INITIAL FORMATION OF SPERMONDE ARCHIPELAGO, THE LARGEST REEF PLATFORM IN INDONESIA, EFFORT TO DISCLOSE ITS TIME FRAME

Abstract

Coral samples were taken from Langkai island waters of Spermonde archipel at four meter depth using university boat and equipped with professional diver. After having been washed, samples were brought into laboratory and cleaning coral by chemical and physical separation. Grinded sample was then acidified with hydrochloric acid 10% to produce CO2 gas, coral origin, and finally absorbed in 5N sodium hydroxyde solution forming Na2CO3 and then calculating carbon amount by volumetric analysis. Eight mL of solution was mixed with twelve mL scintillating solution before measuring it in liquid scintillation counter Hidex 300 SL. Results showed that specific activity of carbon-14 in sample was 14.72 dpm/gC equivalent to 317 years. By application of absorbers other than NaOH, results were relatively the same. It can be concluded that the coral age investigated in Spermonde archipel was about 317 years. Further investigations are required to confirm the results especially in area and depth variations.