Our Projects

INTRODUCTION

Tethyan is focused on precious and base metal exploration in the Balkan region, and holds the rights to exploration on over 120km2 in Serbia at the northern end of the Trepca silver-zinc-lead mining district, within the western Tethyan Metallogenic Belt (TMB). This includes two past producing silver-zinc-lead open pit mines within Tethyan’s Kizevak and Sastavci exploration licences with historical mineral resources, as well as two confirmed copper-gold porphyry centres at Rudnica and Kremice.

Significant, Tier One copper-gold discoveries have been made in the Balkan part of the TMB since the 1960s, including the Bor complex and Majdanpek (Timok Belt, Serbia), the Elatsite and Assarel deposits (Panagyurishte District, Bulgaria) and Rosia Poieni (Apuseni District, Romania). Furthermore, the Trepca mineral belt of Kosovo hosts several underground silver-lead-zinc mines which have been in operation since the turn of the 20th Century. The same belt extends into Macedonia and Greece where operating and development stage projects include the Skouries copper-gold porphyry (Eldorado Gold), Olympias CRD polymetallic deposit (Eldorado Gold) and Sasa polymetallic deposit (Central Asia Metals).

Location of Tethyan’s Raska District Property

PROJECT DESCRIPTION

Tethyan has the right to explore four contiguous exploration licences in the “Raska District” of southwestern Serbia, which is prospective for silver-lead-zinc, epithermal style mineralisation as well as copper-gold porphyry deposits, summarised in the below table. The licence package is located in SW Serbia, 250 km from Belgrade and is situated close to the existing road, rail and power network.

Tethyan also holds 100% of the Zukovac and Bucje exploration licences in SE Serbia, along strike from the Timok Magmatic Complex, totalling 168 km2.

Map showing Tethyans exploration licences and prospects, Raska District

GEOLOGICAL SETTING

The TMB formed as result of the convergence and collision of the Arabian, African and Indian tectonic plates during closure of the Tethys Ocean, and extends from eastern Europe to Southeast Asia. In the Balkan region, the Tethyan Orogeny resulted in the formation of several distinct arcuate belts of accreted microcontinents, obducted marine sedimentary rocks and ophiolites, within which discrete clusters of porphyry copper gold and polymetallic epithermal and CRD deposits have formed.

The Raska District comprises a Neogene andesite volcanic sequence with coeval diorite intrusions, overlying a serpentinised ophiolitic basement. All units are intruded by later granodiorite stocks. Porphyry and related epithermal mineralisation is spatially associated with diorite intrusions and andesite domes on the flanks of the larger granodiorite stocks.

Details of the more advanced Kizevak-Sastavci, Rudnica and Kremice prospects are given on the relevant project pages.

EXPLORATION POTENTIAL

Tethyan’s Raska District prospects display similar size alteration halos, metal zonation and geophysical characteristics to other major porphyry districts worldwide. By way of comparison, the below image demonstrates the scale of the alteration and mineralisation observed at surface in the Raska District relative to the major copper deposits of the Timok Belt in eastern Serbia.

Tethyan’s Rudnica, Bukovik and Kremice porphyry prospects in the Raska District have typical geochemical and geophysical characteristics associated with copper-gold porphyry systems, including:

  • Strong metal zonation at surface which provides vectors to mineralisation
  • Coincident copper-gold-molybdenum in soil and channel samples at Rudnica and Kremice
  • Depleted zinc and manganese overlying porphyry mineralisation
  • Elevated arsenic and bismuth in soils
  • Alteration is indicative of upper levels of hydrothermal system
  • Alunite, vuggy silica and specular hematite observed at Bukovik, inferred to represent a lithocap environment, potentially overlying or on the shoulders of a deeper porphyry
  • Strong sericite and weak silica alteration at surface indicates the roots of a lithocap are exposed at Rudnica, i.e the top of a porphyry
  • Mapping has confirmed the presence of porphyry style veining coincident with the geochemical anomalies at Rudnica and Rudnica North, and detailed mapping of the Kremice and Bukovik prospects is planned to follow up the geochemical anomalies.
  • Coincident geophysical anomalies underly the geochemical anomalies and alteration zones
  • Moderate magnetic highs observed at Rudnica and Rudnica North, related to magnetite stable alteration and serpentinite basement
  • Magnetic data provides excellent basis for broad scale structural interpretation
  • Chargeable highs and resistivity lows are coincident with the magnetic anomalies

In addition, several lead-zinc-silver vein and breccia hosted targets are observed peripheral to the porphyry prospects and present stand-alone exploration targets. Tethyan infers that the porphyry and lead-zinc-silver (intermediate sulphidation) deposits are related to the same mineralising events.

RUDNICA OVERVIEW

  • Coincident 1.5 km geochemical and geophysical anomaly containing two copper-gold-(molybdenum) porphyry centres
  • Mineralisation is coincident with anomalous gold, copper and molybdenum in soil and depleted zinc and manganese, as well as magnetic highs and zones of elevated chargeability and low resistivity
  • Geochemical and alteration zoning indicates that the lithocap has been eroded and the upper parts of the porphyry system is exposed at surface
  • Mineralisation is open in all directions
  • Significant drill intercepts at the southern Rudnica prospect include
    • 567 m @ 0.28 % copper and 0.45 g/t gold (from surface, RDD-001)
    • 356 m @ 0.38 % copper and 0.31 g/t gold (from 48m, RDD-004)
    • 460 m @ 0.21 % copper and 0.20 g/t gold (from surface, RDD-006)
    • 335 m @ 0.36 % copper and 0.31 g/t gold (from 68 m, RDD-014)
  • Scout drilling at the Rudnica North prospect intersected an intact porphyry with only minor levels of erosion

Tethyan Resource Corp. entered into an option agreement over the Raska exploration license, which contains the Rudnica copper-gold porphyry project, in September 2016 (see press release dated 27th September 2016). According to the option agreement, Tethyan holds the option to purchase 100% of the license at any time during an 8 year period for a EURO 6 million cash payment provided that Tethyan achieves certain exploration and payment milestones (terms of the Option Agreement are discussed below).

Figure 1: Data compilation at Rudnica copper-gold porphyry project

Rudnica is the most advanced target and has been subject to historic drilling as well as 8,560 m  of diamond drilling by Tethyan. Tethyan has also completed detailed soil sampling, channel sampling and a TITAN 24 geophysical survey. As a result of this drilling, mineralisation has been defined over 400 by 200 m at surface and to 550 m below surface, but remains open in all directions. A 20 to 45 m  thick zone of supergene copper enrichment has been identified at approximately 100 m below surface, overlying hypogene copper-gold porphyry style mineralisation (stockwork veins and disseminated mineralisation).

Rudnica North is situated 750 m  north of Rudnica and Tethyan has drilled three scout holes for a total of 862 m. Porphyry style quartz veins have been mapped over an area of 300 by 300 m and are coincident with an ovoid magnetic high and chargeability high, which is present between 300 and 600 m below surface. Channel sampling by Tethyan intersected significant gold bearing mineralisation:

  • RCH: 40 m @ 0.21 g/t gold
  • RCH015: 30 m @ 0.24 g/t gold
  • RCH017: 10 m @ 0.26 g/t gold

The channel samples also returned anomalous molybdenum, indicative of the upper levels of a porphyry system. Drilling demonstrated presence of an intact porphyry system with only minor erosion. Holes were terminated early due to poor ground conditions meaning only the peripheries of the chargeability and magnetic anomaly were tested. Intercepts include:

  • 65 metres @ 0.12% Cu and 0.17 g/t Au (from 65 metres, RDD-009)
  • 69 m @ 0.05% Cu and 0.21 g/t Au (from 93 metres, RDD-010)
  • 50 m @ 0.03% Cu and 0.23 g/t Au (from 71 m, RDD-013)

Figure 2. Long section of Rudnica and Rudnica North projects

RUDNICA – SIGNIFICANT DRILLING INTERCEPTS

Rudnica North Drill Results

The results of these drill holes have expanded the known extent of the Rudnica porphyry system, and have returned long intervals of porphyry-style stockwork copper mineralisation hosted in multi-phase porphyritic dacite/diorite intrusions. The true widths of the drill intersections cannot be determined with the information available as mineralisation is disseminated throughout the large system.

GEOLOGY

Rudnica comprises Neogene andesite and andesitic volcaniclastics which unconformably overlie Paleozoic serpentinite.  At Rudnica these units have been intruded by a suite of steeply northwest dipping hornblende diorite stocks and dykes and tonalite dykes. The intrusive suite occurs over a north-south area of at least 600 by 250 m. Four stages of intrusions have been recognised: early-mineralisation (P10), intra-mineralisation (P20) and late-mineralisation (P30 and P40). Several generations of late-mineral faults are observed offsetting mineralisation on a small (10s of meters) scale.

Rudnica North is inferred to lie on the northern, downthrown side of a west-northwest trending, post-mineral normal fault and therefore represents a more shallowly eroded porphyry than Rudnica.

MINERALISATION

The upper 30 to 100m of the Rudnica deposit has been leached by weathering resulting in a copper-poor, gold bearing cap which contains gold grades of between 0.2 and 0.5 g/t gold. The leached zone overlies a 20 to 45 m thick zone of supergene copper enrichment (chalcocite blanket) which contains copper-gold grades of between 0.7 % and 1.5 % copper and 0.2 and 0.5 g/t gold.

At Rudnica, copper-gold mineralisation comprises steeply northwest and northeast dipping porphyry style (A and B) stockwork quartz-pyrite-chalcopyrite ± magnetite veins and disseminated sulphides associated primarily with P10 intrusions, with lower copper-gold grades observed in P20 intrusions. This hypogene mineralisation has been defined over 400 by 200 m to a depth of 550 m below surface, and remains open at depth and along strike as indicated from drilling results, geochemical data analysis and ASD alteration mineral mapping.

Figure 3: Spectral data, molybdenum distribution and vein abundance provide vectors to porphyry mineralisation

% Cu Equivalent = % Cu + 0.63 x g/t Au (US$ 3 US per lb Cu and US$ 1300 per troy oz Au).

Copper-gold mineralisation sits at the core of the intrusive suite and is enveloped by an outer zone of weakly anomalous (>10ppm) molybdenum, overlying a chargeability high. The molybdenum zonation is typical of most porphyry systems and indicates that the upper parts of the porphyry system are exposed.

Late gold-silver-lead-zinc veins cross cut the copper-gold porphyry mineralisation and trend east-west.

ALTERATION

Rudnica is characterised by a central zone of early relict secondary biotite (potassic) alteration and magnetite-stable chlorite-epidote-actinolite (propylitic) alteration overprinted by late magnetite-destructive quartz-sericite-pyrite (phyllic) alteration. The late phyllic alteration is observed near-surface and locally at depth, with a narrow transitional zone of chlorite-sericite-clay (intermediate argillic) alteration observed between the early and late alteration assemblages. This alteration zonation is indicative of the upper parts of a porphyry system.

PHOTO GALLERY

Option Agreement

Under the terms of the Agreement Tethyan is entitled to purchase 100% of the License or Deep Research (at Tethyan’s discretion) for a cash payment of €6 million, plus a percentage of the eventual capital cost of building the mine (details set out below), at any time during the total duration of the License and any future extensions of the License (a minimum of 7 years from the date of the Agreement).

The decision whether or not to exercise the Option during this period is at the sole discretion of the Company. The percentage of the capital costs payable by Tethyan in relation to the building of the mine (the “CAPEX”), which will only become clear once a bankable feasibility study has been conducted over the License, will only become payable if Tethyan exercises the Option, secures the necessary financing and proceeds with the building of the mine. The percentage of these costs due to the shareholders of Deep Research will be calculated as follows:

  • 4% of CAPEX up to €200m;
  • 2% of CAPEX between €200 – 500m;
  • 1% of CAPEX in excess of €500m.

Pursuant to the terms of the Agreement, and in order to retain the Option, the Company will arrange to complete, at its sole discretion, the following work program on the License:

  • a minimum of 2,000m drilling before 28 December 2016;
  • a minimum of 5,000m additional drilling before 28 December 2018;
  • complete a preliminary economic assessment before the sixth anniversary of the date of the Agreement;
  • complete an economic feasibility study before the seventh anniversary of the Agreement.

The Company estimate that the full cost of the drilling programme to be completed by 28 December 2018 will be less than £500,000. The drilling programme can be stopped at any stage at the Company’s sole discretion. The purpose of the drilling programme is to assess the prospectivity of the License so that Tethyan can make an informed decision with regards to the exercise of the Option.

In order to satisfy the first requirement under the work programme Tethyan intends to start work immediately with respect to drilling 2,000 meters by 28 December 2016. Discussions have commenced with local drill contractors who have drill rigs standing-by to commence work. Land access is currently being assessed in order to allow for drilling during the next 3 years,

The Company will also make certain milestone payments, at its sole discretion, in order to retain the Option:

  • €100,000 by 1 March 2017;
  • €100,000 on each anniversary of the signing the Agreement up until the third year.

KIZEVAK AND SASTAVCI OVERVIEW

Kizevak and Sastavci are two past-producing zinc, lead and silver open pit mines located within the Raska District. The property comprises the Kizevak and Sastavci exploration licences which cover a total area of 3.28 km2 and are 100% owned by EFPP d.o.o., a private Serbian company. On 1st April 2020 Tethyan entered into an arms length agreement to purchase a 100% ownership stake in EFPP d.o.o. The Kizevak and Sastavci exploration licences are contiguous with Tethyan’s existing exploration rights in the district.

The Kizevak and Sastavci mines were discovered in the mid 1970s and operated by the Yugoslav geological survey between 1984 and 2000, when mining ceased due to the Balkans conflict. The projects benefit from numerous infrastructure advantages including water, power, road and rail access all within 5 kilometres, and a local workforce with a long history of mining. Additionally, the land comprising the wider project area is designated for mining purposes under the Serbian State spatial plan, providing many permitting benefits and efficiencies.

No significant exploration work has been conducted on either licence since mining ceased, and the projects offer significant exploration potential for expansion of existing, in-situ mineralisation along strike and down dip from the open pits at Kizevak and Sastavci.

Tethyan has completed a review of historic data and digitised historic drilling and underground sampling results from which initial drill targets have been identified for both verification of the location and tenor of mineralisation, as well as testing exploration potential down dip and along strike. Tethyan has also worked extensively along strike from the Kizevak and Sastavci pits within adjacent exploration licences since 2018, including soil sampling, detailed mapping and diamond drilling. This work resulted in significant intercepts reported in September 2018 and the identification of undrilled targets at the Kizevak South and Sastavci Gold prospects.

Mineralisation at both targets is vein type, intermediate sulphidation epithermal comprising quartz-carbonate-sulphide vein breccias and stockwork zones, hosted in an andesitic volcanic sequence.

HISTORIC MINERAL RESOURCE ESTIMATE

The state geological survey reported a resource estimate for the Kizevak, Sastavci and Karadak deposits in 1994 shown in the table below. This data presents Tethyan with immediate drill targets and further work including soil sampling, mapping and geophysical surveys will be completed to generate additional exploration targets.

The historic mineral resource estimates at Kizevak, Sastavci and Karadak were reported by the state geological survey in 1994. The estimates are reported according to Yugoslav GKZ guidelines and do not comply with NI 43-101 reporting requirements and associated CIM definition standards. The authors caution that a qualified person has not done sufficient work to validate the historical estimates, and Tethyan is not treating the historical estimates as current mineral resources or reserves. Tethyan has not completed a detailed review of the historical resource or completed a new mineral resource estimate. The historical resource estimates were completed using the polygonal method using data acquired from diamond drilling and underground sampling. The historical resource estimate does not use the categories set out in sections 1.2 and 1.3 of NI 43-101. For readers not familiar with Yugoslav mineral estimates, such estimates were always stated as “reserves” and classified according to the A+B+C1+C2 or “alphabetical” classification, which was derived from the Russian system and is still applied throughout many countries in southeast Europe. The reserves had to be approved by the official Commission for Ore Reserves. The A, B, C1 and C2 categories reflect the levels of confidence in the actual tonnage exploited from a reserve, with confidence levels being – 95%, 80%, 70% and 35% respectively. Henley (2004) and others have evaluated the alphabetical classification system with respect to the compliant codes in Canada and Australia, and concluded that A+B is comparable to “measured”, C1 to “indicated” and C2 to “inferred” in internationally acceptable codes for reporting resources. However, these comparisons are only an approximation, and cannot be considered as equivalents. To verify the historical resource estimate as current mineral resources or mineral reserves, drilling, mapping, detailed geological interpretation, geological modelling, grade mapping by interpolation using geostatistical analysis and mineral resource classification, using industry standard software, is required.

KIZEVAK

Mineralisation at Kizevak comprises steeply dipping, southeast striking, structurally controlled lenses of quartz-carbonate-sulphide vein breccias and stockwork zones hosted in andesite volcanics. Historic drilling and underground sampling data indicate that mineralisation occurs over a strike length of at least 1.2 kilometres, between 1 and 30 metres wide, and up to 200 metres down dip (Figures 2 & 3). This dominant southeast striking trend is intersected by at least one perpendicular southwest striking mineralised structure, which is inferred as an important control on high grade shoots.

Mineralisation is open down dip and along strike to the northwest, southwest and southeast. In 2018 Tethyan drilled four drill holes on its wholly owned licence 1.2 kilometres along strike to the southeast of the mine (refer to Tethyan’s news release dated September 4th 2018 and Figure 2) that returned mineralized intervals including:

  • 12 metres at 22.03 % zinc, 10.29 % lead, 167 g/t silver, and 0.18 g/t gold for 35.09 % ZnEq (Hole KSEDD002, from 130 m)
  • 43 metres at 4.30 % zinc, 2.49 % lead, 26 g/t silver, and 0.21 g/t gold for 7.39 % ZnEq (Hole KSEDD001, from 193 m)                                                                                                                       o including 13.1 m @ 11.28 % zinc, 5.05 % lead, 57 g/t silver, and 0.32 g/t gold for 17.44 % ZnEq (from 221 m)
  • 40.0 m @ 4.35 % zinc, 2.14 % lead, 27 g/t silver, and 0.34 g/t gold for 7.37 % ZnEq (Hole KSEDD003, from 137 m)

Map showing historical exploration drilling and adits that define a mineralised zone in excess of 1.2 km in strike length, overlain on satellite imagery in which the Kizevak open pit is visible. Selected significant intercepts are labelled and all mineralised intervals >2 % Pb+Zn are shown for reference.

Long section through the Kizevak deposit showing historic drill and exploration adit intercepts >2 % Pb+Zn. Note the intercepts down to 530 metre elevation in the northwest versus intercepts to only 680 metre elevation in the southeast, indicating significant upside to depth.

SASTAVCI

Sastavci was also mined historically by open pit on a smaller scale than at Kizevak and represents a priority drilling target. Outcropping, steeply dipping, massive sulphide veins up to 5 metres wide are visible in the pit walls. Tethyan collected 65 rock-chip samples across the Sastavci area, which returned assays ranging from trace to >30 % zinc (over range), 7.1 % lead, 94.3 g/t silver and 0.47 g/t gold in the Sastavci pit.

Additionally, to the north of the Sastavci open pit Tethyan has defined a greater than 100 ppb gold in soil anomaly over 800 metres long and 400 metres wide in strongly silica altered volcanic rocks. Rock-chip sample assays range from trace to 3.7 g/t gold, representing a separate epithermal gold exploration target.

Significant historic drill intercepts are shown below:

  • 18 m @ 5.5 % Zn, 2.2 % Pb and 26 g/t Ag (SB-3, from 47.4 m)
  • 2.5 m @ 14.8 % Zn, 6.0 % Pb and 58 g/t Ag (SB-3, from 175.4 m)
  • 4.5 m @ 4.3 % Zn, 3.4 % Pb and 69 g/t Ag (SB-12, from 0.5 m)
  • 6.8 m @ 4.4 % Zn, 1.9 % Pb and 50 g/t Ag (SB-14, from 164 m)

View west along strike of the mineralised vein and broad clay-hematite (after pyrite) alteration zone at Sastavci open pit.

IMAGE GALLERY

KREMICE OVERVIEW

  • 10 km north of Tethyan’s Rudnica copper-gold porphyry in the Raska District
  • Coincident gold-copper-molybdenum soil anomaly up to 1,200 m by 600 m
  • Geochemical and geophysical (magnetic data) modelling by Fathom Geophysics indicates a potential porphyry core between 150 metres and 700 metres below surface, with lateral dimensions of 750 metres by 500 metres
  • Channel sampling has identified a 450 m by 350 m area grading more than 0.1 g/t gold with a 125 m by 100 m core exceeding 0.3 g/t gold. Significant intercepts include:
    • 25 m @ 0.4 g/t Au (KCH010)
    • 10 m @ 0.49 g/t Au (KCH009)
    • 18 m @ 0.34 g/t Au (KCH007)
  • Two exploration diamond core holes returned:
    • 71.2 m @ 0.27 g/t Au, 0.07% Cu and 29 ppm Mo from (from surface, KRDD-001)
    • 45 m @ 0.19 g/t Au (from surface, KRDD-002)
  • Related epithermal gold-silver mineralisation at Kremice East was drilled historically but remains untested by Tethyan
  • The limited drilling to date has demonstrated near-surface mineralisation and a narrow zone of supergene copper enrichment. The significant zone of outcropping mineralisation and gold-molybdenum in soil remains largely untested.

Figure 1: Geology, RTP magnetic data and soil anomalies at Kremice Prospect

Figure 2: Geology, channel sample results and drill collars, Kremice Prospect. Note the greatest abundance of porphyry veins is coincident with the highest grade channel samples

KREMICE DRILLING AND CHANNEL RESULTS

GEOLOGY

At Kremice, Neogene andesite volcanics and volcaniclastics unconformably overlie a basement of Paleozoic serpentinite.  Steeply east and northeast dipping diorite porphyry stocks and dykes intrude the basement and volcanics over an area of 1,400 x 700 m at surface. Three phases of porphyry have been defined to date: a mineralised fine-grained diorite porphyry (KD10), syn-mineral hornblende-feldspar diorite porphyry (KD20) and a post-mineralcrowded feldspar diorite porphyry (KD30).

MINERALISATION

Soil sampling results display a northwest-trending gold-copper-molybdenum anomaly spanning 1,200 m by 600 metres, with weakly anomalous zinc, arsenic and bismuth and depleted manganese. The geochemical footprint at Kremice is indicative of a shallowly eroded porphyry system, and 3D geochemical modelling by Fathom Geophysics produced a near-surface zone of increased probability for the occurrence of a porphyry type deposit.

Detailed geological mapping of the soil anomaly defined a porphyry centre with rare magnetite-secondary K-feldspar-leucoxene-biotite alteration overprinted by clay-sericite-pyrite, crosscut by quartz-magnetite-pyrite stockwork veins hosted in diorite porphyry. A 450 m by 350 m area grading at more than 0.1 g/t gold with a 125 m by 100 m core exceeding 0.3 g/t gold was defined by channel sampling and followed up with two scout holes for 680 metres, which intersected gold porphyry mineralisation from surface.

The gold-molybdenum soil anomaly and outcropping stockwork mineralisation is located on the eastern flank of a northwest trending magnetic high, adjacent to a distinct circular magnetic low. Weak molybdenum in soil is coincident with the magnetic low and further work is required to determine the potential for porphyry mineralisation in this area. 3D structure detection of the magnetic data by Fathom Geophysics identified a major NW trending structure spatially associated with the gold-molybdenum soil anomaly, and several second order NE trending crossing structures. The intersection of these structural trends are considered important vectors to mineralisation.

Figure 3: 3D structure detection and geochemical model derived from ground magnetic and soil sampling data. Note the greatest probability of porphyry potential is coincident with elevated gold in soil along a NW trending structural contact in the magnetic data

Figure 4: Cross section showing the greatest probability of porphyry potential from geochemical modelling and drill results. Note mineralisation was intercepted from surface, coincident with a large surface extent of porphyry veins. The geochemical anomaly remains to be fully tested

ALTERATION

Central magnetite-secondary K-feldspar-leucoxene-biotite (potassic) alteration and magnetite-stable chlorite-epidote-actinolite (propylitic) alteration is overprinted by widespread quartz-sericite-pyrite alteration and flanked by an outer propylitic halo (actinolite-epidote-chlorite-calcite-sericite).

PHOTO GALLERY

Overview

INTRODUCTION

Tethyan is focused on precious and base metal exploration in the Balkan region, and holds the rights to exploration on over 120km2 in Serbia at the northern end of the Trepca silver-zinc-lead mining district, within the western Tethyan Metallogenic Belt (TMB). This includes two past producing silver-zinc-lead open pit mines within Tethyan’s Kizevak and Sastavci exploration licences with historical mineral resources, as well as two confirmed copper-gold porphyry centres at Rudnica and Kremice.

Significant, Tier One copper-gold discoveries have been made in the Balkan part of the TMB since the 1960s, including the Bor complex and Majdanpek (Timok Belt, Serbia), the Elatsite and Assarel deposits (Panagyurishte District, Bulgaria) and Rosia Poieni (Apuseni District, Romania). Furthermore, the Trepca mineral belt of Kosovo hosts several underground silver-lead-zinc mines which have been in operation since the turn of the 20th Century. The same belt extends into Macedonia and Greece where operating and development stage projects include the Skouries copper-gold porphyry (Eldorado Gold), Olympias CRD polymetallic deposit (Eldorado Gold) and Sasa polymetallic deposit (Central Asia Metals).

Location of Tethyan’s Raska District Property

PROJECT DESCRIPTION

Tethyan has the right to explore four contiguous exploration licences in the “Raska District” of southwestern Serbia, which is prospective for silver-lead-zinc, epithermal style mineralisation as well as copper-gold porphyry deposits, summarised in the below table. The licence package is located in SW Serbia, 250 km from Belgrade and is situated close to the existing road, rail and power network.

Tethyan also holds 100% of the Zukovac and Bucje exploration licences in SE Serbia, along strike from the Timok Magmatic Complex, totalling 168 km2.

Map showing Tethyans exploration licences and prospects, Raska District

GEOLOGICAL SETTING

The TMB formed as result of the convergence and collision of the Arabian, African and Indian tectonic plates during closure of the Tethys Ocean, and extends from eastern Europe to Southeast Asia. In the Balkan region, the Tethyan Orogeny resulted in the formation of several distinct arcuate belts of accreted microcontinents, obducted marine sedimentary rocks and ophiolites, within which discrete clusters of porphyry copper gold and polymetallic epithermal and CRD deposits have formed.

The Raska District comprises a Neogene andesite volcanic sequence with coeval diorite intrusions, overlying a serpentinised ophiolitic basement. All units are intruded by later granodiorite stocks. Porphyry and related epithermal mineralisation is spatially associated with diorite intrusions and andesite domes on the flanks of the larger granodiorite stocks.

Details of the more advanced Kizevak-Sastavci, Rudnica and Kremice prospects are given on the relevant project pages.

EXPLORATION POTENTIAL

Tethyan’s Raska District prospects display similar size alteration halos, metal zonation and geophysical characteristics to other major porphyry districts worldwide. By way of comparison, the below image demonstrates the scale of the alteration and mineralisation observed at surface in the Raska District relative to the major copper deposits of the Timok Belt in eastern Serbia.

Tethyan’s Rudnica, Bukovik and Kremice porphyry prospects in the Raska District have typical geochemical and geophysical characteristics associated with copper-gold porphyry systems, including:

  • Strong metal zonation at surface which provides vectors to mineralisation
  • Coincident copper-gold-molybdenum in soil and channel samples at Rudnica and Kremice
  • Depleted zinc and manganese overlying porphyry mineralisation
  • Elevated arsenic and bismuth in soils
  • Alteration is indicative of upper levels of hydrothermal system
  • Alunite, vuggy silica and specular hematite observed at Bukovik, inferred to represent a lithocap environment, potentially overlying or on the shoulders of a deeper porphyry
  • Strong sericite and weak silica alteration at surface indicates the roots of a lithocap are exposed at Rudnica, i.e the top of a porphyry
  • Mapping has confirmed the presence of porphyry style veining coincident with the geochemical anomalies at Rudnica and Rudnica North, and detailed mapping of the Kremice and Bukovik prospects is planned to follow up the geochemical anomalies.
  • Coincident geophysical anomalies underly the geochemical anomalies and alteration zones
  • Moderate magnetic highs observed at Rudnica and Rudnica North, related to magnetite stable alteration and serpentinite basement
  • Magnetic data provides excellent basis for broad scale structural interpretation
  • Chargeable highs and resistivity lows are coincident with the magnetic anomalies

In addition, several lead-zinc-silver vein and breccia hosted targets are observed peripheral to the porphyry prospects and present stand-alone exploration targets. Tethyan infers that the porphyry and lead-zinc-silver (intermediate sulphidation) deposits are related to the same mineralising events.

Rudnica Copper-Gold Porphyry

RUDNICA OVERVIEW

  • Coincident 1.5 km geochemical and geophysical anomaly containing two copper-gold-(molybdenum) porphyry centres
  • Mineralisation is coincident with anomalous gold, copper and molybdenum in soil and depleted zinc and manganese, as well as magnetic highs and zones of elevated chargeability and low resistivity
  • Geochemical and alteration zoning indicates that the lithocap has been eroded and the upper parts of the porphyry system is exposed at surface
  • Mineralisation is open in all directions
  • Significant drill intercepts at the southern Rudnica prospect include
    • 567 m @ 0.28 % copper and 0.45 g/t gold (from surface, RDD-001)
    • 356 m @ 0.38 % copper and 0.31 g/t gold (from 48m, RDD-004)
    • 460 m @ 0.21 % copper and 0.20 g/t gold (from surface, RDD-006)
    • 335 m @ 0.36 % copper and 0.31 g/t gold (from 68 m, RDD-014)
  • Scout drilling at the Rudnica North prospect intersected an intact porphyry with only minor levels of erosion

Tethyan Resource Corp. entered into an option agreement over the Raska exploration license, which contains the Rudnica copper-gold porphyry project, in September 2016 (see press release dated 27th September 2016). According to the option agreement, Tethyan holds the option to purchase 100% of the license at any time during an 8 year period for a EURO 6 million cash payment provided that Tethyan achieves certain exploration and payment milestones (terms of the Option Agreement are discussed below).

Figure 1: Data compilation at Rudnica copper-gold porphyry project

Rudnica is the most advanced target and has been subject to historic drilling as well as 8,560 m  of diamond drilling by Tethyan. Tethyan has also completed detailed soil sampling, channel sampling and a TITAN 24 geophysical survey. As a result of this drilling, mineralisation has been defined over 400 by 200 m at surface and to 550 m below surface, but remains open in all directions. A 20 to 45 m  thick zone of supergene copper enrichment has been identified at approximately 100 m below surface, overlying hypogene copper-gold porphyry style mineralisation (stockwork veins and disseminated mineralisation).

Rudnica North is situated 750 m  north of Rudnica and Tethyan has drilled three scout holes for a total of 862 m. Porphyry style quartz veins have been mapped over an area of 300 by 300 m and are coincident with an ovoid magnetic high and chargeability high, which is present between 300 and 600 m below surface. Channel sampling by Tethyan intersected significant gold bearing mineralisation:

  • RCH: 40 m @ 0.21 g/t gold
  • RCH015: 30 m @ 0.24 g/t gold
  • RCH017: 10 m @ 0.26 g/t gold

The channel samples also returned anomalous molybdenum, indicative of the upper levels of a porphyry system. Drilling demonstrated presence of an intact porphyry system with only minor erosion. Holes were terminated early due to poor ground conditions meaning only the peripheries of the chargeability and magnetic anomaly were tested. Intercepts include:

  • 65 metres @ 0.12% Cu and 0.17 g/t Au (from 65 metres, RDD-009)
  • 69 m @ 0.05% Cu and 0.21 g/t Au (from 93 metres, RDD-010)
  • 50 m @ 0.03% Cu and 0.23 g/t Au (from 71 m, RDD-013)

Figure 2. Long section of Rudnica and Rudnica North projects

RUDNICA – SIGNIFICANT DRILLING INTERCEPTS

Rudnica North Drill Results

The results of these drill holes have expanded the known extent of the Rudnica porphyry system, and have returned long intervals of porphyry-style stockwork copper mineralisation hosted in multi-phase porphyritic dacite/diorite intrusions. The true widths of the drill intersections cannot be determined with the information available as mineralisation is disseminated throughout the large system.

GEOLOGY

Rudnica comprises Neogene andesite and andesitic volcaniclastics which unconformably overlie Paleozoic serpentinite.  At Rudnica these units have been intruded by a suite of steeply northwest dipping hornblende diorite stocks and dykes and tonalite dykes. The intrusive suite occurs over a north-south area of at least 600 by 250 m. Four stages of intrusions have been recognised: early-mineralisation (P10), intra-mineralisation (P20) and late-mineralisation (P30 and P40). Several generations of late-mineral faults are observed offsetting mineralisation on a small (10s of meters) scale.

Rudnica North is inferred to lie on the northern, downthrown side of a west-northwest trending, post-mineral normal fault and therefore represents a more shallowly eroded porphyry than Rudnica.

MINERALISATION

The upper 30 to 100m of the Rudnica deposit has been leached by weathering resulting in a copper-poor, gold bearing cap which contains gold grades of between 0.2 and 0.5 g/t gold. The leached zone overlies a 20 to 45 m thick zone of supergene copper enrichment (chalcocite blanket) which contains copper-gold grades of between 0.7 % and 1.5 % copper and 0.2 and 0.5 g/t gold.

At Rudnica, copper-gold mineralisation comprises steeply northwest and northeast dipping porphyry style (A and B) stockwork quartz-pyrite-chalcopyrite ± magnetite veins and disseminated sulphides associated primarily with P10 intrusions, with lower copper-gold grades observed in P20 intrusions. This hypogene mineralisation has been defined over 400 by 200 m to a depth of 550 m below surface, and remains open at depth and along strike as indicated from drilling results, geochemical data analysis and ASD alteration mineral mapping.

Figure 3: Spectral data, molybdenum distribution and vein abundance provide vectors to porphyry mineralisation

% Cu Equivalent = % Cu + 0.63 x g/t Au (US$ 3 US per lb Cu and US$ 1300 per troy oz Au).

Copper-gold mineralisation sits at the core of the intrusive suite and is enveloped by an outer zone of weakly anomalous (>10ppm) molybdenum, overlying a chargeability high. The molybdenum zonation is typical of most porphyry systems and indicates that the upper parts of the porphyry system are exposed.

Late gold-silver-lead-zinc veins cross cut the copper-gold porphyry mineralisation and trend east-west.

ALTERATION

Rudnica is characterised by a central zone of early relict secondary biotite (potassic) alteration and magnetite-stable chlorite-epidote-actinolite (propylitic) alteration overprinted by late magnetite-destructive quartz-sericite-pyrite (phyllic) alteration. The late phyllic alteration is observed near-surface and locally at depth, with a narrow transitional zone of chlorite-sericite-clay (intermediate argillic) alteration observed between the early and late alteration assemblages. This alteration zonation is indicative of the upper parts of a porphyry system.

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Option Agreement

Under the terms of the Agreement Tethyan is entitled to purchase 100% of the License or Deep Research (at Tethyan’s discretion) for a cash payment of €6 million, plus a percentage of the eventual capital cost of building the mine (details set out below), at any time during the total duration of the License and any future extensions of the License (a minimum of 7 years from the date of the Agreement).

The decision whether or not to exercise the Option during this period is at the sole discretion of the Company. The percentage of the capital costs payable by Tethyan in relation to the building of the mine (the “CAPEX”), which will only become clear once a bankable feasibility study has been conducted over the License, will only become payable if Tethyan exercises the Option, secures the necessary financing and proceeds with the building of the mine. The percentage of these costs due to the shareholders of Deep Research will be calculated as follows:

  • 4% of CAPEX up to €200m;
  • 2% of CAPEX between €200 – 500m;
  • 1% of CAPEX in excess of €500m.

Pursuant to the terms of the Agreement, and in order to retain the Option, the Company will arrange to complete, at its sole discretion, the following work program on the License:

  • a minimum of 2,000m drilling before 28 December 2016;
  • a minimum of 5,000m additional drilling before 28 December 2018;
  • complete a preliminary economic assessment before the sixth anniversary of the date of the Agreement;
  • complete an economic feasibility study before the seventh anniversary of the Agreement.

The Company estimate that the full cost of the drilling programme to be completed by 28 December 2018 will be less than £500,000. The drilling programme can be stopped at any stage at the Company’s sole discretion. The purpose of the drilling programme is to assess the prospectivity of the License so that Tethyan can make an informed decision with regards to the exercise of the Option.

In order to satisfy the first requirement under the work programme Tethyan intends to start work immediately with respect to drilling 2,000 meters by 28 December 2016. Discussions have commenced with local drill contractors who have drill rigs standing-by to commence work. Land access is currently being assessed in order to allow for drilling during the next 3 years,

The Company will also make certain milestone payments, at its sole discretion, in order to retain the Option:

  • €100,000 by 1 March 2017;
  • €100,000 on each anniversary of the signing the Agreement up until the third year.
Kizevak and Sastavci Zinc-Lead-Silver

KIZEVAK AND SASTAVCI OVERVIEW

Kizevak and Sastavci are two past-producing zinc, lead and silver open pit mines located within the Raska District. The property comprises the Kizevak and Sastavci exploration licences which cover a total area of 3.28 km2 and are 100% owned by EFPP d.o.o., a private Serbian company. On 1st April 2020 Tethyan entered into an arms length agreement to purchase a 100% ownership stake in EFPP d.o.o. The Kizevak and Sastavci exploration licences are contiguous with Tethyan’s existing exploration rights in the district.

The Kizevak and Sastavci mines were discovered in the mid 1970s and operated by the Yugoslav geological survey between 1984 and 2000, when mining ceased due to the Balkans conflict. The projects benefit from numerous infrastructure advantages including water, power, road and rail access all within 5 kilometres, and a local workforce with a long history of mining. Additionally, the land comprising the wider project area is designated for mining purposes under the Serbian State spatial plan, providing many permitting benefits and efficiencies.

No significant exploration work has been conducted on either licence since mining ceased, and the projects offer significant exploration potential for expansion of existing, in-situ mineralisation along strike and down dip from the open pits at Kizevak and Sastavci.

Tethyan has completed a review of historic data and digitised historic drilling and underground sampling results from which initial drill targets have been identified for both verification of the location and tenor of mineralisation, as well as testing exploration potential down dip and along strike. Tethyan has also worked extensively along strike from the Kizevak and Sastavci pits within adjacent exploration licences since 2018, including soil sampling, detailed mapping and diamond drilling. This work resulted in significant intercepts reported in September 2018 and the identification of undrilled targets at the Kizevak South and Sastavci Gold prospects.

Mineralisation at both targets is vein type, intermediate sulphidation epithermal comprising quartz-carbonate-sulphide vein breccias and stockwork zones, hosted in an andesitic volcanic sequence.

HISTORIC MINERAL RESOURCE ESTIMATE

The state geological survey reported a resource estimate for the Kizevak, Sastavci and Karadak deposits in 1994 shown in the table below. This data presents Tethyan with immediate drill targets and further work including soil sampling, mapping and geophysical surveys will be completed to generate additional exploration targets.

The historic mineral resource estimates at Kizevak, Sastavci and Karadak were reported by the state geological survey in 1994. The estimates are reported according to Yugoslav GKZ guidelines and do not comply with NI 43-101 reporting requirements and associated CIM definition standards. The authors caution that a qualified person has not done sufficient work to validate the historical estimates, and Tethyan is not treating the historical estimates as current mineral resources or reserves. Tethyan has not completed a detailed review of the historical resource or completed a new mineral resource estimate. The historical resource estimates were completed using the polygonal method using data acquired from diamond drilling and underground sampling. The historical resource estimate does not use the categories set out in sections 1.2 and 1.3 of NI 43-101. For readers not familiar with Yugoslav mineral estimates, such estimates were always stated as “reserves” and classified according to the A+B+C1+C2 or “alphabetical” classification, which was derived from the Russian system and is still applied throughout many countries in southeast Europe. The reserves had to be approved by the official Commission for Ore Reserves. The A, B, C1 and C2 categories reflect the levels of confidence in the actual tonnage exploited from a reserve, with confidence levels being – 95%, 80%, 70% and 35% respectively. Henley (2004) and others have evaluated the alphabetical classification system with respect to the compliant codes in Canada and Australia, and concluded that A+B is comparable to “measured”, C1 to “indicated” and C2 to “inferred” in internationally acceptable codes for reporting resources. However, these comparisons are only an approximation, and cannot be considered as equivalents. To verify the historical resource estimate as current mineral resources or mineral reserves, drilling, mapping, detailed geological interpretation, geological modelling, grade mapping by interpolation using geostatistical analysis and mineral resource classification, using industry standard software, is required.

KIZEVAK

Mineralisation at Kizevak comprises steeply dipping, southeast striking, structurally controlled lenses of quartz-carbonate-sulphide vein breccias and stockwork zones hosted in andesite volcanics. Historic drilling and underground sampling data indicate that mineralisation occurs over a strike length of at least 1.2 kilometres, between 1 and 30 metres wide, and up to 200 metres down dip (Figures 2 & 3). This dominant southeast striking trend is intersected by at least one perpendicular southwest striking mineralised structure, which is inferred as an important control on high grade shoots.

Mineralisation is open down dip and along strike to the northwest, southwest and southeast. In 2018 Tethyan drilled four drill holes on its wholly owned licence 1.2 kilometres along strike to the southeast of the mine (refer to Tethyan’s news release dated September 4th 2018 and Figure 2) that returned mineralized intervals including:

  • 12 metres at 22.03 % zinc, 10.29 % lead, 167 g/t silver, and 0.18 g/t gold for 35.09 % ZnEq (Hole KSEDD002, from 130 m)
  • 43 metres at 4.30 % zinc, 2.49 % lead, 26 g/t silver, and 0.21 g/t gold for 7.39 % ZnEq (Hole KSEDD001, from 193 m)                                                                                                                       o including 13.1 m @ 11.28 % zinc, 5.05 % lead, 57 g/t silver, and 0.32 g/t gold for 17.44 % ZnEq (from 221 m)
  • 40.0 m @ 4.35 % zinc, 2.14 % lead, 27 g/t silver, and 0.34 g/t gold for 7.37 % ZnEq (Hole KSEDD003, from 137 m)

Map showing historical exploration drilling and adits that define a mineralised zone in excess of 1.2 km in strike length, overlain on satellite imagery in which the Kizevak open pit is visible. Selected significant intercepts are labelled and all mineralised intervals >2 % Pb+Zn are shown for reference.

Long section through the Kizevak deposit showing historic drill and exploration adit intercepts >2 % Pb+Zn. Note the intercepts down to 530 metre elevation in the northwest versus intercepts to only 680 metre elevation in the southeast, indicating significant upside to depth.

SASTAVCI

Sastavci was also mined historically by open pit on a smaller scale than at Kizevak and represents a priority drilling target. Outcropping, steeply dipping, massive sulphide veins up to 5 metres wide are visible in the pit walls. Tethyan collected 65 rock-chip samples across the Sastavci area, which returned assays ranging from trace to >30 % zinc (over range), 7.1 % lead, 94.3 g/t silver and 0.47 g/t gold in the Sastavci pit.

Additionally, to the north of the Sastavci open pit Tethyan has defined a greater than 100 ppb gold in soil anomaly over 800 metres long and 400 metres wide in strongly silica altered volcanic rocks. Rock-chip sample assays range from trace to 3.7 g/t gold, representing a separate epithermal gold exploration target.

Significant historic drill intercepts are shown below:

  • 18 m @ 5.5 % Zn, 2.2 % Pb and 26 g/t Ag (SB-3, from 47.4 m)
  • 2.5 m @ 14.8 % Zn, 6.0 % Pb and 58 g/t Ag (SB-3, from 175.4 m)
  • 4.5 m @ 4.3 % Zn, 3.4 % Pb and 69 g/t Ag (SB-12, from 0.5 m)
  • 6.8 m @ 4.4 % Zn, 1.9 % Pb and 50 g/t Ag (SB-14, from 164 m)

View west along strike of the mineralised vein and broad clay-hematite (after pyrite) alteration zone at Sastavci open pit.

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Kremice Gold-Copper Porphyry

KREMICE OVERVIEW

  • 10 km north of Tethyan’s Rudnica copper-gold porphyry in the Raska District
  • Coincident gold-copper-molybdenum soil anomaly up to 1,200 m by 600 m
  • Geochemical and geophysical (magnetic data) modelling by Fathom Geophysics indicates a potential porphyry core between 150 metres and 700 metres below surface, with lateral dimensions of 750 metres by 500 metres
  • Channel sampling has identified a 450 m by 350 m area grading more than 0.1 g/t gold with a 125 m by 100 m core exceeding 0.3 g/t gold. Significant intercepts include:
    • 25 m @ 0.4 g/t Au (KCH010)
    • 10 m @ 0.49 g/t Au (KCH009)
    • 18 m @ 0.34 g/t Au (KCH007)
  • Two exploration diamond core holes returned:
    • 71.2 m @ 0.27 g/t Au, 0.07% Cu and 29 ppm Mo from (from surface, KRDD-001)
    • 45 m @ 0.19 g/t Au (from surface, KRDD-002)
  • Related epithermal gold-silver mineralisation at Kremice East was drilled historically but remains untested by Tethyan
  • The limited drilling to date has demonstrated near-surface mineralisation and a narrow zone of supergene copper enrichment. The significant zone of outcropping mineralisation and gold-molybdenum in soil remains largely untested.

Figure 1: Geology, RTP magnetic data and soil anomalies at Kremice Prospect

Figure 2: Geology, channel sample results and drill collars, Kremice Prospect. Note the greatest abundance of porphyry veins is coincident with the highest grade channel samples

KREMICE DRILLING AND CHANNEL RESULTS

GEOLOGY

At Kremice, Neogene andesite volcanics and volcaniclastics unconformably overlie a basement of Paleozoic serpentinite.  Steeply east and northeast dipping diorite porphyry stocks and dykes intrude the basement and volcanics over an area of 1,400 x 700 m at surface. Three phases of porphyry have been defined to date: a mineralised fine-grained diorite porphyry (KD10), syn-mineral hornblende-feldspar diorite porphyry (KD20) and a post-mineralcrowded feldspar diorite porphyry (KD30).

MINERALISATION

Soil sampling results display a northwest-trending gold-copper-molybdenum anomaly spanning 1,200 m by 600 metres, with weakly anomalous zinc, arsenic and bismuth and depleted manganese. The geochemical footprint at Kremice is indicative of a shallowly eroded porphyry system, and 3D geochemical modelling by Fathom Geophysics produced a near-surface zone of increased probability for the occurrence of a porphyry type deposit.

Detailed geological mapping of the soil anomaly defined a porphyry centre with rare magnetite-secondary K-feldspar-leucoxene-biotite alteration overprinted by clay-sericite-pyrite, crosscut by quartz-magnetite-pyrite stockwork veins hosted in diorite porphyry. A 450 m by 350 m area grading at more than 0.1 g/t gold with a 125 m by 100 m core exceeding 0.3 g/t gold was defined by channel sampling and followed up with two scout holes for 680 metres, which intersected gold porphyry mineralisation from surface.

The gold-molybdenum soil anomaly and outcropping stockwork mineralisation is located on the eastern flank of a northwest trending magnetic high, adjacent to a distinct circular magnetic low. Weak molybdenum in soil is coincident with the magnetic low and further work is required to determine the potential for porphyry mineralisation in this area. 3D structure detection of the magnetic data by Fathom Geophysics identified a major NW trending structure spatially associated with the gold-molybdenum soil anomaly, and several second order NE trending crossing structures. The intersection of these structural trends are considered important vectors to mineralisation.

Figure 3: 3D structure detection and geochemical model derived from ground magnetic and soil sampling data. Note the greatest probability of porphyry potential is coincident with elevated gold in soil along a NW trending structural contact in the magnetic data

Figure 4: Cross section showing the greatest probability of porphyry potential from geochemical modelling and drill results. Note mineralisation was intercepted from surface, coincident with a large surface extent of porphyry veins. The geochemical anomaly remains to be fully tested

ALTERATION

Central magnetite-secondary K-feldspar-leucoxene-biotite (potassic) alteration and magnetite-stable chlorite-epidote-actinolite (propylitic) alteration is overprinted by widespread quartz-sericite-pyrite alteration and flanked by an outer propylitic halo (actinolite-epidote-chlorite-calcite-sericite).

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