ABSTRACT
The most striking apparent ‘magnetic indicator’ of palaeoclimate is the intensity of natural remanent magnetisation (NRM). Cool temperature episodes correspond with high NRM intensities and vice versa. Concentration-related parameters which effectively monitor changes in the flux-density of terrigenous components to the sediment, are superimposed on a background rate of carbonate deposition, which also fluctuates in response to changes in climate The apparent geomagnetic-palaeoclimatic linkage is an expression of changing magnetic mineral concentrations and types, and is essentially independent of changes in the Earth’s magnetic field. The nature of this climatic control is to be sought in the relationship between climate and the processes of weathering, erosion, transport and deposition which determine the flux of magnetic minerals to deep-sea sediments. Hydrothermal products are of greatest importance in the immediate vicinity of features such as seamounts, mid-oceanic ridges, transform faults and fracture zones.
