Other
Scientific paper
May 1998
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998e%26psl.158..121f&link_type=abstract
Earth and Planetary Science Letters, vol. 158, Issue 3-4, pp.121-130
Other
17
Himalayan Orogeny, Erosion, Pb-208/Pb-206, Ferromanganese Composition, Crust, Indian Ocean
Scientific paper
A high resolution Pb isotope time-series for the last 26 Ma, dated by 10 Be/ 9 Be chronology, is reported for a north Indian Ocean ferromanganese crust. This record is compared with available Pb isotope time-series of six other crusts from the Atlantic, Indian and Pacific Oceans, each of which is based on 10 Be/ 9 Be chronology. The seven Pb isotope records reveal some remarkable features. In contrast to the Nd isotope time-series of these crusts which show a long-term (~60 Ma) provinciality between the three main ocean basins, the Pb isotopes only show comparable provinciality over the last ~5 Ma. Prior to about 15 Ma ago no distinct Indian Ocean Pb isotope signal existed. Within this established framework of Pb isotope distribution in the oceans the 208 Pb/ 206 Pb data for the north Indian Ocean crust reported here are anomalous. The 208 Pb/ 206 Pb ratio is particularly high and exceeds a value of 2.08 during the time interval from 20 to 8 Ma ago. Consideration of potential sources of Pb in the Indian Ocean which might provide such high 208 Pb/ 206 Pb ratios suggests that this crust most probably has recorded a time-varying erosional input of Pb from the Himalayas. The timing of the isotopic shift is in good agreement with maximum Himalayan exhumation rates deduced from crystallisation and cooling ages of synorogenic granites (20-14 Ma) and the sedimentation history of the Bengal Fan.
Frank Michael
Keith O'Nions R.
No associations
LandOfFree
Sources of Pb for Indian Ocean ferromanganese crusts: a record of Himalayan erosion? 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 Sources of Pb for Indian Ocean ferromanganese crusts: a record of Himalayan erosion?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sources of Pb for Indian Ocean ferromanganese crusts: a record of Himalayan erosion? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1368824