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Titiribi - Cerro Vetas, NW Breccia, Chisperos |
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Colombia |
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Au Cu
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Super Porphyry Cu and Au
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IOCG Deposits - 70 papers
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All papers now Open Access.
Available as Full Text for direct download or on request. |
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The Titiribi cluster of porphyry gold-copper and gold deposits, occurrences and historic mines, including the main Cerro Vetas deposit complex, are located ~1 km to the west and south of the town or Titiribi and ~70 km SW of Medellin in northwestern Colombia (#Location: 6° 3' 46"N, 75° 48' 32"W).
Mining is documented in the Titiribi district from as early as 1793, with production from at least 14 mines within a 3 km radius of the town of Titiribi during the 19th and early 20th centuries totalling between an estimated 90 to 155 tonnes of gold.
Regional Setting
The Titiribi deposits is located on the northwestern margin of the Central Cordillera, one of four sub-parallel, generally north-south trending mountain ranges that constitute the western Colombian Andes, each separated by an intermontane depression. The Eastern and Central Cordillera are separated by the Magdalena Valley, whilst the Central and Western Cordillera lie on either side of the Cauca-Patia (or Inter-Andean) Graben/Depression. The Pacific Coast Range or Serrania de Baudó, is separated from the Western Cordillera by the Atrato-San Juan depression.
The Central Cordillera has a Precambrian and Palaeozoic polymetamorphic basement (McCourt, et aI., 1984) that has been intruded by numerous Mesozoic and Cenozoic batholiths and stocks, the most significant of which is the 8500 km2 Antioquia Batholith. Regionally, the western limit of the polymetamorphic basement is formed by the generally north-south striking, dextral transcurrent Lower Cretaceous Romeral-San Jacinto fault system (McCourt, 1984; Aspden and McCourt, 1986). This fault zone also marks a suture of Lower Cretaceous age along which the late Jurassic(?) to early Cretaceous allochthonous oceanic plateau basalts and related ophiolitic rocks of the Romeral Terrane of Cediel, et aI. (2003), or Amaime terrane of Aspden and McCourt (1986), were accreted to the Lower Palaeozoic continental margin. The Romeral Fault zone and the western Romeral Terrane have been strongly sheared to produce a broad mélange that comprises mega-scale blocks and fragments of the oceanic allochthon and crustal slivers of autochthonous Paleozoic metamorphic rocks of the Pre-Cretaceous continental margin. This broad zone of structural complexity formed the core of the Cauca-Patia (or Inter-Andean) Graben/Depression, which underwent thrust and fold-style deformation both prior to and following Cretaceous and Cenozoic intrusions (Shaw, 2000).
The Cauca-Patia Graben is a 30 to 50 km wide dextral transpressional pull-apart structure, above which a number of overlapping elongated basins are filled with volcanic, volcaniclastic and sedimentary rocks, with associated Tertiary intrusions, of Oligocene to Recent age in Colombia. It is bounded by the Romeral Fault to the east and Cauca Fault to the west, interpreted to represent branches of an upwardly expanding flower structure encompassing the Romeral Terrane mélange.
Deposition within the Cauca-Patia Graben commenced with autochthonous Oligocene siliciclastic sedimentary sequences following the oblique docking from the southwest of the oceanic plateau basalts of the Dagua Terrane of Cediel et al. (2003). This was followed by further compressional deformation in the early to middle Miocene and again in the middle-late Miocene as the Gorgona and Cañas Gordas-Baudó terranes, further slivers of Cretaceous oceanic plateau basalts was progressively accreted from the southwest along major dextral suture zones. In the late Miocene, both the Romeral terrane and the Oligocene siliciclastic sediments were syntectonically intruded by a series of mineralised and altered stocks, dykes, and sills and associated extrusive equivalents, which return K-Ar whole rock dates of from 8 Ma to 6 Ma (Andrew, 2011; Kedahda, 2003). The emplacement of Miocene intrusives and syn-mineral volcanic rocks was followed by a period of continued volcanism dominated by dacitic-andesitic dykes, tuffs and ash.
For more detail of the regional setting and geology, see the separate record for the North Andes and Panama copper-gold province.
District and Deposit Geology
The geology of the Titiribi district is dominated by multiple intrusions of the Miocene Cerro Vetas porphyry system, a cluster of separate stocks, plugs and dykes of porphyritic, generally diorite and monzonite, intrusives that may be connected at depth. The intrusive porphyry complex intrudes a Palaeozoic to Cretaceous basement that is unconformably overlain by an Oligocene to Miocene sedimentary sequence. The porphyries also intrude a diatreme breccia interpreted to represent an earlier precursor to the porphyries.
The Oligocene-Miocene sedimentary sequence that overlies the Lower Palaeozoic basement commences with the Amaga Group, composed of folded and faulted siliciclastic sedimentary rocks dominated by marine-continental quartz pebble conglomerates, sandstone, green, black and red shale, and coal. The underlying Palaeozoic to Cretaceous basement comprises strongly tectonised rocks of the Jurassic to early-Cretaceous Arquía Complex and the Palaeozoic Cajamarca-Valdivia Group.
Both the basement rocks and overlying Amaga Group sediments are intruded by sills and dykes, and are locally overlain by coeval andesitic volcanic rocks of the late Miocene to Pliocene Combia Formation.
The local geology, particularly the basement stratigraphy and structure, is complex, as there are few recognizable marker horizons, and the individual units have been tectonically displaced and interleaved across multiple large shear and fault zones, which themselves have been intruded by younger magmas.
The geological succession is as follows, from the base:
Palaeozoic
• Cajamarca-Valdivia Group - a complexly deformed Middle Ordovician to Silurian sequence, which is regionally composed of greenschist to lower amphibolite facies pelitic and graphite-bearing schists, amphibolites, intrusive rocks, and rocks of ophiolitic origin (olivine gabbro, pyroxenite, chromitite, and serpentinite), which geochemical analyses indicate have an intra-oceanic arc and continental-margin affinity (Restrepo-Pace, 1992). This unit is most common in the northeastern section of the Titiribi district.
Mesozoic
• Arquía Complex - a late Jurassic to early Cretaceous suite of dark green amphibolitic schists with intervals of black, pyritic, graphitic schist. The composition of these rocks has a tholeiitic affinity after basalts and basaltic andesites, and are interpreted to be metamorphosed oceanic plateau rocks of the Romeral Terrane tectonically interleaved with the Cajamarca-Valdivia Group within the Romeral fault zone.
• Quebradagrande Formation - basaltic to andesitic volcanic rocks and low-grade meta-sedimentary rocks. Some units may have originally been ultramafic. This formation comprises much of the basement in the western part of the district at Chisperos, Cerro Vetas and Candela, and are predominantly Cretaceous in age. They are dark green to black, often porphyritic with hornblende phenocrysts, and are locally pyritic and nearly universally chloritised. The green to black basaltic rocks have been intersected in nearly all of the drilling. The contact with the overlying Amaga Formation is discordant and regionally dips at ~40° NE.
Cenozoic
• Amaga Formation - which is of Oligocene to Miocene in age and has been subdivided into lower, middle and upper members. It reaches a stratigraphic thicknesses of >1400 m, although in the Candela, Margarita and Cerro Vetas areas, only 50 to 75 stratigraphic metres of the lower member is preserved as diapirically domed roof pendants or west-verging thrust slices, resting upon the basement complex. The middle and upper members have been eroded in the much of the immediate district, and are consequently absent. The Amaga Formation sedimentary rocks are an important hosts for stratabound replacement-, contact- and reverse fault-hosted mineralisation in the northeastern part of the Titiribi District.
- Lower Member - is the most extensively exposed in the district. The basal bed is a coarse to medium grained conglomerate that unconformably overlies basement graphitic schists, and has been a common host to high-grade bedding and shear hosted veins throughout the district. The conglomerate is overlain by a series of white and grey sandstone units with interbedded carbonaceous beds, carbonaceous sandy mudstone, and grey claystone, passing upwards into a violet colored claystone with thick interbeds of sandstone at the top of the member. Regionally this member is ~200 m thick, although at Titiribi, only 50 to 75 m of the stratigraphic section remains.
- Middle Member - regionally this member is ~200 to 250 m thick and comprises white, argillaceous and ferruginous sandstones, interbedded with an alternating series of at least 5 separate coal seams, each up to 2.5 metres in thickness. This member is exposed to the east and north, but has been eroded in the Titiribi district.
- Upper Member - which is regionally up to 1000 m thick and comprises well-cemented cream, green and brown coloured sandstones, with local thin conglomerate and coal seams. It has largely been eroded in the district.
• Combia Formation - is considered to be late Miocene to Pliocene age (20 to 6 Ma) and outcrops over the entire central section of the district, between the Junta and Candela-Porvenir faults, including at Chisperos, Cerro Vetas and Candela. In the Chisperos and Cerro Vetas areas, both volcanic and sedimentary units are present as a series of crystal tuffs, lithic tuffs and conglomerates consisting of quartz pebbles and re-worked Cretaceous basement rocks and Amaga Formation. It has been subdivided into:
- Lower Member - dominantly composed of volcanic rocks, which are andesitic in composition, consisting of agglomeratic breccias, basalt and andesite dikes. The agglomerates are volcanic rocks of andesitic composition, whilst the crystal and lithic tuffs are composed of crystalline fragments of augite, hornblende, biotite, quartz, kaolinized feldspar, and variable proportions of volcanic glass and fragments of volcanic rock. The basalt flows are generally feldspar-rich. Flow tops are frequently auto-brecciated and amygdaloidal with amygdules locally filled with chalcedony.
- Upper Member - which is dominantly volcaniclastic, comprising poorly consolidated, interstratified conglomerate, sedimentary breccia, fine to medium-grained sandstone, and reddish to cream coloured argillite that unconformably overlie both the Combia Formation lower member and the Amaga Formation.
Intrusions
• Amaga Granodiorite - which is pre-mineral and comprises a medium to coarse grained granodiorite that intrudes the Palaeozoic basement rocks, but has in turn, been cut by intrusive breccias and the mineralised Cerro Vetas intrusive. It generally shows evidence of having undergone some shearing, and compositionally, is mostly granodioritic, but also includes diorite to tonalite phases. It may possibly be of late Cretaceous to Eocene age, although no age dating data has been encountered in the available information sources, nor information on the relationship with the Amaga or Combia formations.
• Cerro Vetas Diorite - which is syn-mineral and gold-copper mineralised, and ranges in composition from diorite to quartz-diorite to monzonite. It is composed of biotite, hornblende, feldspar and quartz, and is enriched in magnetite. It occurs as stock-like bodies to plugs and wide dykes that appear to taper at depth. Based on its geometry and the present level of exposure, it may represent the remnant roots of a larger eroded intrusive. The diorite porphyry intrudes Palaeozoic basement, the Amaga granodiorite, diatreme breccias, the lower member of the Amaga Formation and the volcano-sedimentary units of the Miocene to Pliocene Combia Formation. It was intruded along the NW-SE trending Cauca-Romeral fault zone, although the dyke like intrusive bodies are aligned in an ENE-WSW direction parallel to some faults and tensional structures within the Cauca-Romeral fault zone. Similar diorite intrusives are indicated at the Junta, Maria Jo, Porvenir and Candela prospects with magnetic highs aligned along the Cauca-Romeral fault trend.
• Dacite-Andesite Intrusives - which is post-mineral, and generally occurs as dykes that range from dacite to andesite in composition. The dacite dykes are light coloured, composed of quartz, plagioclase, biotite and opaque minerals, whilst the andesite dykes, which are more common in the southern part of the district, are dark grey, and comprise plagioclase, hornblende, biotite, opaque minerals and rare quartz. Neither are hydrothermally altered or mineralised.
Breccias
The three main breccias types are recognised the district, as follows:
• Diatreme breccia - which is interpreted to have been formed by explosive activity above early phases of the dioritic magma. This style of breccia occurs throughout the Cerro Vetas-NW Breccia-Chisperos area affecting both basement and the overlying sedimentary package. The largest development, the NW Breccia, hosts mafic and ultramafic clasts, whilst at Cerro Vetas and Chisperos to the southeast and east respectively, there appears to be fewer ultramafic, but more mafic fragments. Hornblende-rich mafic porphyry clasts in the diatreme breccia are similar in appearance to coarse hornblende crystal-rich porphyries found within the Quebradagrande Formation.
The diatreme breccias are mostly dyke-like, and are parallel/sub-parallel to, and intruded by, mineralised diorite dykes. At Chisperos, diatreme breccia is cut by parallel and sub-parallel NW-SE striking, NE dipping faults that control mineralisation within both the diatreme breccia and along the contact between basement volcaniclastic rocks and the Amaga Formation conglomerate. As such, the diatreme breccias are regarded to be pre-mineral.
• Intrusive and contact breccia - which are regarded as having formed during intrusion of the Cerro Vetas porphyry, occurring on the margins adjacent to and within the intrusive, acting as passageways for hydrothermal alteration and mineralisation. The breccias occur on all sides of the main Cerro Vetas intrusive. Much of the better mineralised contact breccia occurs in the phyllic alteration zone of the Cerro Vetas porphyry. Berhre Dolbear (2013) suggest there are probably three different breccia types represented at Titiribi. The first is true contact breccia mostly composwed of brecciated, altered, and mineralised wall rock, whilst the second is true intrusive breccia consisting mostly of diorite fragments. A third breccia style includes multiple phases of mineralisation and includes fragments of diorite and wall rock. Fluidised features containing rounded fragments often with higher-grade mineralisation are likely vertical hydrothermal fluidised pebble dykes.
• Fault breccias - are common throughout the main deposit, but generally are only associated with minor displacement. They may have acted as the channel ways for auriferous hydrothermal fluids that mineralised favourable shallow dipping stratigraphic hosts.
Structural Control
Pre-existing structures, particularly the Cauca-Romeral fault zone, have provided foci for the development of diatreme breccias and later the emplacement of the mineralised Cerro Vetas porphyry stock, plugs and dykes. It is also possible that bedding plane faulting was also important in ground preparation for the emplacement of high-grade base and precious metal veins and replacement deposits of the historically mines in the Titiribi District.
The structural framework within the district is dominated by two NW-SE trending parallel structures that are ~1.5 km apart, the Cerro Vetas-Juntas Fault to the east and the Candella-Porvenir fault to the west, parallel to the broad regional Cauca-Romeral fault zone. These structures are connected by NE-SW tensional openings that control the orientation of both the diatreme breccias and the Cerro Vetas intrusive bodies.
Mineralisation and Alteration
The Titiribi district contains several separate mineralised areas, all of which appear to be related to a large Miocene age gold-copper porphyry/epithermal system composed of multiple gold-copper bearing intrusive centres. This includes a single large bulk tonnage gold-copper porphyry complex, which has a boomerang shape in plan, and is made up of the contiguous and overlapping NW Breccia, Cerro Vetas and Chisperos zones, each of which is related to a separate intrusive centre, surrounded by contact aureoles with breccia hosted gold-dominant mineralisation and shallower epithermal gold mineralisation.
At the Cerro Vetas bulk-tonnage gold and copper deposit, which is in the elbow of the boomerang, most mineralisation is directly associated with the Cerro Vetas diorite porphyry, related contact breccias and its immediate contact aureole.
At the NW Breccia the mineralisation is gold-dominant in the diatreme breccia to the NW of Cerro Vetas.
At Chisperos, higher-temperature gold-copper mineralization is hosted within and adjacent to diorite dykes and as structurally and stratigraphically controlled, gold-dominant low-temperature epithermal vein mineralization, surrounded by thick intervals of lower-grade sediment and volcanic, hosted replacement mineralisation.
These three centres contain NI 43-101 compliant gold-copper resources, while the Maria Jo occurrence, ~750 m to the SE, hosts zones of copper-dominant and gold-copper mineralisation, and Junta a further kilometre to the SE hosts near-surface supergene enriched mineralisation in a stock-like porphyry intrusive and structurally controlled breccia. This group of deposits forms a NW-SE trending alignment reflected as a string of 'highs' in magnetic data.
A second, parallel string of areally more extensive highs occurs ~1.5 km to the SE, and corresponds to the Candela occurence which hosts thick zones of prospective mineralised homfels and diorite porphyry and the similarly prospective Porvenir mineralisation. The Margarita and Rosa anomalies occur further to the SE along this trend.
In more detail, the individual zones of the main composite deposit have the following characteristics:
• Cerro Vetas - The core of this gold-copper porphyry deposit is occupied by a stock of the Cerro Vetas diorite porphyry. Although this stock was intruded along structures that are within the broad NW-SE trending Cauca-Romeral fault zone, dykes emanating from it are controlled by a series of tensional ENE-WSW striking faults. Diatreme breccia are similarly controlled by these same pre-exiting structural trends. The Cerro Vetas diorite porphyry bodies, which have domed the shallowly dipping upper country rocks, have vertical to steeply (70 to 80°) eastward plunges. The intrude all rocks from the Palaeozoic basement to the Combia volcano-sedimentary sequence, and the diatreme breccia units.
The Cerro Vetas diorite porphyry is fine to medium grained and locally exhibits typical porphyry copper alteration. It is a multiple-phase intrusion with a range of grain sizes, slightly differing mineralogies, and various associated intrusive breccias. The central stock has a diameter of ~550 to 600 m. Bedrock is exposed in only about 5% of the deposit area, generally only in creek beds, ridge tops, or new man-made road cuts.
The core of the Cerro Vetas diorite intrusive has undergone potassic alteration forming a roughly circular to slightly NE-SW elongated zone that apparently terminates at an elevation of about 1950 masl. The alteration assemblage comprises secondary biotite, K feldspar, quartz, magnetite and pyrite, occurring as disseminations, veins and fracture fillings. It is at best only very weakly mineralised.
A well-developed phyllic zone is developed above and surrounding the potassic core. It is composed of minor quartz-sericite-pyrite veinlets and sericite selvages on feldspars, accompanied by disseminated, stockwork and veinlet chalcopyrite, and veinlet magnetite and only a low pyrite content. This alteration zone hosts much of the gold-copper mineralisation. It appears to be thickest above the core zone and tapers on all sides at depth, and is very thin on the SW side of the Cerro Vetas intrusive. It has been superimposed over the outer margin of the diorite and a contact breccia that consists of intrusive and intruded rocks. Erosion has removed a portion of the uppermost phyllic zone.
A well-developed but narrow argillic zone with similar mineralisation borders the phyllic zone. The argillic zone is, in turn surrounded by a halo of propylitic alteration zone with intense silica-flooded hornfels nearest the diorite intrusion, passing outward into widespread areas of green chloritic rocks. Strong to weak silicification accompanies much of porphyry style alteration, particularly in the potassic zone.
Mineralisation hosted by the Cerro Vetas diorite porphyry is both disseminated and fracture controlled, with the principal metallic minerals being native gold, chalcopyrite, pyrite and magnetite. Within the diorite, there is generally a good correlation between gold values and the content of copper and magnetite.
Geophysical and drilling data suggest the higher-grade gold-copper zones take the form of a domed, saucer-shaped, contact breccia-related shell within the intrusive where brecciated diorite with xenolithic fragments of sedimentary rocks dominate. This higher-grade domed shell is, at least in part, coincident with the phyllically altered intrusive-sedimentary contact breccia. The contact breccia has been sub-divided into three lithologic types with diffuse boundaries, namely: i). true contact breccia composed mostly of brecciated, altered, and mineralised wall rock, ii). mineralised intrusive breccia mostly consisting of diorite fragments, iii). a style that comprises multiple phases of mineralisation that includes clasts of both diorite and wall rock.
Within the Cerro Vetas diorite, multiple phases of mineralisation are common, occurring as veins of quartz-magnetite-chalcopyrite that are cut by younger grey quartz (possibly with extremely fine-grained pyrite)-magnetite, which in turn cut by quartz-sericite-magnetite veins. In general, there is a strong positive correlation between gold and copper, but little correlation between gold and pyrite. High metal values are often accompanied by large amounts of magnetite, although the reverse is also true in the magnetite-rich but gold-copper poor potassic core. Other sulphide minerals, such as bornite, pyrrhotite and arsenopyrite, are uncommon to rare.
• NW Breccia - is dominated by diatreme breccia, intruded on the south by the main Cerro Vetas diorite stock and dykes, although another small diorite plug-like body intrudes the diatreme breccia in the north. The diatreme breccia in this area is characterised by mafic and ultramafic clasts and relatively high nickel and chrome levels. Gold assays in the deposit have a strong positive correlation with nickel and chrome values, suggesting that ultramafic fragments are very favorable host rocks. Where the diatreme breccia is in close proximity to diorite, it contains both gold and copper mineralisation, although distal to these intrusions it only hosts gold mineralisation with virtually no accompanying copper.
A poorly defined potassic alteration core is recognised in the in a plug-like diorite in the northern part of the zone.
Mineralisation similar to that described above at Cerro Vetas is found in the plug-like diorite described above and in the proximity of diorite dykes, although a second style of gold-only mineralisation is dominant in the diatreme breccias.
• Chisperos - occurs as NE-SW elongated complex of near vertical diorite dykes intruding diatreme breccia to the NE of the main Cerro Vetas diorite stock from which they appear to emanate. The diorite dykes are more extensive along strike than the diatreme breccia which occurs over greater width where present. Both intrude both basement rocks and the overlying Amaga-Combia sedimentary-volcanic units. The diatreme breccia contains mafic clasts including very coarse-grained hornblende- and biotite-rich mafic porphyry, but usually contains few ultramafic fragments compared to those in the NW Breccia zone.
Both gold-dominant and gold-copper mineralised zones are recognised. The former generally correlate to the presence of diorite dykes and their immediate contact area, whilst the gold-dominant zones are hosted in diatreme breccia, but also as substantial epithermal, lower-temperature mineralisation within parallel to sub-parallel zones that are both stratigraphically and structurally controlled and hosted in a sedimentary-volcanic sequences. Higher-grade zones in the latter often carry free gold.
Much of the mineralisation at Chisperos is structurally and stratigraphically controlled. The dominant vein orientations are in a NW-SE direction, while other zones of mineralisation are concordant to bedding, striking NW and dipping at 40 to 50° NE.
Two sub-vertical sets of parallel to subparallel, steeply dipping faults, one striking NW-SE, the other ENE-WSW, are interpreted to extend from the basement meta-basalt, and appear to have acted as feeders, transferring fluids to focus hydrothermal alteration and depositing sulphide and gold mineralisation into i). parallel zones in the crystal and lithic tuffs of the Combia Formation; ii). the contact between Amaga conglomerate and basement rocks; iii). basement schistose rocks; and iv). diatreme breccia.
Zones of bedding-controlled mineralisation in volcaniclastic sedimentary rocks apparently pass uninterrupted through diatreme breccias that cut the same rocks, whilst mineralized diorite dykes cut through diatreme breccia. Early diatreme breccia is also pre-Iow angle thrusting and pre-northwest striking hydrothermal feeder faults, as mineralisation related to those faults also mineralises the breccia and mineralisation along the low-angle faults passes uninterrupted through the diatreme breccia.
Near the surface, propylitic (chlorite-dominant) alteration predominates in the diatreme breccia, although at deeper levels, potassic alteration in diorite intrusives is very evident.
Although there is some disseminated and stockwork developments in broad zones at Chisperos, most of the higher-grade mineralisation is in narrow, sulphide-rich veins consisting mostly of pyrite and occasionally sphalerite. Pyrite is found in at least three paragenetic settings, including i). very fine-grained auriferous and argentiferous grains, ii). laminations along bedding, and iii). coarser-grained veins.
Sphalerite is the next most common sulphide, occurring as both massive crystalline aggregates and as isolated grains mostly in veins and veinlets, and is generally associated with higher grades of gold-silver mineralisation. It is coarse-grained compared to chalcopyrite and pyrite, and often occurs in thin, multi-directional veins with pyrite. Arsenopyrite is recognised, but is only locally common, whilst pyrrhotite also occurs and although magnetite and magnetite-ilmenite are present, they may be less prevalent than at Cerro Vetas.
Gangue minerals in the mineralised veins include calcite and quartz with restricted occurrences of dolomite, sericite, adularia and possibly barite. The vein textures are low-temperature epithermal, with fine drusy crystals, cockscomb structures, open-space filling, and crustiform banding. The presence of stibnite, laumontite and chalcedony provide further evidence of the low-temperature origin. These narrow higher-grade, sulphide-rich zones are surrounded by much lower grade rock. This lower-temperature epithermal style of mineralisation is common in the historic mines of the district, such as in the 'Mina El Cateador' gallery, the old Zancudo mine and the Otra Mina.
Reserves and Resources
Published ore reserves and mineral resources (at a 0.3 g/t Au cut-off) at 31 July, 2013 (Sunward Resources web site, 2016) were:
Measured + indicated resources
Cerro Vetas
measured resource - 51.6 Mt @ 0.49 g/t Au, 0.17% Cu (= 25.380 t Au)
indicated resource - 132.4 Mt @ 0.48 g/t Au, 0.16% Cu (= 63.949 t Au)
NW Breccia
indicated resource - 39.7 Mt @ 0.62 g/t Au (= 24.541 t Au)
Chisperos
indicated resource - 62.1 Mt @ 0.48 g/t Au (= 30.077 t Au)
TOTAL measured + indicated resource - 285.8 Mt @ 0.50 g/t Au (= 143.947 t Au)
Inferred resources
Cerro Vetas
153.0 Mt @ 0.57 g/t Au, 0.064% Cu (= 87.712 t Au)
NW Breccia
96.2 Mt @ 0.543 g/t Au (= 52.285 t Au)
Chisperos
100.2 Mt @ 0.47 g/t Au (= 46.811 t Au)
TOTAL inferred resource - 349.4 Mt @ 0.53 g/t Au (= 186.807 t Au).
TOTAL resource - 635.2 Mt @ 0.52 g/t Au (= 330.754 t Au).
This summary is drawn from: "Behre Dolbear, 2013 - Technical report on the Titiribi Project, Department of Antioquia, Colombia; an NI 43-101 Technical Report prepared by Behre Dolbear and Company (USA), Inc. for Sunward Resources Limited, 187p."
The most recent source geological information used to prepare this decription was dated: 2013.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Titiribi - Cerra Vetas
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Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
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