A record of changing redox conditions in the northern Peru Basin during the Late Quaternary deduced from Mn/Fe and growth rate variations in two diagenetic manganese nodules

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

Two diagenetic manganese nodules from the Peru Basin were investigated by thermal ionization mass spectrometry and high resolution alpha spectrometry for uranium and thorium. The TIMS concentrations for nodule 62KD (63KG) vary as follows: 0.12-1.01 ppb (0.06-0.59) 230Th, 0.51-1.98 ppm (0.43-1.40) 232Th, 0.13-0.80 ppb (0.09-0.49) 234U, and 1.95-13.47 ppm (1.66-8.24) 238U. Both nodules have average growth rates of ~110 mm per million years. However, from the variations of excess 230Th with depth we estimate partial accumulation rates which range from 50 to 400 mm per million years. The δ234U dating method cannot be applied due to remobilization of U from the sediment and subsequent incorporation into the nodules' crystal lattice, reflected by decay corrected δ234U values far above the ocean water value. Sections of fast nodule growth are related to those layers having high Mn/Fe ratios (up to 200) and higher densities. As a possible explanation we develop a scenario that describes similar glacial/interglacial trends in both nodules as a record of regional changes of sediment and/or deep water chemistry.

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

A record of changing redox conditions in the northern Peru Basin during the Late Quaternary deduced from Mn/Fe and growth rate variations in two diagenetic manganese nodules 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 A record of changing redox conditions in the northern Peru Basin during the Late Quaternary deduced from Mn/Fe and growth rate variations in two diagenetic manganese nodules, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A record of changing redox conditions in the northern Peru Basin during the Late Quaternary deduced from Mn/Fe and growth rate variations in two diagenetic manganese nodules will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1620455

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