Sediments of Lake Vens (SW European Alps, France) record large-magnitude earthquake events

Petersen, J.; Wilhelm, Bruno; Revel, M.; Rolland, Y.; Crouzet, C.; Arnaud, F.; Brisset, E.; Chaumillon, E.; Magand, O. (2014). Sediments of Lake Vens (SW European Alps, France) record large-magnitude earthquake events. Journal of Paleolimnology, 51(3), pp. 343-355. Kluwer Academic 10.1007/s10933-013-9759-x

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We studied sediment cores from Lake Vens (2,327 m asl), in the Tinée Valley of the SW Alps, to test the paleoseismic archive potential of the lake sediments in this particularly earthquake-sensitive area. The historical earthquake catalogue shows that moderate to strong earthquakes, with intensities of IX–X, have impacted the Southern Alps during the last millennium. Sedimentological (X-ray images, grain size distribution) and geochemical (major elements and organic matter) analyses show that Lake Vens sediments consist of a terrigenous, silty material (minerals and organic matter) sourced from the watershed and diatom frustules. A combination of X-ray images, grain-size distribution, major elements and magnetic properties shows the presence of six homogenite-type deposits interbedded in the sedimentary background. These sedimentological features are ascribed to sediment reworking and grain sorting caused by earthquake-generated seiches. The presence of microfaults that cross-cut the sediment supports the hypothesis of seismic deposits in this system. A preliminary sediment chronology is provided by 210Pb measurement and AMS 14C ages. According to the chronology, the most recent homogenite events are attributable to damaging historic earthquakes in AD 1887 (Ligure) and 1564 (Roquebillière). Hence, the Lake Vens sediment recorded large-magnitude earthquakes in the region and permits a preliminary estimate of recurrence time for such events of ~400 years.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences

UniBE Contributor:

Wilhelm, Bruno

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

0921-2728

Publisher:

Kluwer Academic

Language:

English

Submitter:

Sarah Antenen

Date Deposited:

14 Aug 2015 10:52

Last Modified:

17 Sep 2015 08:26

Publisher DOI:

10.1007/s10933-013-9759-x

BORIS DOI:

10.7892/boris.70821

URI:

https://boris.unibe.ch/id/eprint/70821

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