Molybdenum isotopes have emerged as novel tracers for high-temperature igneous and metamorphic processes. The debate remains to what extent different subducted slab lithologies, such oceanic crust marine sediments, contribute the Mo isotope signature of arc magmas and, hence, exert controls on terrestrial cycle. Here we investigate systematics from input output at Tongan subduction zone: Arc la...

Bulk-rock major and trace element geochemistry of a range of eclogite, garnet blueschist and garnet amphibolite rocks from northern New Caledonia has been determined in order to geochemically characterise subducted oceanic crust. The rocks experienced peak metamorphic conditions of 1.9 GPa and 600 jC and represent excellent samples of oceanic crust that was subducted to depths of approximately ...

At the Kakkonb geothermal area, Japan, a large Quaternary granitic body is dstributed below ca 2.5 km ckpth from the surface, associating with thick high-temperature contact me&amorphic zones in the overlying formations, and a meteoric-water-cbminated type hydrothermal system is developedat present time. During the 'Deep-seated Geothermal Resources Survey', WD-la well was drilled to 3729 m dept...

The Marun–Keu complex (Polar Urals, Russia) is a poorly known member of a group of high P complexes outcropping along the length of the Uralide orogen. The central and southern parts of the complex are metamorphosed at high P, medium T conditions (Tmaxf600–650 jC and Pf14–17 kbar) and differ from its northern part and the rest of the Uralian high P complexes which are metamorphosed at blueschis...

Small-volume Late Cretaceous monogenetic alkaline volcanism along the southern margin of North America resulted in a broad igneous belt more than 1200 km long from the Trans Pecos region of west Texas to central Mississippi, collectively forming a northern Gulf of Mexico magmatic zone (NGMMZ). The locus of igneous activity is associated with the discontinuity separating Mesoproterozoic cratonic...

This study presents a new geochemical, petrological, and geochronological U–Pb dataset from Ediacaran metabasites of the Canigó Cap de Creus massifs, Eastern Pyrenees. The rocks are composed calcic amphibole + plagioclase chlorite epidote ± quartz plus titanite apatite ilmenite biotite rutile as accessory phases show relict igneous textures. Peak pressure-temperature determinations share common...

GRA 06128/9: Since their discovery at Graves Nunataks icefield during the 2006/2007 Antarctic Search for Meteorites field season, GRA 06128 and GRA 06129 have received considerable scientific attention. Their elevated modal abundances of oligoclase (>75%), blocky or slab-like character, granoblastic textures and ‘andesitic’ bulk compositions set them apart from all other meteorite classes. It h...

Introduction In the following chapters we will find that nearly all of the varied aspects of volcanism are either directly or indirectly controlled by the chemical composition of magma and the rate at which it cools and solidifies. If you are to understand and appreciate subsequent discussions of volcanoes and related volcanic phenomena, it is essential that you have a good grasp of the basic c...

 Igneous Rocks form from the solidification of molten rock. Intrusive igneous rocks are composed of crystals that are large enough to be seen with the naked eye because these rocks cooled slowly, deep within the Earth thereby allowing time for the crystals to grow. In contrast, extrusive (volcanic) igneous rocks cool very quickly after they erupt from a volcano, and so are composed of microsco...