John D. Greenough

• PhD
• University of British Columbia - Okanagan

For 100 years, placer gold has been important to the settlement, economic development, and, recently, recreational geology of the Kelowna, British Columbia, area. It is best-known to occur in modern-day, Mission Creek and Lambly Creek sedimentary rocks, as well as a paleoplacer occurrence in Miocene sediments of the historical Winfield mine. The Mi...

Rare Earth Element (REE) mineralization at Debert Lake (Nova Scotia, Canada) is hosted by the anorogenic Hart Lake-Byers Lake granites which are associated with the Late Devonian to Early Carboniferous Wentworth plutonic complex in the Cobequid Highlands. Mineralized zones contain up to 1.2 wt.% REE2O3, 3.4 wt.% ZrO2, and 0.4 wt.% Nb2O5 produced by...

Rocks in the Late Proterozoic Horsethief Creek Group at Quartz Creek in British Columbia display rare ‘pinolitic’ textures resembling those described in some sparry magnesite deposits elsewhere in the world. Elongated white magnesite crystals up to 30 cm long occur in a contrasting, dark, fine-grained matrix of dolomite, chlorite, organic material,...

Our understanding of mantle evolution suffers from a lack of age data for when the mantle geochemical variants (mantle components) developed. Traditionally, the components are ascribed to subduction of ocean floor over Earth history, but their isotopic signatures require prolonged storage to evolve. Here we report U-Pb age results for mantle-derive...

Porcelain wares containing calcined bone ash and gypsum in their pastes were some of the most commercially successful high-fired wares produced in Britain and America during the third quarter of the 18th century. They were produced by the two earliest porcelain manufactories in America (the Bartlam and the Bonnin & Morris factories) and by several...

Trace elements in native gold provide a “fingerprint” that tends to be unique to individual gold deposits. Fingerprinting can distinguish gold sources and potentially yield insights into geochemical processes operating during gold deposit formation. Native gold grains come from three historical gold ore deposits; Hollinger, McIntyre (quartz-vein or...

Microanalysis of native gold specimens has been hampered by the lack of a suitable RM (reference material) known to be sufficiently homogeneous at the scale of microanalytical sampling. The suitability of gold reference material AuRM2 for microanalysis was assessed. This RM was created for bulk analysis of refined gold, and was only certified for h...

Incompatible elements and isotopic ratios identify three endmember mantle components in oceanic island basalt (OIB); EM1, EM2, and HIMU. We estimate compatible to mildly incompatible transition metal abundance trends (Ni, Co, Fe, Cu, Cr, V, Mn, Sc, and Zn) in 'primitive' basalt suites (Mg# = Mg/(Mg + 0.9*Fe) atomic = 0.72) from 12 end-member oceani...

The Wadi Qutabah layered mafic intrusion in northwestern Yemen, considered part of a giant (>250 km2), Neoproterozoic (∼638.5 Ma) intrusion referred to as the Suwar – Wadi Qutabah Complex, has significant potential for economic platinum-group element and Ni–Cu–Co mineralization. A search for platinum-group element mineralization at Wadi Qutabah yie...

Glass rinds on small Hessian crucibles from Jamestown are interpreted as samples of the experimental "tryal of glasse" known to have taken place in this early-17th-century Virginia colony. Compositional analysis of the rinds indicates that, compared with the glass produced in northern Europe (Waldglas), they are strongly enriched in soda and deplet...

Ceramics and glass represent synthetic metamorphic rocks and obsidian, respectively. Consequently, it is not surprising that many archaeologists have collaborated with geologists on projects dealing not only with lithic artifacts, but with ceramic and glass objects as well. This paper presents an overview of these latter two materials from a geolog...

Depositional evidence of Early Pleistocene glaciations in British Columbia are documented at only a few sites. Near Kelowna, in southern British Columbia, a construction project exposed glacial sediments beneath Lambly Creek Basalt, providing a minimum age for this glaciation. The basalt is composed of a number of flows yielding ages that range fro...

The mineralogy and bulk chemical compositions of 15 Kintampo (Late Stone Age) potsherds from the Birimi site on the Gambaga Escarpment and eight samples of local sediment were determined with the intent of characterizing these wares and identifying the material used in their manufacture. Sediment from clay pits still used by potters north of the es...

Geochemical data, from the Mars Meteorite Compendium web site, for 13 basaltic meteorites, possibly from only four localities on Mars, are used to study Martian petrogenetic processes. To achieve this goal, an exploratory data analysis technique, multidimensional scaling (MDS), is used to quantitatively assess the relative behavior (measured with c...

During construction of a road cut related to the Westside Road Interchange Project in West Kelowna, British Columbia, a till was encountered below one of the Lambly Creek valley basalts. The basalts are composed of a number of flows, ranging in age from 0.97 +- 0.05 Ma to 1.62 +-0.25 Ma based on new and available 40Ar/39Ar dating of basalt ground m...

Granulite-facies xenoliths from Late Jurassic alkaline lamprophyres may represent basement to the Dunnage Zone in north-central Newfoundland (Notre Dame Bay area). At 143 Ma the xenoliths had positive εNd values between 0.9 and 4.7. They give Nd depleted mantle model ages around 700 Ma and have trace element and major element compositions reminisce...

High-precision U–Pb isotope dilution – thermal ionization mass spectrometry (ID–TIMS) geochronology on chemically abraded zircon grains from a noritic gabbro of the Ni-bearing Suwar mafic–ultramafic layered complex, northwestern Yemen, gives a mean 206Pb/238U age of 638.46 ± 0.73 Ma (2; MSWD = 1.4). At Wadi Qutabah, 30 km to the north, a similar ma...

Extremely fine-grained, hypocrystalline, microporphyritic dacite (whole-rock SiO2 = 65–70 oxide wt.%), called "glassy basalt" by archaeologists, was commonly used to manufacture lithic artefacts found in the British Columbia (B.C.) Interior. Geochemical fingerprinting of dacite minerals can help identify the geologic source of these artefacts. Mult...

"Fingerprinting" lithic artefacts using whole-sample geochemistry is a simple, inexpensive, technique that can supply archaeologists with important provenance and trade information. To demonstrate its utility, it is applied here to basalt vessels produced by Near East societies encompassing the millennia and geographic areas where civilization aros...

The thematic set provides examples of the many techniques that earth scientists can offer for use in archaeology. These studies use methods such as electron microprobe analysis, inductively coupled plasma – mass spectrometry, X-ray fluorescence, optically stimulated luminescence, and soil and sediment stratigraphic analysis. Materials examined rang...

Sodium-rich, potassium-poor granulite in the Long Range Inlier contains Ab + Qtz + Crd + Bt + Opx + Ilm and either gedrite or garnet, but rarely both. The distribution of garnet in the sodic gneiss was influenced by bulk compositional controls (e.g., higher Al2O3/SiO2). Textural evidence indicates that gedrite was metastable with respect to Crd + O...

U-Pb zircon and monazite dates for granulite-facies basement xenoliths from the Popes Harbour dyke on the eastern shore of Nova Scotia provide strong evidence that the Meguma terrane overlies Avalonian basement. Slightly discordant (1.6%), "facetted" zircons from a mafic granulite indicate a minimum crystallization age of ~629 Ma, with near-concord...

Mafic sills from Cape St. Mary's on the Avalon Peninsula of Newfoundland give an U–Pb baddeleyite age of 441 ± 2 Ma. This age corresponds with the earliest ages recorded for the climactic Silurian orogenic event that dominantly affected rocks of the Central Mobile Belt in Newfoundland. The age is consistent with but in no way necessitates that the...

Middle Cambrian basaltic flows, lapilli tuffs, and their feeder pipes, on the Avalon Peninsula, Newfoundland, show high Nb/Y and low Zr/Nb ratios and high concentrations of incompatible elements, such as Nb and Zr, which are typical of alkaline rocks. The compositions of relict clinopyroxenes are consistent with these conclusions. Relatively low Mg...

The Caraquet dyke of New Brunswick is one of three early Mesozoic dykes recognized in Atlantic Canada. It has a quartz-normative tholeiitic composition intermediate in character between "low-Ti" and "high-Ti" Appalachian diabase. Major-element (e.g., MgO, SiO2) and trace-element concentrations (e.g., Ba, Zr) suggest that the dyke is less evolved th...

Basalts totalling 236 m in thickness were intersected in the wildcat oil well Mobil Gulf Chinampas N-37 in the Bay of Fundy. A 5.5 m section of conventional core retrieved from the middle of the basalt section sampled two fine-grained, phenocryst-poor, amygdaloidal basalt flows. The basalts, though somewhat altered, show concentrations of ferromagn...

The early Mesozoic, quartz normative, North Mountain basalts in southwestern Nova Scotia (Digby area) form three units: a coarse massive lower flow (~190 m) bearing minor lenses of mafic pegmatite, a middle unit of thin amygdaloidal basaltic flows (~50 m), and an upper flow unit of massive phenocryst-rich basalt (~160 m). The two thick units show p...

A recently recognized series of northwest-trending mafic dykes cuts the Cambro-Ordovician Meguma Group along the eastern shore of Nova Scotia. Some of the dykes contain gneissic and (meta)plutonic xenoliths interpreted here as including fragments of the basement to the Meguma Group.Most of the gneissic xenoliths in the dyke exposed at Popes Harbour...

Early Jurassic quartz-normative tholeiitic basalts occur in a series of fault blocks at four localities (Cap d'Or, Parrsboro, Five Islands, and Bass River) along the north shore of the Bay of Fundy. Major-element and trace-element data show that they represent outliers of the North Mountain basalt (NMB), which from the south shore of the Bay of Fun...

A group of related mafic dykes is present along the eastern shore of Nova Scotia from Halifax to Country Harbour. The dykes are generally vertical, strike about 150°, and have an abundance of carbonate, apatite, and hydrous mafic minerals, indicating that the dykes may have formed from an alkaline (lamprophyric) magma. They postdate the Acadian fol...

Quartzofeldspathic xenoliths representing the probable structural basement to the northern Dunnage Zone occur in lamprophyre dykes on Alcock Island and vicinity, Notre Dame Bay. The dykes occur close to the boundary between seismically defined lower crustal blocks (LCB) below the Dunnage Zone, so the assignment of the xenoliths to a specific subsur...

Oceanic-island tholeiitic basalts recovered from four sunken oceanic islands along the Reunion hot-spot trace show trace-element and mineralogical characteristics ranging from typical oceanic-island tholeiites to incompatible-element-depleted tholeiites resembling mid-ocean-ridge basalts. There are also variable degrees of magma evolution at each i...

High-precision U–Pb isotope dilution – thermal ionization mass spectrometry (ID–TIMS) geochronology on chemically abraded zircon grains from a noritic gabbro of the Ni-bearing Suwar mafic–ultramafic layered complex, northwestern Yemen, gives a mean ²⁰⁶Pb/²³⁸U age of 638.46 ± 0.73 Ma (2σ; MSWD = 1.4). At Wadi Qutabah, ∼30 km to the north, a similar...

Between 2000 and 2005, 50 sugar maple (Acer saccharum Marshall, 1785) syrup samples from 16 producers in northern Nova Scotia, were analyzed (for 39 elements) using new techniques and inductively coupled plasma - mass spectrometry. Multidimensional scaling (exploratory statistics) using all samples and chemical data indicates that composition corre...

High-precision U–Pb isotope dilution – thermal ionization mass spectrometry (ID–TIMS) geochronology on chemically abraded zircon grains from a noritic gabbro of the Ni-bearing Suwar mafic–ultramafic layered complex, north-western Yemen, gives a mean 206 Pb/ 238 U age of 638.46 ± 0.73 Ma (2s; MSWD = 1.4). At Wadi Qutabah, *30 km to the north, a simi...

Potsdam sandstone from quarries and outcrops near 19th-century glassworks sites in Redwood, NY, and Saranac, NY, Mallorytown, ON, and Como and Hudson, QC, commonly contains _97% silica, so in terms of its purity can compete with other historical producers of silica sand (e.g., Cheshire quartzite, MA; southern New Jersey sand). Exploratory analysis...

An elegantly simple, aqua regia-based, ICP-MS analytical procedure is used to compare the trace element composition of density-separated alluvial native Au from seven stream silt samples with three samples of geographically-associated Au from a prospective ore deposit in central British Columbia. Not all of the alluvial Au could have come from the...

A 20-m-thick alkali basalt flow on the Peng Hu Island, Taiwan, shows three well-developed segregation veins in its upper 8.5 meters. Each pegmatitic and "vesicular" (ocelli-bearing?) segregation displays distinct whole-sample chemical traits that are shared with the enclosing basalt. Augite, plagioclase and olivine exhibit major-element (electron-m...

Analysis of elements in wines by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) may help protect prestigious wineries from counterfeit wines and permit source confirmation for government certification. Thirty-three elements were determined in 17 white and 10 red wines from 13 Okanagan Valley (B.C, Canada) wineries. Multidimensional scaling (...

The chemical composition and origin of the isotopically identified end-member mantle components have been difficult to describe because their melted samples—oceanic basalts—are affected by many processes such as variable degrees of partial melting. Exploratory data analysis [multidimensional scaling (MDS)] applied to 200 basalts from French Polynes...

Microchemical analysis of minerals present in pottery and stone artefacts may help determine their provenance. Electron microprobe major element analyses of augite suggest that minor elements (Ti02,MnO, Aa2O) are important in fingerprinting basalts. This points to the potential usefulness of trace elements. Augite present in six basalt samples (rep...

New, and previously determined, trace- element analyses (20 elements) for 162 wines from five regions across Canada (Nova Scotia, Quebec, Ontario (Niagara and Pelee Island) and British Columbia (Okanagan and Vancouver Island)) test the hypothesis that wines can be regionally "fingerprinted", using routine ICP- MS analyses. Exploratory statistics sh...

Oceanic island basalts (OIBs) have been central to understanding evolution of the Earth and mantle because their isolated positions in ocean basins limit the potential for magma contamination by continental crust. Melting processes (e.g., percentage melting) affect OIB chemistry but isotopic and trace-element ratios provide information on mantle-so...

Oceanic islands tend to occur at the young ends of hotspot trails because they record the passage of oceanic, plates over rising convection cells (plumes) in the mantle, or the propagation of cracks in the lithosphere. Basaltic volcanism on oceanic islands is generally unexplosive and, although potentially destructive, poses less threat to human li...

Ancient geologists in Yemen and Egypt recognized that quartz veins surrounding caldera-collapse complexes (exhumed explosive volcanoes) were gold bearing and actively sought out these geologic environments. Rock hammerstones, anvils and grinders are found in camps on both sides of the Red Sea, indicating that mining and metallurgical extraction tec...

Lack of internal textural evidence for flow tops and small chemical variability among late Proterozoic basalt samples suggest the presence of a single flow at Henley Harbour, Labrador, Canada, despite spectacular, m-scale layering in outcrop. Total chemical variation just slightly exceeds analytical uncertainty for many elements. Multidimensional s...

Migmatitic granulites from the Indian Head Range (IHR) are dominated by granoblastic, Opx-bearing (quartz) dioritic gneiss with subordinate garnet+orthopyroxene+biotite+albite (±quartz±microcline±cordierite±sillimanite) gneiss and comparatively biotite-rich, sapphirine+cordierite+orthopyroxene+albite (±microcline±sillimanite±corundum) gneiss. The l...

Trace element fingerprints were deciphered for wines from Canada's two major wine-producing regions, the Okanagan Valley and the Niagara Peninsula, for the purpose of examining differences in wine element composition with region of origin and identifying elements important to determining provenance. Analysis by ICP-MS allowed simultaneous determina...

207Pb/204Pb versus 206Pb/204Pb model ages using Shonkin Sag data and published analyses for magmas of the Cenozoic Wyoming-Montana alkaline province (WYMAP) provide evidence of an Archean age for the subcontinental lithospheric mantle (SLM) associated with the Wyoming craton. The SLM imprint on magmas is expressed as Ba, Ta, Nb and Ti "anomalies" w...

The trace element compositions of 52 Okanagan wines from 26 vineyards were examined to test for correlations between wine and soil/bedrock composition, and to estimate total variability in Okanagan wine composition. Trace element concentrations in wines analysed are shown to provide verification of vineyard of origin, indicating that trace element...

Basalt vessels are rare, but ubiquitous items in elite Predynastic (4000-3100 BCE) and First Dynasty (3100-2800 BCE) Egyptian burials. Where the bedrock sources can be identified, these artefacts can be used to study trade and social interaction between communities before the advent of writing. Seven Egyptian, post-Jurassic (unaltered), alkali and...

Discrimination diagrams have been developed that source Egyptian basaltic artefacts using whole-rock major element geochemistry. These include K2O versus SiO2, TiO2 and P2O5 against MgO/Fe2O3t (total Fe as Fe2O3), and a discriminant analysis diagram using SiO2, Fe2O3t, CaO, and MnO. A complementary set of diagrams uses easily obtained trace element...

Cordierite+orthoamphibole (Crd+Oam)-bearing gneisses in the Cormacks Lake complex are regionally associated with metapelites containing prismatic sillimanite and K-feldspar, metabasites that locally contain metamorphic orthopyroxene, and other high-grade rocks in the Central Gneiss (Dashwoods) subzone, in the southwestern Newfoundland Appalachians....

Conventional petrographic analysis suggests that basalts in Old Kingdom funerary temples are mineralogically and texturally similar to the Haddadin basalt flow of northern Egypt. To affirm that the Haddadin flow is the stone source, a total of 88 augite and 74 plagioclase electron microprobe analyses were obtained from two Abu Sir (Sahure, Fifth Dy...

About 22% of all Predynastic stone vessels are basaltic in composition. As a result of their nondescript petrography the raw-material source of these common artefacts is challenging to determine. Electron microprobe analyses of pyroxene and plagioclase in ≥0·0001g samples from nine Predynastic basalt vessels indicate compositions consistent with an...

Pegmatite cutting chlorite schist in the Minas fault at McKay Head, Nova Scotia, consists of Cl-rich (2.7 - 3.8 wt.% Cl) marialitic scapolite (EqAn21-32) with interstitial, apparently primary analcite, hematite and rutile, and later (including vug-lining) analcite, pyrite, chlorite, titanite and calcite, and cross-cutting epidote veins. Some of the...

An approximately 20-m-thick alkali basalt flow on the Penghu Islands contains ∼20 cm thick, horizontally continuous (>50 m), vesicular layers separated by ∼1.5 m of massive basalt in its upper 8.5 m. The three layers contain ocelli-like "vesicles" filled with nepheline and igneous carbonate. They are coarse grained and enriched in incompatible elem...

A Tertiary, dacitic volcanic land-form in Kelowna, British Columbia, shows layering that has not been recognized elsewhere. Layering is expressed as thin (0.5 m) layers separated by thick (4.5 m) layers exposed along a weathered fault scarp. The major elements show that both thick and thin layers are dacitic and geochemically very similar. Trace el...

Of twelve flows at Pavagadh Hill, the two three-phenocryst-basalt flows with Mg#0.70 and Ni/MgO33 are the most primitive and perhaps as primitive as any basalts in the Deccan province. Scatter on variation diagrams and the occurrence of primitive flows at two different levels in the volcanic sequence implies that most rocks are probably not, strict...

A New Kingdom spinning bowl from Karnak (Luxor) Egypt is similar in form to spinning bowls commonly found at other Egyptian sites and has a bulk chemical composition in the range for other Egyptian marl vessels. These data support a domestic origin. The matrix of the bowl contains unaltered, sand-sized, mafic rock fragments with volcanic, subophiti...

Trace-element concentrations determined by inductively coupled plasma-mass spectrometry (ICP-MS) show that three groups of Nile “silt” pottery from Mendes and Karnak (Akhenaten Temple Project excavations) can be distinguished using Pb, Li, Yb and Hf data. Heavy rare earth-element variations between these groups may be related to climatic fluctuatio...

Migmatitic rocks near Grenville, Quebec, preserve features indicative of reactions at the onset of granulite facies metamorphism. In this area, metapelites and metacarbonates of the classic Grenville Series are spatially associated with granitic gneiss and metabasite, and flank a Paleozoic, Fe-rich syenite stock. Near this intrusion, the metapelite...

Differentiated rocks in thick flows ofthe Jurassic North Mountain Basalt, Nova Scotia, display evidence for fractionation of noble metals (Au, Pd, ft, Rh, Ru, and Ir). Meter-thick layers of mafic pegmatile and vesicular basalt high in the flbws are enriched in Au and Pd but depleted in Pt, Rh, Ru and Ir relative to undifferentiated basalt. Mineral...

The Red Bay pluton (RBP) occurs near the northeastern extremity of the Grenville Province, which contains the world's most voluminous series of Middle Proterozoic (c. 1.0-1.4 Ga), massif-type anorthosites. Mineralogically, the RBP resembles jotunites associated with anorthosites. Furthermore, the pluton is Fe2O3(t)-, TiO2-, and P2O5-rich. Non-layer...

Migmatitic granitic gneiss and associated garnetiferous granite at Grand Lake are tectonically interleaved with high-pressure ( ∼ 9 kbar) metapelites that contain Barrovian (Ky-St-Grt-Bt-Ms-Rt) mineral assemblages. The migmatites contain metabasites that are compositionally similar to the latest Proterozoic Long Range dykes, suggesting that the gne...

Devonian, spessartite dykes, known as the Weekend dykes, on the Eastern Shore of Nova Scotia contain panidiomorphic textures and mineral (amphibole, clinopyroxene, and biotite) compositions typical of shoshonitic lamprophyres. The major element and trace element geochemistry of the Weekend dykes is also representative of shoshonitic lamprophyres wi...

A thick (25-cm-thick differentiated layers separated by 130 cm of basalt in its upper 34m. Upper layers (5 m below the lava top) are highly vesicular whereas lower ones are pegmatitic and contain a thin (2 cm) rhyolite band. The layering of the flow closely resemble that of some Hawaiian lava lakes. The eesicular basalts and mafic pegmatites are in...

The Potato Hill pluton is a nested, composite, Grenvillian intrusion ( c. 1020 Ma) consisting of pyroxene-bearing quartz monzodiorite, equigranular biotite + hornblende + garnet granite, and K-feld-spar megacrystic hornblende + biotite quartz monzodiorite. All members are potassic with high Fe/Mg ratios, and have elevated concentrations of trace el...

The upper 35 m of a thick (~<175 m) Early Jurassic North Mountain Basalt flow at KcKay Head contains 25 cm thick differentiated layers that are separated by 130 cm sections of basalt. The lower layers are mafic, pegmatitic, and contain thin (2 cm), fine-grained 'rhyolite' bands. Evidence that the rhyolite represents a Si-rich immiscible liquid incl...

The rift-related, Late Proterozoic Long Range continental dykes of western Newfoundland have platinum-group element (PGE; Pd, Pt, Rh, Ru and Ir determined) concentrations that correlate with indicators of magma evolution [e.g., ] and magma alkalinity (La/Sm), suggesting that metamorphism had a minimal effect on the PGE. The low-melting-point (LMP)...

The early Mesozoic North Mountain basalts of Nova Scotia are quartz-normative tholeiites with compositions comparable to other Northern Appalachian Triassic- Jurassic tholeiitic lavas, dikes, and sills related to the initial stages of the opening of the Atlantic. The subaerial basalts form a northeast-southwest-trending belt, - 2 0 0 km long, with...

Oceanic-island tholeiitic basalts recovered from four sunken oceanic islands along the Reunion hot-spot trace show trace-element and mineralogical charactersitics ranging from typiecal oceanic-island tholeiites to incompatible-element-depleted tholeiites resembling mid-ocean-ridge basalts. There are also variable degrees of magma evolution at each...

Spinel-sapphirine-corundum-rutile parageneses in metapelitic xenoliths from the lamprophyric Popes Harbour dyke are enclosed by feldspathic (±rare quartz) haloes that embay aluminosilicates and biotite. These feldspathic haloes contain plagioclase (An20–40) and/or an alkali or ternary (hypersolvus) feldspar, and show a variety of igneous and devitr...

The late Permian, primitive and alkaline Qamprophyric) Malpeque Bay sill, Prince Edward Island, shows ep6 values of + 5 and es, of -191 similar to those noted for alkaline rocks from many continents and oceanic islands. These epsi lon values indicate a source region showing long+erm deple-tion in large ion lithophile (LIL) and high-field-strength (...

Highly vesicular and glassy pillow basalts from the sunken oceanic island at Ocean Drilling Program Site 706 in the Indian Ocean show variable alteration and the addition of secondary zeolite facies clay minerals. The mineralogical changes reflect chemical additions of K, Rb, Cs, Li, Si, Sc, Fe, and possibly Sr, Pb, Tl, Au, Pt, and Rh. The elements...

A comparison of 50 basalts recovered at Sites 706, 707, 713, and 715 along the Reunion hotspot trace shows that seafloor alteration had little effect on noble metal concentrations (Au, Pd, Pt, Rh, Ru, and Ir), determined by inductively coupled plasma-mass spectrometry (ICP-MS), which generally tend to decrease with magma evolution. Their compatible...

A comparison of 50 basalts recovered at Sites 706, 707, 713, and 715 along the Reunion hotspot trace during Ocean Drilling Program Leg 115 in the Indian Ocean shows that seafloor alteration had little effect on noble metal concentrations (Au, Pd, Pt, Rh, Ru, and Ir), determined by inductively coupled plasma-mass spectrometry (ICP-MS), which general...

Early Mesozoic rift-related mafic rocks of Atlantic Canada (Caraquet, Minister Island, Shelburne and Avalon dykes and North Mountain Basalt) show high initial 87Sr/86Sr ratios (0.705–0.709) suggesting derivation from a LILE-enriched subcontinental mantle or assimilation of continental crust during ascent. Despite wide geographic distribution, Rb, S...

Latest Proterozoic (0.6 Ga) mafic dykes cutting the Grenvillian Long Range Inlier of western Newfoundland show a polymetamorphic imprint attributed to Appalachian-Caledonian orogenesis. Primary assemblages including augite (Wo35En48Fs17), labradorite and ilmenite are replaced by calcic amphiboles, relatively sodic plagioclase, titanite, epidote, bi...

Leg 115 of the Ocean Drilling Program recovered basalts from four locations along the hotspot track that leads from the Deccan flood basalts in India to Reunion Island in the western Indian Ocean (Sites 706, 707, 713, and 715). The drilled basalts range in age from 35 Ma (Site 706) to 64 Ma (Site 707), and including the Deccan basalts (66 to 68 Ma)...

Leg 115 of the Ocean Drilling Program recovered basalts from four locations along the hotspot track that leads from the Deccan flood basalts in India to Reunion Island in the western Indian Ocean (Sites 706, 707, 713, and 715). The drilled basalts range in age from 35 Ma (Site 706) to 64 Ma (Site 707), and including the Deccan basalts (66 to 68 Ma)...

A review of trace- and minor-element distributions in primitive alkaline rocks (alkali basalts to melilitites with Ni = 200–500 ppm and ) shows element patterns consistent with the presence of several residual minor phases in the source regions for some small percentage melts. TiO2 concentrations separate the primitive magmas into two distinct grou...

A 15-m-wide dike at Popes Harbour on the eastern shore of Nova Scotia shows an increase in both the size (up to 1 m) and density (up to ∼50%) of predominantly pelitic xenoliths toward the dike center. These features reflect flowage differentiation processes during dike emplacement. Flow direction is indicated by sillimanite xenocrysts that represen...

Although small in volume, Cambrian volcanic rocks associated with Acado-Baltic sedimentary rocks in Newfoundland. New Brunswick and Nova Scotia, Norway and Poland display characteristics indicating formation in a tensional-tectonic setting. They generally form bimodal (basalt-rhyolite) suites. Mafic rocks are of both alkaline and tholeiitic affinit...

Gabbroic Silurian sills on the Avalon Peninsula of Newfoundland display whole-rock compositions representative of subalkaline rocks. Mineralogically the sills show high concentrations of hydrous minerals (biotite, hornblende), minerals indicative of a wide range of silica activities (baddeleyite, quartz) and very coarse-grained pyroxenes compositio...

Cambrian basaltic flows and volcaniclastic rocks on the Avalon Peninsula of Newfoundland and from the Beaver Harbour area of southern New Brunswick show two phases of alteration which resulted in the formation of chlorite and carbonate in most of the rocks. Calculations which account for volume changes show that chlorite-forming reactions resulted...

Lower to Middle Cambrian volcanic rocks occur within the Avalon Zone of southern New Brunswick at Beaver Harbour and in the Long Reach area. The Beaver Harbour rocks are intensely altered, but the major- and trace-element geochemistry indicates that they could be highly evolved (basaltic andesites) within-plate basalts. The mafic flows from the Lon...