نتایج جستجو برای: mafic dykes
تعداد نتایج: 2656 فیلتر نتایج به سال:
a r t i c l e i n f o Crust extracted from the mantle in arcs is refined into continental crust in subduction zones. During sediment subduction, subduction erosion, arc subduction, and continent subduction, mafic rocks become eclogite and may sink into the mantle, whereas more silica-rich rocks are transformed into felsic gneisses that are less dense than peridotite but more dense than the uppe...
Global maps of thermal and fast neutron fluxes from the moon suggest three end-member compositional units. A high thermal and low fast neutron flux unit correlates with the lunar highlands and is consistent with feldspathic rocks. The South Pole-Aitken basin and a strip that surrounds the nearside maria have intermediate thermal and fast neutron flux levels, consistent with more mafic rocks. Th...
The Jinba deposit is an orogenic gold located in the Markakuli shear zone, southern part of Altay belt, northwestern China. Several granite and diorite dykes are present area mine, with ore bodies occurring dykes. However, diagenetic age, genesis, evolution these magmas, tectonic setting dyke emplacement process, remain unclear. study based on a detailed geological survey, zircon U–Pb dating, L...
The analysis of Anisotropy of Magnetic Susceptibility (AMS) is a powerful and rapid technique to examine the preferred orientations of mineral (magnetic) fabrics and can indicate the nature of a magma transport (vertical or lateral). The relationship between magnetic fabric and geometry of a dyke swarm enables us to understand magma emplacement processes. Depending on the mutual relationship of...
Many volcanic hazard factors--such as the likelihood and duration of an eruption, the eruption style, and the probability of its triggering large landslides or caldera collapses--relate to the depth of the magma source. Yet, the magma source depths are commonly poorly known, even in frequently erupting volcanoes such as Hekla in Iceland and Etna in Italy. Here we show how the length-thickness r...
Where and how melt is stored in the crust uppermost mantle important for understanding dynamics of magmatic plumbing systems evolution rifting. We determine shear velocity radial anisotropy magmatically rifting northern East African Rift to locus orientation melt, both on off-rift. Love Rayleigh fundamental modes are extracted from ambient noise data 9-26 s period then inverted velocity. VSV 0....
Variably oriented dolerite intrusions outcrop in the Albany–Fraser Orogen along south coast of Western Australia with previously unknown ages but where previous studies interpreted Mesoproterozoic to Cretaceous emplacement. Here, we place temporal constraints on seven mafic across ∼150 km using zircon U–Pb, apatite and plagioclase 40Ar/39Ar geochronology, coupled whole-rock major trace-element ...
there are three different basic dykes in the northeast of golpayegan area, central part of sanandaj-sirjan zone (ssz) including: mylonitic gabbros (group 1), alkali dioritic-basanitic dykes (group 2) and alkali monzogabbroic to monzodioritic dykes (group 3). group 2 and 3 cut post-collisional rocks and are related to after subduction processes of neo-tethys. geochemistry characteristic of studi...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید