Phase equilibria modelling incorporating melt reintegration offers a methodology to create hypothetical rock compositions that may have existed prior to melt loss, allowing the potential prograde evolution of rocks to be explored. However, melt reintegration modelling relies on assumptions concerning the volume of melt that was lost and is generally restricted by the absence of direct constrain...

S U M M A R Y . The high-temperature transformation of andalusite (AI2SiOs) into 3/2-mullite (3AIzO32SiO2) plus vitreous silica (SiO2) has been studied within the temperature interval from 13oo to 16oo ~ by means of X-ray powder and single-crystal techniques and by infrared spectroscopy. Results are interpreted in terms of a topotactic transformation in which (oi I) and (oI i) planes of andalus...

Different models are discussed to interpret the presence of kyanite as a stable phase in contact aureoles especially in the andalusite-, sillimanitebearing aureoles. In such aureoles the polymorphic sequence kyanite → andalusite → sillimanite can be explained in terms of an essentially isobaric path during which kyanite initially crystallises from the breakdown of pyrophyllite or more likely mu...

Multiscale structural analysis is carried out to explore the sequence of superposed pre-Alpine chloritoid–staurolite–andalusite metamorphic assemblages in polydeformed Variscan basement upper Val Camonica, central Southalpine domain. The dominant fabric Camonica late-Variscan S2 foliation, marked by greenschist facies minerals and truncated base Permian siliciclastic sequences. intersection wit...

Relevance. When mapping the vast areas of Precambrian polymetamorphic complexes in North Yenisei Ridge, there is a problem metamorphism interpretation and phasing geological development particular area along with thrust tectonics. The solution these issues also great importance for purposes delineation metamorphic rocks that are favorable detection high-alumina (andalusite, kyanite, sillimanite...

This article describes the geology and industrial mineral potential of corundum, pyrophyllite and andaluite at the Empress deposit in the Taseko Lakes area (Figure 1). The Empress is a copper-goldmolybdenum porphyry deposit located 225 kilometres north of Vancouver and 50 kilometres northwest of Goldbridge and the Bralorne mining camp. Fine-grained corundum, in association with andalusite-pyrop...

the relations of fibrolite-biotite are discussed by presenting data from the ardara aureole, nw ireland. biotite-fibrolite intergrowths are developed in all three aureole zones including: the outer kyanite-bearing andalusite zone, the middle kyanite-free andalusite zone and the inner prismatic sillimanite zone. a strain-assisted mechanism is proposed for the fibrolitisation of biotite in the ar...

Int roduct ion. . . Coahuila Mountain Area. Sketch of the Regional Geology. Geological Relations of the Pegmatites General Statement. . . . . Pegmatites of Group I Pegmatites of Group Il Mineralogy of the Pegmatites. Group I General Mineralogy. . . . Andalusite. . . . Other Minerals. Group II General Mineralogy. Evidence for Two Generations of Pegmatites Winchester Area. . . Sketch of the Regio...

The conditions at which monazite and allanite were produced and destroyed during prograde metamorphism of pelitic rocks were determined in a Buchan and a Barrovian regional terrain and in a contact aureole, all from northern New England, USA. Pelites from the chlorite zone of each area contain monazite that has an inclusion-free core surrounded by a highly irregular, inclusion-rich rim. Texture...