scholarly journals Horton Group sedimentary rocks adjacent to the Cobequid Highlands, Nova Scotia

1996 ◽  
Author(s):  
D J W Piper
Keyword(s):  
Nova Scotia ◽  
Sedimentary Rocks

Geochemistry and tectonic discrimination of Late Proterozoic arc-related volcaniclastic turbidite sequences, Antigonish Highlands, Nova Scotia

1993 ◽  
Vol 30 (12) ◽  
pp. 2273-2282 ◽  
Author(s):  
J. Brendan Murphy ◽  
Deborah L. MacDonald
Keyword(s):  
Nova Scotia ◽  
Tectonic Setting ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Widespread Application ◽  
Isotopic Signatures ◽  
Late Proterozoic ◽  
Felsic Volcanic ◽  
Clastic Sedimentary ◽  
End Members

The Late Proterozoic (ca. 618–610 Ma) Georgeville Group of northern mainland Nova Scotia lies within the Avalon Composite Terrane and consists of subgreenschist- to greenschist-facies mafic and felsic volcanic rocks overlain by volcaniclastic turbidites that were deposited in an ensialic basin within a rifted volcanic arc. Geochronological data indicate that the volcanic and sedimentary rocks are coeval. The geochemical and isotopic signatures of the sedimentary rocks are attributed to erosion of the coeval Avalonian volcanic rocks that flank the basin and are consistent with synorogenic deposition. There is no evidence of significant chemical contribution from Avalonian basement.Knowledge of the tectonic setting facilitates the testing of published geochemical discriminant diagrams for clastic sedimentary rocks. Discrimination diagrams using ratios such as K2O/Na2O and Al2O3/(CaO + Na2O) give inconclusive results, probably due to elemental mobility during secondary processes. Plots involving MgO, TiO2, and Fe2O3 detect the chemical contribution of mafic detritus, give much tighter clusters of data, and plot between Aleutian- and Cascade-type arc-derived sediments, suggesting a moderate thickness of continental crust beneath the arc.The arc-related signature of the Georgeville sedimentary rocks is clearly recognizable on ternary plots involving inter-element ratios of high field strength elements (e.g., Ti–Y–Zr, Nb–Y–Zr, and Hf–Ta–Th) in which the samples plot as mixing trends between mafic and felsic end members. Diagrams of this type may have widespread application to tectonic discrimination of sedimentary rocks because in most suites these ratios are relatively insensitive to sedimentary and metamorphic processes.

Structural setting and age of the Partridge Island block, southern New Brunswick, Canada: a link to the Cobequid Highlands of northern mainland Nova Scotia

2014 ◽  
Vol 51 (1) ◽  
pp. 1-24 ◽  
Author(s):  
Adrian F. Park ◽  
Robert L. Treat ◽  
Sandra M. Barr ◽  
Chris E. White ◽  
Brent V. Miller ◽  
...  
Keyword(s):  
Nova Scotia ◽  
New Brunswick ◽  
Tectonic Setting ◽  
Sedimentary Rocks ◽  
Alkali Feldspar ◽  
Early Carboniferous ◽  
Late Devonian ◽  
Island Formation ◽  
Lake Formation ◽  
Saint John

The Partridge Island block is a newly identified tectonic element in the Saint John area of southern New Brunswick, located south of and in faulted contact with Proterozoic and Cambrian rocks of the Ganderian Brookville and Avalonian Caledonia terranes. It includes the Lorneville Group and Tiner Point complex. The Lorneville Group consists of interbedded volcanic and sedimentary rocks, subdivided into the Taylors Island Formation west of Saint John Harbour and West Beach Formation east of Saint John Harbour. A sample from thin rhyolite layers interbedded with basaltic flows of the Taylors Island Formation at Sheldon Point yielded a Late Devonian – Early Carboniferous U–Pb (zircon) age of 358.9 +6/–5 Ma. Petrological similarities indicate that all of the basaltic rocks of the Taylors Island and West Beach formations are of similar age and formed in a continental within-plate tectonic setting. West of Saint John Harbour, basaltic and sedimentary rocks of the Taylors Island Formation are increasingly deformed and mylonitic to the south, and in part tectonically interlayered with mylonitic granitoid rocks and minor metasedimentary rocks of the Tiner Point complex. Based on magnetic signatures, the deformed rocks of the Tiner Point complex can be traced through Partridge Island to the eastern side of Saint John Harbour, where together with the West Beach Formation, they occupy a thrust sheet above a redbed sequence of the mid-Carboniferous Balls Lake Formation. The Tiner Point complex includes leucotonalite and aegirine-bearing alkali-feldspar granite with A-type chemical affinity and Early Carboniferous U–Pb (zircon) ages of 353.6 ± 5.7 and 346.4 ± 0.7 Ma, respectively. Based on similarities in age, petrological characteristics, alteration, iron oxide – copper – gold (IOCG)-type mineralization, and deformation style, the Partridge Island block is correlated with Late Devonian – Early Carboniferous volcanic–sedimentary–plutonic rocks of the Cobequid Highlands in northern mainland Nova Scotia. Deformation was likely a result of dextral transpression along the Cobequid–Chedabucto fault zone during juxtaposition of the Meguma terrane.

Radiometric Age of the Keppoch Formation, Browns Mountain Group, Northern Mainland of Nova Scotia

1974 ◽  
Vol 11 (9) ◽  
pp. 1325-1329 ◽  
Author(s):  
R. F. Cormier
Keyword(s):  
Nova Scotia ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Initial Ratio ◽  
Lower Paleozoic ◽  
Middle Cambrian ◽  
Lower Silurian

The lower Paleozoic Browns Mountain Group of volcanic and sedimentary rocks underlies much of the Antigonish Highlands on the northern mainland of Nova Scotia. The rocks are apparently unfossiliferous and pre-Lower Silurian in age. Volcanic rocks belonging to the Keppoch Formation give a Rb–Sr whole-rock isochron age of 528 ± 40 m.y.; the indicated value for the initial ratio 87Sr/86Sr is 0.7032 ± 0.0020. The apparent stratigraphic age of the lower part of the Browns Mountain Group then is Cambrian with a middle Cambrian age favored.

scholarly journals Paleomagnetism of Devonian sedimentary rocks and mafic sills from the Meguma Terrane, Nova Scotia.

1990 ◽  
Vol 42 (7) ◽  
pp. 833-855 ◽  
Author(s):  
Maurice K. SEGUIN ◽  
Jacques LANGLOIS ◽  
K. V. RAO ◽  
Ernst R. DEUTSCH
Keyword(s):  
Nova Scotia ◽  
Sedimentary Rocks ◽  
Meguma Terrane
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