Richard Tosdal

Richard Tosdal
Independent

About

143
Publications
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5,353
Citations
Citations since 2016
20 Research Items
2506 Citations
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400
20162017201820192020202120220100200300400

Publications

Publications (143)
Article
Preservation of pre-Cenozoic porphyry Cu deposits requires geological events that bury the deposits before significant exhumation. Burial may be due to basin development over the top of the porphyry system or to burial beneath thrust sheets. The porphyry Au–Cu deposits in the Cadia district of central New South Wales underwent both events, and thus...
Article
Hydrothermal white mica in the Highland Valley district, British Columbia, is present in high-temperature alteration assemblages in early halo veins and in intermediate-temperature sericitic alteration assemblages in D-type veins. Pale-gray white micas characterize early halo veins in the Valley and Bethsaida zone porphyry Cu-Mo deposits, whereas p...
Chapter
Neoarchean greenstone-hosted gold deposits in the Eastern Goldfields Superterrane of the Yilgarn craton of Western Australia are diverse in style, timing with respect to magmatic activity, structural environment, host rocks, and geochemical character. Geologic constraints for the range of gold deposits indicate deposit formation synchronous with vo...
Chapter
The Cadia district of New South Wales contains four alkalic porphyry Au-Cu deposits (Cadia East, Ridgeway, Cadia Hill, and Cadia Quarry) and two Cu-Au-Fe skarn prospects (Big Cadia and Little Cadia), with a total of ~50 Moz Au and ~9.5 Mt Cu (reserves, resources, and past production). The ore deposits are hosted by volcaniclastic rocks of the Weema...
Data
This is the data appendix to Bissig et al 2008 on the Cuale VHMS deposit Mexico published in Economic Geology
Chapter
Full-text available
Turkey, located within the western Tethyan-Eurasian Belt contains numerous porphyry copper deposits formed by the subduction, collision and post-collisional events during the closure of NeoTethys Ocean between the latest Cretaceous and late Miocene. These porphyry systems and associated epithermal and skarn deposits are associated with the subducti...
Article
Field relationships and U-Pb data (zircon) are used to constrain the timing of tectonomagmatic events that occurred shortly after the formation of Late Devonian (∼372 Ma) porphyry Cu-Au deposits at Oyu Tolgoi (Mongolia). In the two northernmost of the several discrete porphyry centers (Hugo Dummett deposits), Upper Devonian rocks positioned stratig...
Article
Uranium-lead ages and trace element compositions of zircon from a series of shallow porphyry intrusions document the temporal, chemical, and thermal magmatic evolution of magmatic-hydrothermal porphyry Cu (Mo-Au) ores in the El Salvador district, Chile. Zircons (n = 240) from 15 Eocene age diorite, granodiorite, and granite porphyry intrusions were...
Article
A northerly trending zone of porphyry Cu-Au, porphyry Au, polymetallic replacement Pb-Zn-Au-Ag, and sedimentary rock-hosted Au deposits along the northwest margin of the Late Cretaceous Timok Magmatic Complex forms a part of the Bor metallogenic zone in eastern Serbia. The porphyry Cu-Au, epithermal quartz-alunite, and polymetallic replacement depo...
Article
Full-text available
The Early to early Late Jurassic magmatic arc of the lower Colorado River region of southern California and southwest Arizona spanned ∼30 m.y., from ca. 190 to 158 Ma. The arc-type volcanic and plutonic rocks interacted extensively with the Proterozoic Mojave Province crust and show evidence for geographic-based age and compositional changes. The r...
Article
Porphyry Cu (+/- Mo +/- Au) and epithermal Au-Ag deposits are major sources of mined metals and are commonly formed by magmatic-hydrothermal fluids derived from hydrous magmas in Phanerozoic convergent margin settings. The igneous rock assemblages associated with porphyry mineral deposits are common in modern convergent margin settings, but while m...
Article
SHRIMP-RG U-Pb zircon geochronologic data together with published U-Pb ages from the succession of quartz diorite porphyry intrusions in the western porphyry Cu-Au centers at Reko Diq, western Balochistan, Pakistan, indicate the emplacement of four spatially distinct porphyry Cu centers over ∼1 m.y. in the Miocene between ∼12.9 and 11.9 Ma. Intrusi...
Article
The Late Triassic Galore Creek porphyry district is the largest accumulation of Cu-Au prospects in British Columbia, Canada, in terms of contained metal. The principal economic resource is the Central zone deposit. It comprises three high-grade centers: the Au-rich North and South gold lenses and the Cu-dominated Central replacement zone. Alteratio...
Article
The moderately tilted and faulted Early Jurassic Mt. Milligan Au-Cu deposit provides a cross-section view of the hydrothermal alteration, sulfide mineralogy, and geochemical zonation of a silica-saturated alkalic porphyry system over a vertical distance approaching 700 m. Magnetite-bearing potassic alteration and associated Au-Cu form a core to the...
Article
The Late Triassic Southwest zone alkalic porphyry Cu-Au deposit in the Galore Creek district, northwestern British Columbia, is hosted in hydrothermally cemented breccias that overprinted older matrix-rich breccia and megacrystic orthoclase-phyric syenite and monzonite dikes. Synmineralization cemented breccias and biotite-phyric monzodiorite dikes...
Article
The volcanosedimentary rocks that host the Au-rich porphyry Cu deposits of the Cadia Valley preserve the products of episodic volcanism that erupted into a large sedimentary basin. Volcanogenic sedimentation, including the Forest Reefs Volcanics, overwhelmed the fine-grained sedimentary component that characterized much of the Weemalla Formation. T...
Article
The Lower Main zone of the Lorraine alkalic porphyry Cu-Au district, BC, Canada, is hosted in an intrusive complex that comprises pre- and late mineral biotite pyroxenites, monzonites, and syenites. Some of the biotite pyroxenites have interstitial sulfides, which appear similar to net-textured sulfides in magmatic ore deposits; however, the pyroxe...
Article
Polyphase veins at the low-grade, structurally controlled epithermal gold deposit Endeavour 42 in the Junee- Narromine volcanic belt of the Ordovician to Silurian Macquarie Arc, central New South Wales (Australia), record multiple tectonically driven fluid-flow events during the mid-Paleozoic. Ordovician host rocks consist of a volcano-sedimentary...
Article
Full-text available
Porphyry ore deposits typically form in convergent plate margin or postsubduction settings at depths of 1-6. km. Oxidized hydrous melts derived from the metasomatized mantle wedge transport Cu, Au, Mo, and other metals to upper-crustal magma chambers. Ponding and release of these magmas is promoted by transient compressional events that perturb ste...
Conference Paper
Full-text available
Avala Resources Ltd. is actively exploring a major, north-trending sedimentary rock-hosted gold mineralized belt – the Timok Gold Project – located on the western margin of the Timok Magmatic Complex in the Republic of Serbia. The Timok Gold Project comprises several targets, including Bigar Hill, Korkan and Kraku Pester. All three zones share a si...
Article
The Paleocene to Eocene southern Peru porphyry belt contains three significant porphyry Cu-Mo deposits at Cuajone, Quellaveco, and Toquepala. Ten new zircon U-Pb Sensitive High Resolution Ion Microprobe- Reverse Geometry (SHRIMP-RG) ages for Cuajone and Toquepala, together with published ages for Quellaveco, establish a magmatic history characteriz...
Article
Rapidly changing ore deposit types in the Late Cretaceous and early Tertiary in the Southeastern Anatolian orogenic belt in east-central Turkey, from Baskil on the south to Divrigi on the north, broadly reflect shifting tectonic environments in an evolving collisional orogen, a part of the extensive Tethyan orogen. Late Cretaceous (83-79 Ma) subduc...
Article
The Archean Hope Bay greenstone belt is located in the Bathurst Block of the northeastern part of the Slave Structural Province, a predominantly Archean, granite-greenstone-metasedimentary terrane. The greenstone belt is dominated by mafic volcanic rocks with less common felsic volcanic and volcaniclastic products and subordinate ultramafic bodies...
Article
Full-text available
The >5 Moz (1 oz (troy) = 31.103 g) gold veins of the Liese Zone and nearby prospects in the Goodpaster Mining District of east central Alaska are spatially and temporally associated with late-Early to Late Cretaceous reduced granitoids that are divided into a granite suite, tonalite suite, and diorite suite in decreasing age. Synkinematic to postk...
Article
Full-text available
Uranium–Pb (zircon) ages are linked with geochemical data for porphyry intrusions associated with giant porphyry Cu–Au systems at Oyu Tolgoi to place those rocks within the petrochemical framework of Devonian and Carboniferous rocks of southern Mongolia. In this part of the Gurvansayhan terrane within the Central Asian Orogenic Belt, the transition...
Article
Full-text available
The Central Asian orogenic belt consists of microcontinental blocks and mobile belts positioned between the Siberian craton and the Tarim and North China cratons. Extending across Asia for 5000 km, the belt consists of terranes that decrease in age southward away from the Siberian craton. A time-stratigraphic-structural sequence for the rocks is cr...
Article
Full-text available
Late Cretaceous to Middle Eocene calc-alkaline to alkaline magmatic rocks emplaced within the southeastern Anatolian orogenic belt, the most extensive magmatic belt in Turkey, result from the complex collision between the Afro-Arabian and Eurasian plates and the subduction of the southern and northern Neotethyan oceanic basins beneath the Eurasian...
Article
A ∼10-km-thick sequence of basaltic to rhyolitic volcanic rocks forms the arc component of the Cretaceous Lancones basin in northwestern Peru and underlies part of the Huancabamba deflection. The marine volcanic successions show markedly different compositional features and depositional facies consistent with a maturing arc within a shallowing mari...
Article
The presence of geochemical anomalies, defining haloes around hydrothermal ore deposits, can be used to vector towards mineralization, or identify ore bodies buried at depth. Several important types of ore deposits, including skarn deposits, are often hosted within carbonate-rich sedimentary rocks. Identifying anomalous trace-element concentrations...
Article
Full-text available
The Rondonian-San Ignacio Province (1.56–1.30 Ga) is a composite orogen created through successive accretion of arcs, ocean basin closure and final oblique microcontinent–continent collision. The effects of the collision are well preserved mostly in the Paraguá Terrane (Bolivia and Mato Grosso regions) and in the Alto Guaporé Belt and the Rio Negro...
Data
a b s t r a c t The Rondonian-San Ignacio Province (1.56–1.30 Ga) is a composite orogen created through successive accretion of arcs, ocean basin closure and final oblique microcontinent–continent collision. The effects of the collision are well preserved mostly in the Paraguá Terrane (Bolivia and Mato Grosso regions) and in the Alto Guaporé Belt a...
Article
The worlds most ancient biogenic structures are found in the North Pole Dome of Western Australia, where 3.47-Gyr-old algal mats and stromatolites are closely associated with bedding-conformable and discordant laminar quartz, chalcedony, and barite. Barite-rich quartz hydrothermal veins with similar mineralogy occur throughout the stratigraphy belo...
Article
Full-text available
Auriferous porphyry Cu deposits are restricted to convergent plate settings, whereas epithermal precious metal deposits form at extending convergent plate settings and in rifts. Both deposit types are linked to magma carrying metals and ligands that rises to form an upper-crustal magma chamber. Magma convection and fractionation lead to volatile ex...
Article
Full-text available
Ore deposits spatially and temporally related to high-K calc-alkaline intrusions or domes are widespread in the central Peruvian Cordillera Occidental. Geochronology and petrochemistry of intrusive rocks associated with mineralization reveal that most ore deposits (1) were emplaced in the late Middle to early late Miocene and (2) are related to cal...
Article
The Pliocene El Dorado low-sulfidation epithermal Au-Ag vein system, located within an 84-km2 district in north-central El Salvador, is hosted by volcanic rocks formed along the Caribbean plate margin in response to the subduction of the Cocos plate during the Tertiary. The principal volcanic host rocks to epithermal veins, and effective basement i...
Article
Full-text available
Eocene to late Miocene magmatism in the central Peruvian high-plain (approx. between Cerro de Pasco and Huancayo; Lats. ∼10.2–12°S) and east of the Cordillera Occidental is represented by scattered shallow-level intrusions as well as subaerial domes and volcanic deposits. These igneous rocks are calc-alkalic and range from basalt to rhyolite in com...
Article
The Cuale mining district, situated in the Cordillera Madre del Stir, similar to 30 km southeast of Puerto Vallarta, Mexico, comprises a number of small, polymetallic Pb, Zn, Cu, volcanogenic massive sulfide deposits (VMS), and vein and stockwork-hosted deposits with low-sulfidation epithermal characteristics. Massive sulfide mineralization contain...
Article
Located in the northern part of the El Indio belt of Chile-Argentina, the 12.6-million ounce (Moz) gold, late Miocene Veladero high-sulfidation epithermal deposit is hosted principally in late Oligocene and middle Miocene volcanic and volcaniclastic rocks and to a lesser extent in the underlying Permian rhyolitic pyroclastic rocks. The principal ho...
Chapter
Full-text available
Major Cu, Ni, Cr, Au, Pb, Zn, Fe, W, Sn and rare metal deposits of northern Xinjiang (China) formed during eight tectonic stages, based on their plate tectonic setting. These stages are (1) Precambrian stable continental, (2) Neoproterozoic rift stage, (3) formation of oceans, (4) Silurian-early Carboniferous subduction, (5) Devonian and Carbonifer...
Article
Full-text available
Among supracrustal sequences of the Jurassic magmatic arc of the southwestern Cordillera, the Middle Jurassic Topawa Group, Baboquivari Mountains, south-central Arizona, is remarkable for its lithologic diversity and substantial stratigraphic thickness, ∼8 km. The Topawa Group comprises four units (in order of decreasing age): (1) Ali Molina Format...
Article
Whole rock Pb isotope data can be used to determine the provenance of different blocks within the Rodinia supercontinent, providing a test for paleogeographic reconstructions. Calculated isotopic values for the source region of the Grenville-deformed SW Amazon craton (Rondônia, Brazil), anchored by published U–Pb zircon ages, are compared to those...
Article
The geological relations and geochemical composition of extrusive and subvolcanic intrusive rocks of the Upper Miocene Farallón Negro Volcanic Complex (NW Argentina) were studied to reconstruct the evolution of a deeply eroded andesitic volcano over most its life history of some 3.5 my. This paper is part of an integrated study of the processes tha...
Article
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Porphyry Cu and epithermal deposits are spatially and temporally related to specific volcanic and plutonic rocks emplaced during the formation of long-lived magmatic arcs formed along convergent plate
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Eskay Creek type (ECT) volcanogenic massive sulphide (VMS) deposits represent an attractive exploration target because of their substantial tonnage potential and high precious
Article
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Cu-Au porphyry deposits associated with alkalic igneous rocks are known in only a few mineral provinces worldwide and some of the best-known
Article
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Stratigraphic analyses in central and eastern Nevada reveal the importance of a deformation event in middle Mississippian time that caused widespread deformation, uplift, and erosion. It occurred between middle Osagean and late Meramecian time and resulted in deposition of both synorogenic and postorogenic sediments. The deformation resulted in eas...