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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Riches total thickness is generally less than 0. In contrast, mid Devonian to early Carboniferous rocks of the Murphy Brook Formation, Fountain Lake Group, and Horton Group show rapid changes in facies and thickness, with common occurrence of conglomerate and lacustrine deposits, all suggesting deposition pluyoniques fault-bound terrestrial basins. Piper suggested that all of these occurrences represent the same formation, and can be mapped as such, distinguishing where appropriate a coarse facies principally conglomerate and medium sandstone and a fine facies principally argillite, siltstone, and fine sandstone.
Géologie du Massif central
These ages are consistent with a U-Pb age of Ma on a rhyolite in the lower part of the formation south of New Annan Dunning et al. The Silurian Wilson Brook and early Devonian Portapique River formations were deposited regionally over at least km of the Cobequid Highlands and almost identical facies are recognised 50 km farther east at Arisaig.
The only Nuttby Formation to the north outcrops along the general trend of the fault system at the northern edge of the Pleasant Hills pluton and in the allochthonous New Annan thrust sheet Piper and Pe-Piper In the Bass River block, the Ma Frog Lake gabbro is of similar age to widespread dioritic to granodioritic plutons in the Caledonia and Mira terranes.
Seismic-reflection profiles show basement rocks dipping southward beneath Carboniferous sedimentary rocks for several kilometres south of the Cobequid Fault. The Carboniferous plutons and associated igneous rocks of the western Cobequid Highlands, Nova Scotia.
les roches volcaniques et plutoniques pdf – PDF Files
As argued by Pe-Piper et al. The Whirley Brook intrusion is marked by plutoniquds strong magnetic anomaly Piper et al. Along the plutoniqjes fault zones, highly deformed earlier emplaced plutonic rocks underwent strong solid-state deformation and are cut by progressively less deformed younger plutonic rocks, demonstrating that the faults were persistent conduits for magma Pe-Piper et al.
Atlantic Geology, 29, pp. Field evidence for the extent and style of overthrusting along the northeastern margin of the Cobequid Highlands, Nova Scotia. Not included in either block is the Economy River Gneiss, a granodioritic orthogneiss that has yielded a U-Pb zircon age of Ma Doig et al. Irregular enclaves and sheets of diabase occur within this fine-grained rocehs, with textures suggesting that the mafic magma was immiscible cf.
The km-long Rockland Brook Fault strand Miller et al. Les gabbros roches plutoniques basiques From its present geometry, it may have been the most inboard of these peri-Gondwanan terranes. Geological Survey of Canada Paper E, pp. The granitic Gilbert Hills pluton in the north central Cobequid Highlands is probably of similar age. Transient cookies are kept in RAM and are deleted either when you close all your browser windows, or when you reboot your computer.
Les amphiboles sont pour la plupart des silicates … I. Display large image of Figure 1. Both biostratigraphic and radiometric data Dunning et al. Tectonic evolution of Fundy basin, Canada: Volcanic rocks and turbidite of the Jeffers block were deformed colcaniques a strike-slip regime between Ma and Ma, with the intrusion volcanuques granodiorite and granite.
The Plutoniquess River section: Please click the link in that email to activate your subscription. Geological Association of Canada, Special Paper 24, pp. It is lithologically correlated with coastal outcrops of previously unnamed conglomerate east of Squally Point Salas that unconformably overlies the Fountain Lake Group and contains deformed granite clasts. No registered users and 9 guests.
Canadian Journal of Earth Sciences, 39, pp. The Cobequid Fault Fig. Display large image of Figure 2. Geological Society of America Bulletin,pp.
Its assignment to the mid Devonian is thus based solely on macropaleontological evidence and is inconsistent with the presence of abundant rhyolite clasts. No volcanic rocks are known from the Cobequid Highlands of similar age to the Ma Stirling Group of the Mira terrane. Gabbro intrusions of the Cobequid Shear Zone are of olivine tholeiite composition and appear geochemically related to the basalt.
Pe-Piper and Murphyand intruded by a series of plutonic rocks Table 1, Fig.
Géologie du Massif central — Wikipédia
Late Devonian — earliest Carboniferous basin formation and relationship to plutonism, Cobequid Highlands, Nova Scotia. Display large image of Figure 3. These units have all yielded ages of to Ma by U-Pb on zircon Doig et al. 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 roches magmatiques – PDF – … ; Les roches volcaniques, The stratigraphy and geochemistry of late Devonian to early Carboniferous volcanic rocks of the northern Chignecto peninsula, Cobequid Highlands, Nova Scotia.
If you have persistent cookies enabled as well, then we will be able to remember you across browser restarts and computer reboots. Also unlike other parts of the eastern Canadian Avalonian, Cambrian – Ordovician shelf sedimentary rocks are not known from the Cobequid Highlands. In places, the felsic and mafic rocks appear to have been emplaced as co-existing magmas Pe-Piper et al. We have in general followed their stratigraphic nomenclature.
The field notes and plotting sheets of Donohoe and Wallace are available through the N. Poor quality U-Pb and Rb-Sr ages of ca. Geological Survey of Canada Paperpp. Siltstone in the middle of the basaltic facies of the Diamond Brook Formation was reported as early Tournaisian on the basis of palynomorphs volcanuques D, D of Donohoe and Wallacebut re-interpreted as Late Famennian by Martel et al.
Mineral occurrences in the Cobequid Highlands.