Astronomy and Astrophysics – Astronomy
Scientific paper
Apr 2000
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2000geoji.141..213b&link_type=abstract
Geophysical Journal International, Volume 141, Issue 1, pp. 213-226.
Astronomy and Astrophysics
Astronomy
8
Chemical Remagnetization, Limestones, Magnetic Hysteresis, Magnetic Materials
Scientific paper
Limestones provide an important source of palaeomagnetic information despite their low content of submicroscopic remanence-bearing minerals. The chief sources of these minerals are thought to be clastic volcanic magnetite and titanomagnetite, and organic magnetite, the latter mostly from bacterial sources. Chemically remagnetized limestones carry magnetite or pyrrhotite. Three hysteresis properties prove useful in identifying and characterizing these mineralogical influences on limestones: the ratio of zero-field maximum remanence to saturation remanence (Mr/Ms) in an applied field, coercivity of remanence (Bcr) and coercivity (Bc). To a lesser extent Kf/Ms may be useful, where Kf is the ferrimagnetic susceptibility. Traditionally, these have been plotted on a combination of 2-D graphs that of necessity only preserve two variables (Day et al. 1977; Wasilewski 1973). However, we found that magnetic discrimination and characterization of the limestones was much easier on a three-axis hysteresis projection that preserves the values of Bcr, Bc and Mr/Ms as independent variables. Using logarithmic scales, the regression surfaces through the data become almost planar and distinguish pelagic, shallow marine, shelf and remagnetized limestones on the basis of the slope and intercept of the associated regression surface. Clearly, there are sensitive sedimentological, geochemical or organic influences that dictate the magnetic mineralogy through sedimentary environment. Moreover, the 3-D plot of hysteresis criteria affords easy recognition of remagnetized limestones and may permit the rejection of material unsuitable for palaeomagnetic study. The 3-D hysteresis projection may be useful for the characterization of other rocks and magnetic materials
Borradaile Graham J.
Lagroix France
No associations
LandOfFree
Magnetic characterization using a three-dimensional hysteresis projection, illustrated with a study of limestones 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 Magnetic characterization using a three-dimensional hysteresis projection, illustrated with a study of limestones, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic characterization using a three-dimensional hysteresis projection, illustrated with a study of limestones will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-752646