Density Banding in Coral
The most significant record contained in most surface coral skeletons are the annual density bands . The bands are primary skeletal characteristics that consist of high and low density portion per year discernible by x-ray of a thin slab cut along the axis upward of corallite growth  . Annual variations in density represent changes in both the rate of linear skeletal extension and calcification .
The bands can be used for to establish chronologies and to identify stress events .References
- Druffel, E. R. M. (1997). Geochemistry of corals: Proxies of past ocean chemistry, ocean circulation, and climate. Proceeding of the National Academy of Sciences, 94, 8354-8361.
- Buddemeier, R. W., Maragos, J. E., & Knutson, D. W. (1974). Radiographic studies of reef coral exoskeletons: rates and patterns of coral growth. J. Exp. mar. Biol. Ecol., 14, 179-200.
- McIntyre, I. G., and S. V. Smith. 1974. X- radiographic studies of skeletal development in coral colonies. Proc. 2nd Int. Coral Reef Symp., Brisbane 2:277-287.