The company said the program is centered on the San Marcial Resource Area and will incorporate a 3D Induced Polarization (IP) survey as well as ground magnetometry.
And the survey is scheduled to cover an area of about 8.1 kilometers (km), or about 64% of the concession area.
READ: GR Silver Mining continues to report encouraging drill results from its Plomosas Silver project
As the key structures and mineralization on the concession are oriented northwest-southeast, GR Silver said the geophysical survey lines are designed perpendicular to these structures in a southwest-northeast orientation. This way, the best geological information is obtained from the geophysical results.
In addition to the Resource Area, the program will also encompass high-priority target areas identified by recent lithogeochemical sampling and follow-up mapping and sampling.
GR Silver said the survey will initially focus on the resource area to characterize the known silver-lead-zinc mineralization therein, which hosts the NI 43-101 resource. A higher line density for the survey is planned over the resource area, which allows higher resolution of geophysical data and geological information.
The company noted that this will deliver a guide as to potential extensions to the mineralization along strike, and the 3D IP will provide additional insight into depth extensions to the deposit. The geophysical response of the resource area will then be used to identify similar buried anomalies that could host hidden silver-lead-zinc resources, particularly along the key contact between the lower dacitic units in the southwest and the upper volcanic units in the north and east.
"We are excited to be undertaking the first major geophysical investigation of the San Marcial Project,” said CEO Marcio Fonseca in a statement. "The ground-based survey of 3D IP and magnetometry will assist our technical team to better understand the underlying geology, map key structures – particularly those not apparent at surface – and to identify potentially mineralized zones both in the vicinity of the San Marcial Ag resource, as well as on some of the key target areas identified by the company over the past two years.”
He added the company expects new anomalies derived from this study to generate additional drill targets for follow-up later this year.
GR Silver estimates that the survey will highlight a number of structural and lithological features, in addition to the key contact hosting the San Marcial resource. Recent reconnaissance geological mapping has identified intrusive rocks (granodioritic), particularly south of the resource area.
The survey will also support mapping of mineralized zones that contain chargeable metal sulphide mineralization, which will then allow for interpretation based on the nature of the known mineralized structures on the property.
As the survey moves away from the resource area, the company said it will cover many of the targets already highlighted by previous GR Silver exploration campaigns -- such as Guacamayo and Limoncillos to the south, and Faisanes, Mariposa, Nava, Micuines, and Chachalaca in the west and northwest.
The IP survey is being conducted by DIAS Geophysical of Saskatoon using the company's DIAS32 direct current resistivity and induced polarization distributed array system.
Line cutting for the survey was initiated in December and completed in early February. The field crew is working out of the San Marcial camp, located around the center of the property and grid, under a COVID-19 protocol developed by the company in compliance with the requirements of Mexican authorities.
Contact the author: firstname.lastname@example.org
Follow him on Twitter @PatrickMGraham