Global deep-sea burial rate of calcium carbonate during the last glacial maximum

Global databases concentrations rates in Holocene and last glacial of calcium carbonate and mass accumulation maximum sediments were used to estimate the deep-sea sedimentary calcium carbonate burial rate during these two time intervals. Sparse calcite mass accumulation rate data were extrapolated across regions of varying calcium carbonate concentration using a gridded map of calcium carbonate concentrations and the assumption that accumulation of noncarbonate material is uncorrelated with calcite concentration within some geographical region. Mean noncarbonate accumulation rates were estimated within each of nine regions, determined by the distribution and nature of the accumulation rate data. For core-top sediments data coverage 67% of the high-calcite the regions of reasonable encompass (>75%) sediments globally,and within these regions we estimate an accumulation rate of 55.9 +- 3.6x10¹¹ mol yr^-1. The same regions cover 48% of glacial high-CaCO3 sediments (the smaller fraction is due to a shift of calcite deposition to the poorly sampled South Pacific) and total 44.1 +- 6.0x10¹¹ mol yr^-1. Projecting to 100% coverage South and total 44.1 +- 6.0x10¹¹ both estimates yields accumulation estimates of 8.3x10¹² mol yr^-1 today and 9.2x10¹² mol yr^-1 during glacial time. This is little better than a guess given the incomplete data coverage, but it suggests that glacial deep sea calcite burial rate was probably not considerably faster than today in spite of a presumed decreasein shallow water burial during glacial time.