Lake Pavin History, geology, biogeochemistry, and sedimentology of a deep meromictic maar lake

© Springer International Publishing Switzerland 2016 143
T. Sime-Ngando et al. (eds.), Lake Pavin, DOI 10.1007/978-3-319-39961-4_8

Distribution, Tephrostratigraphy

and Chronostratigraphy

of the Widespread Eruptive Products

of Pavin Volcano

Etienne Juvigné and Didier Miallier

Abstract

A tephra erupted by Pavin volcano was found as millimetre- to centimetre-thick tephra beds

in numerous peat-bogs and lake deposits of the Massif Central (France). At least two dis-

tinct Plinian pulses are attested by differences in chemical compositions of glass shards. A

southern lobe was clearly delimited; it is widespread at least to Cantal (30 km from the

volcano). At three northern localities as far as the Gour de Tazenat (50 km from the vol-

cano), two populations of glass shards present in the tephra deposit indicate either overlap-

ping of two compositionally-distinct lobes or a single lobe characterized by bimodal

differences arising from magma mixing in the source volcano in the Chaîne des Puys. The

Bayesian application, RenDateModel, to a sequence of radiocarbon and TL dates enabled

us, at the 95 % confi dence level, to constrain the age of Pavin eruption to 4720 ± 170 B.C.,

i.e. a current age of 6,730 ± 170 year, and to assess that between 100 and 700 years lapsed

between the eruptions of Montcineyre and Pavin. Since Pavin Tephra was identifi ed in sedi-

ments containing known pollen sequences pertaining to each lobe, the volcanic activity can

be placed within the Atlantic palynozone between the spreading of Fraxinus and the syn-

chronous palynozones of Abies and Fagus in that part of the Massif Central. The Pavin

volcano generated the latest cataclysmic eruption of Plinian type in the Massif Central.

Keywords

France • Massif Central • Volcanoes • Pavin • Montcineyre • Tephra • Pollen diagram

8.1 Introduction

Brousse et al. ( 1969 ) and Brousse and Rudel ( 1973 ) inter-
preted sandy beds as tephras which were plotted in pollen
diagrams, but no mineralogical or geochemical control was
undertaken. Nevertheless, the former two works initiated
Holocene tephrostratigraphy of the Massif Central

(Fig. 8.1 ). Camus et al. ( 1973 ) and Bourdier ( 1980 )

described outcropping proximal products of the volcanoes

of the group of Besse-en-Chandesse as well as Montcineyre

volcano (Compains), so that it was demonstrated that the

relevant eruptions had taken place in the following order:

Montcineyre, Estivadoux , Montchal, and Pavin. Brousse

and Bardintzeff ( 1987 ) proposed a tephrochronologic

model based on the previous works of Brousse et al. ( 1969 )

and Brousse and Rudel ( 1973 ) (see above). Later on, cores

were taken from peat-bogs and lakes in the Cézalier that

enabled Gewelt and Juvigné ( 1988 ) to confi rm and develop

the tephrostratigraphic model of Bourdier ( 1980 ) (see

above).

Then, more cores were taken from some forty peat-bogs

and lake deposits of the Massif Central from the northern

Chaîne des Puys to the Planèze de Saint Flour/Cantal

E. Juvigné (*)
Laboratoire de Géomorphologie et de Géologie du Quaternaire,
Sart-Tilman, Bât. 11 , Université de Liège , B 4000 Liège , Belgium
e-mail: [email protected]

D. Miallier
Laboratoire de Physique Corpusculaire, BP 10448 , Clermont
Université, Université Blaise Pascal, CNRS/IN2P3 ,
F-63000 Clermont-Ferrand , France

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