Vein assemblages and fluid evolution in 18O-depleted Neoproterozoic igneous rocks of the Mira terrane, Cape Breton Island, Nova Scotia1This article is one of a series of papers published in CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology.2Laboratory for Stable Isotope Science (LSIS) Contribution 251.

2012 ◽  
Vol 49 (1) ◽  
pp. 359-378 ◽  
Author(s):  
Joanna Potter ◽  
Frederick J. Longstaffe ◽  
Sandra M. Barr
Keyword(s):  
Fluid Inclusions ◽  
Meteoric Water ◽  
Limited Range ◽  
Igneous Rocks ◽  
Cape Breton Island ◽  
Carbon Isotopic ◽  
Vein Formation ◽  
Cape Breton ◽  
Calcite Veins ◽  
Stable Isotopic

Fluids responsible for regional 18O-depletion of Neoproterozoic igneous rocks in Avalonia are investigated here through a petrographic, microthermometric, and stable isotopic examination of fluid inclusions and minerals from the abundant vein networks of the Mira terrane, Cape Breton Island. Six categories of vein assemblages — from oldest to youngest — are present: (i) quartz–albite, (ii) quartz–epidote, (iii) quartz, (iv) quartz–chlorite–calcite, (v) quartz–calcite, and (vi) calcite. Vein system temperatures were initially as high as ∼300 °C and gradually decreased to ∼200 °C. Moderate salinities (<8 equivalent wt.% NaCl) characterize entrapped fluids in the early quartz–albite veins but decrease in later quartz–epidote and quartz–calcite veins to <1 equiv. wt.% NaCl. The limited range of fluid δ18O values (–1.9‰ to +1.4‰) calculated for most of the vein assemblages is suggestive of a seawater-dominated system, as are the δDH2O values (–12‰ to –3‰) obtained for epidote. Decreasing fluid salinities, however, suggest that meteoric water became dominant during later stages of vein formation. The carbon isotopic compositions of trace CO2 and CH4 from the fluid inclusions (δ13CCO2 = –22‰ to –4‰; δ13CCH4 = –52‰ to –37‰) are indicative of externally derived (i.e., non-magmatic) fluids of organic origin.

Geochemistry of a fossil hydrothermal system at Barton Peninsula, King George Island

1995 ◽  
Vol 7 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Chil-Sup So ◽  
Seong-Taek Yun ◽  
Maeng-Eon Park
Keyword(s):  
Hydrothermal System ◽  
Meteoric Water ◽  
Volcanic Rocks ◽  
King George Island ◽  
Sulphur Isotope ◽  
Alteration Zones ◽  
Vein Formation ◽  
Calcite Veins ◽  
Lead Zinc ◽  
Barton Peninsula

A fossil hydrothermal system on Barton Peninsula, King George Island, Antarctica, formed a series of lead-zinc- and pyrite + native sulphur-bearing epithermal quartz ± calcite veins, filling fault-related fractures in hydrothermally altered volcanic rocks of Eocene age. The lead-zinc veins occur within argillic hydrothermal alteration zones, whereas the pyrite + native sulphur veins are found within advanced argillic alteration zones. Fluid inclusion data indicate that the vein formation occurred at temperatures between about 125° and 370°C (sphalerite deposition formed at 123–211°C) from fluids with salinities of 0.5–4.6 wt.% eq. NaCl. Equilibrium thermodynamic interpretation of mineral assemblages indicates that the deposition of native sulphur in the upper and central portions of the hydrothermal system was a result of the mixing of condensates of ascending magmatic gases and meteoric water giving rise to fluids which had lower pH (<3.5) and higher fugacities of oxygen and sulphur than the lead-zinc-depositing fluids at depth. The δ34S values of sulphide minerals from the lead-zinc veins (δ34S = −4.6 to 0.7‰) are much higher than the values of pyrite and native sulphur from the pyrite + native sulphur veins (δ34S = −12.9 to −20.1‰). This indicates that the fluids depositing native sulphur had higher sulphate/H2S ratios under higher fo2 conditions. Sulphur isotope compositions indicate an igneous source of sulphur with a δ34SΣS value near 0‰, probably the Noel Hill Granodiorite. Measured and calculated δ18O and δD values of the epithermal fluids (δ18Owater = −6.0 to 2.7‰, δDwater = −87 to −75‰) indicate that local meteoric water played an important role for formation of lead-zinc and native sulphur-bearing quartz veins.

Nd isotopic compositions of felsic igneous rocks in Cape Breton Island, Nova Scotia

1992 ◽  
Vol 29 (4) ◽  
pp. 650-657 ◽  
Author(s):  
Sandra M. Barr ◽  
Ernst Hegner
Keyword(s):  
New Brunswick ◽  
Small Variation ◽  
Igneous Rocks ◽  
Northwestern Part ◽  
Isotopic Data ◽  
Cape Breton Island ◽  
Late Precambrian ◽  
Cape Breton ◽  
Depleted Mantle ◽  
Juvenile Crust

Nd isotopic data from 18 felsic plutonic and volcanic units in Cape Breton Island show variations consistent with other geological and geophysical evidence for at least three distinct terranes. A ca. 1.2 Ga syenite considered to be part of Grenvilleage basement exposed in the northwestern part of the island yields an initial εNd value of +0.4 and a depleted-mantle model age (TDM) of 1.66 Ga, suggesting substantial involvement of older (Archean or Early Proterozoic) crust in its petrogenesis. A TDM of 1.38 Ga indicated by Nd isotopic data for a Devonian granite spatially associated with the syenite is also consistent with the presence of older crust in that part of Cape Breton Island. In contrast, Silurian rhyolite and Devonian granites from the Aspy terrane have TDM ranging from 0.7 to 1.1 Ga and initial εNd between +2.8 and −1.2, and overlap in isotopic characteristics with late Precambrian and Early Ordovician plutons in the Bras d'Or terrane that yield TDM of 0.9–1.1 Ga and initial εNd of +1.4 to −1.8. The relatively small variation in εNd and TDM in these terranes suggests that old crust like that under the Blair River Complex may not be present. Granitic plutons and rhyolite in the Mira terrane of southeastern Cape Breton Island have a range in TDM (0.8–1.2 Ga) similar to that of the Aspy and Bras d'Or terranes, but initial εNd values ranging from +0.8 to +5.0 indicate more juvenile crust. This juvenile crust also appears to be present under southern New Brunswick and eastern Newfoundland and may be characteristic of the Avalon terrane.

The ecology of the lynx (Lynx canadensis) on Cape Breton Island

1983 ◽  
Vol 61 (4) ◽  
pp. 770-786 ◽  
Author(s):  
G. R. Parker ◽  
J. W. Maxwell ◽  
L. D. Morton ◽  
G. E. J. Smith
Keyword(s):  
Limited Range ◽  
Forest Harvesting ◽  
Snowshoe Hare ◽  
Home Ranges ◽  
Lynx Lynx ◽  
Lynx Canadensis ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Hunting Success ◽  
Main Component

Recruitment of lynx (Lynx canadensis) on Cape Breton Island declined from 1977–1978 through 1979–1980 concurrent with a decrease in snowshoe hare (Lepus americanus) densities. Suppressed recruitment resulted from a decline in pregnancy rates, especially in the yearling cohort, and increased mortality of kits during the first 6 months of life. Snowshoe hare was the main component in the diet of lynx during both winter and summer. Lynx rarely travelled together except for females with kits. Hunting success (percent successful chases) increased wth group size. Overall hunting success increased through the winter. Winter kill rates averaged one hare per lynx per 24 h. Home ranges of adults were larger in summer (25–32 km2) than in winter (12–18 km2). Daily cruising distances (kilometres per 24 h) were greater in summer (~9 km) than in winter (~8 km). Although lynx used all habitats within their home ranges, they selected for the advanced successional habitat (~20 years after cutting) both winter and summer. Mature conifer habitat was used more in summer than in winter. The short-term impact of extensive forest harvesting within the limited range of lynx on the highlands of Cape Breton Island is uncertain; in the long-term it should prove beneficial by increasing the availability of preferred advanced successional habitat. Harvesting of lynx should be closely controlled, especially during periods of reduced densities of snowshoe hares and suppressed recruitment of lynx.

Altering Avalonia: oxygen isotopes and terrane distinction in the Appalachian peri-Gondwanan realmLaboratory for Stable Isotope Science (LSIS), The University of Western Ontario, Contribution 236.

2008 ◽  
Vol 45 (7) ◽  
pp. 815-825 ◽  
Author(s):  
Joanna Potter ◽  
Frederick J. Longstaffe ◽  
Sandra M. Barr ◽  
Margaret D. Thompson ◽  
Chris E. White
Keyword(s):  
Large Scale ◽  
Sedimentary Basins ◽  
Igneous Rocks ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Fluid Infiltration ◽  
Geochemical Fingerprint ◽  
Appalachian Orogen ◽  
Late Neoproterozoic ◽  
The University

Distinct 18O depletion is characteristic of a large majority of the 620–550 Ma felsic igneous rocks of Avalonia in the northern Appalachian orogen. Neoproterozoic rocks in the Boston Avalon terrane have the lowest δ18OWR values (≥–3.1‰), followed by the Mira terrane in Cape Breton Island and the Caledonia terrane in New Brunswick (≥–1.2‰), the Avalon terrane in Newfoundland (≥+2.8‰), and the Antigonish Highlands in Nova Scotia (≥+5.3‰). In contrast, this depletion of 18O is observed in very few of the Paleozoic felsic igneous rocks from these Avalonian terranes, and also in very few of the Neoproterozoic and Paleozoic felsic igneous rocks from the inboard Ganderian terranes. The low-18O character of the Neoproterozoic igneous rocks is related to regional pervasive, post-magmatic alteration by predominantly meteoric-hydrothermal fluids (δ18OH2O ∼–6‰ to –4‰) at 200–450 °C. The alteration likely occurred during late Neoproterozoic transtensional extension of Avalonia. Large-scale fluid infiltration and circulation within the Avalonian crust accompanied this extension with development of pull-apart sedimentary basins and extension-related magmatism that were the prelude to Cambrian submergence of Avalonia. This regional 18O depletion provides a geochemical fingerprint by which Avalonia can be distinguished from other peri-Gondwanan terranes. These data suggest that Avalonia existed as a composite terrane on the Gondwanan margin in the Neoproterozoic, separate from Ganderia.

Culinary tourism on Cape Breton Island

2019 ◽  
Vol 6 (2) ◽  
Author(s):  
Erna MacLeod
Keyword(s):  
Tourism Destination ◽  
Cape Breton Island ◽  
Culinary Tourism ◽  
Economic Significance ◽  
Cape Breton ◽  
Local Stakeholders ◽  
Resilient Communities ◽  
World Class ◽  
Ecological Relations ◽  
Developed World

Cape Breton Island is a well-known North American tourism destination with long-standing attractions such as the Cabot Trail and more recently developed world-class offerings such as the Cabot Links Golf Course. Tourism contributes significantly to Cape Breton’s economy, particularly since the mid-20th century as traditional resource-based industries have declined. In the 21st century, culinary tourism has become increasingly important to expand the island’s tourism offerings and to provide “authentic” tourism experiences. This study examines local-food tourism in Cape Breton to illuminate its cultural and economic significance. I conducted interviews with food producers, restaurateurs, government representatives, and tourism executives. I also consulted websites and policy documents and compared local stakeholders’ experiences and perspectives with official tourism strategies. Promoting culinary tourism raises questions of power, autonomy, inclusion, and accountability. My study accentuates possibilities for aligning economic and ecological goals to create resilient communities, foster equitable social and ecological relations, and establish Cape Breton as a culinary tourism destination.

Cape Breton ruby, a new Canadian gemstone discovery, Cape Breton Island, Nova Scotia

2007 ◽  
Vol 30 (5) ◽  
pp. 279-286 ◽  
Author(s):  
David J. Mossman ◽  
James D. Duivenvoorden ◽  
Fenton M. Isenor
Keyword(s):  
Nova Scotia ◽  
Cape Breton Island ◽  
Cape Breton
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