Buddy Doyle - Academia.edu (original) (raw)
Papers by Buddy Doyle
International Kimberlite Conference Extended Abstracts: 2003
The Slave craton is a small and well-exposed Archean nucleus within the larger Canadian shield (f... more The Slave craton is a small and well-exposed Archean nucleus within the larger Canadian shield (figure 1). It is bounded on the east by the Thelon continental marginal magmatic arc (2.0-1.9 Ga) that defines the western edge of the Archean Rae Province and on the west by the Great Bear magmatic arc of the Wopmay Orogen (1.88-1.84 Ga). The northern and northeastern boundary of the Slave craton is defined by the overlapping Upper Proterozoic and Phanerozoic supracrustal rocks of the Canadian Arctic. On the south, the Slave craton is separated by the large Great Slave Lake Shear Zone from the Lower Proterozoic Chinchaga and Buffalo Head terranes.
International Kimberlite Conference: Extended Abstracts, 1998
International Kimberlite Conference Extended Abstracts: 2003
Eclogite xenoliths from Tertiary-Cretaceous Lac de Gras kimberlites include quartz-, kyanite-, di... more Eclogite xenoliths from Tertiary-Cretaceous Lac de Gras kimberlites include quartz-, kyanite-, diamond-, graphite-, phlogopite-and calcite-bearing types, and include a suite of opx-bearing rocks with correlated CaO and Cr 2 O 3 contents (pyroxenites), suggesting a multiplicity of origins. Eclogites were studied in detail petrographically and for major and trace-element and isotopic composition in order to elucidate questions such as when and where they formed, their spatial relationship within the lithospheric mantle and their relationship to tectonic events evident in the overlying crust. We will focus here on the origin of three suites of eclogites, based on the Ca-content of garnets (Pearson et al., 1999; Griffin et al., 1999): a high-Ca suite, including kyanite (± diamond/graphite/rutile) bearing eclogites and a low-Ca suite (± quartz/rutile). The low-Ca suite is subdivided into high-Mg and low-Mg types.
The Slave Province in Canada is a small Archean fragment within the larger North American craton.... more The Slave Province in Canada is a small Archean fragment within the larger North American craton. It is bounded on the east by the Thelon magmatic arc (2.0-1.9 Ga) on the western edge of the Archean Rae Province and on the west by the Great Bear magmatic arc of the Wopmay Orogen (1.88-1.84 Ga). The northern and north-eastern part is overlapped by Upper Proterozoic and Phanerozoic supracrustal rocks. On the south, the Slave craton is separated by the Great Slave Lake Shear Zone from the Lower Proterozoic Chinchaga and Buffalo Head terranes.
International Kimberlite Conference Extended Abstracts: 1998
This is the first report of an ongoing investigation of diamonds (mineral inclusions, diamonds' p... more This is the first report of an ongoing investigation of diamonds (mineral inclusions, diamonds' physical and chemical characteristics) from kimberlite pipe DO-27, near Lac de Gras in the Slave Craton, Canada. This study is a component of our Lithosphere Mapping project on the Slave Craton, which integrates petrological and geophysical data to understand the composition, structure and origin of the lithospheric mantle; this information is critical to diamond exploration models for the Slave Craton, which has a unique lithospheric structure (Griffin et al., this volume). Physical Characteristics Diamonds examined weigh between 0.01 and 0.42 carats; 75% were <0.10 carat. 75% of the stones are coloured, from shades of brown (55%) to yellow/brown (5%), yellow (9%) and grey (6%). Morphology ranges from planar octahedra and composite octahedra with minor resorption (30% of stones) to heavily resorbed dodecahedra. All resorption categories (Robinson et al., 1989) are represented, and more than half of the diamonds have lost 25% to 65% of their original mass. Resorbed forms consist of equal proportions of dodecahedra, flattened dodecahedra, aggregates and fragments with resorbed external faces. 12% of stones are cubes and cubo-octahedra, many of which are fibrous and/or have hopper faces. Octahedral diamonds have smooth finely stepped planar surfaces and ribbed edges. Negative etch trigons and hexagons are common on primary faces. Dodecahedral forms preserve dissolution laminae and large drop-shaped hillocks. Ruts are common and resorbed surfaces are often frosted. Slip plane dislocations resulting from plastic deformation are evident on about half the stones, as glide planes and shagreen texture on resorbed dodecahedral faces. Diamond Inclusions Mineral inclusions were extracted by breaking diamonds in an enclosed cell, then placed in epoxy on glass slides and polished for electron microprobe analysis. Small inclusions exposed on cleavage surfaces were analysed in situ. Representative analyses are given in Table 1. Eclogitic paragenesis: =50% of the inclusions are eclogitic. Eclogitic garnets have 9-16% CaO and variable Na^ contents; no majorite component is present. Their composition suggests they are derived from kyanite-bearing eclogites, similar to observed xenoliths (Pearson et al., this vol.). One "omphacite" has a high level of opx solid solution, implying a high-T origin; another contains Jd=25%. Diopside inclusions also occur but may be epigenetic (Table 1). Low-Ni (<2.9% Ni) iron sulfides of the eclogite paragenesis were recovered from 5 diamonds .
SEG Technical Program Expanded Abstracts 2016, 2016
The Leading Edge, 2016
Currently, Stratus Aeronautics is developing an unmanned aircraft system (UAS), called the Ventur... more Currently, Stratus Aeronautics is developing an unmanned aircraft system (UAS), called the Venturer, for aeromagnetic surveying. On 2 October 2013, in southern Alberta, Canada, an experimental survey of the UAS was conducted. Approximately 13 km of preprogrammed survey lines, along with calibration maneuvers, were flown, providing 45 minutes worth of data collection. The UAS was stable in flight and only required operator intervention for takeoff and landing. There was a + 2 m offset from the nominal altitude of 150 m, with variations of approximately ± 1.4 m. Deviations from a straight flight path were approximately ± 0.9 m along traverse lines and ± 25 m along tie-lines, the latter being affected mainly by crosswind. The noise envelope for the magnetic data acquired during the survey was approximately ± 0.05 nT, allowing a high-quality total-magnetic-intensity map to be created.
ASEG Extended Abstracts, 2004
... of the lithosphere beneath the Slave Craton (Canada) Yvette Poudjom Djomani* Suzanne Y. O&... more ... of the lithosphere beneath the Slave Craton (Canada) Yvette Poudjom Djomani* Suzanne Y. O'Reilly William L. Griffin ... ypoudjom@els.mq.edu.au soreilly@els.mq.edu.au wgriffin@els.mq.edu.au Lev M. Natapov Norman J. Pearson Buddy J. Doyle ...
Precambrian Research, 2003
The composition of the subcontinental lithospheric mantle (SCLM) varies in a systematic way with ... more The composition of the subcontinental lithospheric mantle (SCLM) varies in a systematic way with the age of the last major tectonothermal event in the overlying crust. This secular evolution in SCLM composition implies quasi-contemporaneous formation (or modification) of the crust and its underlying mantle root, and indicates that crust and mantle in many cases have remained linked through their subsequent history. Archean SCLM is distinctively different from younger mantle; it is highly depleted, commonly is strongly stratified, and contains rock types (especially subcalcic harzburgites) that are essentially absent in younger SCLM. Some, but not all, Archean SCLM also has higher Si/Mg than younger SCLM. Attempts to explain the formation of Archean SCLM by reference to Uniformitarian processes, such as the subduction of oceanic mantle ("lithospheric stacking"), founder on the marked differences in geochemical trends between Archean xenolith suites and Phanerozoic examples of highly depleted mantle, such as abyssal peridotites, island-arc xenolith suites and ophiolites. In Archean xenolith suites, positive correlations between Fe, Cr and Al imply that no Cr-Al phase (i.e. spinel or garnet) was present on the liquidus during the melting. This situation is in direct contrast to the geochemical patterns observed in highly depleted peridotites from modern environments, which are controlled by the presence of spinel during melting. It is more likely that Archean SCLM represents residues and/or cumulates from high-degree melting at significant depths, related to specifically Archean processes involving major mantle overturns or megaplumes. The preservation of island-arc like SCLM at shallow levels in some sections (e.g. Slave Craton, E. Greenland) suggests that this specifically Archean tectonic regime may have coexisted with a shallow regime more similar to modern plate tectonics. Preliminary data from in situ Re-Os dating of sulfide minerals in mantle-derived peridotites suggest that much Archean SCLM may have formed in a small number of such major events >3.0 Ga ago. The survival of Archean crust may have been critically determined by the availability of large plugs of very buoyant SCLM (a "life-raft model" of craton formation). Many Archean SCLM sections have been strongly affected by Proterozoic and Phanerozoic metasomatism, and much of the observed secular evolution in SCLM composition, at least through Proterozoic time, may reflect the progressive modification of relict, buoyant Archean lithosphere.
Lithos, 2004
The 613±6 Ma Anuri kimberlite is a pipelike body comprising two lobes with a combined surface are... more The 613±6 Ma Anuri kimberlite is a pipelike body comprising two lobes with a combined surface area of approximately 45 ha. The pipe is infilled with two contrasting rock types: volcaniclastic kimberlite (VK) and, less common, hypabyssal kimberlite (HK). The HK is an ...
Lithos, 2004
Melt inclusions in clinopyroxenes from lherzolitic xenoliths from the deep lithospheric mantle be... more Melt inclusions in clinopyroxenes from lherzolitic xenoliths from the deep lithospheric mantle beneath the Slave Craton (Lac de Gras area, Canada) reveal multiple origins for carbonatitic melts. One type of inclusions consists of a series of silicatecarbonatesilicate concentric ...
Lithos, 2004
Major- and trace-element analyses of garnets from heavy-mineral concentrates have been used to de... more Major- and trace-element analyses of garnets from heavy-mineral concentrates have been used to derive the compositional and thermal structure of the subcontinental lithospheric mantle (SCLM) beneath 16 areas within the core of the ancient Laurentian continent and 11 areas in the craton margin and fringing mobile belts. Results are presented as stratigraphic sections showing variations in the relative proportions of
Lithos, 2004
A mineral inclusion, carbon isotope, nitrogen content, nitrogen aggregation state and morphologic... more A mineral inclusion, carbon isotope, nitrogen content, nitrogen aggregation state and morphological study of 576 microdiamonds from the DO27, A154, A21, A418, DO18, DD17 and Ranch Lake kimberlites at Lac de Gras, Slave Craton, was conducted. Mineral inclusion data show the ...
Journal of Petrology, 1999
from some highly depleted ophiolites from convergent-margin settings, Heavy-mineral concentrates ... more from some highly depleted ophiolites from convergent-margin settings, Heavy-mineral concentrates (garnets, chromites) and xenoliths from and may have formed in a similar situation during the accretion of 21 Cretaceous-Tertiary kimberlite intrusions have been used to map the Hackett and Contwoyto terranes (magmatic arc and accretionary the lithospheric mantle beneath the Lac de Gras area in the central prism, respectively) to the ancient continental Anton terrane at part of the Slave Province. Analyses of Nickel Temperature (T Ni) 2•6-2•7 Ga. The deeper layer is interpreted as a plume head, and Zinc Temperature (T Zn) have been used to place garnet and which rose from the lower mantle and underplated the existing chromite xenocrysts, respectively, in depth context. Paleogeotherms lithosphere at 2•6 Ga; evidence includes a high proportion of the derived from both xenoliths and concentrates lie near a 35 mW/ superdeep inclusion assemblage (ferropericlase-perovskite) in the m 2 conductive model at T Ζ 900°C, and near a 38 mW/m 2 diamond population. This event could have provided heat for model at higher T, implying a marked change in conductivity and/ generation of the widespread 2•6 Ga post-tectonic granites. Proteroor a thermal transient. Plots of garnet composition vs T Ni also zoic subduction from east and west may have modified the cratonic show a sharp discontinuity in mantle composition at 900°C. root, mainly by introduction of eclogites near its base. Garnets from <145 km depth are ultradepleted in Y, Zr, Ti and Ga, whereas those from greater depths (to [200 km) are similar to garnets from Archean mantle worldwide. Relative abundances of garnet types indicate that the shallow layer consists of~60% (clinopyroxene-free) harzburgite and 40% lherzolite, whereas the
Journal of Petrology, 2007
Geology, 2002
Quenched carbonate-silicate inclusions in lherzolitic clinopyroxene macrocrysts, derived from 200... more Quenched carbonate-silicate inclusions in lherzolitic clinopyroxene macrocrysts, derived from 200 km beneath the Slave craton in northern Canada, are interpreted as natural samples of mantle carbonatites. Oxygen, carbon, and strontium isotope data provide evidence for the ...
International Kimberlite Conference Extended Abstracts: 2003
The Slave craton is a small and well-exposed Archean nucleus within the larger Canadian shield (f... more The Slave craton is a small and well-exposed Archean nucleus within the larger Canadian shield (figure 1). It is bounded on the east by the Thelon continental marginal magmatic arc (2.0-1.9 Ga) that defines the western edge of the Archean Rae Province and on the west by the Great Bear magmatic arc of the Wopmay Orogen (1.88-1.84 Ga). The northern and northeastern boundary of the Slave craton is defined by the overlapping Upper Proterozoic and Phanerozoic supracrustal rocks of the Canadian Arctic. On the south, the Slave craton is separated by the large Great Slave Lake Shear Zone from the Lower Proterozoic Chinchaga and Buffalo Head terranes.
International Kimberlite Conference: Extended Abstracts, 1998
International Kimberlite Conference Extended Abstracts: 2003
Eclogite xenoliths from Tertiary-Cretaceous Lac de Gras kimberlites include quartz-, kyanite-, di... more Eclogite xenoliths from Tertiary-Cretaceous Lac de Gras kimberlites include quartz-, kyanite-, diamond-, graphite-, phlogopite-and calcite-bearing types, and include a suite of opx-bearing rocks with correlated CaO and Cr 2 O 3 contents (pyroxenites), suggesting a multiplicity of origins. Eclogites were studied in detail petrographically and for major and trace-element and isotopic composition in order to elucidate questions such as when and where they formed, their spatial relationship within the lithospheric mantle and their relationship to tectonic events evident in the overlying crust. We will focus here on the origin of three suites of eclogites, based on the Ca-content of garnets (Pearson et al., 1999; Griffin et al., 1999): a high-Ca suite, including kyanite (± diamond/graphite/rutile) bearing eclogites and a low-Ca suite (± quartz/rutile). The low-Ca suite is subdivided into high-Mg and low-Mg types.
The Slave Province in Canada is a small Archean fragment within the larger North American craton.... more The Slave Province in Canada is a small Archean fragment within the larger North American craton. It is bounded on the east by the Thelon magmatic arc (2.0-1.9 Ga) on the western edge of the Archean Rae Province and on the west by the Great Bear magmatic arc of the Wopmay Orogen (1.88-1.84 Ga). The northern and north-eastern part is overlapped by Upper Proterozoic and Phanerozoic supracrustal rocks. On the south, the Slave craton is separated by the Great Slave Lake Shear Zone from the Lower Proterozoic Chinchaga and Buffalo Head terranes.
International Kimberlite Conference Extended Abstracts: 1998
This is the first report of an ongoing investigation of diamonds (mineral inclusions, diamonds' p... more This is the first report of an ongoing investigation of diamonds (mineral inclusions, diamonds' physical and chemical characteristics) from kimberlite pipe DO-27, near Lac de Gras in the Slave Craton, Canada. This study is a component of our Lithosphere Mapping project on the Slave Craton, which integrates petrological and geophysical data to understand the composition, structure and origin of the lithospheric mantle; this information is critical to diamond exploration models for the Slave Craton, which has a unique lithospheric structure (Griffin et al., this volume). Physical Characteristics Diamonds examined weigh between 0.01 and 0.42 carats; 75% were <0.10 carat. 75% of the stones are coloured, from shades of brown (55%) to yellow/brown (5%), yellow (9%) and grey (6%). Morphology ranges from planar octahedra and composite octahedra with minor resorption (30% of stones) to heavily resorbed dodecahedra. All resorption categories (Robinson et al., 1989) are represented, and more than half of the diamonds have lost 25% to 65% of their original mass. Resorbed forms consist of equal proportions of dodecahedra, flattened dodecahedra, aggregates and fragments with resorbed external faces. 12% of stones are cubes and cubo-octahedra, many of which are fibrous and/or have hopper faces. Octahedral diamonds have smooth finely stepped planar surfaces and ribbed edges. Negative etch trigons and hexagons are common on primary faces. Dodecahedral forms preserve dissolution laminae and large drop-shaped hillocks. Ruts are common and resorbed surfaces are often frosted. Slip plane dislocations resulting from plastic deformation are evident on about half the stones, as glide planes and shagreen texture on resorbed dodecahedral faces. Diamond Inclusions Mineral inclusions were extracted by breaking diamonds in an enclosed cell, then placed in epoxy on glass slides and polished for electron microprobe analysis. Small inclusions exposed on cleavage surfaces were analysed in situ. Representative analyses are given in Table 1. Eclogitic paragenesis: =50% of the inclusions are eclogitic. Eclogitic garnets have 9-16% CaO and variable Na^ contents; no majorite component is present. Their composition suggests they are derived from kyanite-bearing eclogites, similar to observed xenoliths (Pearson et al., this vol.). One "omphacite" has a high level of opx solid solution, implying a high-T origin; another contains Jd=25%. Diopside inclusions also occur but may be epigenetic (Table 1). Low-Ni (<2.9% Ni) iron sulfides of the eclogite paragenesis were recovered from 5 diamonds .
SEG Technical Program Expanded Abstracts 2016, 2016
The Leading Edge, 2016
Currently, Stratus Aeronautics is developing an unmanned aircraft system (UAS), called the Ventur... more Currently, Stratus Aeronautics is developing an unmanned aircraft system (UAS), called the Venturer, for aeromagnetic surveying. On 2 October 2013, in southern Alberta, Canada, an experimental survey of the UAS was conducted. Approximately 13 km of preprogrammed survey lines, along with calibration maneuvers, were flown, providing 45 minutes worth of data collection. The UAS was stable in flight and only required operator intervention for takeoff and landing. There was a + 2 m offset from the nominal altitude of 150 m, with variations of approximately ± 1.4 m. Deviations from a straight flight path were approximately ± 0.9 m along traverse lines and ± 25 m along tie-lines, the latter being affected mainly by crosswind. The noise envelope for the magnetic data acquired during the survey was approximately ± 0.05 nT, allowing a high-quality total-magnetic-intensity map to be created.
ASEG Extended Abstracts, 2004
... of the lithosphere beneath the Slave Craton (Canada) Yvette Poudjom Djomani* Suzanne Y. O&... more ... of the lithosphere beneath the Slave Craton (Canada) Yvette Poudjom Djomani* Suzanne Y. O'Reilly William L. Griffin ... ypoudjom@els.mq.edu.au soreilly@els.mq.edu.au wgriffin@els.mq.edu.au Lev M. Natapov Norman J. Pearson Buddy J. Doyle ...
Precambrian Research, 2003
The composition of the subcontinental lithospheric mantle (SCLM) varies in a systematic way with ... more The composition of the subcontinental lithospheric mantle (SCLM) varies in a systematic way with the age of the last major tectonothermal event in the overlying crust. This secular evolution in SCLM composition implies quasi-contemporaneous formation (or modification) of the crust and its underlying mantle root, and indicates that crust and mantle in many cases have remained linked through their subsequent history. Archean SCLM is distinctively different from younger mantle; it is highly depleted, commonly is strongly stratified, and contains rock types (especially subcalcic harzburgites) that are essentially absent in younger SCLM. Some, but not all, Archean SCLM also has higher Si/Mg than younger SCLM. Attempts to explain the formation of Archean SCLM by reference to Uniformitarian processes, such as the subduction of oceanic mantle ("lithospheric stacking"), founder on the marked differences in geochemical trends between Archean xenolith suites and Phanerozoic examples of highly depleted mantle, such as abyssal peridotites, island-arc xenolith suites and ophiolites. In Archean xenolith suites, positive correlations between Fe, Cr and Al imply that no Cr-Al phase (i.e. spinel or garnet) was present on the liquidus during the melting. This situation is in direct contrast to the geochemical patterns observed in highly depleted peridotites from modern environments, which are controlled by the presence of spinel during melting. It is more likely that Archean SCLM represents residues and/or cumulates from high-degree melting at significant depths, related to specifically Archean processes involving major mantle overturns or megaplumes. The preservation of island-arc like SCLM at shallow levels in some sections (e.g. Slave Craton, E. Greenland) suggests that this specifically Archean tectonic regime may have coexisted with a shallow regime more similar to modern plate tectonics. Preliminary data from in situ Re-Os dating of sulfide minerals in mantle-derived peridotites suggest that much Archean SCLM may have formed in a small number of such major events >3.0 Ga ago. The survival of Archean crust may have been critically determined by the availability of large plugs of very buoyant SCLM (a "life-raft model" of craton formation). Many Archean SCLM sections have been strongly affected by Proterozoic and Phanerozoic metasomatism, and much of the observed secular evolution in SCLM composition, at least through Proterozoic time, may reflect the progressive modification of relict, buoyant Archean lithosphere.
Lithos, 2004
The 613±6 Ma Anuri kimberlite is a pipelike body comprising two lobes with a combined surface are... more The 613±6 Ma Anuri kimberlite is a pipelike body comprising two lobes with a combined surface area of approximately 45 ha. The pipe is infilled with two contrasting rock types: volcaniclastic kimberlite (VK) and, less common, hypabyssal kimberlite (HK). The HK is an ...
Lithos, 2004
Melt inclusions in clinopyroxenes from lherzolitic xenoliths from the deep lithospheric mantle be... more Melt inclusions in clinopyroxenes from lherzolitic xenoliths from the deep lithospheric mantle beneath the Slave Craton (Lac de Gras area, Canada) reveal multiple origins for carbonatitic melts. One type of inclusions consists of a series of silicatecarbonatesilicate concentric ...
Lithos, 2004
Major- and trace-element analyses of garnets from heavy-mineral concentrates have been used to de... more Major- and trace-element analyses of garnets from heavy-mineral concentrates have been used to derive the compositional and thermal structure of the subcontinental lithospheric mantle (SCLM) beneath 16 areas within the core of the ancient Laurentian continent and 11 areas in the craton margin and fringing mobile belts. Results are presented as stratigraphic sections showing variations in the relative proportions of
Lithos, 2004
A mineral inclusion, carbon isotope, nitrogen content, nitrogen aggregation state and morphologic... more A mineral inclusion, carbon isotope, nitrogen content, nitrogen aggregation state and morphological study of 576 microdiamonds from the DO27, A154, A21, A418, DO18, DD17 and Ranch Lake kimberlites at Lac de Gras, Slave Craton, was conducted. Mineral inclusion data show the ...
Journal of Petrology, 1999
from some highly depleted ophiolites from convergent-margin settings, Heavy-mineral concentrates ... more from some highly depleted ophiolites from convergent-margin settings, Heavy-mineral concentrates (garnets, chromites) and xenoliths from and may have formed in a similar situation during the accretion of 21 Cretaceous-Tertiary kimberlite intrusions have been used to map the Hackett and Contwoyto terranes (magmatic arc and accretionary the lithospheric mantle beneath the Lac de Gras area in the central prism, respectively) to the ancient continental Anton terrane at part of the Slave Province. Analyses of Nickel Temperature (T Ni) 2•6-2•7 Ga. The deeper layer is interpreted as a plume head, and Zinc Temperature (T Zn) have been used to place garnet and which rose from the lower mantle and underplated the existing chromite xenocrysts, respectively, in depth context. Paleogeotherms lithosphere at 2•6 Ga; evidence includes a high proportion of the derived from both xenoliths and concentrates lie near a 35 mW/ superdeep inclusion assemblage (ferropericlase-perovskite) in the m 2 conductive model at T Ζ 900°C, and near a 38 mW/m 2 diamond population. This event could have provided heat for model at higher T, implying a marked change in conductivity and/ generation of the widespread 2•6 Ga post-tectonic granites. Proteroor a thermal transient. Plots of garnet composition vs T Ni also zoic subduction from east and west may have modified the cratonic show a sharp discontinuity in mantle composition at 900°C. root, mainly by introduction of eclogites near its base. Garnets from <145 km depth are ultradepleted in Y, Zr, Ti and Ga, whereas those from greater depths (to [200 km) are similar to garnets from Archean mantle worldwide. Relative abundances of garnet types indicate that the shallow layer consists of~60% (clinopyroxene-free) harzburgite and 40% lherzolite, whereas the
Journal of Petrology, 2007
Geology, 2002
Quenched carbonate-silicate inclusions in lherzolitic clinopyroxene macrocrysts, derived from 200... more Quenched carbonate-silicate inclusions in lherzolitic clinopyroxene macrocrysts, derived from 200 km beneath the Slave craton in northern Canada, are interpreted as natural samples of mantle carbonatites. Oxygen, carbon, and strontium isotope data provide evidence for the ...