South Atlantic Project

Figure 1: South Atlantic Project location

The South Atlantic Project is located within the Rio Grande do Sul Coastal Plain, a region located in the southernmost state of Brazil, Rio Grande do Sul, along the coast of the Atlantic Ocean. 

The coastal plain is a relatively flat and low-lying area that stretches over approximately 620km from the border with Uruguay in the south to the city of Osório in the north.

The tenements are held by RGM.  Four main deposits have been identified within the project area:  Retiro, Estreito, Capao do Meio and Bujuru with Exploration Targets developed for the Retiro and Bujuru deposits.

Heavy minerals (HM) within the project area were first described in 1958.  In 1988, RTZ Mineracao Ltda (RTZM) conducted exploration drilling resulting in the discovery of Retiro and Estreito.  In late 1989, a pilot plant trial was carried out to produce one tonne of HM concentrate which was subjected to further mineral separation processing test work.  In the early 1990’s, Paranapanema SA conducted an exploration program in Bujuru leading to bulk sampling programs in 1992 and 1999. 

Figure 2: South Atlantic Project – prospects, including Retiro and Bujuru Exploration Targets

RGM acquired the tenements previously held by Rio Tinto and Paranapanema, and has undertaken numerous environmental, technical and economic studies.  In 2014, extensive reverse circulation air core (RCAC) drilling was carried out in addition to bulk sample test work programs around this time.

In 2022, a program of sonic drilling was carried out by RGM over Retiro and Bujuru and test pitting was carried out on Bujuru as part of a campaign to investigate grade discrepancies between historical drilling prior to 2014, the 2014 RCAC drilling and bulk test work programs.

South Atlantic Project – Exploration Target Estimates

Retiro

The Exploration Targets for the area of interest have been developed from all available geological, drill hole and assay information.  Requisite checks and balances have been applied to supporting information and all care has been taken to prepare Exploration Target ranges that reflect both conventional mining methodologies and economic cut-off grade considerations.

Figure 3: Retiro Exploration Target

The Exploration Target is reported at a cut-off grade range of 1% HM to 2% HM. These are considered by the Competent Person to reflect reasonable reporting ranges based on the dimensions and grade distribution of the identified mineralisation (including HM and mineral assemblage) and taking into account potential future mining methodologies.

The potential quantity and grade of the Exploration Target is conceptual in nature and is therefore an approximation.  There has been insufficient exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a Mineral Resource.  The Exploration Target, being conceptual in nature, takes no account of geological complexity, possible mining method or metallurgical recovery factors. The Exploration Target was estimated in order to provide an assessment of the potential scale of exploration for the South Atlantic Project.

The Retiro Exploration Target is estimated between 250 and 380 Mt of material at an average grade of 3.9% to 3.0% HM for a total contained estimate of HM tonnes of between 10 and 12 Mt.  These estimates of Exploration Target ranges have been made at HM cut-off grades of between 2% and 1% HM.

Table 1: Exploration Target Summary - Retiro deposit (February 2023)

Bujuru

The Bujuru area of interest has been estimated to have an Exploration Target of between 250 and 340 Mt of material at an average grade of 4.0% to 3.3% HM for a total contained estimate of HM tonnes of between 10 and 11 Mt.  These estimates of Exploration Target ranges have been made at HM cut-off grades of between 2% and 1% HM.

Table 2: Exploration Target Summary - Bujuru deposit (February 2023)

Notes:
(1) Exploration Target reported at a lower cut-off grade of 1% HM and an upper cut-off-grade of 2% HM.
(2) Mineral assemblage is reported as a percentage of in situ HM content.
(3) The Exploration Target is reported at a cut-off grade range of 1% HM to 2% HM. The potential quantity and grade of the Exploration Target is conceptual in nature and is therefore an approximation. There has been insufficient exploration to estimate a Mineral Resource and it is uncertain if further exploration will result in the estimation of a Mineral Resource. The Exploration Target, being conceptual in nature, takes no account of geological complexity, possible mining method or metallurgical recovery factors. The Exploration Target was estimated in order to provide an assessment of the potential scale of exploration for the South Atlantic Project.

Figure 4: Bujuru Exploration Target