| In the cooler middle and upper crust, felsic magmatism and aqueous metasomatism are most important. |
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| The alternating bands of mafic and felsic minerals are a striking and distinctive feature of all gneisses. |
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| The occurrence of these felsic extrusive igneous rocks potentially provides key information on the complex interplay of magmatism and tectonics. |
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| Some andesitic and felsic intrusions created a minor, stratified volcaniclastic component via hydrovolcanic eruptions. |
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| It comprises several mafic, mafic-felsic and felsic intrusions with distinctive geochemical affinities and apparent radiometric ages. |
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| Increasing proximity to a subduction zone during plate convergence is indicated by the appearance of felsic tuff. |
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| The rocks of the complex show an overall trend of decreasing mafic minerals and increasing felsic minerals spatially from west to east. |
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| The sample of Omonville granodiorite was collected from the foliated felsic phase of the intrusion at Pointe Jardeheu. |
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| The matrix is dominantly felsic, but also contains biotite, muscovite, epidote and titanite. |
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| These felsic rocks are contemporaneous with or only slightly younger than rocks from the Guevgueli ophiolite. |
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| Their lower viscosity and greater lateral mobility explain why the mafic magmas were distributed over a much wider area than the felsic magmas. |
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| The volcanics are predominantly felsic pyroclastics with lesser intermediate and mafic flows and subvolcanic gabbroic sills and dykes. |
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| The mafic sheets have not contributed at all to the felsic volcanic-derived volcaniclastic breccias, thus supporting an intrusive origin for the mafic volcanic rocks. |
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| It is also possible that upper mantle mafic plumes acted as a heat source for, and made some contribution to, the melting of more felsic rocks in the lower crust. |
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| Also, those workers noted that eclogites, in particular with felsic composition, are theologically weak, relative to their granulitic equivalents. |
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| Voluminous quantities of Late Ordovician to Wenlockian felsic pyroclastics and lava flows record the extensive volcanism associated with the collision and deformation. |
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| The second sector is in the north-west section where the bedrock source likely corresponds to a deformation zone bordering on a felsic intrusion. |
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| In contrast, mafic and felsic intrusive rocks in the Coal Creek inlier are rare. |
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| The horizon is situated north of an intermediate lobate and spherulitic flow and a felsic breccia. |
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| Epiclastic rocks and interbedded fine-grained felsic pyroclastic rocks are dominantly found within the stratigraphic footwall. |
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| The Late Mississippian felsic volcanic rocks from Cumberland Bay differ from those of Harvey and Piskahegan groups. |
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| Diamond drilling in 1970, defined a felsic centre of over 4.5 km in length. |
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| Isolated Megatem anomalies located to the top of felsic centre have remained un-tested and represent future drilling targets. |
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| It consists of a mafic to felsic suite of rocks, which are pictured here in this aggregate quarry. |
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| The property covers part of the Waconichi felsic formation, which hosts the Lemoine Mine. |
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| As shown on a previous slide, the outcrop overlies the magnetic feature interpreted to be a large felsic igneous complex. |
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| The Musgrave Block consists of granulite-facies felsic gneisses, granites, felsic and mafic granulites, and voluminous mafic-ultramafic intrusive rocks. |
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| The contemporaneity in ophiolite formation and felsic arc magmatism suggests that intraoceanic subduction started soon after the opening of the ocean basin. |
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| The enclaves probably represent globules of mafic magma in felsic magma. |
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| The present day volumetric variation in the amount of mafic and felsic volcanic rocks preserved in the Parana and Etendeka provinces is interesting. |
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| Local hybridization between the mafic and felsic magmas is common. |
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| This Archaean subprovince is made up of felsic to ultramafic volcanics, clastic sediments and tonalitic and granitic, pre to post-tectonic intrusions. |
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| The bedrock in the area is dominated by porphyritic, pillowed and locally magnetic basalts, cut by diorite intrusions, felsic porphyry intrusions, and a swarm of NE-trending diabase dykes. |
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| The Toqui property is situated in an area of Jurassic-Cretaceous volcanic and volcano-sedimentary rocks, which are intruded by intermediate to felsic porphyritic bodies of Upper Cretaceous to Tertiary age. |
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| At the property scale, the above-mentioned shear cuts mafic to felsic flows as well as sediments intruded by numerous quartz-feldspar porphyritic dykes. |
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| As originally presented, the terms felsic and mafic were used in a broadly descriptive sense to indicate the relative abundances of light-coloured and dark-coloured minerals, respectively, in an igneous rock. |
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| The Massicotte, Casgrain and Nantel properties are located along the Massicotte-Grasset deformation break while the Sicotte property is located to the east of the Brouillian pluton and the Ste-Helene felsic complex. |
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| Much of the plateau is underlain by felsic to mafic volcanic rocks, interlayered metasedimentary strata, and small to medium-sized granitic plutons. |
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| The gabbro-diorite intrusion is within silicified felsic schist and mylonite of a linear zone referred to as the Pistol Bay Corridor. |
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| The belt is Archaean and consists of ultramafic, mafic and felsic volcanic rocks, clastic sedimentary rocks and tonalitic to granitic intrusions, early to post-tectonic. |
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| The mineralization of these showings are associated with a network of quartz veins hosted in carbonate and silicified felsic rock and contains dissemination of pyrite and chalcopyrite. |
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| It contains fragments of volcanics, 0.5 to more than 6.0 centimeters in size, consisting of felsic to mafic volcanics, as well as chert blocks, in a wacke type matrix. |
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| Alunitization may occur in both felsic and mafic rocks in places. |
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| At El Mna, the drilling that began in 2007 was carried on and reached interval 470.15 m. It first intersected felsic volcanic facies, then clay sediments. |
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| In addition, felsic volcanic or granitic rocks are likely the source of geochemical and airborne radiometric anomalies in the Caledonian Highlands. |
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| The southern part of the property is a large band of felsic to mafic metavolcanics which include intermediate flows, quartz and feldspar intrusive and extrusive rocks. |
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| The property is located in the central part of Duhesme lake volcano-sedimentary complex, part of one of five small felsic complexes along La Grande Rivière. |
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| The minettes of Buell Mountain are felsic, and many contain ground-mass quartz. |
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| Immediately east of the mineralized zone, and on its entire length, an intrusive felsic facies, moderately coarse and strongly seriticized was identified. |
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| The Lawson Brook Formation consists mainly of a variety of volcanic rocks such as pillow basalts as seen here in the top photo, tuffs, and gabbros, interbedded with felsic volcanic rocks and minor volcaniclastic units. |
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| They tend to overlie felsic volcanic rocks or granitic rocks, which are less porous than sedimentary strata and hence are more likely to retain water. |
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| The supracrustal strata of NKGBS consist of metabasalts, metakomatiites and felsic to intermediate metavolcanics. |
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| Chemically, mafic rocks are on the other side of the rock spectrum from the felsic rocks. |
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| Mafic lava, before cooling, has a low viscosity, in comparison with felsic lava, due to the lower silica content in mafic magma. |
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| Igneous oceanic plateaus have a ratio intermediate between continental and oceanic crust, although they are more mafic than felsic. |
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| Granite has a felsic composition and is more common in recent geologic time in contrast to Earth's ultramafic ancient igneous history. |
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| These rocks are intruded by metamorphosed gabbro, diabase, and felsic dikes and sills and granite intrusions. |
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| Quartz is a defining constituent of granite and other felsic igneous rocks. |
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| Trace element composition indicates a felsic source. |
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| The geology consists of a complex assemblage of felsic tuffs and felsic to intermediate fragmental intrusives trending east-west, with a subvertical dip. |
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| The porphyritic biotite granite is a felsic rock as a result of the presence of larger amount of leucocratic minerals that include the quartz and the feldspars. |
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| The gemstones are closely related to the contact between mafic schists and felsic gneisses and pegmatites. |
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| Sugarloaf Mountain near Campbellton represents a Devonian volcanic neck that became plugged with felsic lava during the final stages of volcanism. |
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| Areas underlain by felsic volcanic rocks typically have shallow, stony soils of the Lomond Unit on the hilltop sites and compact loams of the Popple Depot Unit on the low ridges and slopes. |
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| Based on the presence of black matrix felsic breccia in the Harry Brook inlier, these rocks were tentatively correlated with black rhyolite domes of Cambrian age that occur along strike in the Annidale Group. |
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| Mafic igneous rocks with microlithic to intergranular texture are ubiquitous but less abundant than more felsic compositions. |
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| These highly folded and deformed rocks consist primarily of felsic and mafic volcanic rocks with some non-calcareous meta-sedimentary rocks including schist, slate, and phyllite. |
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| Tin mineralization is focused within a chloritic, garnetiferous amphibolite unit within felsic mica schists. |
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| The conglomerate contains well-rounded felsic and mafic volcanic clasts that are presumably derived from the roughly coeval volcanic rocks of the Bryant Point and Benjamin formations. |
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| Plagioclase is commonly the only feldspar phyric phase in the felsic to intermediate volcanic clasts, including lapilli and vitric tuff and probable ash-flow tuff. |
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| These Prospects exhibit REE mineralization consisting of allanite, zircon and fergusonite, associated with felsic volcanic rocks in a mafic-felsic bi-modal volcanic belt. |
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| Lava domes are formed by the extrusion of viscous felsic magma. |
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| Felsic magma, such as rhyolite, is usually erupted at low temperature and is up to 10,000 times as viscous as basalt. |
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