scholarly journals Structural history of pre-Carboniferous rocks in parts of eastern Cape Breton Island

1972 ◽  
Author(s):  
H Helmstaedt ◽  
S Tella

10.4138/1438 ◽  
1973 ◽  
Vol 9 (3) ◽  
Author(s):  
Herwart Helmstaedt ◽  
Subhas Tella


2008 ◽  
Vol 140 (1) ◽  
pp. 128-141 ◽  
Author(s):  
Christopher G. Majka ◽  
Yves Bousquet ◽  
Christine Noronha ◽  
Mary E. Smith

AbstractFourteen species of Carabidae are added to Prince Edward Island’s (P.E.I.) faunal list, bringing the known fauna to 167 species. Bembidion nitidum (Kirby) and Bembidion obtusum Audinet-Serville are newly recorded for the Maritime Provinces. Six species are removed from P.E.I.’s faunal list. The history of collecting of Carabidae on P.E.I. is briefly recounted. Despite differences in land area and distance from the mainland between P.E.I., Cape Breton Island, and insular Newfoundland, their carabid faunas exhibit many similarities in size and composition. The native carabid fauna of P.E.I. comprises 49% of the species in the combined Maritime Provinces fauna, perhaps reflecting an island-related diminution of species diversity. The proportion of flightless species on P.E.I. (4.9%) is less than that in the Maritime Provinces as a whole (7.1%), an apparent indication that the Northumberland Strait has been a barrier to colonization. Twenty-seven introduced species are found on P.E.I., 26 of which can be classified as synanthropic and may have originated in dry-ballast quarries in southwestern England. Although the earliest dates of detection of many introduced species on P.E.I. are substantially later than elsewhere in the Maritimes, this reflects the paucity of early collecting. Land-management practices on P.E.I. (large-scale and early forest clearances, intensive agriculture, and the extensive use of biocides) may have had an impact on P.E.I.’s carabid fauna.



Author(s):  
MacKinnon Richard ◽  
MacKinnon Lachlan

Islands are places that foster a unique sense of place-attachment and community identity among their populations. Scholarship focusing on the distinctive values, attitudes and perspectives of ‘island people’ from around the world reveals the layers of meaning that are attached to island life. Lowenthal writes: ‘Islands are fantasized as antitheses of the all-engrossing gargantuan mainstream-small, quiet, untroubled, remote from the busy, crowded, turbulent everyday scene. In reality, most of them are nothing like that. …’ 1 1 D. Lowenthal, ‘Islands, Lovers and Others’, The Geographical Review 97 (2007): 203. Islands, for many people, are ‘imagined places’ in our increasingly globalised world; the perceptions of island culture and reality often differ. Cape Breton Island, Nova Scotia, in eastern North America, a locale with a rich history of class struggle surrounding its former coal and steel industries, provides an excellent case study for the ways that local history, collective memory and cultural expression might combine to combat the ‘untroubled fantasy’ that Lowenthal describes.



1995 ◽  
Vol 69 (3) ◽  
pp. 475-495 ◽  
Author(s):  
Ed Landing

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.



2011 ◽  
Vol 85 (4) ◽  
pp. 678-694 ◽  
Author(s):  
ED Landing ◽  
Richard A. Fortey

The Chesley Drive Group, an Upper Cambrian-Lower Ordovician mudstone-dominated unit, is part of the Ediacaran–Ordovician cover sequence on the North American part of the Avalon microcontinent. The upper Chesley Drive Group on McLeod Brook, Cape Breton Island (previously “McLeod Brook Formation”), has two lithofacies-specific Tremadocian biotas. An older low-diversity benthic assemblage (shallow burrowers, Bathysiphon, phosphatic brachiopods, asaphid trilobites) is in lower upper Tremadocian green-gray mudstone. This wave-influenced, slightly dysoxic facies has Bathysiphon–brachiopod shell lags in ripple troughs. The upper fauna (ca. 483 +/- 1 Ma) is in dysoxic-anoxic (d-a), unburrowed, dark gray-black, upper upper (but not uppermost) Tremadocian mudstone with a “mass kill” of the olenid Peltocare rotundifrons (Matthew)—a provincial trilobite in Avalonian North America that likely tolerated low oxygen bottom waters. Scandodus avalonensis Landing n. sp. and Lagenochitina aff. conifundus (Poumot), probable nektic elements and the first upper Tremadocian conodont and chitinozoan reported from Avalon, occur in diagenetic calcareous nodules in the dark gray-black mudstone. An upper Tremadocian transition from lower greenish to upper black mudstone is not exposed on McLeod Brook, but is comparable to a coeval green-black mudstone transition in Avalonian England. The successions suggest that late late Tremadocian (probable Baltic Hunnebergian Age) sea level was higher in Avalon than is suggested from successions on other paleocontinents. The Tremadocian sea-level history of Avalon was a shoaling-deepening-shoaling sequence from d-a black mudstone (lower Tremadocian), to dysoxic green mudstone (lower upper Tremadocian), and back to black mudstone (upper upper Tremadocian).Scandodus Lindström is emended, with the early species S. avalonensis Landing n. sp. assigned to the emended Family Protopanderodontidae. Triangulodus Van Wamel is considered a junior synonym of Scandodus. Peltocare rotundifrons is emended on the basis of complete specimens.



2018 ◽  
pp. 021-080 ◽  
Author(s):  
Sandra M. Barr ◽  
Deanne Van Rooyen ◽  
Chris E. White

Granitoid plutons are a major component of pre-Carboniferous rocks in Cape Breton Island and knowledge of the time and tectonic setting of their emplacement is crucial for understanding the geological history of the island, guiding exploration for granite-related economic mineralization, and making along-orogen correlations. The distribution of these plutons and their petrological characteristics have been used in the past for recognizing both Laurentian and peri-Gondwanan components in Cape Breton Island, and for subdividing the peri-Gondwanan components into Ganderian and Avalonian terranes. However, ages of many plutons were assumed on the basis of field relations and petrological features compared to those of the relatively few reliably dated plutons. Seventeen new U–Pb (zircon) ages from igneous units reported here provide enhanced understanding of the distribution of pluton ages. Arc-related plutons in the Aspy terrane with ages of ca. 490 to 475 Ma likely record the Penobscottian tectonomagmatic event recognized in the Exploits subzone of central Newfoundland and New Brunswick but not previously recognized in Cape Breton Island. Arc-related Devonian plutonic activity in the same terrane is more widespread, continuous, and protracted (445 Ma to 395 Ma) than previously known. Late Devonian magmatism in the Ganderian Aspy terrane is similar in age to that in the Avalonian Mira terrane (380 to 360 Ma) but the tectonic settings are different. In contrast, magmatic activity in the Bras d’Or terrane is almost exclusively arc-related in the Late Ediacaran (580 to 540 Ma) and rift-related in the Late Cambrian (520 to 490 Ma). The new data support the terrane distinctions previously documented.



2020 ◽  
Vol 460 ◽  
pp. 117869
Author(s):  
Olaf Thomas Bouman ◽  
Michael Anthony Mazzocca ◽  
Emily Elizabeth Bennett ◽  
Kenneth Donald Oakes


2005 ◽  
Vol 19 (4) ◽  
pp. 49-76 ◽  
Author(s):  
O. T. Bouman ◽  
N. Vaninetti ◽  
G. E. M. Williams ◽  
D. B. McCorquodale


1986 ◽  
Vol 23 (11) ◽  
pp. 1673-1685 ◽  
Author(s):  
Rex J. E. Johnson ◽  
Rob Van der Voo

Volcanogenic sediments of the Fourchu Group and a gabbroic intrusion, which are found in the Avalonian terrane of south-eastern Cape Breton Island, have been sampled for paleomagnetic analysis. Upon detailed thermal and alternating-field demagnetization, three often-superimposed components of magnetization are obtained. One of these is aligned with the present-day geomagnetic field direction in Nova Scotia and is assumed to be of recent origin. The second group of directions is south-southeasterly and shallow, is postfolding in age, and is inferred to represent a Carboniferous overprint. The third direction, carried almost always by hematite, is also postfolding and yields a dual-polarity mean direction to the northwest or south-east, with a fairly steep inclination (D = 132°, I = −63°). This last direction is not seen in Avalonian or other North American rocks of Devonian or younger age; it is, therefore, bracketed in age between the earliest folding of the rocks and the latest Silurian. Given that Taconic folding has not been reported for this area, we assume that this magnetization was introduced in the rocks during uplift and oxidation after an Avalonian folding phase. For the Avalon terrane of Nova Scotia, the available paleomagnetic data reveal a set of moderately high paleolatitudes for the Late Precambrian and early Paleozoic, in contrast to the near-equatorial values predicted for the area under the assumption that it remained fixed with respect to the craton. On the other hand, strong similarities exist between Avalonian paleolatitudes and those for Armorica and Gondwana; a tentative reconstruction is proposed in which Avalon is adjacent to Armorica and Gondwana in the Late Precambrian and early Paleozoic.



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