Surface Features and Geology of Selected Cores from Elizabeth Reef, Tasman Sea, Australia: ABSTRACT

Abstract

Elizabeth reef is one of the southernmost coral reefs in the world. Located at approximately 30°S latitude in the Tasman Sea, this atoll is situated near the southern limit of environmental tolerance for reef formation. The atoll has a well-developed outer reef flat encrusted with calcareous red algae and a lagoon consisting of patch reefs, sand flats, and a central mesh reef complex. A relatively small number or coral species occur, and significant coral growth is restricted to the lagoon. Offshore there is a well-developed erosional spur and groove zone (0 to 8 m), a deeper buttress zone (9 to 30 m), and a carbonate sand flat (30 to 40 m) before the steep seaward drop-off. Detailed evaluation of eleven rotary cores from the Elizabeth reef flat indicates that a peri d of more active coral growth existed in the past. C14 age dates on scleractinian corals from the cores indicate a maximum age of about 7,000 years B.P. in the upper 3 to 4 m of the reef flat with maximum accumulation rates of approximately 90 cm per 1,000 years. The atoll has reached equilibrium with sea level, and it is now influenced more by erosion than growth. End_of_Article - Last_Page 987------------