Tim Baker

Eldorado Gold Corporation · Exploration

The Skouries Au-Cu porphyry deposit is located in northern Greece and hosted by quartz monzonites and mon-zogranites of early Miocene age (~20 Myr). The host rocks show geochemical similarities to other mafic to felsicintrusions in the district that have a similar strike direction, but which are 6 Myr older and lack evidence of economicmineralizati...

The ERASMUS+ ARTeMIS (Action for Research and Teaching Mineral exploration Inclusive School) program is a training-through-research project for mineral exploration that brings together Master students from four partner universities (Univ. Lorraine, FAU Erlangen-Nürnberg, Aristotle University of Thessaloniki and NKUA Athens) and the mining company H...

Le projet ARTeMIS est un projet de formation par la recherche qui regroupe les étudiants en Master exploration des 4 Universités partenaires (Univ. Lorraine, Nürnberg-Erlangen, Thessalonique et Athènes) et l’entreprise Hellas Gold. Au programme, des formations pour les enseignants et les étudiants aux outils d’analyses spectroscopiques de terrain (...

The Skouries deposit in NE Greece is a platinum-group element enriched (⌀=149 ppb Pd, ⌀=30 ppb Pt) Au-Cu porphyry system hosted by monzonite-syenite intrusions. The porphyry stockwork consists of quartz-rich A-and B-type veins associated with potassic alteration, followed by massive sulfide-bearing veins related to chlorite-sericite alteration, and...

The Karavansalija Mineralized Center (KMC) with its Au–Cu skarn mineralization associated with the Rogozna Mountains magmatic suite in southwestern Serbia belongs to the Oligocene Serbo-Macedonian magmatic and metallogenic belt (SMM-MB). Samples from intrusive and volcanic rocks at the KMC show typical arc signatures of subduction-derived magmas th...

Pore fluid pressure and differential stress are among the most important controls on the mechanical behavior of mineralizing systems. Their separate influences can be readily identified on failure mode diagrams, which show failure envelopes for pore fluid factor or pore fluid pressure at failure against differential stress. The effect of the interm...

The Miocene Kışladağ deposit (~17 Moz), located in western Anatolia, Turkey, is one of the few global examples of Au-only porphyry deposits. It occurs within the West Tethyan magmatic belt that can be divided into Cretaceous, Cu-dominant, subduction-related magmatic arc systems and the more widespread Au-rich Cenozoic magmatic belts. In western Ana...

The Au-rich polymetallic massive sulfide orebodies of the Kassandra mining district belong to the intrusion-related carbonate-hosted replacement deposit class. Marble lenses contained within the Stratoni fault zone host the Madem Lakkos and Mavres Petres deposits at the eastern end of the fault system, where paragenetically early skarn and massive...

Major Au and Cu deposits in the Western Tethyan magmatic belt formed during two main periods of Cretaceous and Cenozoic magmatism. The Cretaceous deposits are dominantly Cu-Au porphyry, high-sulfidation epithermal, and volcanic massive sulfide deposits, whereas in the Cenozoic Cu is significant only in porphyry systems. However, the Cenozoic contai...

Greece hosts a variety of magmatic-hydrothermal ore deposits/prospects with porphyry- and epithermal styles playing a major role in its total gold endowment. These deposit types are mainly clustered in two areas, the Rhodope- and Attico-Cycladic massifs, and formed from about 33 Ma to the Pleistocene, as a result of back-arc extension in the Aegean...

The Konos Hill prospect in NE Greece represents a telescoped Mo-CuRe -Au porphyry occurrence overprinted by deep-level high-sulfidation mineralization. Porphyry-style mineralization is exposed in the deeper parts of the system and comprises quartz stockwork veins hosted in subvolcanic intrusions of granodioritic composition. Ore minerals include py...

The Kassandra mining district of northern Greece contains about 12 Moz Au in porphyry Au-Cu and Au-Ag-Pb-Zn-Cu carbonate replacement deposits that are associated with Oligocene-Miocene intrusions emplaced into polydeformed metamorphic basement rocks belonging to the Permo-Carboniferous to Late Jurassic Kerdilion unit and the Ordovician-Silurian Ver...

Exhumation of metamorphic core complexes during extension, triggered by detachment faulting, can provide a favorable environment for ore formation. In northern Greece and southern Bulgaria, the Rhodope-Serbo-Macedonian massif represents a world-class case to study exhumation processes in an extensional back-arc setting, looking at supra-detachment...

The Rhodope Massif in northeastern Greece hosts a broad variety of magmatic-hydrothermal ore deposits, which include skarn and Pb-Zn-Au-Ag carbonate-replacements at Thermes, reduced intrusion-related gold systems at Kavala and Pangeon, intrusion-hosted Mo-Cu-W-Bi-Au veins at Kimmeria, high- to intermediate-sulfidation epithermal Au-Ag-bearing polym...

The Kis¸ladag porphyry gold deposit (16.8 Moz) is located in western Anatolia, Turkey, and is hosted in a nested complex of monzonite porphyries that intruded coeval volcanic rocks of the Beydagı stratovolcano and the Menderes metamorphic basement. The intrusions and volcanic rocks have a high K calc-alkaline to shoshonitic affinity similar to the...

The Kisladag porphyry gold deposit (16.8 Moz) is located in western Anatolia, Turkey, and is hosted in a nested complex of monzonite porphyries that intruded coeval volcanic rocks of the Beydagı stratovolcano and the Menderes metamorphic basement. The intrusions and volcanic rocks have a high K calc-alkaline to shoshonitic affinity similar to the r...

Iron oxide – Cu ± Au ± U ± Co (IOCG) mineralization is associated with numerous Proterozoic breccia bodies, collectively known as Wernecke Breccia, in Yukon Territory, Canada. Multiphase breccia zones occur in areas underlain by Paleoproterozoic Wernecke Supergroup metasedimentary rocks and are associated with widespread sodic, potassic, and carbon...

The Late Archean Sunrise Dam gold deposit (∼10 Moz) is hosted within greenschist-facies rocks and is characterized by extreme structural complexity, resulting from a protracted deformation history with evidence of structural reactivation and multiple phases of gold mineralization. Early Group I orebodies are hosted within shallow- to moderately dip...

The Suicide Ridge Barren Breccia Pipe (∼1527±4Ma) is one of numerous breccia occurrences that characterize the Cloncurry district, Australia. Interest in breccia systems in the Cloncurry district is related to their possible link with iron oxide copper–gold deposits. The Suicide Ridge Barren Breccia Pipe is temporally and spatially associated with...

The Olympic Copper-Gold Province of the eastern Gawler Craton of South Australia, in hosting the Olympic Dam, Prominent Hill, Carrapateena and Moonta-Wallaroo deposits, has the greatest known iron-oxide, copper, gold and uranium (IOCGU) metal endowment of any geological province on Earth. The historic Moonta-Wallaroo copper-gold mining field is wit...

The Bismark deposit (northern Chihuahua, Mexico) is one of several base metal-rich high-temperature, carbonate-replacement deposits hosted in northern Mexico. Previous fluid inclusion studies based on microthermometry and PIXE have shown that the Zn-rich, Pb-poor Bismark deposit formed from a moderate salinity magmatic fluid [Baker, T. and Lang, J....

The Sunrise Dam Gold Mine is the largest gold deposit in the eastern part of the Yilgarn craton. In several ways it is a typical Archean lode gold deposit, other than its exceptional size. Mineralization is hosted in intermediate-mafic metavolcanics and metasedimentary rocks. The major structures are gently NW to NNW dipping shear zones, which are...

Regionally-distributed brecciation in the Proterozoic Wernecke Mountains of Canada is associated with hydrothermal alteration, that is similar to that seen in the Fe-oxide–Cu–Au class of ore deposit and characterized by variably saline fluid inclusions. Two phase liquid-vapour (LV) fluid inclusions (< 26–30 wt.% salt) in fluorite and barite, plus m...

Proterozoic rocks of the Cloncurry district in NW Queensland, Australia, are host to giant (tens to hundreds of square kilometers) hydrothermal systems that include (1) barren regional sodic–calcic alteration, (2) granite-hosted hydrothermal complexes with magmatic–hydrothermal transition features, and (3) iron oxide–copper–gold (IOCG) deposits. Fl...

Fluid inclusions in late-Isan quartz veins associated with regional Na–Ca alteration (albitisation), in the Mary Kathleen Fold Belt and the Cloncurry District of the Eastern Mt Isa Block, have been analysed for naturally occurring and neutron produced isotopes of Ar, Kr and Xe. The noble gases have been extracted using a thermal decrepitation proce...

We present a 3D geological model that integrates different datasets and incorporates geophysical inversion of airborne gravimetric and magnetic surveys of the northern part of the Drummond and Bowen basins. These basins are known for their endowment of low‐sulphidation, epithermal Au‐Ag mineralisation. The objective of this computer based reconstru...

New data indicate Wernecke Breccia-associated iron oxide copper-gold (IOCG) deposits likely formed from moderate-temperature, high-salinity, non-magmatic brines. The breccias formed in an area underlain by a sedimentary sequence that locally contained evaporites (potential source of chloride and possibly sulfur) and was thick enough to produce elev...

The Carboniferous Pajingo Epithermal System (PES) comprises several low sulphidation Au-Ag ore zones that have a total resource of c. 3 Moz (million ounces). The main Vera-Nancy vein is hosted by andesite that contains alteration which zones from inner silica-pyrite to argillic to distal propylitic alteration. Pyrite is ubiquitous in both alteratio...

The source and transport regions of fluidized (transported) breccias outcrop in the Cloncurry Fe-oxide–Cu–Au district. Discordant dykes and pipes with rounded clasts of metasedimentary calc–silicate rocks and minor felsic and mafic intrusions extend several kilometres upwards and outwards from the contact aureole of the 1530 Ma Williams Batholith i...

Proton-induced X-ray emission (PIXE) has been used to characterize the multielement chemistry of the diverse fluid inclusions found in intrusion-related gold systems in the Tintina gold province, Yukon and Alaska. The studied samples are from shallow-level examples that contain coexisting brine (type 3) and carbon dioxide-bearing vapor (type 4) inc...

A large scale Proterozoic breccia system consisting of numerous individual breccia bodies, collectively known as Wernecke Breccia, occurs in north-central Yukon Territory, Canada. Breccias cut Early Proterozoic Wernecke Supergroup sedimentary rocks and occur throughout the approximately 13km thick deformed and weakly metamorphosed sequence. Iron ox...

Epigenetic gold deposits in metamorphic terranes include those of the Precambrian shields (approx 23,000–25,000 t Au), particularly the Late Archean greenstone belts and Paleoproterozoic fold belts, and of the late Neoproterozoic and younger Cordilleran-style orogens (approx 22,000 t lode and 15,500 t placer Au), mainly along the margins of Gondwan...

The chemistry of fluid inclusions in shallow (coexisting brine and carbon dioxide-bearing vapour inclusions) and deep (low salinity carbon dioxide methane-rich aqueous fluids) intrusion-related gold systems in the Tintina Gold Belt, Alaska and Yukon, has been measured using proton induced x-ray emission (PIXE) in order to compare and contrast these...

Gold is an important by-product in many porphyry-type deposits but the distribution and chemistry of gold in such systems remains poorly understood. Here we report the results of petrographic, electron microprobe, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), and flotation test studies of gold and associated copper sulfid...

Liberation of iron and potassium by widespread postmetamorphic albitization of country rocks was one of the likely contributing processes in the formation of both barren and mineralized magnetite ± chalcopyrite + biotite + gold + hematite + clinopyroxene + actinolite + apatite ironstones in the Cloncurry district of the Proterozoic Mount Isa block....

Intrusion-related gold deposits at the Clear Creek, Scheelite Dome and Dublin Gulch properties of the Tombstone Gold Belt (TGB), Yukon Territory have dominantly E-striking, steeply dipping, auriferous quartz extension veins within intrusions. In adjacent metasedimentary rocks gold is hosted in subvertical NW- to NNW-striking sinistral faults as vei...

The chemistry of brine, vapor, and low-salinity fluid inclusions measured by proton-induced X-ray emission from the Bismark skarn deposit, Mexico, is consistent with an evolving magmatic-hydrothermal system with no evidence for external fluid inputs. The results support a model that invokes early phase separation of magmatic fluids into brine and v...

The chemistry of brine, vapor, and low-salinity fluid inclusions measured by proton-induced X-ray emission from the Bismark skarn deposit, Mexico, is consistent with an evolving magmatic-hydrothermal system with no evidence for external fluid inputs. The results support a model that invokes early phase separation of magmatic fluids into brine and v...

The Bismark deposit (8.5Mt at 8% Zn, 0.5% Pb, 0.2% Cu, and 50g/t Ag) located in northern Mexico is an example of a stock-contact skarn end member of a continuum of deposit types collectively called high-temperature, carbonate-replacement deposits. The deposit is hosted by massive sulfide within altered limestone adjacent to the Bismark quartz monzo...

Phanerozoic intrusion-related gold deposits have many consistent characteristics such as a spatial, temporal, and geochemical association with moderately reduced (predominantly ilmenite-series) 1-type intrusions. The deposits exhibit a range of characteristics that vary over a wide range of emplacement depths (<1->7 km). Deposits in shallow crustal...

Bedrock underlying the Slab iron oxide-copper-gold occurrence consists of fine-grained sedimentary rocks and schist of the Fairchild Lake Group (oldest unit of the Early Proterozoic Wernecke Supergroup), intermediate to mafic Slab volcanics, dioritic Bonnet Plume River Intrusions, and Early Proterozoic Wernecke Breccia that crosscuts all other unit...

The Dublin Gulch intrusion is a member of the Tombstone plutonic suite, a linear belt of middle Cretaceous intrusions that extend across the Yukon Territory. Like many of the intrusions in this suite, the Dublin Gulch intrusion is associated with several different zones of gold and tungsten mineralization, within and immediately adjacent to the int...

Intrusion-hosted, low sulfide, sheeted vein systems are common within many plutons and stocks of the middle Cretaceous Tombstone-Tungsten magmatic belt, Yukon Territory, and host significant gold mineralization. Fluid inclusion characteristics of five such systems, namely Emerald Lake, Dublin Gulch, Scheelite Dome, Mike Lake, and MacTung, constrain...

New radiogenic (Ar-40/Ar-39) and stable (oxygen, hydrogen, and sulfur) isotope analyses of metamorphic and metasomatic minerals constrain the age, metasomatic evolution, and genesis of the Eloise Cu-Au deposit (3.1 Mt @ 5.5% Cu, 1.4 g/t Au, and 16 g/t Ag). Biotite from a pre- to syn-D-2-stage vein has an Ar-40/Ar-39 age of 1555 +/- 4 Ma which is in...

The Ray Gulch tungsten skarn and the Eagle Zone intrusion-related gold deposit are associated with the Dublin Gulch intrusion, which forms part of the mid-Cretaceous Tombstone Plutonic Suite. Tungsten mineralization occurs in a roof pendant of hornfelsed Neoproterozoic to Early Cambrian Hyland Group metasedimentary rocks. Five main paragenetic stag...

Detailed vertical-face mapping of 'Slab Creek' was carried out in the summer of 2001 to evaluate the relations of Wernecke Breccia bodies with alteration, veining and iron oxide-copper-gold mineralization. Slab Creek is situated near the 'Slab' mineral occurrence in the Bonnet Plume River district of the Wernecke Mountains. Meta-sedimentary rocks i...

An under-recognized and economically important class of intrusion-related gold deposits, which occur within magmatic provinces best known for tungsten and/or tin mineralization, is described with reference to seven major deposits (Fort Knox, Mokrsko, Salave, Vasilkovskoe, Timbarra, Kidston and Kori Kollo). These gold deposits contain a metal suite...

The Eloise deposit (3.1 million metric tons, Mt, ≱.5% Cu, 1.4 g/t Au and 16 g/t Ag) is hosted by Proterozoic rocks of the Soldiers Cap Group in the Eastern fold belt of the Mount Isa inlier. The deposit is characterized by very high grade, chalcopyrite-pyrrhotite-rich mineralization hosted by mafic silicate alteration. Alteration and mineralization...

The blind Eloise Cu‐Au deposit is hosted by the subsurface eastward extension of the Proterozoic East Mt Isa Block. The host rocks comprise highly deformed, amphibolite‐grade metasediments and amphibolite of the Soldiers Cap Group. The deposit formed during the waning phase of the Isan Orogeny (D3, 1540–1500 Ma) in a regional Cu‐Au metallogenic eve...

The Red Chris Cu-Au deposit (522.7 Mt at 0.35% Cu and 0.27 g/t Au), northwestern British Columbia, is one of several pre-accretionary porphyry systems in the Cordillera of western Canada. It is hosted by an Early Jurassic hornblende monzonite to quartz monzodiorite porphyry which forms part of a suite of dikes and stocks that intrude Late Triassic...