Journal articles
Late Pleistocene to Holocene palaeoenvironmental variability in the north-west Spanish mountains: insights from a source-to-sink environmental magnetic study of Lake Sanabria
Abstract : We present a source-to-sink environmental magnetic study of a sediment core from Lake Sanabria (north-west Iberian Peninsula) and rocks of its catchment. The results indicate the occurrence of magnetite, and probably also pyrrhotite, in sediments accumulated between ca. 26 and 13 cal ka BP in a proglacial lake environment. These minerals also appear to dominate the magnetic assemblage of Palaeozoic rocks from the lake catchment. This indicates that sedimentation was then driven by the erosion of glacial flour, which suffered minimal chemical transformation due to a rapid and short routing to the lake. A sharp change in magnetic properties observed in the lake sediments between 13 and 12.6 cal ka BP reflects the rapid retreat of glaciers from the lake catchment. Sediments from the upper half of the studied sequence, accumulated after 12.6 cal ka BP in a lacustrine environment with strong fluvial influence, contain magnetite and smaller amounts of maghemite and greigite. We suggest that greigite grew authigenically under anoxic conditions caused by enhanced accumulation of organic matter into the lake. The occurrence of maghemite in these sediments suggests pedogenic activity in the then deglaciated lake catchment before the erosion and transportation of detrital material into the lake.
Cited literature [7 references]
https://hal-insu.archives-ouvertes.fr/insu-01149123
Contributor : Isabelle Dubigeon <>
Submitted on : Tuesday, May 19, 2015 - 3:36:39 PM
Last modification on : Wednesday, August 7, 2019 - 10:48:06 AM
Long-term archiving on: : Thursday, April 20, 2017 - 3:00:43 AM
Contributor : Isabelle Dubigeon <>
Submitted on : Tuesday, May 19, 2015 - 3:36:39 PM
Last modification on : Wednesday, August 7, 2019 - 10:48:06 AM
Long-term archiving on: : Thursday, April 20, 2017 - 3:00:43 AM
File
Borruel_et_al-JQS.pdf
Files produced by the author(s)