Author: J. Duncan KeppiePublisher: St. John's, Nfld., Canada : Geological Association of Canada
ISBN:
Category : Science
Languages : en
Pages : 200
Book Description
Turbidite-hosted Gold Deposits
Author: J. Duncan KeppiePublisher: St. John's, Nfld., Canada : Geological Association of Canada
ISBN:
Category : Science
Languages : en
Pages : 200
Book Description
Turbidite-hosted gold deposits
Author: Prudence Mary LeemingA Comparative Study of the Turbidite-hosted Gold Deposits in the Bendigo-Ballarat and Melbourne Zones, Central Victoria, Australia
Author: Zhan Lin GaoPublisher:
ISBN:
Category : Geology, Stratigraphic
Languages : en
Pages : 596
Book Description
Turbidite-hosted Micro-disseminated Gold Deposits
Author: Xuexiang GuPublisher:
ISBN: 9787561632154
Category :
Languages : en
Pages : 240
Book Description
Turbidite-hosted Gold Deposits, Meguma Domain, Eastern Nova Scotia
Author: P. K. SmithControls on Genesis, Distribution, and Nature of the Turbidite-hosted Gold Deposits, Eastbelt, Southwestern Slave Structural Province, Yellowknife, Northwest Territories
Author: Mark Wesley RichardsonPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
The Ptarmigan and Tom mesothermal gold deposits are located 10 km to the northeast of the city of Yellowknife, Northwest Territories. Both gold deposits comprise a series of en echelon veins. These veins are hosted within upper greenschist to lower amphibolite facies ~2630 Ma rocks. A low-temperature reduced hydrothermal environment during ore deposition formed as either a part of the main arsenopyrite-dominated mineralization or a distinct late-stage ore-formation event. At the deposit scale, the high-grade gold ores are preferentially developed with three contextual scenarios: (1) along contacts, especially the contact between black siltstone host rock and major barren, cleavage-parallel veins; (2) the contact between quartz laminae and carbonaceous host rock slivers; (3) proximity to bismuth telluride mineralization. Thus, competent, barren quartz veins along the axial plane of fold/thrust belts locally host superimposed gold mineralization and provide favourable targets for gold exploration. Hydrothermal apatite is a common accessory mineral in both mineralized and non-mineralized quartz veins in the metasedimentary host rocks that constitute the Ptarmigan and Tom deposits. The apatite in this study likely formed coeval with early stages of sulphide precipitation. The apatite age of 2585 ± 15 Ma is consistent with the intrusions of the 2605 and 2590 Ma two-mica granites of the Prosperous Suite. The near-concordant [superscript 204]Pb-corrected data of the LCT pegmatite hosted apatite reveals two clusters of ages. An older population with an intercept age (N = 4) of 2581 ± 15 Ma, and a younger population with an intercept age (N = 3) of 2519 ± 12 Ma . Furthermore, plotting a regression through all near – concordant data for the pegmatite hosted apatite hints that metamorpic resetting occured around ~2200 Ma. The distribution and abundance of major, minor, and trace elements from in-situ recovered apatite were studied to characterize the nature of mineralizing fluids. Most apatite from mineralized and non-mineralized veins show different Mn, Sr, and Pb contents, as well as chondrite-normalized rare-earth element (REE) and Y abundance patterns. REEs display five unique chondrite-normalized patterns: (1) negative sloped pattern with slight negative Eu anomaly, (2) a flat pattern with a positive Eu anomaly, (3) a positive slope with a negative Eu anomaly, (iv) light rare earth element (LREE) depleted pattern with positive Eu anomaly, and (v) bell-shaped pattern with a negative Eu anomaly. The REE patterns likely reflect both the source of the auriferous hydrothermal fluids and, perhaps, co-precipitating mineral phases. Apatite from the Ptarmigan vein occurs with both: (1) a flat pattern with a positive Eu anomaly and (2) bell-shaped pattern with a negative Eu anomaly. The bell-shaped and flat patterns typify orogenic gold deposits. Vein-hosted apatite commonly displays compositional zoning with a characteristic yellow cathodoluminescence (CL) emission spectra with darker cores and brighter rims. The cores have lower REE, whereas the rims are notably REE higher. It is thought that the darker cores in CL images reflect a transition from an early low REE hydrothermal fluid to one enriched in REE. Lastly, this study breaks ground for conducting a more robust study to classify the trace-element composition of apatite in gold deposits worldwide.
The Metallogeny of Lode Gold Deposits
Author: Ulrich KretschmarPublisher: Elsevier
ISBN: 0128032235
Category : Science
Languages : en
Pages : 356
Book Description
The Metallogeny of Lode Gold Deposits: A Syngenetic Perspective is a synthesis of lode gold vein forming processes, addressing the commonality in similar worldwide deposits. The book’s empirical model incorporates widely known and accepted principles of ore deposition and shows how it applies in the volcanic-sedimentary greenstone belt environment. Several chapters detail outcrop maps and photos of field occurrences and textures. The interpretations flow directly from the authors’ field work, and are coupled with analyses of underlying physical processes. Utilizing detailed geological mapping, field work, and chemical analyses as the basis of a syngenetic formation mode, the text arms readers with the tools necessary to accurately analyze and interpret new data on the subject. This includes information on decoding the significance of asymmetry in vein formation, as well as the role of lamprophyres in gold camps, how Archean geology requires integration into a lode vein formation model, and how to develop an understanding of the worldwide applicability of gold cycles to lode vein formation and exploration and how it can be applied to deposits of all ages. Presents the first book to galvanize lode gold research into a single authoritative reference Simplifies the complexity of lode gold’s underlying processes and presents valid concepts surrounding the lode gold forming environment Features color figures, illustrations, and photos that enrich the content’s focus and aid in the retention of key concepts
Author: Paul R. Duller
Author: P. K. Smith
Author: D. E. Annels