Flood and earthquake disturbance of 210Pb geochronology (Lake Anterne, NW Alps)
Arnaud, F.; Lignier, V.; Revel, M.; Desmet, M.; Beck, C.; Pourchet, M.; Charlet, F. ; Trentesaux, A.; Tribovillard, N. (2002). Flood and earthquake disturbance of 210Pb geochronology (Lake Anterne, NW Alps). Terra nova (Print) 14(4): 225-232. dx.doi.org/10.1046/j.1365-3121.2002.00413.x
In: Terra Nova. Blackwell: Oxford. ISSN 0954-4879; e-ISSN 1365-3121, meer
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Auteurs | | Top |
- Arnaud, F.
- Lignier, V.
- Revel, M.
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- Desmet, M.
- Beck, C.
- Pourchet, M.
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- Charlet, F.
- Trentesaux, A., meer
- Tribovillard, N.
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Abstract |
Dating recent lake sediment records yielding disturbed 210Pb profiles has been a problem of wide interest in palaeoclimatic and palaeoseismic studies over the last few centuries. When applied to an alpine lake sedimentary record, a high-resolution sedimentological study reveals that the 210Pb profile is disturbed by the occurrence of single-event deposits triggered by two different mechanisms: flood events deposits and gravity reworking. Removing disturbed layers from the 210Pb profile yields a logarithmic depth–activity relationship. Using a simple 210Pb decay model (CFCS) provides an assessment of mean accumulation rate of ‘continuous sedimentation’, as opposed to ‘event-linked sedimentation’. The correlation of the thickest four gravity-reworked deposits with historically known earthquakes permits both validation and refinement of the age–depth relationship. This refinement highlights variations in accumulation rate consistent with post-Little Ice Age climatic variations. |
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