Nelly Vanadium Mine (NVM) is a 53-hectare tenement that is located 170km from the capital of San Luis Province in Argentina.
The mine has ready access to mains power and water supplies, while nearby towns can provide supporting services and a skilled labour pool. Further, the transportation infrastructure from the mine to key ports is more than adequate with well-formed gravel tracks, sealed highway and rail network in place.
According to legacy records, the mine was active between 1949 to 1957, with gravimetric separation and a processing plant on-site that produced V2O5 and VO3NH4.
The on-site concentration processes, which were partly experimental advanced technology for the time, prevented the operation reaching a critical scale. The primary customers during the 1950s in Argentina were national alloy and acid manufacturers.
For the 1950s in Argentina, NVM was one of the few operating mines that had an on-site processing plant and accommodation for employees (refer Figure 2 and Figure 3 – satellite pictures), reflecting the significance of the deposit. The mine was initially developed as an open pit and subsequently underground galleries were progressed.
Since the mine closed in 1957, there have been several studies undertaken by local geology teams (1959, 1973, 1974, & 1999) which have repeatedly argued that NVM and surrounding areas are significantly underexplored.
These same studies took samples and assayed them, resulting in confirmation of polymetallic mineralisation for V2O5, Pb, Zn, Cu, Au, Ag, Mo and Bi . The historical assay results for V2O5 ranged up to 1.9% V2O5, with a length weighted sample average of 0.82% V2O5.
NVM is located in the Las Aguadas district (San Luis), where the regional geology is dominated by Precambrian to Cambrian metamorphic rocks, with granitic intrusions of variable dimensions. This is a lead-vanadium mining district with many historic mines that documented their Pb-V production. The regional target mineral is vanadinite, a lead chloro-vanadate, that is by weight 73.1% Pb and 10.8% V. At NVM, vanadinite occurs within quartz mineralised veins.
Unexploited mineralised veins
When NVM was operating during the 1950s, only part of the known deposit was exploited, leaving most the untapped mineralisation intact. The extent of the deposit is a key feature the geology team will be working on in coming months, given NVM delivers considerable exploration upside.
To date, detailed work by the geology team has determined there are several mineralised veins at surface which are emplaced in a structural trend aligned North-East to South-West. More specifically, most of these comprise parallel veins creating a sheeted system. Some of these mineralised veins have been mapped outcropping within alteration halos at surface, but the ones trending underground are completely unexplored.