DEEP GROUND PENETRATING RADAR IMAGING FOR THE PURPOSE OF EXPLORING ORE AND GEOLOGICAL STRUCTURES IN THE CALAMINE MINE, CENTRAL IRAN

Abstract

This study aimed to identify mineralized zones within a sedimentary structure, including its discontinuities such as layer boundaries, and faults. The Loza-N model Deep Ground Penetrating Radar (DGPR) system with a 25 MHz antenna was employed to achieve a target depth of up to 200 meters. The investigation was conducted on mine terraces, berms, and the flat northern part of the Mehdiabad calamine mine located in Yazd, Iran. A total of 23 profiles were surveyed. Data acquisition for some profiles involved parallel transects, while others utilized a series approach where the transmitter and receiver antennas were progressively moved along the ground surface. The processed radargrams from selected profiles were compared amongst themselves and with borehole data collected along the same profiles. The geological structure was successfully visualized using two different software programs. Krot software effectively distinguished all limestone units and their zonation. By combining the GPR data with borehole results, it was possible to identify potential ore mineral zones within the marly units. Based on the DGPR traces at borehole locations, high-grade ore minerals in the marly limestone exhibited positive phase and amplitude values, represented by intermediate to maximum color hues. Conversely, light green and light gray limestone containing iron oxide and calcite veins displayed negative phase and amplitude values, with negative zero to intermediate color hues. Dark green limestone showed the most negative phase and amplitude values, reflected by the maximum negative color hues. Finally, light red limestone, likely containing lowgrade ore, presented positive but minimal phase and amplitude values, visualized by positive minimum color hues.

Keywords

• Deep Ground Penetrating Radar (DGPR)
• Loza-N DGPR System
• geological structure
• limestone units
• Mehdiabad calamine mine