Shallow base metal exploration in northern New Brunswick, Canada

Abstract

This research paper explores the effective utilization of 2-D Resistivity and Induced Polarization (IP) techniques for identifying sulfide deposits in complex geological settings. To enhance the accuracy of the findings, the geophysical data were complemented with geological information, petrophysical data, Digital Elevation Model (DEM), and Electromagnetic data Versatile Time Domain Electro-Magnetics (VTEM) and Total Magnetic Intensity (TMI) Reduced-To-Pole (RTP).

The analysis of DEM, magnetic susceptibility, and magnetic intensity revealed a lack of correlation with the DEM, indicating that these parameters alone were insufficient to confirm the presence of sulfide deposits. Consequently, five regions exhibiting high to moderate conductivity were chosen for conducting six survey lines using the Wenner array with a 10 m electrode spacing. The objective was to map sulfide zones in Restigouche County, located in northeast New Brunswick.

Geophysical measurements were acquired using a RESECS instrument, and the field data were processed using the Res2Dinv software after removing erroneous data points. Since the study area was characterized by thick overburdened glacial sediments and lacked surface exposure, information from numerous boreholes and core samples from the western part of the study area were utilized.

The study achieved successful mapping of the shallow alteration zone containing pyrite mineralization in most of the survey lines. Specifically, resistivity responses below 50 Ω⋅m, coupled with high chargeability, likely corresponded to the alteration zone containing pyrite. Additionally, resistivity responses above 50 Ω⋅m, combined with chargeability and RTP readings, were indicative of the alteration zone with pyrite.