Tephras in lacustrine sediments of the Sarliève marsh (French Massif Central): age and preservation

Abstract. Sedimentation processes occurring in the most recent maar lake of the French Massif Central (Lake Pavin) are documented for the first time based on high resolution seismic reflection and multibeam bathymetric surveys and by piston coring and radiocarbon dating on a sediment depocentre developed on a narrow sub aquatic plateau. This new data set confirms the mid Holocene age of maar lake Pavin formation at 6970±60 yrs cal BP and highlights a wide range of gravity reworking phenomena affecting the basin. In particular, a slump deposit dated between AD 580–640 remoulded both mid-Holocene lacustrine sediments, terrestrial plant debris and some volcanic material from the northern crater inner walls. Between AD 1200 and AD 1300, a large slide scar mapped at 50 m depth also affected the southern edge of the sub aquatic plateau, suggesting that these gas-rich biogenic sediments (laminated diatomite) are poorly stable. Although several triggering mechanisms can be proposed for these prehistoric sub-aquatic mass wasting deposits in Lake Pavin, we argue that such large remobilisation of gas-rich sediments may affect the gas stability in deep waters of meromictic maar lakes. This study highlights the need to further document mass wasting processes in maar lakes and their impacts on the generation of waves, favouring the development of dangerous (and potentially deadly) limnic eruptions.

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Volcanisme et occupation humaine préhistorique dans le Massif Central français : quelques observations / Some observations about volcanic activity and prehistoric human settlement in the french Massif Central

Revue archéologique du Centre de la France ◽

10.3406/racf.1984.2397 ◽

1984 ◽

Vol 23 (1) ◽

pp. 7-20 ◽

Cited By ~ 3

Author(s):

Jean Paul Raynal ◽

Jean-Pierre Daugas

Keyword(s):

Volcanic Activity ◽

French Massif Central ◽

Human Settlement ◽

Massif Central

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East-west diachronism of the collisional stage In the french Massif Central Implications for the European Variscan Orogen

Geodinamica Acta ◽

10.1080/09853111.1992.11105219 ◽

1992 ◽

Vol 5 (1-2) ◽

pp. 51-68 ◽

Cited By ~ 19

Author(s):

Sylvie Costa

Keyword(s):

French Massif Central ◽

Massif Central ◽

Variscan Orogen ◽

East West

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Evaluating Holocene natural hazards in the French Massif Central from a regional lake sediment approach

Quaternary International ◽

10.1016/j.quaint.2021.05.018 ◽

2021 ◽

Author(s):

E. Chapron ◽

A. Foucher ◽

L. Chassiot ◽

W. Fleurdeus ◽

V. Arricau ◽

...

Keyword(s):

Natural Hazards ◽

Lake Sediment ◽

French Massif Central ◽

Massif Central

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Sellaphora labernardierei (Sellaphoraceae, Bacillariophyta), a new epilithic species from French spring and four new combinations within the genus Sellaphora

Phytotaxa ◽

10.11646/phytotaxa.260.3.3 ◽

2016 ◽

Vol 260 (3) ◽

pp. 235 ◽

Cited By ~ 8

Author(s):

AUDE BEAUGER ◽

CARLOS E. WETZEL ◽

OLIVIER VOLDOIRE ◽

ALEXANDRE GARREAU ◽

LUC ECTOR

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Central Area ◽

Mineral Waters ◽

New Combinations ◽

French Massif Central ◽

Small Species ◽

Massif Central ◽

Floristic Survey ◽

Scanning Electron

During a floristic survey of freshwater springs in the French Massif Central region, a new Sellaphora species (Bacillariophyceae) was found and is hereby described: Sellaphora labernardierei sp. nov. This new small species, with linear to linear-elliptical valves, slightly inflated in the middle, is formally described using light and scanning electron microscopy. The species has a single H-shaped chloroplast and striae usually biseriate tending to be uniseriate near the centre of the valve. The valve dimensions, the valve, pole and central area shapes, and the striae density and pattern allow their separation from similar taxa belonging to the genera Eolimna, Naviculadicta and Sellaphora. The ecological preferences of Sellaphora labernardierei are mineral waters with high nitrate concentrations. The examination of similar taxa belonging to the genera Eolimna and Naviculadicta and their characteristics lead to propose four new combinations of Sellaphora species.

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