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Keywords
France • Massif central • Lake Pavin • History • Volcanology • MaarThe circular shape, unusual size and depth, and pure water of
the Lake Pavin as well as the dark forest draping its slopes
down to the shore have always impressed visitors. As Michel
Meybeck pointed out in chapter 3 (this volume), these char-
acteristics have fuelled many legends. This garnered a great
fame to the lake, which attracted the curiosity of many geol-
ogists although they defended a more scientifi c approach.
This article does not aim to describe the side-issue of
research carried out in Auvergne. Rivalry and mutual charges
of theft of discoveries have long beset relationships between
researchers since the beginning of the history of science and
still continues nowadays. Here we deal only with offi cially
published works and we focus on debates related to the for-
mation of the Lake Pavin.
The translation of the quotation was carried out by the
authors, with the invaluable assistance of J.C. Thouret.
5.1 The Discovery of the Auvergne
Volcanoes
Jean-Etienne Guettard , at the time of his trip in 1751, discov-
ered that Auvergne encompassed many extinct volcanoes.
Two criteria guided his hypothesis, namely the texture of
rocks “ des scories qu’ils sont d’un rouge obscur ou d’un noir
sale & matte / scoriae that have a dark red or dirty and mat
black color ” and hill shape, such as, for example, the ‘puy of
La Bannière’ upstream of Volvic, “ Cette montagne a la fi gure
qui est assignée aux volcans dans les descriptions que nous
en avons, elle est conique / This mountain has the shape that is
commonly assigned to volcanoes in descriptions that we
obtained, it is conical ” and “ Un peu avant d’arriver au som-
met, on entre dans un trou large de quelques toises, d’une
forme conique, & qui approche d’un entonnoir; c’est aussi le
nom que l’on donne ordinairement à la bouche des volcans
actuellement enfl ammés/Shortly before arriving at the sum-
mit, one enters a large hole a few ‘toises’ (a toise is 6 feet
long) wide and with a conical form, it is also the name that
one usually gives to the mouth of the currently ignited volca-
noes ” (Guettard 1752a , p. 32). This document, published in
1752, was quickly disseminated through the community of
naturalists (Ellenberger 1978 ). For example, Montet (based
on his communication in 1754 according to Dulieu 1955 )
published an inventory of the volcanoes of Herault (Montet
1760 ). However, these authors applied the shape of conical
volcano with crater that they always restricted to a landform.
Desmarest in 1763, according to the author himself, intro-
duced a new concept as he identifi ed jointed basaltic lava
fl ows and showed that the “ courants de laves / currents of
lava ” always resulted from volcanoes (Desmarest 1771 ).
According to this principle and with the assistance of
Pasumot and Dailley, both engineering geographers of the
King at this time, he drew the fi rst map of the volcanoes of
Auvergne, which appeared in two editions. The fi rst edition
in 1771 covered the ‘Chain of Puys’ and the ‘Monts-Dore-
Sancy Mountain’. The second, posthumous edition in 1823
focused on the Puy-de-Dôme department and extended from
the Comté d’Auvergne to the East up to the Sioule River
Valley to the West (Figs. 5.1 and 5.2 ).
In all reports associated with these geological maps,
Desmarest never quote the Lake Pavin. The latter was
mapped as a common lake with the name of Paven, and not
as a volcano because no ‘courant de lave/ current of lava ’
poured out from this hole in the ground. However, reports
state that Desmaret spread the idea that Lake Pavin was a
‘bouche volcanique/volcanic mouth’ (Monnet 1787 ).
At the end of the eighteenth century, while observations
on the eruptions of Vesuvius made the understanding of the
growth of volcanic edifi ces possible (Hamilton 1767 , 1776 ),
the most popular and relevant question was the origin of the
volcanoes in general (Taylor 2007 ) and in Auvergne in par-
ticular. The majority of authors, including Guettard, pro-
posed the hypothesis involving the combustion of asphalt or
coal: “ La matière nécessaire pour servir d’aliment au feu qui
a brûlé, & qui peut-être brûle encore dans nos volcans
[d’Auvergne] , se présente presque d’elle-même; tous les
environs de ces montagnes sont remplis d’huile de Pétrole,
de charbon de terre & de bitume/The requested material to
feed the fi re which burned, and maybe still burns in our vol-
canoes [of Auvergne] , is almost self explanatory; all theFig. 5.1 Caption of the posthumous map of Desmarest ( 1823 ) : Crater and Modern Current in a small Valley
P. Boivin and S. Jouhannel