Trace elements such as cadmium, barium, manganese and
strontium replace Ca in the lattice of aragonite (a CaCO3
mineral). These trace elements often substitute for Ca as a
result of climate-related variables.
The following relationship between Sr:Ca ratios and temp
was developed: Sr:Ca x 103 = 10.48 (=/- 0.01) - 0.0615
(+/- 0.0004) x temp.
Thus we can measure trends in Sr:Ca ratios in coral aragonite
skeletons as a way to determine surface sea water temps.