CARBONATE PRODUCTION ON ISOLATED BANKS SINCE 20 K.A. BP: CLIMATIC IMPLICATIONS

Abstract

A new database on the distribution of isolated low-latitude banks is evaluated to assess their carbonate production and climatic impact since the last glacial maximum (LGM). Most bank summits are 70 m deep or shallower. The few substrates and the high rates of sea-level rise suggest that neritic carbonate production from the LGM to ca. 14 k.a. BP, when sea level reached −70 m, was generally low. Flooding of banks at ≤70 m depth below sea level after 14 k.a. BP caused carbonate production to rise episodically, although these banks drowned fast. Carbonate production peaked during the Holocene, when maximum flooding of the bank summits occurred. The emission of CO2 to the atmosphere resulting from carbonate production would have risen in line with the steps in production. A crude estimate of this emission is presented.