Additional processes like liquid immiscibility and deuteric
alteration probably played only a minor role in crystallization, and are therefore omitted.
Occasionally amphibole--as deuteric
alteration --is present.
Mineralogy, textures and chemistry suggest that some magma mixing and/or deuteric
alteration may have taken place within the complex.
14), supporting a deuteric origin for the S and metal enrichment; these data are consistent with the observations of Stirling (1979) of 8 enrichment in the most quenched contact zones of a similar dyke.
The groundmass is recrystallized and hydrothermally altered to a variable degree, probably reflecting the autometasomatic effects of deuteric fluids, as well as the slightly later contact metamorphic and metasomatic effects of intrusion of the Lake George granodiorite and antimony vein mineralization in the area.
5) Autobrecciation along the margins of the dyke, subrounded fragments, subhedral to rounded and fragmented plagioclase and quartz phenocrysts (phenoclasts), and the autometasomatic effects of deuteric fluids support fluidization (vapour-magma emulsion) as a key emplacement mechanism for the dyke, i.
complete absence of any deuteric
alteration such as chlorite, white mica, carbonate, etc.
Despite the presence of magmatic sulphide and local alteration minerals, many of the mafic rocks retain igneous textures and assemblages with minimal deuteric overprint.
Mafic rocks in the southern portion of the pluton generally retain much of their original igneous character whereas deuteric alteration is most pervasive in the northern portion of the pluton.
Although the freshest available rocks were sampled, some samples show deuteric alteration.