Exploration

The Tapajós Gold Province is located in the western portion of Pará State, central northern Brazil and covers a total of some 100,000 km². The Tapajós is in the southern-central portion of the Amazon Craton, generally termed the Brazilian Shield, as opposed to the northern portion of the Craton referred to as the Guyanian Shield and extends into the littoral countries of the northern South American continent.

The Brazilian Shield is nucleated on the Archaean granite-greenstone terrain of the Carajás-Imataca Province in eastern Pará State, and progressively becomes younger and shallower towards the west, grading into granite dominated then into granite-volcaniclastic terrain of Paleoproterozoic age rocks of the eastern Amazonas State. In the Jardim do Ouro region lithologies are dominated by granitoids of Paleoproterozoic age.

The Tapajós Province represents a tectonically controlled geological evolution attributed to the Orosirian Proterozoic period, comprising four plutonic events, over a 140 Ma period.

In the Tapajós Province two main units form the basement, the Paleoproterozoic Cuiú-Cuiú metamorphic suite (2.0 -2.4 Ga) and the Jacareacanga metamorphic suite (>2.1 Ga). The Jacareacanga is considered to be the older suite; however the relationship is not yet well defined.

The Jacareacanga suite is comprised of a sedimentary-volcanic sequence, deformed and metamorphosed to a regional greenschist facies, with units of sericitic and chloritic schists and rare banded iron formations.

The Cuiú-Cuiú suite, which is the basement for the Palito area, is comprised of orthogneisses of dioritic to grandioritic composition, locally mylonitized, deformed tonalitic granitoids and enclaves or rafts of amphibolites.

Both the Cuiú-Cuiú and Jacareacanga suites are intruded by monzogranites of the Paráuari suite (2000 -1900 Ma), tonalites, diorites and granodiorites of the Tropas suite (1907 Ma -1898 Ma) and granites and granodiorites of the Creporizão suite (1893 -1853 Ma). These three intrusive suites are considered to have calc-alkaline affiliations and may be considered remnants of a magmatic back arc system interpreted for the region.

Regional structural analysis of the Tapajós Province has identified various compressive deformation regimes including ductile, brittle-ductile and brittle. The deformation is interpreted to have occurred as two separate events, the first compressive event, with peak deformation around 1.96 Ma, resulting in the development of ductile and brittle-ductile deformation regimes. The second event occurring at 1.88 Ma resulted in brittle deformation. These events resulted in major north-south, north west-south east and east-west lineament sets.

The geometry of the lineament and structures are compatible with a combination of Riedel fracturing and strike slip fault systems, where the principle vector of compression is oriented in an east-west and ENE-WSW direction

Gold mineralization is not restricted to a particular suite, with deposits located in all suites including; Cuiú-Cuiú Suite (Cuiú-Cuiú), Paráuari Suite (Tocantinzinho, São Jorge and Palito), Tropas Suite (Ouro Roxo), Salustiano and Bom Jardim Formation (V-series deposits, Bom Jardim), Maloquinha Suite (Mamoal). Gold mineralization associated with quartz and hydrothermal alteration assemblages is reported in all the fracture orientations of the Reidel system, and are dominated by fractures oblique to the principle strike-slip shear orientation.

The Tapajós region has only recently started to be the subject of systematic exploration and therefore the artisanal miners provide a valuable exploration tool with a significant portion of the 7 million ounces of hard rock resource identified to date close to and/or underlying historic artisanal operations.  However, there is much that the artisanal miners will miss as they seek out the “low-hanging fruit” where ease of access and topography suited to the needs of hydraulic mining are important.  Structures that do not outcrop at surface will be missed but may be identified by Serabi’s extensive exploration approach, presenting a significant opportunity for the Company.

The gold occurrences identified in the region to date have all been associated with sulphide mineralisation which is amenable to .geophysical exploration methods.  Serabi has therefore undertaken airborne electro-magnetic surveys (“EM”) which identify areas of potential sulphide mineralisation and facilitate screening of large areas of its tenement.  As much of the surface area of the tenement is given over to pasture or other vegetation, visible indicators which might occur in more arid regions are not present in this part of Brazil.

Not all sulphide bodies will necessarily host gold in commercial quantities, and it is for this reason that a geological data set needs to be built up before any exploration drilling is undertaken.  Serabi’s geological team will conduct follow up ground studies using a variety of tools including induced polarisation (“IP”) to measure the relative conductivity and resistivity of the area, taking stream and surface soil and rock chip samples looking for anomalous geochemical levels of gold and other indicator minerals and mapping, trenching and augur drilling to extract samples a few metres below the surface. Where a number of these coincident mineralisation indicators overlap, then a decision and priority can be established for a specific area of interest.

Over the past few years, Serabi’s systematic exploration approach has been rewarded with a number of significant opportunities, which management is keen and excited to progress.  With a focus on opportunities which are generally within 10 to 20 kilometres of existing operations, this brings substantial benefit to stakeholders.  The Group can leverage off its infrastructure to maximise the pace of exploration advancement and, more importantly, is in the position to quickly translate exploration success into production ounces.Serabi’s tenement holding around its Palito Complex is dominated by an ESE-WNW trending regional structure, known as Mato Cobra, a structure displaying strong magnetic and radiometric anomalism.  A number of Serabi’s  current key targets have initially been selected where multiple electromagnetic anomalies (typically indicators of massive sulphides in the Tapajós) have coincided with the Mata Cobra.

São Domingos (1)

• Acquired in 2020.
• Located to the west of São Chico.
• Tenements host many rich, historic and currently active artisanal pits.  
• Limited previous systematic exploration. 
• Serabi established the baseline geological data to properly evaluate the land package.
• Work programme included mapping and soil sampling and in late 2021, an airborne geophysical survey. 
• Initial area of interest comprises three artisanal pits, Raimundo, Toucano and Grota da Sangue, covering a 600m-long structure (the Toucano trend). 
• Several fertile structural trends that host mineralisation similar to the Toucano trend, including the Mario Dio, Atacadao and Messias trends. Trends are aligned northeast to southwest running parallel and spaced broadly 500-800m throughout the tenements. 
• Many host historic pits extending to depths of ~30m
• Expectation that the São Domingos tenements could yield new high-grade satellite deposits providing supplementary high-grade ore to Serabi’s existing operations.
• Serabi has completed over 4,150m of exploration drilling with main target areas being the Toucano and Atacado prospects.

Matilda (2)

The Matilda target is a four kilometre by four kilometre geochemical anomaly within which lies a two kilometre by two kilometre gold, copper, molybdenum, and tungsten (“Au-Cu-Mo-W”) core. This geochemical anomaly is coincident with anomalous high magnetic susceptibility associated with magnetite alteration. Mapping has identified granites with potassic, propylitic and sericite-chlorite alteration, dacite porphyry and quartz-sulphide veins, all of which bodes well for a bulk target. Further, Matilda sits on a topographic high, with extensive artisanal workings in surrounding rivers and drainages.

The Matilda prospect was initially tested with three drill holes in 2022.

Each hole intercepted porphyry mineralisation with average grades of >0.2% copper equivalent* from top to bottom of the hole.

Approximately 6,500 meters of diamond drilling have been completed in 21 holes at Matilda.

The copper mineralisation and hosting rocks have many characteristics that typify alkalic porphyry deposits found in Australia and Canada.

Reprocessing of data from the airborne geophysical survey completed in 2022 indicates that the positive drill results may lie within a 1.2 kilometre by 800 metre demagnetized structural zone. The zone remains untested both laterally and at depth.

In addition, deep penetrating Induced Polarisation (“IP”) and Audio-Magnetotelluric (“AMT”) geophysical programmes have been designed to complement the drilling.

Cinderella (3)

Located to the east and south east of São Chico, the Cinderella prospect is a five kilometre south west to north east trending IP and EM anomalous area with elevated gold in soil grades and artisanal workings in some of the streams that are fed from this topographical high.

Calico (5), Juca (7) and Forquilha (6)

• All located within 5km of the Palito Complex. 
• Calico is now significant, covering a 2km x 2km area.
• Soil samples returning values as high as 0.8g/t gold have been recorded, better than have been seen in any soils over the Palito orebody. 
• A terrestrial geophysics survey using Induced Polarisation covering the Calico soil anomaly identified multiple chargeability anomalies.
• Scale and signature very comparable to Palito orebody, where over 400koz has been mined and hosting a further 500koz gold mineral resource. 
• Calico prospect and neighbouring Juca and Forquilha prospects initially identified from the interpretation of an airborne electromagnetic survey completed in 2018. 
• Reconnaissance field mapping identified alteration (potassic, haematitic and silicic) and evidence of weathered and primary sulphides in limited outcrop associated with felsic intrusive and volcanic rocks. 
• Systematic grid soil sampling subsequently identified a number of cohesive multi-element geochemical anomalies of which the most significant was the Calico prospect.
• Calico prospect highlighted by a central potassically altered dacite porphyry intrusive with coincident higher temperature soil geochemistry multi-element signature of Mo-Bi-As-Te-W-Sn. 
• Dacite porphyry intruding into a monzogranite is bounded by a broad 2km x 2km high gold/low antimony halo to the northwest and anomalous copper wrapping around the southern part of the intrusive core. 

Ganso (4), Juca (7) and Forquilha (6)

• Each prospect presents coincident geochemical and geophysical anomalies, including EM anomalies indicating the possible presence of sulphide bodies.

• Significant potential for further resource growth.
• Exploration drilling to date focussed on vertical extensions of artisanal discoveries.
• Known continuation of belt for several kilometres to the south.
• Numerous untested geochemical targets to the north following the strike extensions of known deposits.
• Mato Velho area to the north is a significant untested geochemical anomaly.