Chapter I Intro & Objectives - SPREP

PHOENIX ISLANDS PROTECTED AREA MANAGEMENT PLAN
Chapter III. Background, 1. Physical Setting of the Islands
Draft 1 March 2007
(Canton). The coastline was composed of sandstone slabs and coral rubble, with short
stretches of sand (Bryan 1941, 1942, and 1974).
In 1971, the phosphate resources of Enderbury were investigated (Tracey et al 1972). This
included the taking of core samples and the construction of a geologic map of Enderbury (see
Figure III-1.5.
Figure III-1.5. Geologic map of Enderbury
(source: Tracey et al 1972).
There were three forms of phosphate on Enderbury (Tracey et al 1972): (1) powdery crust
(primarily harvested in the 1800’s); (2) finely particulate phosphate in dark organic soil; and
(3) phosphorite or phosphate rock. There remains only about 6.35 cm (2.5 inches) of the
powdery curst (from an original 0.3 m (1 foot). Phosphate types 2 and 3 were not collected in
the 1800s. Test drilling results indicated that phosphatic sand was present 3.7 to 13.8 m (12
to 45 ft) below the surface (at 3 of 4 sites) and were a few feet to 2.4 m (8 ft) thick. Tracey et
al (1972) concluded that phosphates on Enderbury were of no economic interest for the
foreseeable future.
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