40Ar/39Ar ages of detrital muscovite within Lower Cambrian and Carboniferous clastic sequences in northern Nova Scotia and southern New Brunswick: implications for provenance regions

1997 ◽  
Vol 34 (2) ◽  
pp. 156-168 ◽  
Author(s):  
R. D. Dallmeyer ◽  
J. D. Keppie ◽  
R. D. Nance
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Lower Cambrian ◽  
Source Region ◽  
Regional Distribution ◽  
Coarse Grained ◽  
Cape Breton Island ◽  
Late Proterozoic ◽  
Cape Breton ◽  
Meguma Terrane

Detrital muscovite from lowermost Cambrian sequences exposed in the Avalon Composite Terrane in Nova Scotia and New Brunswick record 40Ar/39Ar plateau ages of ca. 625–600 Ma. These are interpreted to date times of cooling in source areas. The regional distribution of coarse-grained detrital muscovite in Lower Cambrian rocks of Avalonian overstep sequences suggests a source region of dimensions considerably larger than any presently exposed in Appalachian segments of the Avalon Composite Terrane. Late Proterozoic tectonic reconstructions locate the Avalon Composite Terrane adjacent to northwestern South America, thereby suggesting a possible source within Late Proterozoic PanAfrican – Brasiliano orogens. Detrital muscovite from clastic sequences of the proximally derived, Lower Carboniferous (Tournaisian) Horton Group and the more distal Upper Carboniferous (Westphalian D – Stephanian) Pictou Group in Nova Scotia records 40Ar/39Ar spectra that define plateau ages of ca. 390–380 Ma (Horton Group) and and ca. 370 Ma (Pictou Group). Finer grained fractions from samples of the Horton Group display more internally discordant age spectra defining total-gas ages of ca. 397–395 Ma. A provenance for the finer muscovite may be found in southern Nova Scotia where Cambrian–Ordovician turbidites of the Meguma Group display a regionally developed micaceous cleavage of this age. The ca. 390–380 Ma detrital muscovites probably were derived from granite stocks presently exposed in proximal areas of northernmost Cape Breton Island. A more distal source for the ca. 370 Ma detrital muscovites in the Pictou Group is suggested by its original extensive distribution, although a local, possibly recycled, source may also have been present. The presence of only 400–370 Ma detrital muscovite suggests a rapidly exhumed orogenic source with characteristics similar to those of crystalline rocks presently exposed in the Cape Breton Highlands and (or) the Meguma Terrane.

Appalachian basement and its intrusion by Cretaceous dykes, offshore southeast Nova Scotia, Canada

1993 ◽  
Vol 30 (12) ◽  
pp. 2495-2509 ◽  
Author(s):  
L. F. Jansa ◽  
G. Pe-Piper ◽  
B. D. Loncarevic
Keyword(s):  
Nova Scotia ◽  
Short Wavelength ◽  
Lower Grade ◽  
Aeromagnetic Data ◽  
Cape Breton Island ◽  
Late Proterozoic ◽  
Cape Breton ◽  
Depleted Mantle ◽  
Half Graben ◽  
Meguma Terrane

Aeromagnetic data collected between eastern Nova Scotia and southern Newfoundland provide new information about the offshore extension of the Avalon and Meguma terranes. A zone of short-wavelength anomalies that delineates Scatarie Ridge extends westward to the Late Proterozoic Fourchu Group in southeastern Cape Breton Island and eastward towards the Burin Peninsula of Newfoundland, suggesting that both regions belong to the same tectono-stratigraphic province of the Avalon composite terrane. A different zone of short-wavelength, discontinuously lineated anomalies at the northern edge of the Canso Ridge correlates with amphibolite-facies metamorphic rocks of the Meguma terrane on the Canso Peninsula, interpreted as an exhumed deeper metamorphic level of the Meguma terrane at its boundary with the Avalon terrane. The S-shaped pattern of long linear magnetic trends, characteristic of lower grade Meguma rocks on the southern flank of the Canso Ridge, indicates plastic deformation of the Meguma terrane during the Acadian orogeny when emplaced against the rigid Cape Breton Island block indentor. Analogous patterns occur off western Nova Scotia, suggesting little strike-slip motion occurred between the Meguma and Avalon terranes since the Acadian orogeny.Late Proterozoic rocks on Scatarie Ridge are intruded by Cretaceous diabase dykes. The diabase is alkaline with a within-plate geochemical signature, similar in composition to basalt flows in the Orpheus half-graben. A depleted-mantle model age TDM (Nd) of 731 Ma, εNd = +6.5, suggests that the magma was sourced from a lithospheric mantle reservoir involved in Late Proterozoic magmatic activity. Aeromagnetic data interpretation confirms the distribution of Cretaceous basalt flows and sills within Mesozoic sedimentary strata of the Orpheus half-graben previously outlined by seismic methods but was unable to differentiate between Proterozoic and Mesozoic intrusive rocks where the Proterozoic rocks lay near to the ocean floor.

The Ciidae (Coleoptera: Tenebrionoidea) of the Maritime Provinces of Canada: new records, distribution, zoogeography, and observations on beetle-fungi relationships in saproxylic environments

Zootaxa ◽  
2007 ◽  
Vol 1654 (1) ◽  
pp. 1-20 ◽  
Author(s):  
CHRISTOPHER G. MAJKA
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Prince Edward Island ◽  
New Records ◽  
Regional Distribution ◽  
Distribution Patterns ◽  
Host Use ◽  
Maritime Provinces ◽  
Cape Breton Island ◽  
Cape Breton

The Ciidae of the Maritime Provinces of Canada are surveyed. Fifteen species are now known to occur in the region, thirteen in Nova Scotia, six in New Brunswick, and two on Prince Edward Island. Ten new provincial records  are reported. Seven species including Ceracis sallei Mellié, Ceracis thoracicornis (Ziegler), Cis creberrimus Mellié, Cis pistoria Casey, Cis subtilis Mellié, Malacocis brevicollis (Casey), and Orthocis punctatus (Mellié) are newly recorded in the Maritime Provinces as a whole. Cis americanus Mannerheim and Cis levettei (Casey) are newly recorded on Prince Edward Island, the first records of this family from the province.Collecting effort on Cape Breton Island, Prince Edward Island, and in New Brunswick has apparently been insufficient to fully document the ciid fauna of these areas. Some local and regional distribution patterns of ciids in the mainland of Nova Scotia and in the Maritime Provinces are suggested from the present data, but further collecting is required to confirm these. Zoogeographically, most of the region's ciids are members of either a boreal fauna (9 species) with Holarctic affinities, or a southeastern North American Nearctic fauna (5 species). The Maritime Provinces ciid fauna has representatives of five of the six known ciid host-use groups. Records of host fungi indicate that there are suitable hosts for all species of ciids found in the region in all three Maritime Provinces, indicating that ciids in the region appear not to be limited by availability of suitable host-fungi. However, Cis horridulus Casey, Cis striolatus Casey, and Cis subtilis Mellié, the three species in the Trametes host-use group, are very infrequently collected and apparently rare.Forests in Maritime Provinces have been greatly affected by forestry and disease, and such activities are known to impact fungal communities. Consequently such practices could have important repercussions for groups like the Ciidae that are reliant on fungi as both a food source and a habitat

scholarly journals New and noteworthy records of Orthoptera and allies in the Maritimes and the Îles-de-la-Madeleine, Quebec

2014 ◽  
Vol 127 (4) ◽  
pp. 332 ◽  
Author(s):  
Paul M. Catling ◽  
Donald F. McAlpine ◽  
Christopher I. G. Adam ◽  
Gilles Belliveau ◽  
Denis Doucet ◽  
...  
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Prince Edward Island ◽  
Forficula Auricularia ◽  
Cape Breton Island ◽  
Cape Breton ◽  
La Madeleine

Chortophaga viridifasciata, Forficula auricularia, Melanoplus stonei, Scudderia furcata furcata, Scudderia pistillata, and Trimerotropis verruculata from Prince Edward Island and Doru taeniatum, Melanoplus punctulatus, Orchelimum gladiator, and Spharagemon bolli from New Brunswick are new provincial records. Other records of interest include the endemic Melanoplus madeleineae from Île d’Entrée in the Îles-de-la-Madeleine, Quebec; Trimerotropis verruculata from the Îles-de-la-Madeleine, Quebec; and Chortophaga viridifasciata, Stethophyma lineatum, and Tetrix subulata, new for Cape Breton Island, Nova Scotia. The ranges of Conocephalus brevipennis, Tetrix arenosa angusta, Tetrix ornata, and Tetrix subulata are significantly extended in New Brunswick. A previously unpublished record from 2003 of Roeseliana roeselii (Metrioptera roeselii) is the earliest report of this European introduction to the Maritimes.

scholarly journals Effects of fluid flow, cooling and deformation as recorded by 40Ar/39Ar, Rb–Sr and zircon fission track ages in very low- to low-grade metamorphic rocks in Avalonian SE Cape Breton Island (Nova Scotia, Canada)

2014 ◽  
Vol 152 (5) ◽  
pp. 767-787 ◽  
Author(s):  
ARNE P. WILLNER ◽  
SANDRA M. BARR ◽  
JOHANNES GLODNY ◽  
HANS-JOACHIM MASSONNE ◽  
MASAFUMI SUDO ◽  
...  
Keyword(s):  
Nova Scotia ◽  
Fission Track ◽  
White Mica ◽  
Low Grade ◽  
Cape Breton Island ◽  
Cape Breton ◽  
Zircon Fission Track ◽  
Meguma Terrane ◽  
Fission Track Ages ◽  
Oriented Parallel

Abstract40Ar/39Ar in situ UV laser ablation of white mica, Rb–Sr mineral isochrons and zircon fission track dating were applied to determine ages of very low- to low-grade metamorphic processes at 3.5±0.4 kbar, 280±30°C in the Avalonian Mira terrane of SE Cape Breton Island (Nova Scotia). The Mira terrane comprises Neoproterozoic volcanic-arc rocks overlain by Cambrian sedimentary rocks. Crystallization of metamorphic white mica was dated in six metavolcanic samples by 40Ar/39Ar spot age peaks between 396±3 and 363±14 Ma. Rb–Sr systematics of minerals and mineral aggregates yielded two isochrons at 389±7 Ma and 365±8 Ma, corroborating equilibrium conditions during very low- to low-grade metamorphism. The dated white mica is oriented parallel to foliations produced by sinistral strike-slip faulting and/or folding related to the Middle–Late Devonian transpressive assembly of Avalonian terranes during convergence and emplacement of the neighbouring Meguma terrane. Exhumation occurred earlier in the NW Mira terrane than in the SE. Transpression was related to the closure of the Rheic Ocean between Gondwana and Laurussia by NW-directed convergence. The 40Ar/39Ar spot age spectra also display relict age peaks at 477–465 Ma, 439 Ma and 420–428 Ma attributed to deformation and fluid access, possibly related to the collision of Avalonia with composite Laurentia or to earlier Ordovician–Silurian rifting. Fission track ages of zircon from Mira terrane samples range between 242±18 and 225±21 Ma and reflect late Palaeozoic reburial and reheating close to previous peak metamorphic temperatures under fluid-absent conditions during rifting prior to opening of the Central Atlantic Ocean.

Upper Placentian—Branchian series of mainland Nova Scotia (middle-upper Lower Cambrian): Faunas, paleoenvironments, and stratigraphic revision

1995 ◽  
Vol 69 (3) ◽  
pp. 475-495 ◽  
Author(s):  
Ed Landing
Keyword(s):  
Nova Scotia ◽  
Lower Cambrian ◽  
Preliminary Evidence ◽  
Middle Cambrian ◽  
Cape Breton Island ◽  
Cape Breton ◽  
History Of ◽  
Placentia Bay ◽  
Stratigraphic Nomenclature ◽  
Eastern Massachusetts

Lithostratigraphy and depositional and epeirogenic history of the upper Placentian Series (Cuslett-Fosters Point Formations of the Bonavista Group) and Branchian Series (Brigus Formation) are identical in the northern Antigonish Highlands; Cape Breton Island; and eastern Placentia Bay, southeastern Newfoundland. Preliminary evidence suggests that the lower Middle Cambrian is present in the field area. A unified, uppermost Precambrian–Lower Cambrian, formation- and member-level nomenclature is appropriate to Avalonian North America, and the stratigraphic nomenclature of southeastern Newfoundland is applied in northern mainland Nova Scotia.Latest Placentian shoaling and deposition of a peritidal carbonate lithosome and unconformable onlap of the trilobite-bearing Branchian Series occurred in shallow Avalonian shale basins from eastern Massachusetts to central England.Uppermost Placentian Series faunas are very diverse in the Fosters Point Formation. Limited similarities with the South Australian Lower Cambrian are indicated by the presence of Camenella sp. cf. C. reticulosa, Conotheca australiensis, and Hyptiotheca sp., but these forms do not contribute to highly resolved correlation.Twenty-eight taxa are illustrated from the upper Placentian and Branchian Series. Caveacus rectus n. gen. and sp., a phosphatic problematicum, is limited to the upper Placentian Series. The oldest, skeletalized, macrophagous predators are the Pseudoconodontida and the later appearing Protoconodontida (n. orders). The Pseudoconodontida includes the Protohertzinacea n. superfamily and Strictocorniculacea n. superfamily (with the Rhombocorniculidae and Strictocorniculidae n. families). Strictocorniculum vanallerum n. gen. and sp. is described. The tommotiid family Sunnaginiidae emend. includes Eccentrotheca, Sunnaginia, Kulparina, and Jayceia deltiformis n. gen. and sp.

Geochemistry of Late Proterozoic basaltic rocks from southeastern Cape Breton Island, Nova Scotia

1990 ◽  
Vol 27 (5) ◽  
pp. 619-631 ◽  
Author(s):  
J. Dostal ◽  
J. D. Keppie ◽  
J. B. Murphy
Keyword(s):  
Nova Scotia ◽  
Volcanic Rocks ◽  
Progressive Increase ◽  
Cape Breton Island ◽  
Basaltic Rocks ◽  
Late Proterozoic ◽  
Cape Breton ◽  
Intermediate Units ◽  
Light Rare Earth Elements ◽  
Greenschist Facies Metamorphism

Late Proterozoic volcanic rocks of the Fourchu Group from the Avalon Zone in southeastern Cape Breton Island, Nova Scotia, are composed predominantly of mafic and felsic types with subordinate intermediate units that were all affected by subgreenschist- to greenschist-facies metamorphism. The rocks crop out in four fault blocks (Coastal, Stirling, East Bay Hills, and Coxheath) and have geochemical characteristics of ensialic orogenic volcanic suites. The basaltic rocks range from tholeiitic to calc-alkaline and show a distinct compositional zonation that resembles the across-arc variation observed in recent volcanic-arc systems. The variations include a progressive increase in abundances of light rare-earth elements, Th, Zr, Hf, Nb, and Ta and in the ratios of Zr/SiO2, Th/SiO2, Zr/Y, La/Yb, and Th/Hf from the Coastal block in the southeast to the Coxheath block in the northwest. The zonation may be explained in terms of a northwesterly-dipping subduction zone, with the trench lying to the southeast of Nova Scotia.

Latridiidae (Coleoptera) of Atlantic Canada: new records, keys to identification, new synonyms, distribution, and zoogeography

2009 ◽  
Vol 141 (4) ◽  
pp. 317-370 ◽  
Author(s):  
Christopher G. Majka ◽  
David Langor ◽  
Wolfgang H. Rücker
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Prince Edward Island ◽  
Habitat Preferences ◽  
Valid Species ◽  
Atlantic Canada ◽  
Cape Breton Island ◽  
New Synonyms ◽  
Cape Breton

AbstractThirty-five species of Latridiidae are reported in Atlantic Canada as a whole, 17 in New Brunswick, 14 in Newfoundland, 31 in Nova Scotia, and 14 on Prince Edward Island. Fifty-six new provincial records are reported (11 in New Brunswick, 9 in Newfoundland, 23 in Nova Scotia, 13 in Prince Edward Island). Twenty-two species are newly recorded for Atlantic Canada. Of these, Cartodere (Aridius) bifasciata (Reitter), Enicmus histrio Joy and Tomlin, Latridius consimilis (Mannerheim), Corticaria elongata (Gyllenhal), C. impressa (Olivier), C. saginata Mannerheim, Corticarina longipennis (LeConte), Melanophthalma helvola Motschulsky, and M. inermis Motschulsky are newly recorded in Canada, and C. bifasciata, E. histrio, and C. saginata are newly recorded in North America. Dienerella filiformis (Gyllenhal) is removed from the New Brunswick and Prince Edward Island lists. Corticaria dentigera LeConte is removed from the Labrador and Atlantic Provinces lists. Melanophthalma inculta Motschulsky syn. nov. and M. signata Belon syn. nov. are designated as a junior synonyms of M. inermis Motschulsky and M. picta (LeConte), respectively. Melanophthalma helvola Motschulsky is reinstated as a valid species. Lectotypes and paralectotypes of M. helvola and M. americana (Mannerheim) are designated. Approximately half of the species are adventive (16 Palaearctic, 1 Australian) and half are native (13 Nearctic, 3 Holarctic). Two species are of uncertain zoogeographic status. Although some species are synanthropic, several have colonized native habitats. Nova Scotia has the largest number of adventive species, probably as a result of trans-Atlantic shipping. New Brunswick has the fewest, at least in part because of insufficient collecting there. Early detection dates and introduction processes are discussed. The native faunas on Prince Edward Island, Cape Breton Island, and Newfoundland appear diminished (33%–40%) compared with those of the neighbouring mainland. Although all latridiids are mycetophagous, many in the region show clear habitat preferences; however, the ecological role of those species requires further investigation.

Taxonomic revision of the long-tailed shrew, Sorex dispar Batchelder, 1911, from the Appalachian Region of North America, with the description of a new subspecies

2019 ◽  
Vol 100 (6) ◽  
pp. 1837-1846 ◽  
Author(s):  
Victor E Diersing
Keyword(s):  
Nova Scotia ◽  
North America ◽  
New Brunswick ◽  
Geographic Variation ◽  
Skull Morphology ◽  
Connecticut River ◽  
Cape Breton Island ◽  
New Subspecies ◽  
Morphological Studies ◽  
Cape Breton

Abstract The long-tailed shrew, Sorex dispar Batchelder, 1911, and Gaspe shrew, S. gaspensis Anthony and Goodwin, 1924, from the Appalachian Mountains of North America have been characterized as genetically highly similar, and that one is morphologically a clinal variate of the other, i.e., there is a single species. I measured 24 characters of the skull on 196 shrews from throughout the range of the species. Geographic variation in skull shape and size was not gradual or continuous, but abrupt. These abrupt changes in morphology are associated with major water barriers, primarily the Connecticut River, middle Saint John River, and the Strait of Canso, which separates mainland Nova Scotia from Cape Breton Island. The morphological analyses presented here and previous genetic studies indicate that S. dispar and S. gaspensis are likely conspecific. Shrews with the largest skull occur from North Carolina north to Vermont and are referable to S. d. dispar with S. d. blitchi as a synonym. Shrews from New Hampshire northeast to southern New Brunswick and mainland Nova Scotia have a medium-sized skull and are referable to a new subspecies. Those from northern New Brunswick, Gaspe Peninsula of Quebec, and Cape Breton Island have a small skull and are referable to S. d. gaspensis. The skull morphology of S. d. gaspensis and the new subspecies are more similar to each other than to S. d. dispar. Results of this study differ from those of previous morphological studies because measurement error and within-group variation were reduced, which allowed for visibility of otherwise “hidden” between-group differences, or geographic variation.

Cambrian volcanism in Nova Scotia, Canada

1985 ◽  
Vol 22 (4) ◽  
pp. 599-606 ◽  
Author(s):  
J. B. Murphy ◽  
K. Cameron ◽  
J. Dostal ◽  
J. Duncan Keppie ◽  
A. J. Hynes
Keyword(s):  
Nova Scotia ◽  
Lower Cambrian ◽  
Basaltic Magma ◽  
Volcanic Rocks ◽  
Felsic Magma ◽  
Middle Cambrian ◽  
Cape Breton Island ◽  
Shallow Marine ◽  
Cape Breton ◽  
Pull Apart Basin

Cambrian volcanic rocks in Nova Scotia occur in small grabens or half grabens in the Avalon Zone (Composite Terrane) as part of a thin sequence of continental to shallow-marine Cambro-Ordovician rocks. In the northern Antigonish Highlands, the volcanic rocks occur mainly in the Lower Cambrian McDonalds Brook Group. In southern Cape Breton Island, they occur predominantly in the Middle Cambrian Bourinot Group. The chemistry of these volcanic rocks indicates that they are bimodal (basalts–rhyolites) and within plate. The basalts are alkalic in the Antigonish Highlands and tholeiitic in Cape Breton Island. The rising basaltic magma is postulated to have produced the felsic magma by anatexis of the crust. It is proposed that the Antigonish Highlands volcanic rocks erupted in a small pull-apart basin. A similar structural setting is probable in southern Cape Breton Island, but there the bounding faults are poorly exposed. These basins probably formed during a period of transpression in the last stages of the late Hadrynian Cadomian deformation.

Sign in / Sign up

Export Citation Format

Share Document