데이터셋 상세
캐나다
Genesis of the Blende Carbonate hosted ZN-Pb-Ag deposit, north central Yukon Territory: Geologic, fluid inclusion and isotopic constraints
The Blende zinc-lead-silver deposit, 60 km northeast of Keno City, Yukon Territory, is spatially associated with a mid-Proterozoic fault zone that crosscuts stromatolitic dolostones of the Middle Proterozoic, upper Gillespie Lake Group. It is the largest known strata-bound, carbonate-hosted, zinc-lead deposit in the Yukon Territory. Mineralization, largely epigenetic, consists of sphalerite and galena, with lesser pyrite and chalcopyrite, and trace friebergite in quartz-carbonate veins and veinlets. Veining is zoned from copper- and silver-rich mineralization at the base of the deposit, through lead- and zinc-rich, to zinc-dominated at the top. Detailed cross-section mapping indicates that controls on the deposit are both stratigraphic and structural. Many of the stromatolite beds are mineralized and are especially rich in lead and zinc close to normal faults. Fluid inclusion studies indicate that mineralizing fluids were about 285 degrees C during main-stage mineralization. Sulfur isotope analyses of unmineralized whole-rock samples cluster tightly around an average delta 34 S value of 23.6 + or - 0.4 per mil. The source of sulfur is apparently seawater sulfate, probably from minor anhydrite in the host dolostone. Sulfide sulfur isotope ratios define three populations. Local blebs of pyrite associated with stromatolites have markedly negative ratios (- 15.1%) that are probably bacteriogenic in origin. Vein sulfides in tight dololutites have ratios between 19.0 and 26.3 per mil, with an average delta 34 S value of 23.2 PM 0.9 per mil. This is virtually identical to the whole-rock sulfur isotope ratio. Veins that crosscut stromatolitic beds have sulfur isotope ratios between 18.3 and 7.4 per mil with a mean of 15.0 + or - 1.2 per mil. Intermediate sulfur isotope ratios apparently reflect a mixed sulfur source of both whole-rock sulfate and biogenic sulfide. Carbon and oxygen isotopes in host rocks and ore-stage dolomite spar are related genetically; both are related to ancient seawater. The calculated isotopes for mineralizing fluids are characteristic of basinal brines...
데이터 정보
연관 데이터
Blende property, central Yukon
공공데이터포털
The Blende is a large epigenetic zinc-lead-silver deposit hosted by brecciated middle Proterozoic dolomite. Mineralization occurs intermittently along a zone about 6 km long and up to 200 m wide. Based on 1990 drilling, reserves are estimated at 11.4 million tonnes grading 2.2% Zn, 3.0% Pb and 50.1 g/t Ag.
Ar-Ar geochronology and Pb isotopic constraints on the origin of the Rau gold-rich carbonate replacement deposit, central Yukon
공공데이터포털
The Rau deposit in central Yukon is a gold-rich carbonate replacement deposit hosted in mid-Paleozoic carbonate rocks of the Mackenzie Platform in the footwall of the Dawson thrust. Gold-bearing sulphide mineralization is peripheral to a zone of hornfels and local tungsten-bearing skarn that is associated with several small bodies of granitic aplite and pegmatite that have yielded 40Ar/39Ar muscovite ages of 62.3 ± 0.7 Ma, 62.4 ± 1.8 Ma and 59.1 ± 2.0 Ma. These intrusions are geochemically different and slightly younger than the 65.2 ± 2.0 Ma McQuesten plutonic suite farther to the south. Most Pb isotopic analyses of sulphides from the Rau deposit cluster within compositions of igneous feldspars from the associated intrusions; however, some analyses fall on a trend toward more radiogenic compositions that were determined for the host carbonate rocks. The data are consistent with the Rau sulphide mineralization being genetically related to the early Paleocene felsic intrusions, and forming peripheral to more proximal zones of hornfelsing and tungsten-bearing skarns.
A field, petrographic and preliminary S isotopic study of the Walt and Tyrala sediment-hosted barite occurrences (105O/7), and associated Ba-Zn-Pb mineralization, MacMillan Pass district, Yukon.
공공데이터포털
The MacMillan Pass district (map sheet 105O) located in east Yukon contains several sedimenthosted Ba ± Zn ± Pb deposits including the Tom and Jason deposits, as well as a multitude of 'barren' sediment-hosted barite occurrences. A classic sedimentary-exhalative (SEDEX) model has been postulated for these occurrences in which the barite horizons represent distal expressions of a hydrothermal vent system. Fieldwork was completed at the Walt and Tyrala barite occurrences that occur within the MacMillan Pass district in order to examine the deposit-scale geology and to sample undeformed barite horizons for subsequent geochemical analysis. Samples were also collected from drill core from the Hess barite occurrence. Barium mineralization occurs in both the Devonian Portrait Lake Formation (Lower Earn Group) and in underlying Ordovician-Silurian limestone of the Road River Group. A variety of textures were encountered that were indicative of both synsedimentary deposition of barite, as well as diagenetic to epigenetic barite mineralization. Base metal sulphides that are interpreted to post-date the barite mineralization were encountered at depth in drill core and are primarily hosted by Road River Group carbonates.
New U-Pb geochronology of Early Cretaceous porphyry and skarn mineralization in southwest Yukon
공공데이터포털
not_specified
Detrital zircon U-Pb and Hf isotope signature of Carboniferous and older strata of the Yukon-Tanana terrane in Yukon, Canadian Cordillera: Implications for terrane correlations and the onset of Late Devonian arc magmatism
공공데이터포털
The Yukon-Tanana terrane in Yukon, Canada, records Late Devonian (ca. 366–360 Ma) rifting and the onset of latest Devonian–Carboniferous arc and back-arc magmatism (ca. 360–325 Ma) in the Northern Cordillera. Detrital zircon U-Pb and Hf isotope analyses indicate that the metasedimentary basement of the Yukon-Tanana terrane was sourced in northwestern Laurentia. Sandstones in Late Devonian–Carboniferous successions generally have robust Late Devonian–Mississippian age peaks, and their Hf isotope signatures are characterized by strongly negative εHft values in Late Devonian zircons followed by progressively more juvenile εHft values in Carboniferous zircons. This Hf isotopic “pull-up” reflects the melting of Precambrian crust related to regional extension in the Late Devonian, followed by progressively more juvenile magmatism as the arc matured through the Carboniferous. Paleozoic rocks of the Tracy Arm terrane in southeastern Alaska, USA (formerly Yukon-Tanana south), have been compared with the Yukon-Tanana terrane in Yukon. Detrital zircons from the metasedimentary basement to the Tracy Arm terrane have distinct Precambrian populations that indicate sources along a different segment of the Laurentian margin compared to basement of the Yukon-Tanana terrane. Magmatism in the Tracy Arm terrane ranges from 440 Ma to 360 Ma and is characterized by an Hf isotopic “pull-down” in the Silurian to Early Devonian, followed by a “pull-up” in the Middle to Late Devonian and a second “pull-down” in the Late Devonian to early Mississippian. Thus, the Yukon-Tanana and Tracy Arm terranes record distinct pre-Carboniferous histories. Interactions between these two terranes are suggested by the influx of exotic early Mississippian clasts and detrital zircons on the Tracy Arm terrane that match sources in the Yukon-Tanana terrane. This paper is available via open access. You can also contact the Yukon Geological Survey (geology@gov.yk.ca) for a copy of this paper.
Bedrock Geology, Dorsey Lake (NTS 105B/4), southern Yukon (1:50,000 scale)
공공데이터포털
The layered rocks in this area originated as continental shelf sediments overlain by volcanic arc successions. Now called Yukon-Tanana terrane, they tectonically over-rode the western edge of ancient North America beginning in Middle Jurassic time. Three elements are present in the map area. The west half comprises the Big Salmon Complex; the east half is a separate, in part contemporaneous succession composed of the Dorsey Complex and Swift River Group. Unconformably overlying both these elements are less metamorphosed Klinkit Group and Triassic sediments that are here interpreted as overlap assemblages. The unexposed contact between Big Salmon Complex and Swift River Group is inferred to be an east-side-down normal fault.
Birth of the northern Cordilleran orogen, as recorded by detrital zircons in Jurassic synorogenic strata and regional exhumation in Yukon
공공데이터포털
This paper is available via open access. You can also contact the Yukon Geological Survey (geology@gov.yk.ca) for a copy of this paper.
Neoproterozoic-hosted Carlin-type mineralization in central Yukon, part 1: regional to prospect-scale geological controls
공공데이터포털
not_specified
Preliminary O-S isotopic compositions of Cretaceous granitoids in the Cassiar Platform and Selwyn Basin, Yukon and Northwest Territories
공공데이터포털
A regional stable isotopic study of Cretaceous granitoids (109-90 Ma) emplaced into miogeoclinal Cassiar Platform and Selwyn Basin rocks was undertaken to provide new insights into the origin of several plutonic suites (Cassiar, Hyland, Tay River, Tungsten, Mayo and Tombstone).
Preliminary detrital zircon geochronology of the Neruokpuk Formation in the Barn Mountains, Yukon
공공데이터포털
Neoproterozoic to Cambrian siliciclastic rocks in the Barn Mountains, Yukon are stratigraphically similar to coeval strata on the northwest Laurentian margin and the North Slope subterrane of the Arctic Alaska terrane. Sandstone samples collected for detrital zircon U/Pb geochronology from Oldhamia-bearing sections in the Barn Mountains yield age spectra with major Paleoproterozoic and subordinate Mesoproterozoic and Archean peaks that are compatible with a Laurentian cratonal provenance. Comparison of data from the Barn Mountains with available data from the Laurentian margin is permissive of derivation from either the northwestern or the north to northeastern margin of Laurentia.
목록