introduction volcanic rocks with a porphyritic texture have experienced two crystallization stages. the first is slow, resulting in phenocrysts, and the second, which took place at, or near the surface, or during intrusion into a cooler body of rock, result in a groundmass of glass, or fine crystals. the pressure and temperature history of a magma during crystallization is recorded in the chemi...

Previous studies have shown that the 2.04 Ga Kangâmiut dyke swarm of SW Greenland was injected into an active tectonic environment associated with the formation of the Nagssugtoqidian orogenic belt. Major and trace element modelling of the swarm shows that its chemical evolution was controlled by simple clinopyroxene–plagioclase fractionation. However, such trends — although typical of continen...

A total of 73 peridotitic mantle xenoliths and a set of garnet and clinopyroxene xenocrysts from the recently discovered Jurassic Monk Hill kimberlite (UCO-H77A) in South Australia were used to constrain the thermal and compositional structure of the lithospheric mantle beneath the Adelaide Fold Belt, which is located at the southeastern margin of the Australian craton. The xenoliths contain mo...

The Hunt Mo skarn deposit is one of the best examples of a late tectonic, granitic pegmatite-related, skarn system in the Grenville province. An Re-Os age of 1069 ± 11 Ma was obtained from a molybdenite crystal (6.4 ppm Re) hosted in proximal skarn (sample 50O) consistent with a contact metasomatic origin related to the granitic body. Although less evolved than other Grenvillian pegmatites, the...

Step-scanning calorimetric measurements using a Setaram HT1500 calorimeter were performed between 800 and 1400~ on two natural samples: a ugandite from the East African rift and an olivine basalt from the western Mexican arc. Our measurements provide the first in-situ quantitative assessment of enthalpy during melting of initially crystalline natural samples. The distribution of latent heat acr...

The prograde metamorphism of eclogites is typically obscured by chemical equilibration at peak conditions and by partial requilibration during retrograde metamorphism. Eclogites from the Eastern Blue Ridge of North Carolina retain evidence of their prograde path in the form of inclusions preserved in garnet. These eclogites, from the vicinity of Bakersville, North Carolina, USA are primarily co...