December 9, 2020 – District Metals Corp. (TSX-V: DMX) (FRA: DFPP); (“District” or the “Company”) is pleased to announce that a ground gravity survey has commenced on the Tomtebo Property located in the Bergslagen Mining District in south-central Sweden. This gravity survey is focused on the Tomtebo Mine Trend (Figure 1) that was delineated by numerous conductive and magnetic high anomalies identified from the July 2020 SkyTEM survey.
Garrett Ainsworth, CEO of District, commented: “We continue to follow our approach of systematic modern exploration at the Tomtebo Property with the commencement of a ground gravity survey over the Tomtebo Mine Trend. This is the first time Tomtebo has ever seen a ground gravity survey, which is surprising given its proven effectiveness in identifying significant massive sulphide deposits within other districts. The large density differential between the surrounding host felsic volcanic rocks, and targeted massive sulphide mineralization on Tomtebo offers another important layer of geophysical data that we will utilize to prioritize drilling within the Tomtebo Mine Trend.”
The ground gravity survey area will cover a 2 km by 3 km portion of the Tomtebo Mine Trend with 200 m line spacings and stations 50 m along the lines, which will total approximately 400 gravity stations. GeoVista AB in collaboration with GeoPartner Ltd. are utilizing a two-person geophysical crew for the ground gravity survey. The crew will be carrying a Scintrex CG-6 gravity reader, and a Trimble R12 RTK GPS device capable of locating the XYZ-location of each survey station with centimeter accuracy.
Volcanic Massive Sulphide (VMS) or Sedimentary Exhalative (SedEx) targets are often greatly enhanced by gravity survey data, which generally follows other geophysical (magnetic, electrical, or electromagnetic) and geochemical surveys. Gravity data is used to detect the excess mass of a potential massive sulphide deposit as well as estimating its potential size and tonnage. Here are some examples of where gravity surveys have detected significant VMS or SedEx deposits or extensions:
- Las Cruces VMS Deposit in the Iberian Pyrite Belt, which is hosted in siliciclastic-felsic rock was discovered by a regional gravity survey that indicated an extension of the Pyrite Belt lithologies beneath 120 m of cover.
- Lagoa Salgada VMS Deposit in the Iberian Pyrite Belt was discovered through gravity due to the relatively dense ore body that is hosted in a much less dense volcaniclastic-sedimentary host rock. This deposit is covered by a 128 m thick cover of Tertiary strata and is associated with a 15 m thick gossan.
- Greens Creek VMS Deposit in Alaska where ground gravity data confirmed the extension of the mined ore body at depth and provided valuable information for exploration drilling. The survey area is characterized by very steep topography, muskeg, and poor topographic information, which is not the case on the Tomtebo Property.
- Macmillan Pass SedEx Project in the Yukon recently utilized ground gravity that identified gravity high anomalies. Drill testing of these gravity high anomalies returned wide zones of massive sulphide (sphalerite-galena-pyrite) mineralization.
- Tambogrande VMS System in northwest Peru utilized ground gravity in 1999 that produced significant anomalies. Drill testing of these gravity anomalies resulted in the discovery of the TG3 and B5 Deposits, and increased mineral resources of the TG1 Deposit.
- Bisha VMS Deposit in Eritrea showed as two gravity high anomalies in 2003.
- Emba Derho Deposit in Eritrea showed as one gravity high anomaly in 2005.
- VMS deposits in the Bathurst Mining Camp have been targeted with the use of gravity survey data, which has been especially effective where mineralization is often dominated by non-conductive zinc sulphides (sphalerite).
CLICK HERE to read the full news release.