New isotopic studies of Nd, the daughter product of the short-lived and now extinct isotope Sm, have revealed that the accessible part of the silicate Earth (e.g., upper mantle and crust) is more radiogenic in Nd/Nd than that of chondritic meteorites. The positive Nd anomaly of the Earth’s mantle implies that the Sm/Nd ratio of the mantle was fractionated early in Earth’s history and that the c...

Radiographic imaging of magma dynamics in a volcanic conduit provides detailed information about ascent and descent of magma, the magma flow rate, the conduit diameter and inflation and deflation of magma due to volatile expansion and release. Here we report the first radiographic observation of the ascent and descent of magma along a conduit utilizing atmospheric (cosmic ray) muons (muography)...

In open conduit volcanoes, volatile-rich magma continuously enters into the feeding system nevertheless the eruptive activity occurs intermittently. From a practical perspective, the continuous steady input of magma in the feeding system is not able to produce eruptive events alone, but rather surplus of magma inputs are required to trigger the eruptive activity. The greater the amount of surpl...

We model the ascent and eruption of lunar mare basalt magmas with new data on crustal thickness and density (GRAIL), magma properties, and surface topography, morphology and structure (Lunar Reconnaissance Orbiter). GRAIL recently measured the broad spatial variation of the bulk density structure of the crust of the Moon. Comparing this with the densities of lunar basaltic and picritic magmas s...

Crustally-derived granites may be generated in a variety of tectonic settings, but whatever the ultimate causse of heating crustal thickening, crustal extension, enhanced heat flux from the mantle, or magmatic advection by mantle-derived melts crustal melting likely occurs in a dynamic environment. Under these conditions deviatoric stress acting on an anisotropic crustal source region will lead...

Strong ground motions induce large dynamic stress changes that may disturb the magma chamber of a volcano, thus accelerating the volcanic activity. An underground nuclear explosion test near an active volcano constitutes a direct treat to the volcano. This study examined the dynamic stress changes of the magma chamber of Baekdusan (Changbaishan) that can be induced by hypothetical North Korean ...

Within the volcanological community there is a growing awareness that many large- to small-scale, point-source eruptive events can be fed by multiple melt bodies rather than from a single magma reservoir. In this study, glass shard major- and trace-element compositions were determined from tephra systematically sampled from the outset of the Puyehue-Cordón Caulle (PCC) eruption (~1 km(3)) in so...

Numerical models show that maximum dike width at oceanic spreading centers should scale with axial lithospheric thickness if the pre-diking horizontal stress is close to the Andersonian normal faulting stress and the stress is fully released in one dike intrusion. Dikes at slow-spreading ridges could be over 5 m wide and maximum dike width should decrease with increasing plate spreading rate. H...

the aligoodarz granitoid occurs in sanandaj-sirjan zone (ssz), western iran. tonalite, granodiorite and granite are the main rock types cropping out in the area. comparison of aligoodarz granitoid with dehno and boroujerd granitoids reveals several similarities in their chemical characteristics. thus, the above mentioned granitoids can be assigned as a co-genetic magmatic suite, in which pluton...