Exploration and Mining Geology

Research Article| July 01, 2010 The Geological Setting, Mineralogy, and Paragenesis of Gold-Bearing Polymetallic (Cu+Co+Ag+Au+Bi±Pb±Ni±U) Veins of the Merico-Ethel Property, Elk Lake, Northeastern Ontario, Canada E.G. Potter; E.G. Potter † 1Department of Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 †Corresponding Author: E-mail: Eric.Potter@NRCan.gc.ca Search for other works by this author on: GSW Google Scholar R.P. Taylor; R.P. Taylor 1Department of Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 Search for other works by this author on: GSW Google Scholar P.C. Jones; P.C. Jones 1Department of Earth Sciences, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario K1S 5B6 Search for other works by this author on: GSW Google Scholar K. Rees; K. Rees 3Temex Resources Corp., 141 Adelaide Street West, Suite 1660, Toronto, Ontario M5H 3L5 Search for other works by this author on: GSW Google Scholar I. Campbell I. Campbell 3Temex Resources Corp., 141 Adelaide Street West, Suite 1660, Toronto, Ontario M5H 3L5 Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2010) 19 (3-4): 81–98. https://doi.org/10.2113/gsemg.19.3-4.81 Article history received: 17 Jul 2009 accepted: 09 Oct 2010 first online: 29 Sep 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation E.G. Potter, R.P. Taylor, P.C. Jones, K. Rees, I. Campbell; The Geological Setting, Mineralogy, and Paragenesis of Gold-Bearing Polymetallic (Cu+Co+Ag+Au+Bi±Pb±Ni±U) Veins of the Merico-Ethel Property, Elk Lake, Northeastern Ontario, Canada. Exploration and Mining Geology 2010;; 19 (3-4): 81–98. doi: https://doi.org/10.2113/gsemg.19.3-4.81 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract The Cobalt embayment is a large domain of Paleoproterozoic clastic sedimentary rocks that unconformably overlies the Archean Abitibi greenstone belt. Regionally extensive sills and dikes of Nipissing diabase, emplaced circa 2219 Ma, occur throughout the embayment and are the preferential host to gold-bearing polymetallic vein systems on the Merico-Ethel property, near the northeastern margin of the Cobalt embayment. These gold-bearing, polymetallic veins are predominantly east–west-trending, steeply dipping, discordant calcite-quartz vein systems that formed close to the time of crystallization (within ~15 m.y., based on Pb-Pb ages) of the Nipissing diabase. The ore mineralogy is complex in character, typically comprising sulfides, arsenides, native metals (gold and silver), and specular hematite, preferentially concentrated along the interface between silicate and calcite gangue. A simplified sequence of mineral deposition in the veins is: (1) “Early-stage” pyrite ± chalcopyrite hosted in quartz ± chlorite gangue; (2) “Main-stage” polymetallic (Cu + Co + As + Ag + Au + Bi ± Pb ± Ni ± U) sulfides, arsenides, and native metals hosted in calcite gangue; and (3) “Late-stage” calcite flooding ± galena. Wall-rock alteration in Nipissing diabase is restricted to narrow (<5 cm) haloes of calcite-chlorite-epidote-bearing assemblages, whereas a weak alteration halo of specular hematite, calcite, and allanite-epidote has been observed in the surrounding sedimentary rocks. In terms of their age, geology, mineralogy, paragenesis, and morphology, the gold-bearing vein systems at Merico-Ethel closely resemble the silver-sulfarsenide vein deposits of the historic Cobalt and Gowganda mining camps. These observations indicate that the Au-bearing veins are variants of the Ag-vein systems and as such, have a common genesis belt. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Alkali/alumina and MgO/alumina molar ratio plots graphically portray both chemical and mineralogical changes accompanying potassic, phyllic, argillic, chloritic, and alunitic alteration of quartz monzonites and granodiorites hosting porphyry (as well as lode and greisen) ore deposits. The molar ratio plots can be used to identify different types of alteration. In most cases, the identification based on molar ratios coincides with petrographic data. In those instances where the molar ratio and petrographic identifications do not agree, the mineralogy might need to be re-examined. Hydrothermal alteration studies using trace elements could benefit from the application of complementary alkali/alumina molar ratio plots. © 2010 Canadian Institute of Mining, Metallurgy and Petroleum. All rights reserved. Sommaire Le diagramme des rapports molaires alkali/alumine et MgO/alumine illustre clairement les changements chimiques et mineralogiques qui accompagnent les alterations potassique, phyllique, argillique, chloritique, and alunitique des monzonites a quartz et des granodiorites encaissant les gites de type porphyrique, ainsi que des veines et des greisens qui leur sont associes. Les diagrammes de rapports molaires peuvent etre utilises pour identifier divers types d’alteration. Dans la plupart des cas, l’identification basee sur les rapports molaires est en accord avec celle basee sur les donnees petrographiques. La ou il y a desaccord entre les rapports molaires et les donnees petrographiques, il peut etre necessaire de reexaminer la mineralogie. Les etudes de l’alteration hydro-thermale accompagnees d’une etude des elements traces auraient avantage a utiliser un diagramme des rapports molaires alkali/alumine. © 2010 Canadian Institute of Mining, Metallurgy and Petroleum. All rights reserved.

Research Article| January 01, 2010 Geological and Hydrogeological Conditions for Forming Uranium Occurrences in the Froqlos–Jabal Abou Rabah Region, Palmyrides, Syria J. Asfahani; J. Asfahani † †Corresponding Author: Telephone: +96 311 6111926; Facsimile: +96 311 6112289; E-mail: scientific@aec.org.sy Search for other works by this author on: GSW Google Scholar R. Al-Hent; R. Al-Hent 1Geology Department, Atomic Energy Commission, P.O. Box 6091, Damascus, Syria Search for other works by this author on: GSW Google Scholar M. Aissa M. Aissa 1Geology Department, Atomic Energy Commission, P.O. Box 6091, Damascus, Syria Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2010) 19 (1-2): 1–12. https://doi.org/10.2113/gsemg.19.1-2.1 Article history received: 05 Nov 2009 accepted: 20 Feb 2010 first online: 29 Sep 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation J. Asfahani, R. Al-Hent, M. Aissa; Geological and Hydrogeological Conditions for Forming Uranium Occurrences in the Froqlos–Jabal Abou Rabah Region, Palmyrides, Syria. Exploration and Mining Geology 2010;; 19 (1-2): 1–12. doi: https://doi.org/10.2113/gsemg.19.1-2.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract This paper focuses on determining the favorable geological and hydrogeological conditions for forming uranium occurrences in the Froqlos–Jabal Abou Rabah region, Palmyrides, Syria. Eighty rock samples from this area were analyzed by spectrometric gamma-ray technique to determine the radioactive concentrations of eU and eTh, and of %K. Uranium concentrations in shallow and deep groundwaters were also determined. High uranium concentrations were registered owing to the presence of phosphatic outcrops in the study region. The uranium migration trends and its remobilization were analyzed through the analysis of the behavior of eU, eTh, and their ratio. A positive relationship between eU and eU/eTh, and a negative relationship between eTh and eU/eTh in geological formations of different ages supports the secondary remobilization of uranium. The role of groundwater movement in transportation and redeposition of uranium mineralization is discussed: deep waters are less oxidizing than near-surface waters, and do not appear to have significantly remobilized uranium. This indicates that the source of secondary uranium mineralization is surficial or near surficial, and is mainly related to the leaching of outcropping phosphatic layers.Integration of the results with established radioactive and geological sections reveals four radioactive anomalous zones: north Froqlos, Kherbet Hannora, northwestern flanks of Jabal Abou Rabah (Kherbet Al-Hajar), and the northwestern limit of the Ghuntor depression. The high uranium concentration in north Froqlos is because of its original presence in the phosphate beds and extensive fracturing, which allows groundwaters to penetrate and remobilize the uranium. High uranium concentrations in the other three locations are caused by the presence of evaporites and capillary action, which draws solutions upwards and causes redeposition as surface crusts (gypcrete). You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

The Buffalo gold deposit is a small deposit consisting of auriferous quartz-tourmaline veins within a granodiorite stock in the Red Lake greenstone belt. This study aims to characterize the mineralizing fluids through fluid inclusion and stable isotope analyses and to compare them with those of the world-class Campbell-Red Lake deposit. Four types of fluid inclusions were recognized, including carbonic, aqueous-carbonic, aqueous, and halite-bearing aqueous, with the carbonic type being the most abundant. Raman analyses indicate that the carbonic phase mainly consists of CO 2 , with minor amounts of N 2 and CH 4 , and rarely detectable H 2 S. The homogenization temperatures of the carbonic inclusions range from −41.7° to 30.9°C. The homogenization temperatures and salinities of the aqueous, halite-bearing aqueous, and aqueous-carbonic inclusions are 130° to 276°C and 9.7 to 23.6 wt.% NaCl equiv., 155° to 207°C and 32.9 to 42.3 wt.% NaCl equiv., and 215° to 357°C and 8.3 to 19.7 wt.% NaCl equiv., respectively. The δ 18 O VSMOW values of tourmaline range from 8.2‰ to 9.0‰, and those of quartz from 11.4‰ to 11.9‰, with estimated fluid temperatures from 323° to 399°C based on the quartz-tourmaline isotopic geothermometer. It is postulated that separate CO 2 -dominated and aqueous fluids intermittently invaded the fracture/vein system in response to fluid pressure fluctuations, with limited mixing. The CO 2 -dominated fluid, previously recognized in Campbell-Red Lake as the main mineralizing fluid, is inferred to have been derived from deeper parts of the crust. This deep CO 2 -dominated fluid reservoir might have been a common source for gold mineralization in the Red Lake greenstone belt.

Research Article| July 01, 2010 Paleoproterozoic Age Relationships in the Three Bluffs Archean Iron Formation-Hosted Gold Deposit, Committee Bay Greenstone Belt, Nunavut, Canada* T. Davies; T. Davies 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar J.P. Richards; J.P. Richards † 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada †Corresponding Author: E-mail: Jeremy.Richards@ualberta.ca Search for other works by this author on: GSW Google Scholar R.A. Creaser; R.A. Creaser 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar L.M. Heaman; L.M. Heaman 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar T. Chacko; T. Chacko 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar A. Simonetti; A. Simonetti 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar J. Williamson; J. Williamson 2Committee Bay Resources Ltd., #220, 9797 45 Avenue, Edmonton, Alberta, T6E 5V8, Canada Search for other works by this author on: GSW Google Scholar D.W. McDonald D.W. McDonald 2Committee Bay Resources Ltd., #220, 9797 45 Avenue, Edmonton, Alberta, T6E 5V8, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information T. Davies 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada J.P. Richards † 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada R.A. Creaser 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada L.M. Heaman 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada T. Chacko 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada A. Simonetti 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3, Canada J. Williamson 2Committee Bay Resources Ltd., #220, 9797 45 Avenue, Edmonton, Alberta, T6E 5V8, Canada D.W. McDonald 2Committee Bay Resources Ltd., #220, 9797 45 Avenue, Edmonton, Alberta, T6E 5V8, Canada †Corresponding Author: E-mail: Jeremy.Richards@ualberta.ca Publisher: Canadian Institute of Mining, Metallurgy and Petroleum Received: 07 Oct 2009 Accepted: 31 Mar 2011 First Online: 02 Mar 2017 © 2011 Canadian Institute of Mining, Metallurgy & Petroleum Exploration and Mining Geology (2010) 19 (3-4): 55–80. https://doi.org/10.2113/gsemg.19.3-4.55 Article history Received: 07 Oct 2009 Accepted: 31 Mar 2011 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation T. Davies, J.P. Richards, R.A. Creaser, L.M. Heaman, T. Chacko, A. Simonetti, J. Williamson, D.W. McDonald; Paleoproterozoic Age Relationships in the Three Bluffs Archean Iron Formation-Hosted Gold Deposit, Committee Bay Greenstone Belt, Nunavut, Canada. Exploration and Mining Geology 2010;; 19 (3-4): 55–80. doi: https://doi.org/10.2113/gsemg.19.3-4.55 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract The Three Bluffs gold deposit is located in the Committee Bay greenstone belt, which forms part of the Rae domain of the western Churchill province, Nunavut, Canada. Gold mineralization is hosted by iron formation of the Neoarchean volcanosedimentary Prince Albert Group, and is associated with silicification (quartz veining) and sulfidation of magnetite and other Fe-rich minerals.Conventional U-Pb zircon dating of a conformable dacite unit within the volcanosedimentary host-rock sequence and a crosscutting diorite intrusion confirm a ~2.7 Ga age for deposition of the supracrustal package.U-Pb monazite dates and Pb isotopic analyses of sulfides were obtained by laser ablation–multicollector–inductively coupled plasma–mass spectrometry (LA-MC-ICP-MS). A subset of U-Pb monazite (1813.8 ± 8.7 Ma) and Re-Os arsenopyrite (1822 ± 21 Ma) dates, combined with a Pb-Pb secondary errorchron age for pyrite and arsenopyrite (1829 ± 77 Ma), suggest that gold mineralization associated with sulfidation of the iron formation occurred at ~1815 Ma, prior to high-grade (upper amphibolite facies) tectonometamorphism in the Three Bluffs area (D2TB/(M2TB).An ~1815 Ma age for deposit formation is broadly consistent with evidence from elsewhere in the western Churchill province and to the southwest in Manitoba and Saskatchewan for a late Trans-Hudson (1.9–1.8 Ga) gold mineralizing event. The majority of U-Pb monazite ages form a second population at 1780.6 ± 4.2 Ma, similar to the age of the majority of Re-Os arsenopyrite analyses (1763 ± 11 Ma). These dates are thought to reflect the timing of peak M2TB metamorphism. 40Ar/39Ar dating of amphibole, biotite, and muscovite yielded plateau ages ranging from 1723.8 ± 9.0 Ma to 1710 ± 17 Ma, which are interpreted to record the timing of postpeak metamorphic cooling to below the respective closure temperatures for Ar diffusion in these minerals. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Research Article| January 01, 2010 Base Metal Sulfide Mineralization in Lower Carboniferous Strata, Northwest Ireland C.J. Persellin; C.J. Persellin 1Boone Pickens School of Geology, Oklahoma State University, Stillwater, Oklahoma 74078 U.S.A Search for other works by this author on: GSW Google Scholar J.M. Gregg; J.M. Gregg † †Corresponding Author: E-mail: jay.gregg@okstate.edu Search for other works by this author on: GSW Google Scholar K.L. Shelton; K.L. Shelton 3Department of Geological Sciences, University of Missouri, Columbia, Missouri 65211 U.S.A Search for other works by this author on: GSW Google Scholar I.D. Somerville; I.D. Somerville 4School of Geological Sciences, University College Dublin, Belfield, Dublin 4, Ireland Search for other works by this author on: GSW Google Scholar E.A. Atekwana E.A. Atekwana 1Boone Pickens School of Geology, Oklahoma State University, Stillwater, Oklahoma 74078 U.S.A Search for other works by this author on: GSW Google Scholar Author and Article Information C.J. Persellin 1Boone Pickens School of Geology, Oklahoma State University, Stillwater, Oklahoma 74078 U.S.A J.M. Gregg † K.L. Shelton 3Department of Geological Sciences, University of Missouri, Columbia, Missouri 65211 U.S.A I.D. Somerville 4School of Geological Sciences, University College Dublin, Belfield, Dublin 4, Ireland E.A. Atekwana 1Boone Pickens School of Geology, Oklahoma State University, Stillwater, Oklahoma 74078 U.S.A †Corresponding Author: E-mail: jay.gregg@okstate.edu Publisher: Canadian Institute of Mining, Metallurgy and Petroleum Received: 16 Apr 2009 Accepted: 20 Feb 2010 First Online: 29 Sep 2017 © 2011 Canadian Institute of Mining, Metallurgy & Petroleum Exploration and Mining Geology (2010) 19 (1-2): 35–54. https://doi.org/10.2113/gsemg.19.1-2.35 Article history Received: 16 Apr 2009 Accepted: 20 Feb 2010 First Online: 29 Sep 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation C.J. Persellin, J.M. Gregg, K.L. Shelton, I.D. Somerville, E.A. Atekwana; Base Metal Sulfide Mineralization in Lower Carboniferous Strata, Northwest Ireland. Exploration and Mining Geology 2010;; 19 (1-2): 35–54. doi: https://doi.org/10.2113/gsemg.19.1-2.35 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract Zn-Pb sulfide mineralization at Abbeytown mine and Twigspark quarry comprise the only known carbonate-hosted base metal sulfide deposits in the Sligo syncline, northwest Ireland. Limestone sedimentation occurred uniformly throughout the region during the Early Carboniferous (Mississippian) as observed by field relationships and lithofacies; however, petrographic and stable isotope evidence indicate that host-rock dolomitization occurred under different conditions at localities to the west and east of the Ox Mountains inlier, suggesting significant uplift and geologic isolation of these areas prior to dolomitization. Localized fluid flow systems are thought to be responsible for sulfide mineralization and associated epigenetic carbonate cements. West of the Ox Mountains inlier at Abbeytown, evidence of three geochemically distinct fluids are observed: (1) a lower-temperature, lower-salinity fluid (70°–130°C, 4–9 wt.% equiv. NaCl); (2) a lower-temperature, higher-salinity fluid (70°–140°C, 15–24 wt.% equiv. NaCl); and (3) a higher-temperature, moderate-salinity fluid (165°–220°C, 8–14 wt.% equiv. NaCl). Similar fluid types were observed at the Twigspark deposit. The source of the higher-salinity fluid is likely seawater evaporated to near the point of halite precipitation. The higher-temperature fluid is thought to have been derived from deep circulation of basinal brines. It is speculated that mixing of the higher-salinity fluid with the high-temperature fluid was vital for ore formation at Abbeytown because fluid inclusions in sphalerite have homogenization temperatures and salinity values that fall along a mixing trajectory of these end member fluids. Also, areas where the high-salinity end member fluid is absent are barren of sulfides. Less complex fluid systems are indicated for sites east of the Ox Mountains inlier where no sulfide mineralization was observed. Data from base metal sulfide prospects in northwest Ireland indicate no connection with the regionally extensive flow system thought to be responsible for Zn-Pb deposits throughout the Irish Midlands. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

By compiling geological, structural, geophysical, and geochemical information into a 3D geological model, we evaluated the orogenic gold potential in the vicinity of a hidden segment of an important Archean fault zone, the Cadillac–Larder Lake fault (CLLF) in the region of Rouyn-Noranda. The segment of CLLF in the present study is partly covered by Proterozoic sedimentary rocks. Because more than 2000 t Au have been extracted along the CLLF to date, our objective is to evaluate the gold potential at depth along a poorly known segment of this fault. A 3D geological model (50 km × 9 km × 1.5 km) including the covered segment was built through the compilation and homogenization of available geological data and the construction of 23 cross sections. The geology under the Proterozoic cover was evaluated using geophysical inversions, drill holes (42 in total), and surrounding geology. All available assays were filtered and upscaled to a 250 m × 250 m × 250 m regular cell grid to determine and quantify spatial relationships between geological features and mineralized occurrences using the weights of evidence method. Structural features, such as E–W-trending faults and fault intersections, and certain lithologies with a high primary porosity such as volcanoclastic rocks of the Blake River Group and Timiskaming sedimentary rocks, proved to be very prospective, yielding favourable factors with a weight of evidence index W + > 0.24. These salient features were then assigned a combination index for ultimately evaluating the orogenic gold potential under the sedimentary cover. The zones resulting in an optimization of exploration targeting were attributed the highest probability, representing ~1% of the initial volume.

Economic returns for the copper industry have been assessed by building cash flow models for each of the 100 new mines brought into production over the past 20 years. Ninety-one of the 100 new mines returned the assumed 8% cost of capital and generated a positive net present value (NPV) at the development decision point. Economic criteria for individual mines are highly variable with NPV ranging from −$111 million (−$111M) to +$3850M (all money values are presented in United States dollars) and internal rate of return (IRR) ranging from −8% to +95%. The copper industry collectively would generate approximately $39 billion dollars in NPV through the development of the 100 new mines. The returns to exploration ($174M per deposit) were measured by deducting the cost of exploration per deposit ($221M) from the returns to development per deposit ($395M). Overall, the copper business has provided positive returns to exploration. However, the variability in returns across deposits means that only 41 of the 100 new mines can carry the average cost of exploration. The long lead times and high costs associated with exploration result in only those deposits with large amounts of contained copper being able to cover the average finding cost of the industry. The returns to development and exploration are shown to be highly sensitive to the cost of capital and metal price assumptions. With respect to deposit type, porphyry deposits are both larger (NPV) and exhibit lower profitability (IRR) than the nonporphyry deposits. On a geographic basis, returns to development and exploration are higher in Chile than elsewhere, reflecting the larger average deposit size and lower average exploration cost per deposit. © 2010 Canadian Institute of Mining, Metallurgy and Petroleum. All rights reserved. Sommaire Les retours sur investissement ont ete evalues par des modeles de valeur actualisee de flux de tresorerie pour chacune des 100 dernieres mines mises en production au cours des dernieres 20 annees. Quatre-vingt onze des cent mines les plus recentes ont retourne les couts en capital assumes de 8% et genere une valeur actualisee nette positive (VAN) au moment de la prise d’une decision de developper. Les criteres economiques de ces mines individuelles sont hautement variables avec des VAN allant de −$111 million (−$111M) a +$3850M (toutes les valeurs monetaires sont presentees en dollars Americains) et les taux de retour internes (TRI) vont de −8% a +95%. L’industrie du cuivre genererait collectivement environ $39 milliards de dollars en VAN par le developpement de 100 nouvelles mines. Les retours sur l’exploration ($174M par gisement) ont ete calcules en deduisant le cout de l’exploration par gisement ($221M) des retours sur le developpement par gisement ($395M). L’industrie du cuivre a generalement genere des retours sur l’exploration positifs. La variabilite des retours d’un gisement a l’autre n’a toutefois permis qu’a 41 des 100 nouvelles mines de soutenir les couts moyens d’exploration. La longueur des delais de mise en production et les couts d’exploration eleves font que seuls les gisements contenant une grande quantite de cuivre peuvent soutenir les couts moyens encourus par l’industrie pour leur decouverte. Les retours sur le developpement et l’exploration s’averent etre tres sensibles au cout du capital et aux assomptions sur le prix des metaux. En ce qui a trait aux types de gisement, les gites de type porphyrique presentent a la fois une plus grande taille (VAN) et une profitabilite moindre (TRI) que les autres types de gisement. D’un point de vue geographique, le retour sur le developpement et l’exploration est plus grand au Chili qu’ailleurs, ce qui decoule de la taille moyenne des gisements qui y est plus grande et des couts moyens d’exploration par gisement qui sont plus faibles. © 2010 Canadian Institute of Mining, Metallurgy and Petroleum. All rights reserved.

The Schlumberger configuration used in geoelectrical sounding is slightly adapted here to obtain reliable data for both shallow and deep penetration depths from the same survey. In this configuration, two kinds of current electrode half-spacings are used: the first enables construction of vertical electrical resistivity sounding (VES) curves for shallow depths (<50 m), and the second for depths ≤250 m. For a given VES location, two field curves are measured and interpreted using two standard approaches. Practical characteristics of such a modified configuration are illustrated with two field applications in Syria. The first aims to characterize the structure of Quaternary and recent deposits in the Al-Ghab depression region, and the second deals with exploration for phosphatic sedimentary units in the Al-Sharquieh mine.

Research Article| January 01, 2009 Use of Twinned Drillholes in Mineral Resource Estimation M.Z. Abzalov M.Z. Abzalov † 1MASSA Geoservices, Mt. Claremont, Western Australia, Australia WA6010. *Present address: Rio Tinto Exploration, PO Box 175, Western Australia, Australia WA6984. †Corresponding Author: E-mail: marat.abzalov@riotinto.com Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2009) 18 (1-4): 13–23. https://doi.org/10.2113/gsemg.18.1-4.13 Article history received: 13 Jan 2009 accepted: 30 May 2009 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation M.Z. Abzalov; Use of Twinned Drillholes in Mineral Resource Estimation. Exploration and Mining Geology 2009;; 18 (1-4): 13–23. doi: https://doi.org/10.2113/gsemg.18.1-4.13 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract Drilling twinned holes is a traditional technique used for verification of intersections of high-grade mineralization, testing of historic data, or confirmation of drillhole data during geological due diligence studies. Twinned holes can also be used for special tasks such as correcting earlier data that are recognized to be biased.Successful implementation of the twinned-holes technique requires thorough planning. Experience suggests that good practice is to drill twinned holes no more than 5 m apart. Many unsuccessful twinned-holes programs could possibly have failed because the twinned holes have been drilled too far apart.Twinned holes are best compared by mineralization intersections and, if the data and geological characteristics of the deposit permit, by samples, equal-length composites, or geological units. Variables to be verified by twinned holes should include the thicknesses of the geological units of interest (e.g., mineralized thickness) as well as the presence of significant geological features (e.g., ore/mineralization contacts, alteration, etc.).A formal, rigorous analysis of twinned-hole data is essential. Repeatability of sampling, analytical results, and bias must be analyzed and statistically quantified. The number of twinned holes required for conclusive statistical and geostatistical analysis can be as high as 20–30, in particular where the studied variables are characterized by high short-range (local) variability.The efficiency of this approach is demonstrated by several examples of successfully applied twinned-hole projects, including applications to orogenic gold, mineral sands, bauxite, and iron ore deposits. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Research Article| January 01, 2009 Geology of the Ore Fault Ni-Cu Deposit, Bird River Sill Complex, Manitoba D. Good; D. Good † 1Marathon PGM Corp., Suite 1505-330 Bay St., Toronto, Ontario, M5H 2S8. †Corresponding Author: E-mail: dgood@marathonpgm.com Search for other works by this author on: GSW Google Scholar C. Mealin; C. Mealin 1Marathon PGM Corp., Suite 1505-330 Bay St., Toronto, Ontario, M5H 2S8. Search for other works by this author on: GSW Google Scholar P. Walford P. Walford 1Marathon PGM Corp., Suite 1505-330 Bay St., Toronto, Ontario, M5H 2S8. Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2009) 18 (1-4): 41–57. https://doi.org/10.2113/gsemg.18.1-4.41 Article history received: 20 Apr 2009 accepted: 14 Sep 2009 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation D. Good, C. Mealin, P. Walford; Geology of the Ore Fault Ni-Cu Deposit, Bird River Sill Complex, Manitoba. Exploration and Mining Geology 2009;; 18 (1-4): 41–57. doi: https://doi.org/10.2113/gsemg.18.1-4.41 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract The geology of the Ore Fault Ni-Cu deposit has been reinterpreted in the light of recent studies of the geology of the Neoarchean Bird River Sill Complex and the occurrence of economic Ni-Cu and Zn-Cu-Ag mineralization. The Ni-Cu sulfides are hosted by the lower of two parallel NNW-trending and moderately W-dipping mafic–ultramafic intrusions related to the Bird River Sill Complex. The bodies intruded a bimodal volcanic suite consisting of weakly deformed mafic flows and felsic pyroclastic rocks. The mafic volcanic rocks are geochemically related to the MORB-type rocks of the Lamprey Falls Formation, and the felsic volcanic rocks are related to arc-type rocks of the Peterson Creek Formation. The original pyroxene- and olivine-dominated mineralogy of the sills has been replaced by variable serpentine-amphibole-talc-carbonate assemblages.The Ni-Cu sulfide assemblage exhibits textures and geochemical signatures typical of orthomagmatic sulfide mineralization. The sulfide minerals are associated with cumulate layers of magnetic ferrochromite that range in thickness from a few to tens of centimeters. A later event of Zn-Cu-Ag sulfide mineralization associated with quartz veining and garnet-chlorite alteration along a fault that strikes north, dips vertically, and cuts all rock types. The mineralized fault is cut by the NE-trending Peterson Creek shear zone. Where the Ni-Cu and Zn-Cu-Ag mineralized zones intersect, remnant magmatic features such as amphibolite or cumulate ferrochromite bands occur within quartz veins or local chlorite alteration. The mixed zones contain a very unusual polymetallic assemblage of Ni, Cu, Zn, Ag, and platinum group elements (PGE). You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Research Article| January 01, 2009 Post-Early Cretaceous Mississippi Valley-type Zn-Pb Mineralization in the Bongara Area, Northern Peru: Fluid Evolution and Paleo Flow from Fluid Inclusion Evidence N.I. Basuki; N.I. Basuki † 1F. Gordon Smith Fluid Inclusion Lab., Department of Geology, University of Toronto, 22 Russell St., Toronto, Ontario M5S 3B1. *Present address: Department of Geology, Institut Teknologi Bandung (ITB), Ganesha 10, Bandung 40132, Jawa Barat, Indonesia. †Corresponding Author: E-mail: basuki@gc.itb.ac.id Search for other works by this author on: GSW Google Scholar E.T.C. Spooner E.T.C. Spooner 1F. Gordon Smith Fluid Inclusion Lab., Department of Geology, University of Toronto, 22 Russell St., Toronto, Ontario M5S 3B1. Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2009) 18 (1-4): 25–39. https://doi.org/10.2113/gsemg.18.1-4.25 Article history received: 05 Nov 2007 accepted: 19 Apr 2009 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation N.I. Basuki, E.T.C. Spooner; Post-Early Cretaceous Mississippi Valley-type Zn-Pb Mineralization in the Bongara Area, Northern Peru: Fluid Evolution and Paleo Flow from Fluid Inclusion Evidence. Exploration and Mining Geology 2009;; 18 (1-4): 25–39. doi: https://doi.org/10.2113/gsemg.18.1-4.25 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract The Bongara area, northern Peru, contains Zn-Pb mineralization with characteristics typical of Mississippi Valley-type (MVT) systems. The northwest–southeast-trending late Triassic–Jurassic carbonate host rocks of the Pucará Group were locally replaced by early (D1) and late (D2) dolomite. Fluid inclusion microthermometric data from dolomite and sphalerite are typical of MVT ore fluids (78° to 187°C; ~15–23 wt.% CaCl2 equivalent), and do not show apparent covariation between temperature and salinity.Homogenization temperature data from D1 and D2 dolomite show a decrease from northern (mean Th = 138°C) to central (mean Th = 126°C) to southern areas (mean Th = 102°C), suggesting fluid flow from north to south. Assuming a geothermal gradient of ~30°C/km and an average surface temperature of ~20°C, the lower temperature limits might approximate the ambient host-rock temperatures, whereas the upper temperature limits may represent minimum temperatures of a deeper aquifer, probably at a maximum depth of ~6000 m. The lower temperature limits are also similar to the estimated temperatures if dolomitization and mineralization took place in the Late Cretaceous at ~2000–3000 m depth, probably during the formation of the Peruvian fold and thrust belt near the present day Peru–Ecuador border.Fluid inclusion data show that the fluids in each studied location had relatively uniform temperatures and salinities during dolomitization and mineralization. A significant salinity drop and a slight temperature decrease are observed during late calcite precipitation, suggesting mixing of brines with dilute, cooler fluids. You do not currently have access to this article.

Research Article| January 01, 2009 Evaluation of the Efficiency of Several Airborne Electromagnetic Systems: Exploration Implications L. Z. Cheng; L. Z. Cheng † 1Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, Québec, J9X 5E4. †Corresponding Author: E-mail: li_zhen.cheng@uqat.ca Search for other works by this author on: GSW Google Scholar R. S. Smith; R. S. Smith 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. Search for other works by this author on: GSW Google Scholar M. Allard; M. Allard 3Xstrata Zinc, 8801, Transcanadienne, Saint-Laurent, Québec, H4S 1Z6. Search for other works by this author on: GSW Google Scholar P. Keating; P. Keating 4Geological Survey of Canada, Natural Resources Canada, 615 Booth Street, Ottawa, Ont., K1A 0E. Search for other works by this author on: GSW Google Scholar M. Chouteau; M. Chouteau 5École Polytechnique de Montréal, Département des Génies civil, géologique et des mines C.P. 6079 Succursale Centre-Ville, Montréal, Québec, H3C 3A7. Search for other works by this author on: GSW Google Scholar J. Lemieux; J. Lemieux 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. Search for other works by this author on: GSW Google Scholar M.A. Vallée; M.A. Vallée 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. Search for other works by this author on: GSW Google Scholar D. Bois; D. Bois 1Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, Québec, J9X 5E4. Search for other works by this author on: GSW Google Scholar D. K. Fountain D. K. Fountain 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. Search for other works by this author on: GSW Google Scholar Author and Article Information L. Z. Cheng † 1Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, Québec, J9X 5E4. R. S. Smith 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. M. Allard 3Xstrata Zinc, 8801, Transcanadienne, Saint-Laurent, Québec, H4S 1Z6. P. Keating 4Geological Survey of Canada, Natural Resources Canada, 615 Booth Street, Ottawa, Ont., K1A 0E. M. Chouteau 5École Polytechnique de Montréal, Département des Génies civil, géologique et des mines C.P. 6079 Succursale Centre-Ville, Montréal, Québec, H3C 3A7. J. Lemieux 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. M.A. Vallée 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. D. Bois 1Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, Québec, J9X 5E4. D. K. Fountain 2Fugro Airborne Surveys, 2191 Thurston Drive, Ottawa, Ontario, K1G 6C9. †Corresponding Author: E-mail: li_zhen.cheng@uqat.ca Publisher: Canadian Institute of Mining, Metallurgy and Petroleum Received: 24 Jul 2008 Accepted: 22 Mar 2009 First Online: 02 Mar 2017 © 2009 Canadian Institute of Mining, Metallurgy and Petroleum Exploration and Mining Geology (2009) 18 (1-4): 1–12. https://doi.org/10.2113/gsemg.18.1-4.1 Article history Received: 24 Jul 2008 Accepted: 22 Mar 2009 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation L. Z. Cheng, R. S. Smith, M. Allard, P. Keating, M. Chouteau, J. Lemieux, M.A. Vallée, D. Bois, D. K. Fountain; Evaluation of the Efficiency of Several Airborne Electromagnetic Systems: Exploration Implications. Exploration and Mining Geology 2009;; 18 (1-4): 1–12. doi: https://doi.org/10.2113/gsemg.18.1-4.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract A comparison of data from INPUT, GEOTEM, and MEGATEM airborne electromagnetic (AEM) systems over the Aldermac deposit, Québec, Canada, was undertaken to evaluate the relative efficiency of these systems for the detection of small, deep conductors. The Aldermac orebody was mined between 1933 and 1934 to a depth of 200 m. A deeper mineralized zone was discovered in 1987. The MEGATEMII system was used to acquire 90- and 30-Hz data over the deposit in 2003 as part of a research project. These MEGATEMII data were compared with data acquired by other AEM systems (GEOTEM and INPUT), and the results show that the MEGATEMII response is ten times larger than the other systems. For the dB/dt response, 30 Hz gives a better signal-to-noise ratio, whereas 90 Hz has a better signal-to-noise ratio on the B-field.The data were evaluated by numerical modeling. The deposit was best represented by a complex model, comprising two weakly conductive bodies to approximate the alteration halo, two deeper prisms representing known orebodies, and three bodies ranging in thickness from 3 to 6 m and in resistivity from 12 to 20 ohm·m, representing the chargeable overburden. This implies that the MEGATEMII system is able to see a small conductive body at more than 200 m depth in an area where the response is contaminated by conductive overburden. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Research Article| January 01, 2008 Characteristics of Mineralization at the Main Zone of the Clarence Stream Gold Deposit, Southwestern New Brunswick, Canada: Evidence for an Intrusion-Related Gold System in the Northern Appalachian Orogen K.G. Thorne; K.G. Thorne † 1New Brunswick Department of Natural Resources, PO Box 6000, Fredericton, New Brunswick, E3B 5H1. †Corresponding Author: E-mail: kay.thorne@gnb.ca Search for other works by this author on: GSW Google Scholar D.R. Lentz; D.R. Lentz 2Department of Geology, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3. Search for other works by this author on: GSW Google Scholar D. Hoy; D. Hoy 3Freewest Resources Canada Inc., 855 Field Street, Thunder Bay, Ontario, P7B 6B6. Search for other works by this author on: GSW Google Scholar L.R. Fyffe; L.R. Fyffe 1New Brunswick Department of Natural Resources, PO Box 6000, Fredericton, New Brunswick, E3B 5H1. Search for other works by this author on: GSW Google Scholar L.J. Cabri L.J. Cabri 4Cabri Consulting Inc., 99 Fifth Avenue, Suite 122, Ottawa, Ontario, K1S 5P5. Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2008) 17 (1-2): 13–49. https://doi.org/10.2113/gsemg.17.1-2.13 Article history received: 19 Dec 2005 accepted: 08 Mar 2008 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation K.G. Thorne, D.R. Lentz, D. Hoy, L.R. Fyffe, L.J. Cabri; Characteristics of Mineralization at the Main Zone of the Clarence Stream Gold Deposit, Southwestern New Brunswick, Canada: Evidence for an Intrusion-Related Gold System in the Northern Appalachian Orogen. Exploration and Mining Geology 2008;; 17 (1-2): 13–49. doi: https://doi.org/10.2113/gsemg.17.1-2.13 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract Mineralization at the Main zone of the Clarence Stream gold deposit in southwestern New Brunswick occurs within a parallel series of quartz veins that occupy a NE-trending, steeply north-dipping, brittle–ductile shear zone related to the nearby terrane-bounding Sawyer Brook fault. This deformation zone cuts volcaniclastic sedimentary and volcanic rocks of the Silurian Waweig Formation, and is intruded by mantle-derived East Branch Brook gabbroic dikes and a number of felsic dikes. Intermittent shear-zone reactivation during local magmatic activity induced heterogeneous deformation and alteration of the country rocks and dikes. The terminal phase of shearing is associated with narrow pegmatite-aplite dikes that grade laterally into granophyric granite, and into an auriferous quartz vein. Gold, aurostibite, and gold-antimony intergrowths, predominantly with vein quartz, are associated with a low ƒO2 sulfide mineral assemblage (pyrrhotite, arsenopyrite, and berthierite) that has a sulfur isotopic signature consistent with a magmatic source. Gold saturation and deposition occurred episodically between 300° and 360°C at low activity of sulfur, predominantly in response to pressure reduction during brittle failure combined with the effects of decreasing temperature and sulfidation reactions during fluid–wall-rock interaction. Geochronological studies demonstrate that the timing of the emplacement of the pegmatite-aplite dikes and associated auriferous veins overlap with that of the Early Devonian Magaguadavic granite. Moreover, the composition of the dikes is consistent with their derivation from this granite as late fractionates. The Main zone of the Clarence Stream deposit is therefore interpreted to be intrusion-related, with the Magaguadavic granite being the ultimate source of the gold-bearing fluids. You do not currently have access to this article.

Research Article| July 01, 2008 Geology and Mineralogy of the Hercynian Koudiat Aïcha Polymetallic (Zn-Pb-Cu) Massive Sulfide Deposit, Central Jebilet, Morocco F. Lotfi; F. Lotfi 1Faculté des Sciences Semlalia, Marrakech, Morocco. *Present Address: ONHYM, Direction Générale, 5, Av. My-Hassan, BP. 99, Rabat, Morocco; E-mail: lotfi_fouad@yahoo.fr Search for other works by this author on: GSW Google Scholar A Belkabir; A Belkabir † 2Faculté des Sciences et Techniques, Laboratoire Géoressources, BP. 549, Marrakech, Morocco. †Corresponding Author: E-mail: abelkabir@sftg-marrakech.ac.ma Search for other works by this author on: GSW Google Scholar A.C. Brown; A.C. Brown 3Dept. of Civil, Geological and Mining Eng., École Polytechnique de Montréal, 2900 boulevard Édouard-Montpetit, Montréal, Québec, Canada, H3T 1J4. Search for other works by this author on: GSW Google Scholar E. Marcoux; E. Marcoux 4Institut des Sciences de la Terre d’Orléans, Université d’Orléans, Orléans, France. Search for other works by this author on: GSW Google Scholar S Brunet; S Brunet 5Reminex-MANAGEM, Marrakech, Morocco. Search for other works by this author on: GSW Google Scholar L. Maacha L. Maacha 5Reminex-MANAGEM, Marrakech, Morocco. Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2008) 17 (3-4): 145–162. https://doi.org/10.2113/gsemg.17.3-4.145 Article history received: 07 May 2007 accepted: 19 Sep 2008 first online: 13 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation F. Lotfi, A Belkabir, A.C. Brown, E. Marcoux, S Brunet, L. Maacha; Geology and Mineralogy of the Hercynian Koudiat Aïcha Polymetallic (Zn-Pb-Cu) Massive Sulfide Deposit, Central Jebilet, Morocco. Exploration and Mining Geology 2008;; 17 (3-4): 145–162. doi: https://doi.org/10.2113/gsemg.17.3-4.145 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract Koudiat Aïcha is a small Zn-Pb-Cu deposit, enclosed in the Visean Sarhlef volcano-sedimentary series of the Moroccan Hercynian Jebilet massif. Base metal mineralization is located between a basal unit consisting of black argillite with arenite intercalations, and an upper unit composed of black argillite with locally fossiliferous calcareous units towards the top. Paraconcordant gabbro sills are present in both the upper and basal units, and the enclosing strata. Three successive phases of deformation linked to regional deformation overprint the volcano-sedimentary rocks and gabbros, as well as the sulfide mineralization.The mineral deposit includes several lenses of massive to semimassive pyrrhotite, 1 to 20 m thick, with a large halo of disseminated sulfide veinlets and sulfide nodules within a zone of intense chlorite alteration in the footwall. The ore mineralogy consists of massive to semimassive pyrrhotite with lesser amounts of sphalerite, chalcopyrite, arsenopyrite, galena, pyrite, and stannite.Lead isotope results (206Pb/204Pb averaging 18.27) suggest that the metals of the Koudiat Aïcha deposit are derived from the volcano-sedimentary host rocks. Sulfur isotopes also indicate a volcano-sedimentary origin, with bacterial reduction of sulfate (δ34SCDT = −7.5‰ to −10.5‰). The conditions for sulfide metamorphic equilibration range from 250° to 330°C (sphalerite and chlorite geothermometers). The gabbroic sills could have been a local heat source for hydrothermal circulation. Based on these geological and mineralogical features, a Besshi-type model seems appropriate for the genesis of the Koudiat Aïcha mineralization. You do not currently have access to this article.

Research Article| July 01, 2008 Two Contrasting Iron Deposits in the Precambrian Mineral Belt of Cameroon, West Africa C.E. Suh; C.E. Suh † 1Economic Geology Unit, Department of Geology and Environmental Science, University of Buea, P.O. Box 63, Buea, South West Province, Cameroon. †Corresponding Author: E-mail: chuhma@yahoo.com Search for other works by this author on: GSW Google Scholar A.R. Cabral; A.R. Cabral 2Department of Geology: Exploration Geology, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa. Search for other works by this author on: GSW Google Scholar E.M. Shemang; E.M. Shemang 3Department of Geology, University of Botswana, Private Bag 0022, Gaborone, Botswana. Search for other works by this author on: GSW Google Scholar L. Mbinkar; L. Mbinkar 4Department of Earth Sciences, Faculty of Science, University of Yaounde I, B.P. 812, Yaounde, Cameroon. Search for other works by this author on: GSW Google Scholar G.G.M. Mboudou G.G.M. Mboudou 1Economic Geology Unit, Department of Geology and Environmental Science, University of Buea, P.O. Box 63, Buea, South West Province, Cameroon. Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2008) 17 (3-4): 197–207. https://doi.org/10.2113/gsemg.17.3-4.197 Article history received: 20 Nov 2007 accepted: 10 Sep 2008 first online: 13 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation C.E. Suh, A.R. Cabral, E.M. Shemang, L. Mbinkar, G.G.M. Mboudou; Two Contrasting Iron Deposits in the Precambrian Mineral Belt of Cameroon, West Africa. Exploration and Mining Geology 2008;; 17 (3-4): 197–207. doi: https://doi.org/10.2113/gsemg.17.3-4.197 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract Two iron deposits within the Precambrian mineral belt of Cameroon are described in detail for the first time: the Archean Metzimevin replacement iron deposit enclosed in Fe-enriched itabirite, and the Proterozoic granite-hosted, shear zone-related Mayo Binka magnetite deposit. In the Metzimevin deposit, quartz is corroded and microplaty hematite overprints martite-textured hematite. The Mayo Binka massive magnetite veins show evidence of deformation in magnetite (fracturing and microbrecciation) and in overgrowths of specular hematite (mechanical twinning and undulating extinction). The magnetite is partially replaced by hematite (martitization) and goethite. Ores from both deposits have >88% total Fe2O3 and low contents of contaminants such as SiO2, Al2O3, MgO, CaO, P2O5, and TiO2. They are also poor in Cu, Pb, Zn, V, Cr, and Ni. The Metzimevin massive hematite is characterized by an accentuated light rare earth element depletion relative to the Fe-enriched itabirite. It is suggested that the Metzimevin iron deposit is the result of hypogene leaching of gangue minerals from, and further hematitization of, an itabirite protore. Although the genesis of the Mayo Binka massive magnetite is unclear, it is spatially related to Neoproterozoic granitic rocks. The data allow some comparison of these little known, but potentially economic iron deposits, with some of the world's better investigated deposits, and are useful to the exploration efforts for iron ore currently underway in Cameroon and the Central African subregion. You do not currently have access to this article.

Research Article| January 01, 2008 Gold Mineralization at the Anomaly A Deposit, Clarence Stream Area, Southwestern New Brunswick: Distal Deposits of a Syn-Deformational Intrusion-Related Gold System? S. Watters; S. Watters 1New Brunswick Department of Natural Resources, Geological Surveys Branch, 207 Picadilly Road, P.O. Box 5040, Sussex, New Brunswick, E4E 5L2. *Present address: Geological Consultant 3262 Route 121, Apohaqui, New Brunswick, E5P 1B1. Search for other works by this author on: GSW Google Scholar S. Castonguay; S. Castonguay † 2Natural Resources Canada, Geological Survey of Canada—Québec division, rue de la Couronne, Québec, Québec, G1K 9A9. †Corresponding Author: E-mail: scastong@nrcan.gc.ca Search for other works by this author on: GSW Google Scholar G.G. Lutes; G.G. Lutes 3Geological Consultant, 87 Venus Crescent, Hanwell, New Brunswick, E3C 1N1. Search for other works by this author on: GSW Google Scholar M.J. McLeod M.J. McLeod 1New Brunswick Department of Natural Resources, Geological Surveys Branch, 207 Picadilly Road, P.O. Box 5040, Sussex, New Brunswick, E4E 5L2. Search for other works by this author on: GSW Google Scholar Author and Article Information S. Watters *Present address: Geological Consultant 3262 Route 121, Apohaqui, New Brunswick, E5P 1B1. 1New Brunswick Department of Natural Resources, Geological Surveys Branch, 207 Picadilly Road, P.O. Box 5040, Sussex, New Brunswick, E4E 5L2. S. Castonguay † 2Natural Resources Canada, Geological Survey of Canada—Québec division, rue de la Couronne, Québec, Québec, G1K 9A9. G.G. Lutes 3Geological Consultant, 87 Venus Crescent, Hanwell, New Brunswick, E3C 1N1. M.J. McLeod 1New Brunswick Department of Natural Resources, Geological Surveys Branch, 207 Picadilly Road, P.O. Box 5040, Sussex, New Brunswick, E4E 5L2. †Corresponding Author: E-mail: scastong@nrcan.gc.ca Publisher: Canadian Institute of Mining, Metallurgy and Petroleum Received: 22 Jan 2004 Accepted: 17 Jun 2006 First Online: 02 Mar 2017 © 2008 Canadian Institute of Mining, Metallurgy and Petroleum Exploration and Mining Geology (2008) 17 (1-2): 67–84. https://doi.org/10.2113/gsemg.17.1-2.67 Article history Received: 22 Jan 2004 Accepted: 17 Jun 2006 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation S. Watters, S. Castonguay, G.G. Lutes, M.J. McLeod; Gold Mineralization at the Anomaly A Deposit, Clarence Stream Area, Southwestern New Brunswick: Distal Deposits of a Syn-Deformational Intrusion-Related Gold System?. Exploration and Mining Geology 2008;; 17 (1-2): 67–84. doi: https://doi.org/10.2113/gsemg.17.1-2.67 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract Gold-bearing mineralization at Anomaly A occurs in polydeformed Ordovician turbidites of the Kendall Mountain Formation of the St. Croix belt in southwestern New Brunswick, and is hosted by WSW-trending, shallow-dipping, brittle–ductile high-strain zones associated with the latest stage of the second of four regional deformation events. Gold-bearing syn-deformational stockwork, massive, and multiply brecciated quartz-sulfide veined zones form irregular pods and sheets up to several meters thick, which contain arsenopyrite, pyrrhotite, pyrite, stibnite, and a variety of rare minerals that are gold-bearing. Mineralized zones are enveloped by locally auriferous, weakly to intensely altered wall rock. Vein paragenesis includes: (1) early (pre- to syn-D2) quartz-chlorite veins that are largely the product of migration of quartz by pressure solution; (2) crosscutting, multiphase, vuggy quartz-sulfide veins that contain most of the gold and are interpreted to be structurally controlled; (3) late, crosscutting, nondeformed, non-gold-bearing veins containing laumontite, chlorite, muscovite, quartz, fluorite, and base metal sulfides. Carbonate-poor alteration associated with zones of gold mineralization is lithology-specific, and appears to reflect overprinting of multiple events. Major elements removed during alteration include Si, Na, Mn, and Mg. The minor and trace elements removed include Co, Li, Sc, and possibly Sr, Ni, and Zn. Minor and trace elements added include Au, Ag, As, Sb, S, and possibly F, Cu, Pb, and Zr. On the basis of proximity, time constraints, and a similar ore mineral assemblage, gold mineralization at Anomaly A is interpreted to be a distal equivalent of the intrusion-related gold mineralization at the nearby Clarence Stream Main zone deposit. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Research Article| July 01, 2008 The Schaft Creek Porphyry Cu-Mo-(Au) Deposit, Northwestern British Columbia* J.E. Scott; J.E. Scott 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3. Search for other works by this author on: GSW Google Scholar J.P. Richards; J.P. Richards † 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3. †Corresponding Author: E-mail: jeremy.richards@ualberta.ca Search for other works by this author on: GSW Google Scholar L.M. Heaman; L.M. Heaman 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3. Search for other works by this author on: GSW Google Scholar R.A. Creaser; R.A. Creaser 1Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta, T6G 2E3. Search for other works by this author on: GSW Google Scholar G.S. Salazar G.S. Salazar 2CopperFox Metals Inc., 650, 340–12th Avenue S.W., Calgary, Alberta, T2R 1L5. Search for other works by this author on: GSW Google Scholar Exploration and Mining Geology (2008) 17 (3-4): 163–196. https://doi.org/10.2113/gsemg.17.3-4.163 Article history received: 27 Mar 2008 accepted: 16 Oct 2008 first online: 13 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation J.E. Scott, J.P. Richards, L.M. Heaman, R.A. Creaser, G.S. Salazar; The Schaft Creek Porphyry Cu-Mo-(Au) Deposit, Northwestern British Columbia. Exploration and Mining Geology 2008;; 17 (3-4): 163–196. doi: https://doi.org/10.2113/gsemg.17.3-4.163 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract Schaft Creek is a calc-alkaline porphyry Cu-Mo-(Au) deposit located in northwestern British Columbia. The deposit formed in a volcanic arc setting, likely on a back-arc rifted continental fragment. It is hosted by Late Triassic basaltic to andesitic volcanic rocks of the Stuhini Group (Stikine Terrane), and is associated with porphyritic granodiorite dikes emanating from the nearby Hickman batholith. The age of the Hickman batholith is approximately constrained here by a composite U–Pb zircon date of 222.1 ± 9.6 Ma, which is in broad agreement with a well-constrained age for mineralization at Schaft Creek of 222.0 ± 0.8 Ma (Re–Os molybdenite). The deposit is in most respects typical of calc-alkaline porphyry systems, but displays silica-poor sericite-chlorite alteration in mafic country rocks in place of classic phyllic alteration. The deposit comprises three distinct, but related, zones: the northern Paramount zone, the Main zone, and the West Breccia zone. Two phases of mineralization are observed. The first phase occurs as hydrothermal veins and breccias, and minor disseminations. It consists of bornite, chalcopyrite, molybdenite, and pyrite with potassic and sericite-chlorite alteration. The second phase is minor and consists of veins of molybdenite ± specularite, as well as Cu–Pb-Zn sulfide veins without any significant corresponding alteration. Extensive structural modification has affected the deposit both during and after its formation. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Research Article| January 01, 2008 Architecture of Gold Mineralization at Anomaly A of the Clarence Stream Deposits, Southern New Brunswick J.-F. Ravenelle; J.-F. Ravenelle † 1Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montréal, Québec, H3A 2A7. *Current address: INRS-ETE, 490 rue de la Couronne, Québec City, Québec, G1K 9A9. †Corresponding Author:jean-francois.ravenelle@ete.inrs.ca Search for other works by this author on: GSW Google Scholar G.G. Lutes; G.G. Lutes 2Geological Consultant, 87 Venus Crescent, Hanwell, New Brunswick, E3C 1N1. Search for other works by this author on: GSW Google Scholar A.J. Hynes A.J. Hynes 1Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montréal, Québec, H3A 2A7. Search for other works by this author on: GSW Google Scholar Author and Article Information J.-F. Ravenelle *Current address: INRS-ETE, 490 rue de la Couronne, Québec City, Québec, G1K 9A9. † 1Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montréal, Québec, H3A 2A7. G.G. Lutes 2Geological Consultant, 87 Venus Crescent, Hanwell, New Brunswick, E3C 1N1. A.J. Hynes 1Department of Earth and Planetary Sciences, McGill University, 3450 University Street, Montréal, Québec, H3A 2A7. †Corresponding Author:jean-francois.ravenelle@ete.inrs.ca Publisher: Canadian Institute of Mining, Metallurgy and Petroleum Received: 23 Jun 2006 Accepted: 03 Feb 2008 First Online: 02 Mar 2017 © 2008 Canadian Institute of Mining, Metallurgy and Petroleum Exploration and Mining Geology (2008) 17 (1-2): 85–100. https://doi.org/10.2113/gsemg.17.1-2.85 Article history Received: 23 Jun 2006 Accepted: 03 Feb 2008 First Online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation J.-F. Ravenelle, G.G. Lutes, A.J. Hynes; Architecture of Gold Mineralization at Anomaly A of the Clarence Stream Deposits, Southern New Brunswick. Exploration and Mining Geology 2008;; 17 (1-2): 85–100. doi: https://doi.org/10.2113/gsemg.17.1-2.85 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyExploration and Mining Geology Search Advanced Search Abstract The Anomaly A area of the Clarence Stream gold deposits in southwestern New Brunswick contains mineralized structures that bear geometrical relationships to regional folding events. The four mineralized zones of Anomaly A (AD, MW, 93, and Murphy) are hosted by turbiditic graywacke, quartzose wacke, siltstone, and argillite sequences of the Kendall Mountain Formation. A regional scale structural analysis reflects at least four deformational events, three of which appear to control the folded geometry of Anomaly A (D2, D3, and D4). F2 and F3 folds are coaxial and are refolded into a dome and basin geometry by F4 folds. The mineralized zones are subparallel to axial surfaces of F2 folds. Structural analysis of a mineralized zone exposed at surface indicates that gold mineralization is hosted by a quartz-vein system that comprises veins generated during both D2 and D3. Three dimensional representations of Anomaly A created using drill-core data and ®GoCAD suggest that the quartz-vein system was emplaced in fault structures during D2 as well as within brecciated dilation zones during D3. Three of the four zones that make up Anomaly A have F2 hinge surfaces that can be linked through a geometry compatible with the style of F3 and F4 folds. The apparent continuity of these three zones indicates the potential for kilometer-scale mineralized structures at Anomaly A. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.