Fluxes of metals to a manganese nodule: Radiochemical, chemical, structural, and mineralogical studies

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

25

Scientific paper

Fluxes of metals to the top and bottom surfaces of a manganese nodule were determined by combining radiochemical (230Th, 231Pa, 232Th, 238U, 234U) and detailed chemical data. The top of the nodule had been growing in its collected orientation at 4.7 mm Myr-1 for at least 0.5 Myr and accreting Mn at 200 μg cm-2 kyr-1. The bottom of the nodule had been growing in its collected orientation at about 12 mm Myr-1 for at least 0.3 Myr and accreting Mn at about 700 μg cm-2 yr-1. Although the top of the nodule was enriched in iron relative to the bottom, the nodule had been accreting Fe 50% faster on the bottom. 232Th was also accumulating more rapidly in the bottom despite a 20-fold enrichment of 230Th on the top.
The distribution of alpha-emitting nuclides calculated from detailed radiochemical measurements matched closely the pattern revealed by 109-day exposures of alpha-sensitive film to the nodule. However, the shape and slope of the total alpha profile with depth into the nodule was affected strongly by 226Ra and 222Rn migrations making the alpha-track technique alone an inadequate method of measuring nodule growth rates.
Diffusion of radium in the nodule may have been affected by diagenetic reactions which produce barite, phillipsite and todorokite within 1 mm of the nodule surface; however, our sampling interval was too broad to document the effect. We have not been able to resolve the importance of nodule diagenesis on the gross chemistry of the nodule.

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

Fluxes of metals to a manganese nodule: Radiochemical, chemical, structural, and mineralogical studies 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 Fluxes of metals to a manganese nodule: Radiochemical, chemical, structural, and mineralogical studies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fluxes of metals to a manganese nodule: Radiochemical, chemical, structural, and mineralogical studies will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1052580

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