... Acknowledgements This paper has stemmed from research undertaken as part of AMIRA International Project P511 Hydrothermal systems, giant ore deposits and a ... not an economic geologist by training and have done some research in the... more
... Acknowledgements This paper has stemmed from research undertaken as part of AMIRA International Project P511 Hydrothermal systems, giant ore deposits and a ... not an economic geologist by training and have done some research in the field either for living or as a hobby. ...
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INTRODUCTION The obduction and reworking of oceanic plateaus at subduction zones are increasingly viewed as important crustal-growth mechanisms and have been advocated for specific Archean and Proterozoic terranes (Kimura et al., 1993;... more
INTRODUCTION The obduction and reworking of oceanic plateaus at subduction zones are increasingly viewed as important crustal-growth mechanisms and have been advocated for specific Archean and Proterozoic terranes (Kimura et al., 1993; Stein and Goldstein, 1996) and for ...
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... The geochemistry of the Coubran Lake basalts will also be compared with that of the Eastern Gabbro, the Two Duck Lake Gabbro and the Geordie Lake Gabbro to see if the basalts may represent the ... Walker, EC, Sutcliffe, RH, Shaw, CSJ,... more
... The geochemistry of the Coubran Lake basalts will also be compared with that of the Eastern Gabbro, the Two Duck Lake Gabbro and the Geordie Lake Gabbro to see if the basalts may represent the ... Walker, EC, Sutcliffe, RH, Shaw, CSJ, Shore, GT and Penczak, RS 1991. ...
... McBride J. 2010, The Mineral Composition of the Eastern Gabbro Xenoliths and Reclassification of the Magnetite-Olivine Cumulate ... tectonic, diorite-monzodiorite-monzonite suites with sanukitoid affinity within the Wabigoon and... more
... McBride J. 2010, The Mineral Composition of the Eastern Gabbro Xenoliths and Reclassification of the Magnetite-Olivine Cumulate ... tectonic, diorite-monzodiorite-monzonite suites with sanukitoid affinity within the Wabigoon and Quetico subprovinces (eg, Shelby Lake batholith ...
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High-resolution paleomagnetic secular variation and relative paleointensity records from the western Canadian Arctic: implication for Holocene stratigraphy and geomagnetic field behaviour This article is one of a series of papers published in this Special Issue on the theme Polar Climate Stabilit...more
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Archean greenstone belts from the northern Superior Province, ranging in age from 3.0 to 2.9 Ga, comprise an association of komatiite–tholeiite sequences, some of which were erupted onto continental crust, intercalated with felsic... more
Archean greenstone belts from the northern Superior Province, ranging in age from 3.0 to 2.9 Ga, comprise an association of komatiite–tholeiite sequences, some of which were erupted onto continental crust, intercalated with felsic volcanic rocks. Komatiites from the Uchi subprovince are characterised by variable LREE enrichment and negative Nb anomalies consistent with contamination of Munro-type Al-undepleted komatiites by a felsic
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New HindIII, RsaI and TaqI restriction fragment length polymorphisms (RFLPs) within the haemopoietic cell kinase gene in chromosome band 20q11.2 are described. These RFLPs provide a useful marker for linkage analysis in proximal 20q.
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ABSTRACT Sediments deposited in volcanically active areas preserve a record of the geochemistry of eroded igneous units. In some instances this record can be more complete than the remaining volcanic rocks. Whole rock geochemistry and... more
ABSTRACT Sediments deposited in volcanically active areas preserve a record of the geochemistry of eroded igneous units. In some instances this record can be more complete than the remaining volcanic rocks. Whole rock geochemistry and detrital zircon geochronology were performed on sedimentary rocks of the Balmer assemblage in the Birch-Uchi Greenstone Belt, western Superior Province, to investigate the types and ages of igneous rocks that were present in the source area at approximately 2.9Ga. Spatially juxtaposed Mesoarchean volcanic rocks were also analyzed for comparative purposes. The detrital zircon geochronology revealed that the sandstones studied are significantly younger than the adjacent volcanic rocks, inferring that their stratigraphic position is the result of tectonic interleaving and they do not belong in the Balmer assemblage. As well, the majority of the detrital zircons were older than the adjacent volcanic rocks severely limiting the potential role of these volcanic units as a source terrain. Extreme geochemical heterogeneity within the sandstone sample set implies the depositional environment was supplied by multiple sediment fed systems, which probably delivered detritus to a submarine ramp environment. A subset of the sandstone samples are HFSE enriched and had, in part, an alkalic igneous source. This infers that the ocean plateau tholeiitic basalts, which are abundant in northwest Superior Province, may have been associated with alkalic eruptive units, similar to modern intra-plate igneous activity. Either erosive or tectonic processes have removed these alkalic igneous units from the preserved rock record, but their detritus is present and identifiable in the sedimentary succession.
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The Uchi subprovince of the Archean Superior Province is a series of greenstone belts extending 600 km east–west along the southern margin of the North Caribou Terrane protocontinent. The 2.7 Ga Confederation tectonostratigraphic... more
The Uchi subprovince of the Archean Superior Province is a series of greenstone belts extending 600 km east–west along the southern margin of the North Caribou Terrane protocontinent. The 2.7 Ga Confederation tectonostratigraphic assemblage of the Birch–Uchi greenstone belt, northwest Ontario, is dominated by volcanic suites of mafic, intermediate and felsic composition. Tholeiitic basalts range compositionally from Mg# 59–26 evolving continuously to greater REE contents (La=2–19 ppm; Th/Lapm˜1), with small negative Nb anomalies. Primitive tholeiites are similar to modern intraoceanic arc basalts, whereas evolved members extend to greater concentrations of Ti, Zr, V, Sc, and Y, and lower Ti/Zr, but higher Ti/Sc and Ti/V ratios characteristic of back arc basalts. Calc-alkaline basalts to dacites are characterised by more fractionated REE (La/Ybn=1–8), high Th/Nbpm ratios and deeper negative Nb anomalies; they plot with modern oceanic arc basalts and some may qualify as high magnesium andesites. The two suites are interpreted as a paired arc–back arc sequence. A third group of Nb-enriched basalts (NEB; Nb=9–18 ppm) extend to extremely high TiO2, Ta, P2O5, Sc and V contents, with strongly fractionated REE and ratios of Nb/Ta and Zr/Hf greater than primitive mantle values whereas Zr/Sm ratios are lower. The most abundant rhyolitic suite has extremely enriched but flat trace element patterns and is interpreted as strongly fractionated tholeiitic basalt liquids. A second group are compositionally similar to Cenozoic adakites and Archean high-Al, high-La/Ybn tonalites; they possess Yb ≤ 0.4 ppm, Y ≤ 6 ppm and Sc ≤ 8 ppm, with La/Ybn of 19–30 and Zr/Sm of 50–59. They are interpreted as melts of ocean lithosphere basaltic crust in a hot shallow subduction zone. Adakites are associated with NEB in Cenozoic arcs where there is shallow subduction of young and/or hot ocean lithosphere, often with oblique subduction. Slab melt adakites erupt, or metasomatise sub-arc mantle peridotite to generate an HFSE-enriched source that subsequently melts during induced mantle convection. The Archean adakite–NEB association erupted during development of the tholeiitic to calc-alkaline arc and its associated back arc. Their coexistence in the Confederation assemblage of the Birch–Uchi greenstone belt implies convergent margin processes similar to those in Cenozoic arcs.
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A compositionally diverse group of basaltic flows are present in the 2.7 Ga St. Joseph assemblage of the St. Joseph greenstone belt, Uchi Subprovince. A spectrum of light rare earth element (LREE) depleted to enriched patterns corresponds... more
A compositionally diverse group of basaltic flows are present in the 2.7 Ga St. Joseph assemblage of the St. Joseph greenstone belt, Uchi Subprovince. A spectrum of light rare earth element (LREE) depleted to enriched patterns corresponds to low-, medium- and high-K series (LKS, MKS, HKS) basalts, shoshonites and leucitites of some modern arcs. More primitive, tholeiitic LKS and MKS
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Research Interests: Earth Sciences and Earth
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The Midcontinent Rift (MCR) of North America comprises a series of basaltic sheets, flows and intrusive rocks emplaced in the Lake Superior region during the Mesoproterozoic. The mafic rocks preserved on the northern flank of Lake... more
The Midcontinent Rift (MCR) of North America comprises a series of basaltic sheets, flows and intrusive rocks emplaced in the Lake Superior region during the Mesoproterozoic. The mafic rocks preserved on the northern flank of Lake Superior represent the older portions of the rift sequence and offer insights into the early development of the rift. New geochronological, geochemical and paleomagnetic
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... Paper handled by associate editor Pete Hollings. ... R. Garrison, M. Greenberg, E. Herrera Paz, P. Hill, M. Ibaraki, M. Kastner, AES Kemp, K. Kvenvolden, R. Langridge, N. Lindsley-Griffin, J. Marseters, E. Martini, R. McCabe, L.... more
... Paper handled by associate editor Pete Hollings. ... R. Garrison, M. Greenberg, E. Herrera Paz, P. Hill, M. Ibaraki, M. Kastner, AES Kemp, K. Kvenvolden, R. Langridge, N. Lindsley-Griffin, J. Marseters, E. Martini, R. McCabe, L. Ocola, J. Resig, AW Sanchez Fernandez, HJ Schrader ...
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Magnesian-, to Fe-rich tholeiitic basalts with near flat REE patterns, locally associated with komatiites, are the prevalent rock type in several areally extensive volcanic sequences of the 2.9–2.7 Ga Archean greenstones belts of the... more
Magnesian-, to Fe-rich tholeiitic basalts with near flat REE patterns, locally associated with komatiites, are the prevalent rock type in several areally extensive volcanic sequences of the 2.9–2.7 Ga Archean greenstones belts of the Superior Province. In each of five greenstone belt sequences in the Uchi, Wabigoon, Wawa and Abitibi subprovinces, there is a continuous trend in compositions from high
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ABSTRACT An understanding of the origin of depletion in the high field strength elements (HFSE), Nb, Zr and Ti, relative to rare earth elements (REE) in arc lavas is critical to models both for magmagenesis in arcs and for the... more
ABSTRACT An understanding of the origin of depletion in the high field strength elements (HFSE), Nb, Zr and Ti, relative to rare earth elements (REE) in arc lavas is critical to models both for magmagenesis in arcs and for the relationship between arc magmatism and growth of ...
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Identifying zones of sulphide oxidation and carbonate buffering is important in the development of a management plan for mine waste-rock piles. In this study, we used a kinetic cell technique to measure rates of O2 consumption and CO2... more
Identifying zones of sulphide oxidation and carbonate buffering is important in the development of a management plan for mine waste-rock piles. In this study, we used a kinetic cell technique to measure rates of O2 consumption and CO2 production in low sulphide (<0.12 wt.% S), low inorganic carbon (<0.20 wt.% C(inorganic)), gneissic waste rock and associated organic-rich lake sediment (0.7 wt.% C(organic)), and forest soil (1.4 wt.% C(organic)) collected from the Key Lake uranium mine in Saskatchewan, Canada. Solid chemistry, stable carbon isotope, pore water sulphate concentration data, and stoichiometric considerations indicated that O2 consumption and CO2 production were constrained by microbial respiration in the lake sediment and forest soil and by pyrite oxidation-carbonate buffering in the gneissic waste rock. Mean ratios of molar CO2 production to O2 consumption rates were 0.5 for lake sediment, 0.7 for forest soil, and 0.2 for gneissic waste rock. The different O2/CO2 ratios suggested that O2-CO2 monitoring may provide a practical tool for identifying the zones of microbial respiration and pyrite oxidation-carbonate buffering in mine waste-rock piles. Rates of O2 consumption and CO2 production were about one order of magnitude greater in lake sediment than in gneissic waste rock, indicating that microbial respiration would exert a control on the distribution of O2 and CO2 gas in waste-rock piles constructed upon the dewatered lake sediments.