The physical properties and the hydrogen release of NaBH4–Mg(BH4)2 and NaBH4−Ca(BH4)2 composites are investigated using in situ synchrotron radiation powder X-ray diffraction, thermal analysis and temperature programmed photographic analysis. The composite, xNaBH4–(1 − x)Mg(BH4)2, x = 0.4 to 0.5, shows melting/frothing between 205 and 220 °C. However, the sample does not become a transparent mo...

Mantle peridotite xenoliths from Archean cratons generally have high molar Mg=(Mg C Fe), or Mg#. The best known suites, from the Kapvaal and Siberian cratons, have high modal orthopyroxene (Opx). These high Opx compositions are probably not residues of partial melting. Less well known cratonic xenolith suites from Greenland and North America include high Mg# peridotites with much lower modal Op...

The geochemical variations of Kilauea's historical summit lavas (1790^1982) document a rapid fluctuation in the mantle source and melting history of this volcano. These lavas span nearly the entire known range of source composition for Kilauea in only 200 yr and record a factor of V2 change in the degree of partial melting. In this study, we use high-precision measurements of the U-series isoto...

[1] The current structure of the South Armorican Domain in the French Variscan Belt, provides an excellent record of the late orogenic evolution, as documented by the complex interactions between extensional structures and partial melting. In the Golfe du Morbihan, the South Brittany Migmatite Belt (SBMB), tectonically overlain by non‐melted metamorphic units, was studied by combined structural...

Eoarchean [3.6 to 4.0 billion years ago (Ga)] tonalite-trondhjemite-granodiorite (TTG) is the major component of Earth's oldest remnant continental crust, thereby holding the key to understanding how continental crust originated and when plate tectonics started in the early Earth. TTGs are mostly generated by partial melting of hydrated mafic rocks at different depths, but whether this requires...