Geoscience Reference
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settlement present at that time. The beacon tower also served another purpose:
it was stocked with provisions for shipwrecked mariners. The construction of
the beacon commenced in May 1844 and the work was carried out by a convict
labour force (Lawrence and Cornelius, 1993). By September of that year, the
beacon was completed.
The beacon was built using phosphatic sandstone blocks that were quarried
from the eastern part of the island, and lime that was obtained by burning
Tridacna and Hippopus shells; Jukes (1847, p266) wrote that the latter were 'to be
got in abundance from the reef at low water'. Timber was taken from the wreck of
the Martha Ridgeway , as was the ship's tank, which was used to collect rainwater
(Loch, 1984). The completed tower comprised a circular tower, 45 feet in height
and 30 feet in diameter at its base. The walls were five feet thick, and a domed roof
carrying a large ball raised the total height of the structure to 63 feet. The large
size of this structure, on a relatively small island (approximately 32 hectares),
indicates that Raine Island sustained a significant geomorphological impact as a
result of the quarrying of the phosphatic rock, as Hopley has acknowledged (1982,
p337). In addition, the removal of Tridacna spp. and Hippopus spp. must have
occurred on a considerable scale and caused localised depletion of those species.
However, those impacts were overwritten by the more extensive alteration of the
island that took place from 1890-1892 as a result of guano mining.
Guano and rock phosphate mining, 1860-1940
Guano - the cemented deposits formed by accumulations of bird droppings -
and rock phosphate represent natural resources that have been extracted from
some islands of the Great Barrier Reef in order to supply phosphatic fertiliser
for agriculture. The mining of guano and rock phosphate in the Great Barrier
Reef has resulted in many changes in islands, ranging from minor modification
of vegetation to the alteration of the geomorphology of entire islands (Heatwole,
1984; Hopley, 1988, 1989). At least ten locations in the Great Barrier Reef have
been mined for guano and rock phosphate; those locations are shown in Figure
10.1. A variety of practices occurred in the guano and rock phosphate mining
industries: some cays, such as Raine Island, were mined intensively with rapid
depletion of the commercial resources. Others, such as Upolu and Michaelmas
Cays, were used less intensively, but over much longer periods. Therefore, this
section describes a group of diverse mining practices, locations and historical
periods, based on evidence found in historical books and in the archival files of
the QEPA, held at the QSA.
The date of the earliest guano mining in the Great Barrier Reef is disputed;
one account, by Golding (1979, pp77-8), stated that the industry was pioneered
by William L. Crowther, of Hobart, who applied to the New South Wales
Government for licences to mine guano from Wreck Reef and Cato's Bank in
1861. Golding (1979) claimed that, before the permits were issued, Crowther
had commenced removing guano from Wreck Reef; one hundred tons of guano
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