Anomalous unblocking temperatures, viscosity and frequency-dependent susceptibility in the chemically-remagnetized Trenton limestone

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

4

Scientific paper

Chemical remagnetization of many carbonate rock units occurred by diagenetic alteration of iron sulfide precursors and by authigenesis of fine-grained magnetite, which can commonly be recognized by a distinctive set of rock-magnetic attributes. These carbonates also typically exhibit anomalously high unblocking temperatures for recent thermoviscous components that have overprinted the characteristic chemical remanence. Recent work has shown that departures from Néel theory (as applied in the model of Pullaiah et al.) can generally be attributed to VRM carried by multidomain particles, to which the theory does not apply. In the remagnetized carbonates, however, rock-magnetic data all point to an overwhelming dominance of fine superparamagnetic and stable single-domain particles. Therefore we explore possible alternative causes for the anomalous unblocking temperatures, including maghemitization and magnetocrystalline rather than shape anisotropy. New blocking-unblocking models for these cases, however, fail to match the observed behavior, leading to the conclusion that the anomalous unblocking temperatures are indeed probably attributable to multidomain carriers. A possible alternative explanation is an increase in coercivity due to maghemitization of single-domain particles after acquisition of the viscous overprint, causing a significant increase in their unblocking temperatures. New frequency-dependent susceptibility measurements at low temperatures allow us to focus on the time-temperature behavior of the particles at the superparamagnetic-stable single-domain threshold, and we find that these do closely follow the predictions of Néel theory, as formulated in the models of Pullaiah et al. and Walton-Middleton-Schmidt.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Anomalous unblocking temperatures, viscosity and frequency-dependent susceptibility in the chemically-remagnetized Trenton limestone does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Anomalous unblocking temperatures, viscosity and frequency-dependent susceptibility in the chemically-remagnetized Trenton limestone, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Anomalous unblocking temperatures, viscosity and frequency-dependent susceptibility in the chemically-remagnetized Trenton limestone will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1007036

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.