`Hotspot' geophysical exploration has passed its zenith. In areas like New Brunswick, where this exploration style has been successful, deposits with a more complex signature have been left behind. Using improved computational power and geophysical modelling, deposits like those found at Nash Creek can be reinvestigated. Nash Creek hosts a Zn-Pb-Ag deposit on the western limb of the Jacquet River Syncline and is truncated by the N-S trending Black Point Arleau Brook (BPAB) Fault. While regional mapping was the goal, the Archibald Settlement and Sunnyside formations which host the deposit were looked at more in depth as well. Previously collected geophysical surveys, surficial mapping efforts, borehole logs, petrophysics, and local perspective were all considered in the modelling process. Using this information, 2D cross sections were created of the survey area. These sections were employed to match geophysics first and elucidate what could be modellable. These sections were then used to derive a 3D geological model that was supported by geophysical data rather than derived from it. This model was inverted to investigate the optimized subsurface structure. The final model and inversion had mixed results. While a regional model could not be derived, BPAB fault and the Archibald Settlement formation were discerned to a reasonable degree. The Archibald Settlement formation had a distinct contrast with the surrounding units which was clear in the inverted data. BPAB fault was found to have a steep (70-80) westward dip, unlike previous research which suggested a near vertical or eastward dip. It is recommended that a more extensive survey be conducted with the express purpose of constraining the fault. An E-W seismic survey would provide both overburden thickness and fault structure over Nash Creek.

Open-Access Online Publication: March 01, 2023