| 7230 |
Creator |
4989dd10527e94ef140e45e8c9fb07e6 |
| 7230 |
Creator |
dcc9fa18f5550ef68ad869008376ba1a |
| 7230 |
Creator |
ext-166bc486e7682d5c271555757d976c7c |
| 7230 |
Creator |
ext-6e3cb07fe9c7cbc5e6a3f3649ddfd4bb |
| 7230 |
Creator |
ext-5bfcdf245b37164a00954f5f77d3f51e |
| 7230 |
Creator |
ext-6a1a8acf1a7ac1920874a53e132d84d5 |
| 7230 |
Creator |
ext-aedd8b11d53e6781436f7eac69e4d3cd |
| 7230 |
Creator |
ext-ed87e3f11d92f0dc436411de7b8a27d4 |
| 7230 |
Date |
2006-09-30 |
| 7230 |
Is Part Of |
repository |
| 7230 |
Is Part Of |
p1385013X |
| 7230 |
abstract |
U-series isotopes have been measured in the dissolved phase, suspended load and bedload
of the main rivers draining basaltic catchments in Iceland. For the dissolved phase,
(234U/238U) and (238U/230Th) range between 1.08 and 2.2, and 7.4 and 516, respectively.
For the suspended load and bedload, (234U/238U) and (238U/230Th) range from 0.97 to
1.09 and from 0.93 to 1.05, respectively. Chemical erosion rates, calculated from
dissolved major elements, range between 13 and 333 t km− 2 yr− 1. Physical erosion
rates have also been estimated, from existing data, and range between 21 and 4864
t/km2/yr, with an average of 519 t km− 2 yr− 1. U-series disequilibria indicate that
weathering in Iceland operates at close to steady-state conditions. A model of continuous
weathering indicates a maximum weathering timescale of 10 kyr, with an average rate
of uranium release into water of 1.6 · 10− 4 yr− 1, which is significant when compared
to granitic terrains located at similar latitudes and to tropical basaltic terrains.
All river waters display (234U/238U) greater than secular equilibrium, consistent
with the effects of alpha-recoil. The same dissolved phase (234U/238U) exhibit a negative
trend with physical erosion rates, explained by the dominant effect of close-to-congruent
chemical weathering of hyaloclastites in the younger basaltic terrains. Therefore,
chemical erosion rate and mineral weathering susceptibility play a major role in determining
234U–238U disequilibria in basaltic river waters. Comparison of global data for river
basins in which weathering was recently strongly limited indicates a negative correlation
between silicate weathering rates estimated with major elements and the age of weathering
estimated with U-series disequilibria. This strongly suggests a key role of time and
soil thickness on the chemical erosion of silicates. |
| 7230 |
authorList |
authors |
| 7230 |
issue |
3-4 |
| 7230 |
status |
peerReviewed |
| 7230 |
volume |
249 |
| 7230 |
type |
AcademicArticle |
| 7230 |
type |
Article |
| 7230 |
label |
Vigier, N.; Burton, K.W. ; Gislason, S.R.; Rogers, N.W. ; Duchene, S.; Thomas, L.;
Hodge, E. and Schaefer, B. (2006). The relationship between riverine U-series disequilibria
and erosion rates in a basaltic terrain. Earth and Planetary Science Letters, 249(3-4)
pp. 258–273. |
| 7230 |
label |
Vigier, N.; Burton, K.W. ; Gislason, S.R.; Rogers, N.W. ; Duchene, S.; Thomas,
L.; Hodge, E. and Schaefer, B. (2006). The relationship between riverine U-series
disequilibria and erosion rates in a basaltic terrain. Earth and Planetary Science
Letters, 249(3-4) pp. 258–273. |
| 7230 |
Title |
The relationship between riverine U-series disequilibria and erosion rates in a basaltic
terrain |
| 7230 |
in dataset |
oro |