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Industrial
mineral resources Cyprus
has been known for its asbestos since the Classical and Roman
times. Chrysotile
asbestos occurs throughout the serpentinite group of the Troodos
Ophiolite but the main deposits occur over an area of about 20
km2 near the village of Amiantos and within highly
fractured plutonic rocks on the eastern slopes of the
serpentinite outcrop. Asbestos
is a fibrous mineral found in veins, the width of which vary
from a few millimetres up to 15 mm (Fig.
8). The
genesis of asbestos is associated with the serpentinisation
of the harzburgite, the basal rock type of the ophiolite.
Reserves of around 9 million tonnes of crude asbestos are
understood to remain within the northeastern flank of the Mount
Olympus area. Gypsum
(CaSO4·2H2O) (Fig.
9) is an industrial mineral with a variety of uses
(including ceiling and wall decorations, heat insulation,
medicine, dentistry, art, agriculture, metallurgy etc.) that is
found in many areas in Cyprus.
It is one of the evaporite minerals, which is formed from
the evaporation of sea water.
The calcium sulphate content ranges between 95% and 99%.
The thickness of gypsum reaches 150 m (Kalavasos
Formation). Crushed
aggregates (sand and gravels) (Fig. 10
and 11) are produced from diabase (Fig.
12), reef limestone (Koronia and Terra Members of the
Pakhna Formation) (Fig. 13) and
calcarenite
units of the Nicosia and Athalassa Formations.
Clay
is a natural material with plastic properties.
Clays suitable for brick and tile manufacture are sourced
from sedimentary deposits of the Nicosia and Kythrea Formations,
from river deposits and from altered and weathered igneous rocks
of the Troodos Ophiolite. Bentonite
is a type of clay consisting predominantly of montmorillonite.
The bentonitic clays of Cyprus were deposited as
deep-water sediments from the alteration of volcanic ash during
the Upper Cretaceous period (approximately 90 Ma). The key property of bentonite that makes it an industrial
mineral with a variety of uses is the ability to swell with
absorption of water and shrink with the expulsion of water. The
main uses of bentonite include drilling muds, foundry sand
binders, civil engineering, iron ore pelletisation and pet
litter. Raw
materials for the manufacture of cement (Fig.
14) comprise chalk or low magnesium limestone, marl or
clay and minor gypsum. These
are all widely available in Cyprus. Building
stone was for centuries the main construction material.
The type of stone was related to the rocks of each area,
such as gabbro, diabase, and harzburgite in the mountainous
areas (Fig. 15), and chalk,
limestone and calcarenite elsewhere (Fig.
16). Cyprus
was known in the antiquity for its natural pigments (Fig.
17) such as the umber (Fig. 18),
ochre (Fig. 19) and
terra
verde, all associated with the ophiolite complex. |
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