XRD analsyis of surface sediment samples collected from the sanded reef-flat physiographic zone of Wistari Reef

Wistari Reef is a lagoonal platform reef, situated on the Tropic of Capricorn, within the Capricorn and Bunker region of the southern Great Barrier Reef. Three sediment surface samples were taken from the lagoon area for X-Ray Diffraction Analysis. This was used to compare the relative percentages of aragonite and calcite in the sample. The results tend to indicate that the proportion of aragonite varies across the sanded reef flats, with decreasing aragonite as you move from the windward margin (70%) towards the leeward margin (43%).