Extraction of high-resolution carbonate data for palaeoclimate reconstruction

TEMPORAL variations in the calcium carbonate content of deepsea sediments provide direct stratigraphic as well as important palaeoenvironmental information relating to the global carbon cycle. Here I present an algorithm that allows carbonate content and porosity to be accurately predicted from saturated bulk density in equatorial pelagic carbonates. Applying the algorithm to continuous laboratory measurements of density made on DSDP and OOP cores yields a nearly continuous carbonate record for the upper ˜200 m of the sediment section. Long, ultra-high-resolution carbonate curves of this type should yield new insight into the evolution of the carbon chemistry of the oceans, as well as the role of external (Milankovitch) forcing in the development of the carbonate system. The algorithm can also be applied to quantitative, high-resolution seismic data, thereby enabling detailed carbonate records to be extracted from remotely derived geophysical data