.7° inclination and declination of 8.5°. However, the regional field trend which has been defined and separated for magnetic and gravity data using the second polynomial degree (Tavakoli et al ., 2012a, 2012b, 2016a) for the magnetic data is somewhat lower than the IGRF value, that is, 51875 nT.…”

Investigating the applicability of induced polarization method in ore modelling and drilling optimization: a case study from Abassabad, Iran

“…IP and ER methods are among the most applicable geophysical methods used in subsurface studies notably for selection of the best drilling points for exploration purposes (Bishop and Emerson 1999;Wynn and Grosz 2000;Ferdows and Ramazi 2015b;Hope and Andersson 2016). Some examples of their increased usage include copper exploration using 3D IP modelling in NSW, Australia (Whaite et al 2001), using combination of ER and IP in polymetal deposit in China (Yang, Liu and Wang 2008), gold exploration at the eastern desert of Egypt by IP measurement (Taha et al 2018), combination of ER, IP and microgravity to detect buried caves in Spain (Martínez-Moreno et al 2013), copper exploration using IP and ER in Iran (Ramazi and Jalali 2014), gold-silver deposit exploration by IP method in Russia (Gurin et al 2015), detection of the uranium mineralization zone in India (Biswas and Sharma 2016), integration of geophysical methods including IP and ER methods for massive sulphide exploration in Sweden (Tavakoli et al 2016), bitumen mineralization exploration in the west of Iran (Mashhadi, Mostafaei and Ramazi 2017), gold deposit exploration by 3D-induced polarization modelling in Indonesia (Halim et al 2017), 3D tomography of induced polarization and its application in polymetallic mine (Jun-Lu et al 2017), copper mineral exploration using 3D model of IP and resistivity in Brazil (Morriera et al 2018), investigation of a rock glacier by 3D tomography of IP and ER in France (Duvillard et al 2018) and urban area investigation by 3D IP and ER in Stockholm (Pazzi et al 2018;Rossi et al 2017Rossi et al , 2018.…”

“…), detection of the uranium mineralization zone in India (Biswas and Sharma ), integration of geophysical methods including IP and ER methods for massive sulphide exploration in Sweden (Tavakoli et al . ), bitumen mineralization exploration in the west of Iran (Mashhadi, Mostafaei and Ramazi ), gold deposit exploration by 3D‐induced polarization modelling in Indonesia (Halim et al . ), 3D tomography of induced polarization and its application in polymetallic mine (Jun‐Lu et al .…”

2D and 3D MT in the central Skellefte Ore District, northern Sweden

“…The correlation is not always very good, in some cases there is a shift in position and in others there are differences of shape or size (García Juanatey, 2012, Paper IV). Later on, Tavakoli et al (2016b) showed that it was possible to resolve these offsets by re-modelling the potential field data.…”