The sand deposits on the south central coast of Jamaica have generated several investigations
regarding its qualitative and quantitative parameters, while assessing its spatial variability. Silica sand as well as Magnetic sand deposits in the Alligator Pond area of south-western
Manchester have been also been studied in some details (Zans 1951; Chubb 1960; Geddes 1976,
1981; Macfarlane, 1977). Thi
s included detail geological mapping of on shore beach dune
deposits followed by chemical, physiochemical and petrographical studies of sand samples. Preliminary investigations conducted by Geddes (1975) using hand magnetic separation indicate
5 million tons of magnetic concentrate in the Alligator Pond dune. A study of the chemical
results however, shows that there is quite likely closer to 8 million tons of magnetic concentrate
in the Alligator Pond dune. It is important to note however that the aforementioned reserve estimates were done for the
entire Alligator Pond Dune. For the purpose of this report however, the focus will be made on a
small northern section of the dune. Hence, the area under investigation is only a small section of
the wider Alligator Pond Dune known as Part of Alligator Pond Valley. The current property
being assessed, accounts for approximately 1.9 hectare of land. Recent laboratory tests, done
specifically for that property were carried out by the Mines and Geology Division (2014). This
chemical analysis was done in order to determine the concentration of Silicon Dioxide, Titanium
Oxide and Iron Oxide present in bulk samples collected from the area under investigation. The
results showed that surficial samples containn 5.66% Silicon Dioxide (SiO2), 13.4% Titanium
Oxide (TiO2) and 51% Iron Oxide (Fe2O3). The local demand for silica sand for use in construction, or beach restoration projects have
grown significantly. Likewise the global demand in black sand (titano-magnetite sand) for use in
the metal industry has shown some increase in recent years. This demand has been driven by the
reduction in high-grade reserves of sand deposits worldwide, resulting in higher global prices. Unlike the traditional mining techniques or quarrying of hard rock, the mining of sand is
generally easier due to ease of accessible( since sand deposits tend to bear a coastal location)
and can be easily extracted at a comparatively lower cost. The spatial distribution of sand deposits across the island varies significantly, showing
particularly higher accumulation of black sand deposits along Jamaica’s South Coast. This heavy
mineral sand occurs as placer deposits sited at numerous locations along the coastline of
Manchester. All these placer deposits are down drift of the mouth of streams draining areas
containing metamorphic and igneous rocks. Such ore deposits generally consist of a high
concentration of magnetite, ilmenite, haematite and other rear earth elements. The Sand deposits investigated in this report is evident as 1.9 hectare lot which constitutes the
northern portion of the wider composite sand dune located in Alligator pond, Manchester. The
area at large represents the single most extensive deposit of black sand found in the region. Black Sand Deposits at Alligator pond locality contains ilmenite magnetite grains. The black
sand concentrations at alligator Pond was investigated by the Geological Survey (Ann. Rep.
1959-60). Here the black sands lie at the landward side of the beaches, evident as a large sand
12
dune. Tests on this material show that 94% of the sample was finer than 72 mesh (13.5). Chemical analyses show that the percentage of TiO2 in magnetic fractions varies between 10 and
17.5%. The portion of sand dune located on the Lot referred to as Part of Alligator Pond River vol 452
& fol 31, consist of a 2:1 ratio of silica sand to black sand. Black sand grains are predominantly
fine grained with a higher specific gravity while silica sand grains are larger (sand sized) with a
lower specific gravity
What has been described are "great opportunities" to responsibly put this material to use, through our dedicated organisation RSQ, for the benefit of Jamaica, Its people and all our customers, local and foreign.
