La composition chimique d’une roche magmatique dépend de: . roches plutoniques et volcaniques, indique deux maximums, l’un correspondant à des roches. PREMIÈRE. PARTIE. CHAPITRE I. DES QUATRE GRANDES CLASSES DE ROCHES AQUEUSES oU SÉDIMENTAIRES, VOLCANIQUES, PLUTONIQUES ET. les roches volcaniques et plutoniques pdf. Quote. Postby Just» Tue Aug 28, am. Looking for les roches volcaniques et plutoniques pdf. Will be.
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les roches volcaniques et plutoniques pdf
Evidence for extension and shortening during passive margin formation. Along most of the Cobequid Shear Zone, the latest Devonian partial melting of lower crust to form granitic magma under more hydrous conditions was synchronous with development of Horton Group basins and was probably triggered plutonques ingress of voluminous water from lakes through crustal-scale faults of the shear zone Pe-Piper et al.
In places, the felsic and mafic rocks plutohiques to have been emplaced as co-existing magmas Pe-Piper et al. It is manifested by a fundamental change in style of sedimentation between the early and late Devonian. Les Roches Magmatiques – scribd. Canadian Journal of Earth Sciences, 35, pp. These units have all yielded ages of to Ma by U-Pb on zircon Doig et al.
Journal of Geology,pp. The Portapique River section: At Clark Head, near Parrsboro, blocks of Devonian—Carboniferous gabbro-granulite outcrop in a melange variously interpreted as a fault breccia Donohoe and Wallacep. Les gabbros roches plutoniques basiques sont donc rares. Some N—S faults of inferred earliest Carboniferous age appear to terminate against plutons cf.
Canadian Society of Petroleum Geologists, Memoir 12, pp. Atlantic Geology, 27, pp. The highlands are dominated by E—W trending faults of the Late Paleozoic Cobequid Shear Zone, which developed during oblique convergence between the Avalon and Meguma terranes, and which facilitated the emplacement of gabbro and granite plutons and their extrusive equivalents Fountain Lake Group volcaniquss the latest Devonian — earliest Carboniferous.
The Cobequid Highlands lie north of the Cobequid – Chedabucto fault zone, the term applied to a series of faults, with a wide range of ages, which mark the upper crustal expression of the crustal scale Minas Geofracture Keppie between the Avalon and Meguma terranes.
Wilson Brook Formation in the Portapique River area is strongly cleaved and folded, and locally overturned, but much of this deformation is associated with the latest Devonian emplacement of the Pleasant Hills Pluton Pe-Piper et al.
Canadian Journal of Earth Sciences, 26, pp. Display large image of Figure 2 Fig. The last significant motion on faults in the northern Cobequid Highlands was predominantly dip slip prior to deposition of the onlapping undeformed late Namurian Boss Point Formation Piper and Pe-Piper Fig. Bulletin of Canadian Petroleum Geology, 39, pp. Falls Formation Donohoe and Wallacewhich unconform-ably overlies mid Tournaisian strata. Individual plutons are difficult to define because of the tectonic dismemberment of the Bass River block, but three principal plutonic rock types are distinguished: Doig, in Murphy et al.
BoxDartmouth, N. In the Mount Thom area, volcanniques Jeffers block shows volcanique major shear zone contact with the Bass River block that has been unaffected by late Paleozoic deformation Pe-Piper et al.
Tectonic influence on sedimentation along the southern flank of the late Paleozoic Magdalen basin in the Canadian Appalachians: In most of these areas, there is a long and complex history of Late Rofhes igneous activity. Displacement and stress field along part of the Cobequid Fault, Nova Scotia.
Irregular enclaves and sheets of diabase occur within this fine-grained granite, with textures suggesting that the mafic magma was immiscible cf.
Donohoe and Wallaceidentified two possible Ordovician rock units. The Jeffers block, which most closely resembles the Antigonish Highlands, shows a major shear zone contact, probably synchronous volcaniquss the Ma Gunshot Brook Pluton, with the Bass River block, which formed in a more inboard position on the Gondwanan margin.
Geological Association of Canada Special Paper 41, pp. The petrology and geochemistry of the Folly Lake pluton and the contact relationships between the mafic and felsic phases, Cumberland and Colchester counties, Nova Scotia.
It is cut by minor late pluoniques dykes at several localities: In both cases you should know how to switch cookies back on! Maritime Sediments and Atlantic Geology, 23, pp. Journal of Geodynamics, 19, pp. The Bass River block 8 The Bass River block Nance and Murphy consists of a series of fault slices of Neoproterozoic lds siliciclastic sedimentary rocks Gamble Brook Formationtectonically juxtaposed with ocean-floor basalt and a thin cover of pelagic sedimentary rocks and fine-grained turbidites Folly River Formation: Points chauds, Volcanisme, Rifting.
Unlike other blocks or terranes in eastern Canadian Avalonion, the Bass River block lacks volcanic rocks synchronous with Late Neoproterozoic plutons, suggesting that it represents a deeper crustal level.
Marys basin, Nova Scotia. Possibly synchronous thrusting occurred north of Cape Chignecto Waldron pluoniques al. Geological Survey of Canada, Paper D, pp.
Methods rodhes data 4 This short synopsis of the geology of the Cobequid Highlands is based in part on new 1: Sometimes, we also use a cookie to keep track of your trolley contents. We also briefly synthesize key information previously published in a dispersed manner over the past twenty years.
In the Bass River block,?
plutoniqques In the south, there was also significant Westphalian and Mesozoic reactivation of the Cobequid and nearby faults. Maritime Sediments and Atlantic Geology, 24, pp. The Kirkhill Fault strand is a fault 60 km long, now truncated at its western end by Triassic basin margin faults.
Le granite est la roche plutonique la plus commune.