The monzogranites and syenogranites of the Early Devonian (Emsian), post-tectonic, high-level, S-type Wilsons Promontory batholith contain magmatic garnet cordierite, in addition to biotite, as well biotite–quartz pseudomorphs after early orthopyroxene. forms southern tip Australian mainland consists four penecontemporaneous plutons, emplaced at shallow crustal depth, intruding Ordovician Lower...

[1] Large igneous provinces are characterized by magmatic activity on two distinct timescales. While these provinces have total active lifetimes of order 10–30 Ma, most of the erupted volume is emplaced within 1 Ma in many cases. The longer timescale is consistent with plume or tectonic models for mantle melting responsible for flood volcanism, but the shorter “main stage” timescale is enigmati...

Earth’s dominant form of magmatism occurs at mid-ocean ridges (MORs), producing the igneous crust for two-thirds of the planet’s surface and conveying significant heat and material fluxes from the mantle to the world’s oceans. Mid-ocean-ridge basalt (MORB) magmas form from upwelling compositionally heterogeneous mantle1 by aggregation of near-fractional melts beneath spreading centres2. Multipl...

The calc-alkaline Ladakh batholith (NW Himalayas) was dated to constrain the timing of continental collision and subsequent deformation. Batholith growth ended when collision disrupted subduction of the Tethyan oceanic lithosphere, and thus the youngest magmatic pulse indirectly dates the collision. Both U-Pb ages on zircons from three samples of the Ladakh batholith and K-Ar from one subvolcan...

Introduction: Group IIE iron meteorites, together with groups IAB and IIICD, are classified as non-magmatic iron meteorites [1]. These are distinguished from magmatic iron meteorites in having element-Ni trends that cannot be explained by fractional crystalli-zation [2,3]. They also contain abundant silicate inclusions , which are largely absent in members of the magmatic groups. The non-magmat...

a r t i c l e i n f o a b s t r a c t Keywords: receiver functions lithosphere lithosphere–asthenosphere boundary mid-lithospheric discontinuity To explore how lithospheric structure varies between tectonic and magmatic terranes of the western United States, we use observations of shear-to-compressional wave conversions across lithospheric velocity interfaces. With a newly developed automatic m...

Magma genesis, migration, and eruption have played prominent roles in the chemical differentiation of the Earth. Plate tectonics has provided the framework of tectonic environments for different suites of igneous rocks and the dynamic mechanisms for moving masses of rock into melting regions. Petrology is rooted in geophysics. Petrological and geophysical processes are calibrated by the phase e...

Between 5 and 6 million years ago, during the so-called Messinian salinity crisis, the Mediterranean basin became a giant salt repository. The possibility of abrupt and kilometre-scale sea-level changes during this extreme event is debated. Messinian evaporites could signify either deep- or shallow-marine deposits, and ubiquitous erosional surfaces could indicate either subaerial or submarine f...

Introduction. It was previously known that S contents were low in the two volatile depleted magmatic iron-meteorite groups IVA and IVB. Group IID, with 21 members, the fourth largest magmatic group, also has a low S content but has high contents of other volatiles. We suggest that this surprising juxtaposition is best understood by two episodes of core formation, with the IID irons forming from...

Mt Ontake in central Japan suddenly erupted on 27(th) September 2014, killing 57 people with 6 still missing. It was a hydro-volcanic eruption and new magmatic material was not detected. There were no precursor signals such as seismicity and edifice inflation. It is difficult to predict hydro-volcanic eruptions because they are local phenomena that only affect a limited area surrounding the exp...