Absolute Age of the Fisset Brook Formation and the Devonian-Mississippian Boundary, Cape Breton Island, Nova Scotia

Cormier, R. F.; Kelly, Abigail

doi:10.1139/e64-009

Cited by 11 publications

(3 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On east Cooper Brook, basaltic lavas, ash-flow tuffs, or water-lain tuffs constitute thin deposits within a predominantly clastic sequence. According to Cormier and Kelly (1964;see (Jamieson and Doucet 1983;Jamieson, in preparation) and are therefore somewhat older than the Fisset Brook Formation. According to Cormier and Kelly (1964;see (Jamieson and Doucet 1983;Jamieson, in preparation) and are therefore somewhat older than the Fisset Brook Formation.…”

Section: Introductionmentioning

confidence: 99%

Late Devonian – Early Carboniferous volcanism in western Cape Breton Island, Nova Scotia

Blanchard¹,

Jamieson²,

More³

1984

Can. J. Earth Sci.

View full text Add to dashboard Cite

The Fisset Brook Formation of western Cape Breton Island and its equivalents at MacMillan Mountain and the north Baddeck River are examples of Late Devonian and Early Carboniferous volcanic sequences associated with the formation of post-Acadian successor basins in the northeastern Appalachians. They consist of bimodal basalt-rhyolite suites interbedded with alluvial fan, lacustrine, and rare fluvial sediments. The earliest volcanic products are rhyolites and somewhat evolved basalts associated with coarse sediments, followed by tholeiitic to transitional basalt flows interlayered with lacustrine-type deposits. Geochemical studies on the Fisset Brook Formation indicate extensive remobilization of alkalies, Ca, Rb, and Sr, making these elements inappropriate for determining tectonic setting or magmatic affinity. Use of less mobile elements (Ti, Nb, Y, and Zr) suggests that the basalts are tholeiitic and that the apparent alkalinity of the type section lavas is a result of alteration. We conclude that volcanism in western Cape Breton Island started at MacMillan Mountain and migrated westwards, probably towards the centre of the deepening Magdalen Basin.La formation de Fisset Brook et les sequences volcano-skdimentaires de MacMillan Mountain et North Baddeck River dans I'ouest de l'ile du Cap Breton sont des exemples de volcanisme du DCvonien superieur -Carbonifkre inferieur reliC au stage anorogtnique post-Acadien dans le nord-ouest des Appalaches. Les roches sedimentaires associees aux coulees de basalte et rhyolite suggerent un environnement propice a la formation de c8nes de dejection et de dtp8ts de type lacustre ou fluvial. Les premikres sequences de laves contiennent surtout des rhyolites et andesites basaltiques associees a des faciks proximaux; les sequences plus jeunes sont formees de basaltes tholeiitiques ou de transition interstratifies avec des dCp8ts lacustres. Nos etudes gtochimiques revelent que I'alteration des laves de la formation de Fisset Brook mobilise de preference les elements alcalins, Ca, Rb et Sr. L'utilisation d' C1Cments relativement "immobiles" (Ti, Nb, Y et Zr) indique que les basaltes sont tholeiitiques et que leur caractkre apparemment alcalin est dQ aux processus secondaires. La gtochronologie et stratigraphie des laves suggkrent I'amorce du v~lcanisme~dans la region de MacMillan Mountain, suivie d'une migration des centres Cruptifs vers I'ouest ou le centre du bassin des Iles-de-la-Madeleine.

show abstract

Section: Introductionmentioning

confidence: 99%

Late Devonian – Early Carboniferous volcanism in western Cape Breton Island, Nova Scotia

Blanchard¹,

Jamieson²,

More³

1984

Can. J. Earth Sci.

View full text Add to dashboard Cite

show abstract

“…Volcanic rocks are also present in the Late Devonian-Early Carboniferous Fisset Brook Formation (Kelly andMacKasey 1965, Cormier andKelley 1964) in Cape Breton Island (Fig. 1).…”

Section: Geological Settingmentioning

confidence: 99%

Petrology and geochemistry of Devono-Carboniferous volcanic rocks in Nova Scotia

Dostál

Keppie

Dupuy

1983

atgeol

View full text Add to dashboard Cite

The Devono-Carboniferous volcanic rocks of Nova Scotia include Middle Devonian basalts from the McAras Brook Formation in the northern Antigonish Highlands (Ballantynes Cove and McAras Brook areas), Middle Devonian and Carboniferous basalts and rhyolites of the Fountain Lake Group in the Cobequid Highlands and the Upper Devonian-Lower Carboniferous basalts and rhyolites of the Fisset Brook Formation in Cape Breton Island. The volcanic rocks were extruded upon the continental crust in an intraplate setting. The basalts are tholeiitic except those from Ballantynes Cove which are alkaline. All these basalts could have been derived from a similar upper mantle source-garnet peridotlte. Rhyolites were probably generated by crustal anatexis related to the ascending basaltic magma. The Devono-Carboniferous volcanism is probably connected with rifting along faults bounding the Magadalen pull-apart basin. In the Cobequid Highlands, the volcanism appears to be spatially and temporally associated with plutonism. Les roches volcaniques Devono-Carboniferes de la Nouvelle-Ecosse comprennent: les basaltes de la formation McAras Brook (Devonien moyen) dans la partie nord des hautes-terres d'Antigonish (regions de Ballantynes Cove et de McAras Brook); les basaltes et les rhyolites du groupe Fountain Lake (Devonien moyen et Carbonifere) des monts Cobequid; et les basaltes et rhyolites (Devonien superieur-Carbonifere inferieur) de la formation Fisset Brook su l'lle du Cap-Breton. Les roches volcaniques furent repandues a la surface de la croute continentale dans un contexte intraplaque. Les basaltes sont tous tholeiitiques a l'exception de ceux de Ballantynes Cove qui sont alcalins. Tous ces basaltes pourraient provenir d'une meme source situee dans la partie superieure de manteau terrestre-peridotite a grenat. Les rhyolites resultent probablement de l'anatexie de la croute associee a la montee du magma basaltique. Le volcanisme Devono-Carbonifere est probablement relie a une fissuration le long des failles qui encadrent le bassin de dechirement des Madeleines. Dans les monts Cobequid, le volcanisme semble associe de faQon spatio-temporelle au plutonisme.

show abstract

“…In Australia, the Cerberean Volcanics have given K-Ar mineral ages of 345-362 x lo6 yr and Rb-Sr total rock and feldspar isochrons at 375 & 10 and 365 I 90 x lo6 yr; t1lz = 47.0 x lo9 yr (377 f 10 and 386 i 90 x lo6 yr; tliz = 50.0 x lo9 yr). The underlying Upper Devonian Snobs Creek Volcanics gave a K-Ar mineral age of 348 x lo6 yr and a Rb-Sr whole rock isochron of 367 22 x lo6 yr; t1iz = 47.0 x log yr (388 i 22 x lo6 yr; tlia = 50.0 x lo9 yr) (McDougall et al 1966) = 47.0 x lo9 yr (378 i: 15 x lo6 yr on Rb-Sr; tliz = 50.0 x lo9 yr) (Cormier and Kelly 1964). Fitch et a1 (1970) placed the boundary at 360 x lo6 yr on the basis of the evidence cited above and on further evidence from the Scottish Carboniferous.…”

Section: The Carboniferous Periodmentioning

confidence: 99%

Geological time scale

Fitch¹,

Forster²,

Miller³

1974

Rep. Prog. Phys.

View full text Add to dashboard Cite

The principal aim of the science of geochronology is to present the history of the Earth as a dated sequence of events of known duration. The only available matrix of evidence is that contained within the rocks of the Earth, supplemented to a minor extent by meteorites and by rocks retrieved from the Moon. The primary requirement of geochronology is the erection of a measured geological time scale. By a painstaking study of the mutual relationships of the rocks of the Earth's crust and their included trace of the evolution of life, geologists over the last 200 years have slowly constructed a more-or-less detailed relative time scale. Precise physical measurements from which the ages of specific rocks and minerals can be estimated only became possible with the discovery of radioactive decay. The first estimates based upon physical measurements were undertaken in 1907. Great advances have been made in the last 15 years and the present state of geochronometry is summarized in this paper. There is a brief discussion of the assumptions, accuracy, precision and geological ' errors inherent in physical geochronometry. The five major physical methods of rock and mineral age determination currently in use are described. The evidence from which an estimate of 4600 x lo6 yr for the age of the Earth has been derived is reviewed and the history of the Earth is divided into a number of 'major cycles' (early Precambrian, 4600-3500 x lo6 yr; mid Precambrian, 3500-2400 x 106 yr; late Precambrian, 2400-1550 x lo6 yr and 1550-850 x 106 yr; Varisco-Caledonian, 850-250 x lo6 yr; and Alpine, 250 x lo6 yr to sometime in the future). Correlation of Precambrian rocks and the Precambrian time scale is almost entirely dependent upon physical age measurements. Our knowledge of the geochronology of the last 600 x lo6 yr of the Earth's history is based upon a careful combination of the evidence from biostratigraphy and physical geochronometry. This latter, or Phanerozoic, portion of the geological time scale is discussed in detail. I t is concluded that geochronology as a science is still in its infancy. A vast amount of age measurement work will have to be done before its principal objectives can be achieved.

show abstract

Absolute Age of the Fisset Brook Formation and the Devonian-Mississippian Boundary, Cape Breton Island, Nova Scotia

Cited by 11 publications

References 2 publications

Late Devonian – Early Carboniferous volcanism in western Cape Breton Island, Nova Scotia

Late Devonian – Early Carboniferous volcanism in western Cape Breton Island, Nova Scotia

Petrology and geochemistry of Devono-Carboniferous volcanic rocks in Nova Scotia

Geological time scale

Contact Info

Product

Resources

About