However, the patterns are relatively fractionated due to the fractionation of hornblende and/or feldspar phases.
2], suggesting crystal fractionation of hornblende ([+ or -]pyroxene) and Fe-Ti oxide (Fig.
5], suggesting fractionation of hornblende ([+ or -] pyroxene), Fe-Ti oxide and apatite.
From combined field, geochemical and isotopical studies it has been concluded that the mantle-derived mafic magmas from which the MMEs crystallized were likely mostly formed by mafic-felsic interaction and mingling, or prior to the mixing crystal fractionation of hornblende ([+ or -] pyroxene) and Fe-Ti oxide.
The amphibolites are dark grey to black foliated rocks composed of hornblende altered plagioclase epidote biotite and opaque.
It grades from prismatic hornblende into actinolite in the transitional zone to chlorite in the underlying green schist facies (Miyashiro 1994).
Hornblende was also dated from the amphibolites in subophiolitic metamorphic rocks that yielded a good K Ar age of 80.
The lithology of the area consists of greenschists, mica schists, quartzites, hornblende schists, amphibolites, garnet-amphibolites, serpentinites and porphyritic hypabyssal rocks with andesitic to dacitic composition (Figure 1).
At the western section of the greenschists, these are in transitional contact with hornblende schists.
At their western part, the hornblende schists are in contact with serpentinites (Figure 1).
The amphiboles show a wide compositional range and very complex zoning from magnesium hornblende, titanium and chromium rich, to ferrous hornblende and actinolite (Arias, 2002).
The dolerites are made of relatively fresh plagioclase and clinopyroxene, which is rimed or generally totally replaced by green hornblende.
Most doleritic dykes show preserved magmatic textures, but clinopyroxene is generaly totally replaced by zoned amphiboles: brown green hornblende ([Al.
Within the mineralized zone hornblendites show well developed crystals of hornblende and trend in N45[degrees]E direction, which shows alteration to vermiculite.
This hypogene process formed secondary phases, such as hornblende and biotite.