Field of Science

Auvergne: between volcanoes and valleys

Until the XVIII century volcanoes were considered local phenomena, without a large impact on regional geology or the morphology of the landscape. In the first half of the 18th Century the French self educated naturalist Jean-Ètienne Guettard (as son of a pharmacist at these times he spent a lot of time searching plants and herbs for medical purpose and become interested in natural sciences) discovered that plants are restricted to areas with specific petrological characteristics. In the following years he travelled a lot, and finally with the acquired experience he compiled one of the first geological maps of France.

Fig.1. In 1771 the amateur geologist Nicholas Desmarest studied and published a map depicting the volcanoes of the "Le Puy".

Fig.2. Quarry in the extinct volcano "Puy Narse" with tephra layers.

In 1751 he travelled to the region of Vichy, in Southeast France. With his friend, the lawyer Malesherbes, he visited the "Puy de Dome (1.465m)", a large mountain west of Clermont-Ferrand. Travelling the city of Moulins, he noted a black rock, used as milestone, near the street, and saw that the same lithology was used extensively as building rock. Tracking down the quarry, near the city of Vichy, he saw his presumptions were right, the quarry was situated in an ancient lava flow, and nearby was located an ancient volcano.

Fig.3. Basalt columns used as bricks in a stone wall in the village Murat.

Fig.4. Quarry with columnar basalt near the village of Le Pont de Alleray.

They returned to Clermont-Ferrand, and with a local naturalist they climbed the Puy de Dome and recognized a chain of volcanic craters, known as Le Puys, distributed from south to north.

On 10 May 1752 Guettard handled to the Académie des Sciences a short communication entitled "Observations on some French mountains that in the past were volcanoes".
These observations will begin a scientific controversy on the origin of rocks, were rocks the sediments of an ancient ocean, or were all lithologies erupted by ancient and recent volcanoes?

The region was also important in debates about geologic time and the ability of current river processes to change the landscape in any significant way.
In the1820s the British geologist George Poulett Scrope (1797-1876) established a chronology of lava flows within central France, showing that there had been a continuous history of eruption and river erosion.

In 1822, William Daniel Conybeare (1787-1857) and William Phillips (1775-1828) argued that "to believe them [valleys in general] to have been formed by their actual rivers, however long their action may have endured, involves the most direct physical impossibilities. It is indeed the more extraordinary that a cause so manifestly inadequate, should ever have been embraced, since the fundamental fact of geology, namely, that the continents, now dry land, were once covered with the ocean . . . [and] however that ocean may have been brought to its present level, it could never (on any view of the matter) have drained off the surface of the lands it has deserted, without experiencing violent currents in its retreat . . ."

In 1823 William H. Fitton (1780-1861) wrote that "The effects of water upon the solid strata of the globe have been the subject of much geological debate; but it is now almost universally admitted, that valleys have been excavated by causes no longer in action."

Later, in a 1829 study of the upper Thames, Conybeare characterized "the opposite theories of the fluvialist and diluvialist, the former ascribing such denudations exclusively to the operation of the streams actually existing, or rather to the drainage of the atmospherical waters falling on the districts, which it is supposed have become thus deeply furrowed by the gradual erosion of these waters, continued through a long and indefinite series of ages; the latter contending that such a cause is totally inadequate to the solution of the phenomena, and maintaining that they afford evidence of having been produced by violent diluvial currents."

Fig.5. Glacier-valley on the "Puy Mary", a large volcanic mountain massiv.


DESMAREST, N. (1771): Mémoire sur l'origine et la nature du basalte à grandes colonnes polygones, determinées par l'histoire naturelle de cette pierre, observée en Avergne In: Mémoires de l'Académie Royale des Sciences à Paris pour 1771.
LEWIS, T.A.(ed) (1985): Volcano (Planet Earth). Time-Life Books: 176
MIALLIER, D. ; MICHON, L. ; EVIN, J. ; PILLEYRE, T. ; SANZELLE, S. & VERNET, G. (2004) : Volcans de la chaine des Puys (Massif central, France): point sur la chronologie Vasset-Kilian-Pariou-Chopine. C.R. Geoscience 336 : 1345-1353

MONTGOMERY, K.: The development of the glacial theory, 1800-1870. 2. Tour Europe in the early19th century - Orientation to the issues, scientists, and landscapes of Europe. Acessed 30.05.2010

DARWIN - the action movie

"In 1835, Charles Darwin went to the Galapagos to discover truth.
But the truth did not reveal itself without a fight..."

"DARWIN": First came action-packed Sherlock Holmes now comes action-packed Darwin. From Dana Carvey & Spike Feresten's new show "Spoof":

Jean Louis Rodolphe Agassiz (28 May 1807 - 14 Dec.1873): No more ice...

"I am afraid you work too much, and (shall I tell you frankly?) that you spread your intellect over too many subjects at once. I think that you should concentrate your moral and also your pecuniary strength upon this beautiful work on fossil fishes .... In accepting considerable sums from England, you have, so to speak, contracted obligations to be met only by completing a work which will be at once a monument to your own glory and a landmark in the history of science ...[ ]...No more ice, not much of echinoderms, plenty of fish..."
2. December 1837, Alexander von Humbolt in a letter to Agassiz

Fig.1. “The period of the Diluvium, or Ice Age, with a glacier invading the land” (picture taken from UNGER 1851).

Today, celebrating the birthday of Agassiz, it’s seems surprising that till and erratic boulders were once considered proof of a flood, even if 100 years ago the field and outcrop data were the same, it needed a new way to interpret the data to recognize the true nature of these deposits. Agassiz (1807-1873) is today remembered as most famous proponent of a glacial origin of these sediments, but much earlier even Hutton (1726-1797) and his friend Playfair (1748-1819) speculated about a glaciation of the northern hemisphere. In 1826 a publication by the Danish mineralogist and mountain climber Jens Esmark (1763–1839) was translated into English, in this paper Jesmark discussed the possibilities that glaciers where much greater in the past then today. J.D. Forbes and Robert Jameson (“The sole effect they produced on me was the determination never as long as I lived to read a book on Geology or in any way to study the science.” C. Darwin in his autobiography 1876) discussed glacial theories during their lectures in Edinburgh. And even Buckland, who still in 1831 argued "northern region of the earth seems to have undergone successive changes from heat to cold", only until 1837 was converted to Lyell's uniformatism and considered that sudden changes, like an ice age, don't happen in geology.
But with the introduction and forcing of the glacial theory by Agassiz between 1837 and subsequent years in the circle of British gentleman geologist, some of them finally become convinced, particularly by reinterpreting field work carried out by themselves years before. After that the most respected geologist gets convinced, the rest, as always, is history:

"advice - never try & persuade ye world of a new theory - persuade 2 or 3 of ye tip top men - & ye rest will go with ye stream, as Dr B. did with Sir H. Davy and Dr. Wollaston in case of Kirkdale Cave"
Jackson, Edward, about an advice given by his professor Buckland in 1832


UNGER, F. (1851): Ideal Views of the Primitive World, in its Geological and Palaeontological Phases. Taylor and Francis, London

BOYLAN, P.J. (1998): Lyell and the dilemma of Quaternary glaciation. Geological Society, London, Special Publications 143: 145-159. doi:10.1144/GSL.SP.1998.143.01.13

Early geological maps: Mapa geognostico del Tirol (1808), a first approach to map the Alps

Considering geology, the Alps are today one of the best studied mountain region of the world. This circumstance can be explained by the geographic location, in the middle of a densely inhabited continent the Alps were never considered a hinderniss, travellers had to pass trough, and these travellers were the first to report on the natural wonders hidden between the mountain peaks.

Beginning with the 18th century local naturalists began to explore more systematically the region.
Surprisingly one of the first geological maps depicting a part of the Alps was drawn by a Spanish naturalist. The Catalan Carlos de Gimbernat (1768-1834) in 1808 produced on behalf of the Spanish King Karl IV the first geological map entitled "Mapa geognostico del Tirol".

Fig.1. Carlos de Gimbernat´s geological map (picture taken from BAUMGARTEN 2007).

Today only two copies are known, both treasured in the Bavarian State Library (Munich, Germany), a much greater project, planed by Gimbernat to map and describe the geology of the entire Alps, was never finished.
Gimbernat visited the eastern Alps between August and October 1803. His geological map was based on the cover sheet of one of the most exact maps available at the time for the region of Tyrol, the "Atlas Tyrolensis" of Peter Anich and Blasius Hueber published in 1774.
The hand-coloured map of Gimbernat depicts like modern geological maps the different lithologies (16 signatures) with different colours, also mines and quarries (9 signatures) are recorded, the map was intended to serve an economic cause. The quality of the map is very approximate (but we also must consider he did the field work and collection of rock descriptions in just three months), Gimbernat discerned only schist as a metamorphic rock, the broad rosé coloured area (Granit) is a misidentification of single and local intrusions in the predominant metamorphic unit.

Fig.2. Legend of rock types used by Gimbernat: Graniticas: Granite; Pizassas: Quartz schist; Calcareo-lamelar: stratified limestone; Calcareo-granulento: solid limestone; Dolomita: dolomite; Magnesiana: magnesite and serpentinite; Grauvaka: sandstones and conglomerates; Porfido: Rhyolite and ignimbrite; Grunstein: amphibole bearing rocks; Basalto: basalt; Arcilla lamelar: argillite; Piedra arenosa: sandstones s.s.; Hieso (Yeso): gypsum

For resources worth mining he distincts Oro (gold), Plata (silver), Cobre (copper), Plomo (lead), Zinc (Zinc), Hierro (Iron), Kobalto (Cobalt), Hulla (Coal) and Sal (Salt).
Tierra verde (seladonite) and Guijarrat (Quartz bearing rocks).

The colour schema adopted by Gimbernat is influenced by the suggestions of the German geologist Abraham Gottlob Werner (1749-1817) and the poet Johann Wolfgang von Goethe (1749-1832):

Colours after Gimbernat 1808*
Colours after Werner 1790**
Schist (Paragneisses and micaschists)
*light green
** grey-blue
Granit (Metamorphic rocks of mainly granitic origin)
*light red
** light red
Quartz porphyries (Acidic lavas, rhyolite and resulting effusive products - ignimbrites)
*light orange
*light yellow
** yellow
*light blue
** blue
*light grey
**dark brown-dark green

Gimbernat shared also the Neptunian vision of Werner; all lithologies were deposited in a primordial ocean, and exposed subsequently by regression of the ocean.
This position is enforced by a letter send in 1808, describing the geology of the mapped area he declares:

"All the rocks were formed by crystallization in situ. Their horizontal position is the proof. It is erroneous to believe that so-called "terrestrial revolutions" have deformed the rocks."


BAUMGARTEN, B. (2007): Carlos de Gimbernat and the first geological map of Tyrol (1808). Geo.Alps, Sonderband: 1-10

VOLKMAR, S. & VOLKMAR, M. (2005): Introduction to the geology of South Tyrol. Ufficio geologia e prove materiali - Provincia Autonoma di Bolzano-Alto Adige: 80

The hard life of being geologist – How to Dress for Every Occasion

The fully equipped geologist most time was considered a reason for distrust by native people. If he was dressed poorly or returned from field work covered with dirt or dust, it could happen that he got arrested and denounced for vagabondage. When he appeared to dressy, causing the impression that he got a lot of money, there was the danger to become a victim of robbery or even murder. Also in many regions (especially in the east border regions) of the Austro-Hungarian Empire there were political aversions against people coming from the capital of the monarchy.

So the appropriate dress for geologist during these times was described as follows:

The pants should be comfortable and wide, cut from a light fabric. Underwear was considered an unnecessary luxury. The jacket should possess a lot of pockets, to carry in a comfortable way the collected mineral and fossil specimens. Cotton shirts were popular. Tie or a fly were considered essential parts of the outfit. Geologists working in the field had to use two kinds of hats: a gray or black felt hat with a wide rim, and a cylinder, when there was the necessity to enter a tavern.

Fig.1. Carl Maria Paul, Franz von Hauer and Guido Stache, fully equipped for field work (ca. 1860, picture taken from GSTÖTTNER 1999).

So dressed and fully equipped, it does no wonder that geologist during their long and solitary field trips were considered sometimes a little bit introverted.

In his story “La vallèe de Trient” the Swiss author Rodolphe Toepffer (1799-1846) wrote: "Geologists are very pleasant companions, especially for geologists. It’s their art, to stop at every stone, and carry out an investigation at every layer of earth! […] And that’s why I love this science so much. It is infinite and boundless as all poetry!"


AVANZINI, M. & WACHTLER, M. (1999): Dolomiten – Reisen in die Urzeit. Athesia G.m.b.H. Bozen

GSTÖTTNER, M. (1999): Ausrüstung und Leben der frühen Geologen im Gelände. In: Geologische Bundesanstalt (ed.), Die Geologische Bundesanstalt in Wien - 150 Jahre Geologie im Dienste Österreichs (1849-1999). Böhlau Verlag. Wien.

The hard life of being geologist – An introduction

150 years ago the practical work of geologists in the field was considerable different to modern standards (at least in Europe), there were differences in the equipment, but also differences in the circumstances of exploring and mapping the area of interest.
These differences begins even how to reach a specific area, today with cars most regions are accessible, 100 years ago geologists used when possible the first established train connections, but most localities were only to approach with carriages or by walking.

Because these voyages were expensive, geologist used to save time and money and after arrival in the designated study area stayed in the field for months during the entire summer.
To map a larger area, most time early geologists established a base camp where heavy equipment was stored. From this base camp they started in the field, sometimes for days, sleeping in farms, cottages or under the sky.

It was a very physical work, for example the Austrian geologist Marcus Vinzenz Lipold mapped in 1853 in only one day the area surrounding the Großglockner (3.797m), and starting from the village of Ferleiten (1.151m), reached the Erzherzog-Johann-Hütte (3.454m), and finally descended back to the village of Heiligenblut (1.188m) - a heigth difference of 2.700m and a linear dist
ance of 28 kilometres.

Every geologist of the Austrian Geological Survey carried during field exploration the standard equipment: maps and a plate to draw on with a tripod, two barometers, pocket-compass, a common telescope and a telescope with incorporated compass, psychrometer (a tool to determinate the humidity of air), thermometer and a camera obscura (an ancestor of modern digital cameras). To these tools we have to add hammers of various sizes and a portable drill.

Fig.1. "Geognosts" around 1800 (unknown author, picture taken from AVANZINI & WACHTLER 1999).

The equipment underscores the broad "uses" for geologists. Because natural science wasn't yet so specialized as today, and geology itself not so clearly delimited against other scientific fields, from a geologist it was also demanded that he possess know-how in meteorology, palaeontology, mineralogy, archaeology, botany and ethnology.
The geologist Johann Czjzek in 1850 describes the requests to be a geologist: "To every geologist mister Wilh. Haidinger, as head of the department, recommended these instructions; not only to carry out their geological tasks, but also to collect a broad variety of minerals, rocks, fossils and measurements, if these are related to science and regional and cultural studies, especially physical, geographical, historic, archaeological and ethnographic data, which connect the fossil world with the beginnings of our own history."

Fig.2. The staff of the Austrian Geological Imperial Institute in 1868 (From left to right, picture taken from GSTÖTTNER 1999):
Foreground: Ferdinand Freiherr von Andrian-Werburg, Karl von Hauer, Guido Stache, Franz von Hauer, Franz Foetterle, Dionys Stur, Adolf Patera.
Background: Karl Griesbach, Melchian Neumayr, Edmund Mojsisovics von Mojsvar, Hans Höfer von Heimhalt, Rudolph Pfeiffer, Viktor Mazer, Heinrich Wolf, Joseph Hofmann, Franz Edler von Vivenot, Urban Schloenbach, Carl Maria Paul, Felix Franz Xaver Kreutz, Alois Pallausch


AVANZINI, M. & WACHTLER, M. (1999): Dolomiten – Reisen in die Urzeit. Athesia G.m.b.H. Bozen
GSTÖTTNER, M. (1999): Ausrüstung und Leben der frühen Geologen im Gelände. In: Geologische Bundesanstalt (ed.), Die Geologische Bundesanstalt in Wien - 150 Jahre Geologie im Dienste Österreichs (1849-1999). Böhlau Verlag. Wien.