RETRACTED: Identification and delineation of potash deposits in Saskatchewan, Canada using pulsed radar technology

Abstract

Note: The GEOPHYSICS Editorial Board is issuing an expression of concern for this paper. An investigation is ongoing to substantiate the methodology and results reported in this work. This expression of concern will be updated upon the conclusion of the investigation. Saskatchewan, Canada, contains almost half of the world’s known potash deposits, within the Middle Devonian Prairie Evaporite Formation. As the global demand for potash increases, so does the need for faster, greener and cheaper methods of potash identification and extraction. The primary methods for exploration and development of potash include traditional 2D and 3D seismic methods, along with exploration drilling, downhole geophysical logging, coring, and assays for geological interpretation. One challenge with existing seismic geophysical methods in potash exploration is the difficulty in differentiating the responses and interpretation between the evaporite (sylvinite and halite (NaCl)) beds which are intermittently deposited within the Prairie Evaporite Formation. We field tested a new pulsed radar method for subsurface geophysical measurements at the Vanguard Area, Saskatchewan, to demonstrate whether subsurface evaporties could be directly identified non-invasively from ground level. In the Vanguard Area, the Prairie Evaporite Formation occurs at a depth of approximately 1500 m below ground surface (BGS). Achieving deep penetration of the transmitted pulsed radar wave packets, whilst discerning the materials from which the reflected wave packets (containing difference frequency and energy levels) bounced back from, was another scientific challenge. Following robust testing and due diligence on the method, we have been able to confirm that the pulsed radar method is capable of identifying broad lithological zones, differentiating halite units from sylvinite units (the potash-bearing members) within the Prairie Evaporite Formation, and also differentiating individual sub-members within each major potash member. A high-level identification of potash grade (%KCl) of the potash sub-members was also assessed. Based on this preliminary work, the results presented provide significant evidence and resulting confidence in the promise of utilizing the pulsed radar technology for successful identification and delineation of potash deposits