Rock magnetic and palaeomagnetic studies of British speleothems

Abstract

The suitability of speleothems (secondary cave deposits) for palaeomagnetic use is being investigated. Previous workers have demonstrated that speleothems often carry a measurable and stable natural remanent magnetization (NRM). Speleothems may often be a more reliable source of palaeosecular variation (PSV) information than soft sediments. The results demonstrate repeatable PSV records from two British stalagmites with overlapping growth periods. Some preliminary rock magnetic data from speleothems is presented which indicate a grain size difference between the magnetic gains in flowstones (laminar speleothems) and stalagmites (columnar speleothems). This has implications for the origin of the NRM. -from Authors