HR: 14:45h
AN: GP43A-04    [Abstracts]
TI: The strength of the Geomagnetic Field During the Cretaceous Normal Superchron: Preliminary Results Using the Microwave Palaeointensity Technique
AU: * Hill, M J
EM: mimi@liverpool.ac.uk
AF: Geomagnetism Laboratory, University of Liverpool, Oliver Lodge Labs., Oxford Street, Liverpool, L69 7ZE, United Kingdom
AU: Davies, C J
AF: Geomagnetism Laboratory, University of Liverpool, Oliver Lodge Labs., Oxford Street, Liverpool, L69 7ZE, United Kingdom
AU: Shaw, J
AF: Geomagnetism Laboratory, University of Liverpool, Oliver Lodge Labs., Oxford Street, Liverpool, L69 7ZE, United Kingdom
AB: The relationship between the strength of the Earth's magnetic field and its tendency to reverse has been a subject of discussion for many years. A key time period to investigate this is the Cretaceous Normal Superchron (CNS). With a paucity of high quality palaeointensity data for this time period however, deducing any such relationship is difficult. Here we present preliminary results from an ongoing investigation, concentrating on producing a set of palaeointensity data spanning the CNS, utilising the microwave palaeointensity technique. The microwave method can significantly reduce alteration during the experimental phase of the investigation compared to the conventional Thellier method, therefore potentially giving higher success rates. As in all palaeointensity investigations, whatever method, ensuring an original thermal remanence is present is paramount. Rock magnetic analyses, SEM imaging and EBSD analyses have been carried out in order to determine the suitability of samples for palaeointensity work. Microwave palaeointensity results are presented and compared to previously published Thellier results (where present) for whole rock samples from Inner Mongolia (113 Ma), Liaoning Province, China (102 Ma) and Madagascar (88 Ma).
DE: 1500 GEOMAGNETISM AND PALEOMAGNETISM
DE: 1521 Paleointensity
DE: 1522 Paleomagnetic secular variation
DE: 1535 Reversals: process, timescale, magnetostratigraphy
DE: 9610 Cretaceous
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Joint Assembly