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Fluid inclusions and mineral chemistry of some detrital
heavy minerals of alluvium sediments from Meluli-
Namuhuca area, Mozambique

Research Authors
M. Yaser Abdel-Aziz1*, M. A. Mohamed1, H. A. Mohamed2 and Muchangos Amadeu3
Research Abstract

Geochemistry and fluid inclusions studies were carried out on garnet and beryl from Quaternary
alluvium deposits of Meluli-Namuhuca area, Mozambique. Garnet occurs as euhedral large crystals and
is commonly brownish red, with a moderate brown hue in transmitted light. Apatite and ilmenite are the
common inclusions. Geochemically, garnet is characterized by nearly homogenous chemical
composition with Pyr (46.72-48.35), Alm (39.77-48.35), Gr (10.03-10.56) and Sps (1.14-1.31) mol %. This garnet is referred
to as iron-rich pyrope or pyrope – almandine. Chemical compositions reflect their crystallization from
magma (Mg-Fe isomorphism).The high-Mg, and low Na of the studied garnet are consistent with high
temperature eclogitic garnet associated with diamond. Fluid inclusions study indicates that garnet was
deposited from high saline and high temperature fluids. Beryl is present as euhedral hexagonal crystals
with different color (green emerald, blue aquamarine, and yellow heliodors). It enclosed cassiterite,
wolframite and barite micro-inclusions, which support that the studied beryl is connected to
hydrothermal ore-bearing fluids. Fluid inclusions study reveal that beryl was deposited due to boiling
process of medium salinity (9-12 wt.% NaCl eq.), and medium temperature (180-240 °C) fluids. Pressure
of trapping was estimated between 400 and 700 bars.

Research Department
Research Journal
Journal of Geology and Mining Research
Research Member
Research Publisher
Academic Journals
Research Rank
1
Research Vol
Vol. 1(1) pp. 001-007
Research Website
http://www.academicjournals.org/jgmr
Research Year
2009
Research Pages
pp. 001-007