Matches in SemOpenAlex for { <https://semopenalex.org/work/W112036768> ?p ?o ?g. }
Showing items 1 to 73 of
73
with 100 items per page.
- W112036768 abstract "The Hammer Down gold prospect is an important example of the numerous mesothermal gold occurrences associated with structural zones of regional extent in the Newfoundland Dunnage Zone. -- The main mineralized zones in the Hammer Down prospect consist of structurally controlled quartz veins with abundant pyrite, chalcopyrite, and sphalerite, hosted by volcanic and sedimentary rocks of the Ordovician (Arenig) Catchers Pond Group, and by Early Silurian felsic porphyry dykes. Gold-bearing veins postdate sub- greenschist metamorphism and an early phase of deformation, and were produced synchronously with a locally intense S₂ fabric related to folding. Veins were preferentially emplaced in narrow brittle-ductile high strain zones within and adjacent to felsic dykes. The gold-bearing veins and Sj fabric are locally folded, and mineralized zones are truncated by a late brittle fault. Barren, paragenetically late veins, characterized by fluorite and low contents of sulphide minerals, are abundant in and near the gold-bearing zones. -- Gold is present within pyrite and along sulphide grain boundaries in veins and in locally sericitized, carbonatized, and pyritized wall rock. Hydrothermal alteration adjacent to veins is restricted to narrow zones, or is absent. Alteration of mafic rocks is characterized by muscovite, calcite, pyrite, quartz, and rutile, and is marked by enrichment in the lithophile elements K and Rb, and by sporadically elevated levels of Cu, Zn, and S. -- Felsic tuff from the Hammer Down prospect has an igneous U-Pb zircon age of 480 + 4/-3 Ma, and records arc volcanism in the Dunnage Zone. Felsic dykes from the prospect, which have a strong spatial association with gold, are petrographically and chemically distinct from the nearby King's Point volcanic-plutonic complex, but they are correlative with the Burlington Granodiorite, a regional plutonic unit of the eastern Baie Verte Peninsula. Zircon from a felsic dyke cut by a gold-bearing vein has a high degree of Proterozoic inheritance. Acicular zircon grains from this dyke have a ²⁰⁷Pb/²⁰⁶Pb age of 437 +/-3 Ma, which is considered the age of intrusion, and is a maximum age limit for gold deposition. -- Isotopic compositions of quartz (δ¹⁸O = 11.4±0.7) and calcite and ferroan dolomite from gold-bearing veins (δ¹³C = -6.2±0.7) are typical of mesothermal vein systems elsewhere. Oxygen isotope thermometry using quartz, chlorite, and muscovite indicates mineralization temperatures between 240 and 320°C. The ore- forming solutions had calculated δ¹⁸O values between 2.2 and 5.2 %o and δD values between -27 and -42 0/00, which are compatible with a predominantly metamorphic source having some meteoric contribution. Age constraints and regional considerations place the gold mineralizing event wthin a period of crustal extension and widespread magmatism that were part of an important Silurian orogenic phase in central Newfoundland. A meteoric component in the vein fluid system is atuibuted to the extensional setting, which promoted influx of surface water to deeper reservoirs." @default.
- W112036768 created "2016-06-24" @default.
- W112036768 creator A5054198165 @default.
- W112036768 date "1993-01-01" @default.
- W112036768 modified "2023-09-27" @default.
- W112036768 title "Geology, U-Pb geochronology and stable isotope geochemistry of the Hammer Down Gold Prospect, Green Bay District, Newfoundland" @default.
- W112036768 hasPublicationYear "1993" @default.
- W112036768 type Work @default.
- W112036768 sameAs 112036768 @default.
- W112036768 citedByCount "0" @default.
- W112036768 crossrefType "dissertation" @default.
- W112036768 hasAuthorship W112036768A5054198165 @default.
- W112036768 hasConcept C112764850 @default.
- W112036768 hasConcept C127313418 @default.
- W112036768 hasConcept C149347711 @default.
- W112036768 hasConcept C151730666 @default.
- W112036768 hasConcept C159055055 @default.
- W112036768 hasConcept C167284885 @default.
- W112036768 hasConcept C17409809 @default.
- W112036768 hasConcept C193429443 @default.
- W112036768 hasConcept C202746551 @default.
- W112036768 hasConcept C2776062231 @default.
- W112036768 hasConcept C2776152364 @default.
- W112036768 hasConcept C2776268066 @default.
- W112036768 hasConcept C2778849375 @default.
- W112036768 hasConcept C2779870107 @default.
- W112036768 hasConcept C2780733770 @default.
- W112036768 hasConcept C37045145 @default.
- W112036768 hasConcept C79766335 @default.
- W112036768 hasConceptScore W112036768C112764850 @default.
- W112036768 hasConceptScore W112036768C127313418 @default.
- W112036768 hasConceptScore W112036768C149347711 @default.
- W112036768 hasConceptScore W112036768C151730666 @default.
- W112036768 hasConceptScore W112036768C159055055 @default.
- W112036768 hasConceptScore W112036768C167284885 @default.
- W112036768 hasConceptScore W112036768C17409809 @default.
- W112036768 hasConceptScore W112036768C193429443 @default.
- W112036768 hasConceptScore W112036768C202746551 @default.
- W112036768 hasConceptScore W112036768C2776062231 @default.
- W112036768 hasConceptScore W112036768C2776152364 @default.
- W112036768 hasConceptScore W112036768C2776268066 @default.
- W112036768 hasConceptScore W112036768C2778849375 @default.
- W112036768 hasConceptScore W112036768C2779870107 @default.
- W112036768 hasConceptScore W112036768C2780733770 @default.
- W112036768 hasConceptScore W112036768C37045145 @default.
- W112036768 hasConceptScore W112036768C79766335 @default.
- W112036768 hasLocation W1120367681 @default.
- W112036768 hasOpenAccess W112036768 @default.
- W112036768 hasPrimaryLocation W1120367681 @default.
- W112036768 hasRelatedWork W1537820568 @default.
- W112036768 hasRelatedWork W1595932820 @default.
- W112036768 hasRelatedWork W1999982623 @default.
- W112036768 hasRelatedWork W2009027943 @default.
- W112036768 hasRelatedWork W2013861795 @default.
- W112036768 hasRelatedWork W2039908575 @default.
- W112036768 hasRelatedWork W2074284157 @default.
- W112036768 hasRelatedWork W2089293898 @default.
- W112036768 hasRelatedWork W2103633515 @default.
- W112036768 hasRelatedWork W2127024150 @default.
- W112036768 hasRelatedWork W2133650428 @default.
- W112036768 hasRelatedWork W2141171682 @default.
- W112036768 hasRelatedWork W2149940972 @default.
- W112036768 hasRelatedWork W2188355956 @default.
- W112036768 hasRelatedWork W2192892804 @default.
- W112036768 hasRelatedWork W2302672439 @default.
- W112036768 hasRelatedWork W2501084571 @default.
- W112036768 hasRelatedWork W2742974878 @default.
- W112036768 hasRelatedWork W2783468746 @default.
- W112036768 hasRelatedWork W3209265609 @default.
- W112036768 isParatext "false" @default.
- W112036768 isRetracted "false" @default.
- W112036768 magId "112036768" @default.
- W112036768 workType "dissertation" @default.