Particulate calcium carbonate in New England shelf waters: result of shell degradation and resuspension*

Abstract

ABSTRACT Aragonite and calcite needles, 30–500 μm long, were found to be prominent visual components throughout the water column in some areas of the New England (northeastern U.S.A.) continental shelf during winter months. Further investigation showed these‘needles’to be laths derived from the degradation of mollusc shells which were resuspended from bottom sediments during winter storms. Such degradation and subsequent transport/dissolution of carbonate particles may help explain why the terrigenous 'starved’shelf sediments off New England contain such small amounts of calcium carbonate.