The environmental significance of magnetic measurements of Late Pleistocene and Holocene sediments from the Grand Lac d'Annecy, eastern France

Citation
Yq. Hu et al., The environmental significance of magnetic measurements of Late Pleistocene and Holocene sediments from the Grand Lac d'Annecy, eastern France, J PALEOLIMN, 25(2), 2001, pp. 193-203
Citations number
45
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Environment/Ecology
Journal title
JOURNAL OF PALEOLIMNOLOGY
ISSN journal
0921-2728 → ACNP
Volume
25
Issue
2
Year of publication
2001
Pages
193 - 203
Database
ISI
SICI code
0921-2728(200102)25:2<193:TESOMM>2.0.ZU;2-P
Abstract
The results of a series of magnetic measurements on sediment samples are il lustrated by means of examples selected from a more specialized parallel pu blication (Hu & Oldfield, submitted). They are interpreted in terms of magn etic components, notably 'magnetite' of varying grain size/domain state, ha ematite, goethite and greigite. Wherever possible, some indication is given of changes in the relative importance of the various magnetic grain size a nd mineral phases through time. The main components of the magnetic assembl age are described for each of the main lithological units identified in the long core which is considered elsewhere in this volume. These assemblages are related to source areas and to depositional processes, especially in th e pre-Holocene parts of the core. In the Holocene sediments, the magnetic p ropel-ties cannot be interpreted solely in terms of shifts in detrital mine ral sources. Evidence is presented for the presence of both biogenic magnet ite and authigenic greigite. The most recent sediments point to renewed cat chment erosion, probably as a result of human activity during historical ti mes.