Figure F14. The record of carbonate and opal at Site 663 from the eastern equatorial Atlantic for comparison with similarly cyclic fluctuations off the Congo. Site 663 data are from deMenocal et al. (1993). A. Oxygen isotope index, standardized permil data, and carbonate index, negative log of noncarbonate, standardized. B. Opal index, log percent of opal, standardized. C. High values of opal coincide with low values of carbonate (see "Background: Deepwater Record" in "Quaternary Record of the Congo and Angola Sites").