نتایج جستجو برای: source of magma
تعداد نتایج: 21186166 فیلتر نتایج به سال:
The Palaeogene Ardnamurchan central igneous complex, NW Scotland, was a defining place for the development of the classic concepts of cone-sheet and ring-dyke emplacement and has thus fundamentally influenced our thinking on subvolcanic structures. We have used the available structural information on Ardnamurchan to project the underlying three-dimensional (3D) cone-sheet structure. Here we sho...
sangan magnetite skarn mine is located 300 km southeast of mashhad, along the eastern part of khaf-drouneh volcanic-plutonic belt. granitoids from three areas within the sangan mine a, c-north and dardvay were studied. within the study area, three intrusive rocks including biotite-hornblende monzonite porphyry, biotite syenite and syenogranite were recognized. based on field cross cutting, abse...
Supereruptions violently transfer huge amounts (100 s-1000 s km(3)) of magma to the surface in a matter of days and testify to the existence of giant pools of magma at depth. The longevity of these giant magma bodies is of significant scientific and societal interest. Radiometric data on whole rocks, glasses, feldspar and zircon crystals have been used to suggest that the Bishop Tuff giant magm...
Over the last several hundred years, Stromboli has been characterized by steady-state Strombolian activity. The volcanic products are dominated by degassed and highly porphyritic (HP-magma) black scoria bombs, lapilli and lava flows of basaltic shoshonitic composition. Periodically (about one to three events per year), more energetic explosive eruptions also eject light coloured volatile-rich p...
Lava dome eruptions commonly display fairly regular alternations between periods of high activity and periods of low or no activity. The time scale for these alternations is typically months to several years. Here we develop a generic model of magma discharge through a conduit from an open-system magma chamber with continuous replenishment. The model takes account of the principal controls on f...
The alkaline and stratoid volcanic rocks of Separdeh district (NE Qazvin), located on the central Albroz zone, are underlain conformably by Early Cretaceous limestones of Tizkuh Formation. These rocks are texturally homogenous and very fine-grained and characterized by microphenocrysts and microliths of plagioclase, pyroxene, olivine, apatite and opaque set in a hyaline matrix. However, few pyr...
Felsic magma commonly pools within shallow mushroom-shaped magmatic intrusions, so-called laccoliths or cryptodomes, which can cause both explosive eruptions and collapse of the volcanic edifice. Deformation during laccolith emplacement is primarily considered to occur in the host rock. However, shallowly emplaced laccoliths (cryptodomes) show extensive internal deformation. While deformation o...
abstract prediction of death anxiety on the basis of demographic characteristics and sp پیش بینی اضطراب مرگ براساس ویژگی های دموگرافیک و مولفه های معنویت در سالمندان به کوشش الهام حسن زهی معنویت از جمله مفاهیمی است که سالیان متمادی در حوزه روان شناسی جایگاه خود را یافته است پیشینه پژوهش نشان داده است که با متغیرهای فراوانی در روانشناسی در ارتباط بوده است. هدف از پژوهش حاضر این اس...
The Alvand complex (Hamedan province) comprises several bodies ranging from acidic to intermediate and basic compositions intruded in the regional metamorphic sequence of the area (the Hamedan phyllites) during various magmatic episodes in Jurassic. In northern part of the complex (the Cheshmeh-ghasaban area) there are some outcrops of hornblende gabbro and olivine gabbronorite. The olivine-gab...
Starting on 21 April 2015, unusual activity on the summit of Kīlauea was detected. Rapid summit inflation and a rising lava lake in Halema‘uma‘u crater were interpreted as early signs of imminent magma intrusion. We explored the three-dimensional (3D) surface motion accompanying this volcanic event using the Interferometric Synthetic Aperture Radar (InSAR) stacking method. Multi-temporal COSMO-...
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