Effect of citrate-bicarbonate-dithionite treatment on fine-grained magnetite and maghemite

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

23

Scientific paper

Mineral magnetic properties of soils and parent materials have been interpreted in terms of paleoclimate and rates of soil formation but it is important to understand which minerals contribute to the mineral magnetic signal. Citrate-bicarbonate-dithionite (CBD) treatment has been used to determine the amounts of fine-grained, often pedogenic, ferrimagnetic minerals relative to coarse-grained, often inherited, magnetic minerals. However, questions have been raised about the effect of particle size on the efficacy of CBD in dissolving magnetite and maghemite grains. In this paper we use magnetic susceptibility and its frequency dependence, and the low-temperature behavior of a saturation isothermal remanent magnetization, to track the dissolution of carefully sized magnetite grains. We found that the standard CBD procedure dissolves fine magnetite particles (ca. < 1 m) but leaves larger particles (ca. > 1 m) essentially intact. Thin oxidized coatings, presumably maghemite, are also dissolved by the CBD procedure. These results support previous interpretations that the CBD procedure can be used to distinguish between pedogenic and lithogenic magnetic grains, assuming that most pedogenic magnetic grains are sufficiently small (ca. < 1 m) and most lithogenic magnetic grains are sufficiently large (ca. > 1 m). These results also show that the standard procedure is too harsh to differentiate between 1 m grains of magnetite and maghemite. A modified CBD extraction that uses half as much dithionite reduces the magnetic susceptibility of 1 m magnetite grains by only 10%. This method may be useful in distinguishing between magnetite and maghemite grains in this size range.

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

Effect of citrate-bicarbonate-dithionite treatment on fine-grained magnetite and maghemite 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 Effect of citrate-bicarbonate-dithionite treatment on fine-grained magnetite and maghemite, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Effect of citrate-bicarbonate-dithionite treatment on fine-grained magnetite and maghemite will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1634350

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