David Bressan – Bressan-Geoconsult

Geomythology: The Beast of Gévaudan

On the last day of June 1764, the 14-year-old Jeanne Boulet was killed near the village of Saint-Étienne-de-Lugdarès, at the time located in the county of Gévaudan, a highland region in the middle of southern France. Only some remains of the young shepherdess were ever recovered. Just a month later, a 15-year-old girl was attacked near Puylaurent. Deadly wounded, she managed with her last breath to describe the attacker as “a horrible beast.”

Animal attacks were common at the time. However, now authorities started to note an unsettling pattern. Already on September 8, 1762, a boy from the village of Laval was killed by an unknown creature. One month before Jeanne Boulet, another shepherdess was attacked near the city of Saint-Flour in the Auvergne. Her herd formed a defensive ring against the attacker, saving the girl in the end. Notable enough, the creature seemed to be less interested in the cattle than in the girl. And now, more and more children and women were killed by the unknown creature – the Beast of Gèvaudan.

“Figure of the ferocious Beast”, one of the first depictions of the Beast published in November 1764.

Overwhelmed by the developing disaster, authorities asked for military support. Jean-Baptiste Duhamel, the captain of the local infantry, organized a hunt involving, as he claims, 30.000 men. But even as the Beast was finally spotted and shot, it escaped unharmed by the bullets into the woods. A local newspaper wrote at the end of the first year:

» … a ferocious beast of unknown type, coming from who knows where, attacks the human species, killing individuals, drinking their blood, feasting on their flesh, and multiplying its carnage from day to day…hunters who are in pursuit have neither been able to stop it, because it is more agile than they, nor lure it into their traps, because it surpasses them in cunning, nor engage in combat when it presents itself to them, because its terrifying appearance weakens their courage, disturbs their vision, sets their hands shaking, and neutralizes their skill. «

The Gévaudan and Auvergne were rural areas, characterized by a rugged and mountainous landscape. Just some years before the killings, physician Jean-Etienne Guettard visited the region. During his visit of Vichy, a city in northern Auvergne, he noted some strange dark rocks, used by locals to make bricks and roofing shingles (“roche tuiliére” in French).

Stone wall made from sections of basalt columns. Town of Murat, Massif Cantal.

Guettard was also interested in geology, offering his skills to rich collectors, helping them classify their rock samples. He noted that the roche tuiliére were very similar to samples of lava coming from Mount Etna in Sicily and hosted in the collection of the Count Of Orléans. Guettard correctly concluded that large parts of the Auvergne and some parts of the Gévaudan were formed by lava flows of ancient, now extinct, volcanoes.

The Francois Pasumot and Nicolas Desmarest volcano-geomorphological map of part of Auvergne, 1774, showing lava flows and volcanic cones.

Various types of rock characterize the area where the Beast of Gévaudan preyed on its victims. The central highlands of Margeride are composed mainly of old metamorphic granitoids (rocks of magmatic origin) and gneiss. The mountain massifs of Cantal, Aubrac and Velay, surrounding the Gévaudan, are composed mainly of younger basaltic lava. Some sedimentary rocks are found in the south.

Simplified geological map of the Gévaudan with recorded attacks by the Beast.

The metamorphic rocks forming the highlands are impermeable to water, the landscape here is characterized by gentle rolling hills, covered by a mosaic of meadows, forests, and swamps. The surrounding volcanic rocks are very resistant to weathering, the landscape here is characterized by a more rugged terrain. Lakes formed by volcanic explosions, volcanic cones and many rocky outcrops of basalt and tephra prevail.

Swamp landscape with eroded volcanic cones in the moor of Narse.

It was extremely difficult to hunt on such a terrain. The hunter D´Enneval de Vaumesle noted after a first survey of the area that “this Beast will not be an easy catch.” Horses could not be used in the swamps, and the creature could easily escape in the forests, hide between the rocky outcrops, or find shelter in caves and crevasses.

Outcrop of volcanic rocks in the extinct volcano of Puy de l’Enfer.

The Cantal Massif, with some peaks over 1.500 meters high, also acts as a barrier for clouds. The weather in the Gévaudan was notoriously bad, with cold and long winters and wet summers. Again and again the Beast escaped into the mist or hunters gave up the pursuit because of heavy rain.

View from the Puy Mary in the Cantal Massif, a large and ancient volcanic edifice.

Despite all efforts, the Beast continued to kill. King Louis XV. was even forced to replace Duhamel, sending his own gun-bearer François Antoine from Paris to the Gévaudan. But also Antoine, despite his experience, had difficulties with the terrain. Only in September 1765, he shot and killed an extraordinarily large wolf near the town of Murat in the Cantal Massif. The king himself announced the death of the Beast.

The town of Murat today, with outcrop of magmatic rocks and a volcanic cone in the background.

But just two brief months later the attacks resumed.

The mysterious killings continued until July 1767, when the local hunter Jean Chastel shot another large wolf in the forest of Teynazére, on the highlands of the Margeride. Until its final demise, the Beast (or maybe a pack of wolves) had killed at least 116 children and women and wounded many more.

References:

SMITH, J.M. (2011): Monsters of the Gévaudan – the Making of a Beast. Harvard University Press:378
TAYLOR, K.L. (2007): Geological travellers in Auvergne, 1751 –1800. From: WYSE JACKSON , P. N. (ed.): Four Centuries of Geological Travel: The Search for Knowledge on Foot, Bicycle, Sledge and Camel. Geological Society, London, Special Publications, 287: 73–96

The Geology Of Star Wars

Geology is strong in the successful Star Wars franchise, be it in the movies or behind the scenes.

Spectacular landscapes, like salt-plains in the Andes, an active volcano in Sicily, the dolo- and limestone peaks of the Dolomites, and the sand dunes of Tunisia act as a background for the struggles of our heroes against the dark side.

The famous lightsaber battle on Mustafar in the 2005 film Star Wars Episode III: Revenge of the Sith, was done by combining computer graphics with real footage of Mount Etna. The crew was filming in 2002 in Italy when just by chance Mount Etna erupted with spectacular lava fountains and flows, so they decided to film there.

In the movie, the fictional planet Mustafar displays a landscape covered entirely in dark rocks, igneous in origin as the many active lava flows and eruptions suggest. Likely the early Earth – some 4,5 billion years ago – was pretty much a lava planet, with a thin crust of basalt covering a fiery ocean of molten magma. Only later, when plate tectonics and erosion by water started, other rocks formed. Planets like Mars and Venus are still today covered mostly by basalt, even if it is not clear if there are active volcanoes to be found.

One of the most recent episodes of Star Wars, The Last Jedi (2017), features some spectacular landscapes, like the Salar de Uyuni, a dry salt-plain located in the Andes. In the movie, Crait is a small planet covered entirely with salty minerals. During a battle scene, it is shown that beneath the white crust of salt lays a red mineral. Halite, the mineralogical name for salt (NaCl), can become dark red/brown when exposed to radioactive radiation. Sylvite, a potassium chloride (KCl), has a reddish color that can become purple if exposed to radiation, but it is a rare mineral on Earth. Later our heroes escape through a cave filled with gigantic red crystals, likely crystallized over millions of years.

In the 2018 spin-off movie Solo: A Star Wars Story, scenes of a train heist on the planet Vandor-1 were filmed in the Dolomites, near the peaks of the Tofane, the Langkofel, Sella Pass and the Drei Zinnen. The base of those mountains are composed of the Cassian-Dolomit, the dolostone cores of former Triassic reefs. The relative plain summits – as seen in some scenes – are formed by erodible marl deposits of the Heiligkreuz- and Travenanzes-Formation, and the plane-bedded Hauptdolomit-Formation.

The fictional desert city of Mos Espa, the hometown of Anakin Skywalker, was built in 1997 for the movie Star Wars Episode I: The Phantom Menace and then abandoned in the Tunisian desert. Over the years it has become a tourist attraction. The dry climate preserves the buildings very well and the only menace for the site comes from the slowly moving barchan dunes, up to 6 meter high windblown accumulations of sand and gypsum grains. The set of Mos Espa, consisting of twenty buildings made of wood and plaster, was built on a flat, clay-rich pan and the city later expanded digitally in size, with dunes only barely visible in the background of some scenes.

However the prevailing wind, blowing from east to west, constantly moves the sand. The dunes are migrating with the wind eastwards, just in the direction of the remains of the abandoned site. Using the buildings as a fixed reference point in a quite featureless landscape, and comparing a series of satellite images from 2002 to 2009 and pictures taken by Star Wars fans over the years, researchers were able to calculate the migration rate of three larger dunes. With 4,8 to 15 meter per year, the dunes move with an average speed. The study notes that the dune located nearest to the film set slowed down in recent years, possibly influenced by changes in the wind pattern caused by the encountered obstacles. Even so, Mos Espa will be buried completely in estimated 80 years by the sand. The slow destruction of his home may also explain why Darth “Anakin” Vader doesn’t really like sand (as revealed in the 2002 film Star Wars Episode II: Attack of the Clones).

Geology, sort of, was also involved behind the scenes of Star Wars. Forty years ago the Death Star was blown up by the rebels in the 1977 sequel Star Wars: A New Hope. The computer animation for the simulated attack on the Moon-sized battle station was done using computers of the University of Illinois. At the time only a few computers were powerful enough to calculate the vector graphics as shown in the scene. Geologist Christopher Scotese had to share his spare computer time, used for simulations of how plate tectonics shapes Earth, with the special effects artists at work.

Nicolas Steno and the Nature Of Fossils

In October 1666, a large shark was captured by a fishing boat in the sea of Livorno (at the time part of the reign of Tuscany). The animal was pulled onto the shore, beaten to death and dismembered. As the body was too heavy to be transported, only the head was saved. It was brought to Florence, where famous Danish anatomist and naturalist Niels Stensen (latinized Nicolas Steno) was asked to dissect the specimen.

Steno later published a detailed anatomical description of the shark, which included a chapter where he compared the shark’s teeth with fossils commonly found in the hills of Tuscany. The fossils of unknown origin were simply referred to as Glossopetrae or tongue stones.

Steno was not the first to speculate about an organic origin of fossils. In his 1565 book De Rerum fossilium, Lapidum et Gemmarum maxime, figuris et similitudinis Liber (On Fossil Objects), Swiss naturalist Conrad Gesner compared fossil sea urchins with living specimens, and argued that some fossils are petrified organisms. In 1616, the Italian naturalist Fabio Colonna argued that glossopetrae were shark teeth.

However, there was a big problem – they couldn’t explain how the supposed remains of sea animals could be embedded in rocks now parts of inland mountains. So most naturalists preferred to explain fossils just as curiously shaped inorganic features growing inside rocks.

Steno was the first to explain why fossilized teeth of a creature from the sea could be found inside rocks that were far distant from the modern sea. Before dissecting the shark in Florence, Steno had visited the Royal Danish Kunstkammer in Copenhagen and the fossils on display there. He wrote in a private note:

Snails, shells, oysters, fish, etc., found petrified on places far remote from the sea. Either they have remained there after an ancient flood or because the bed of the seas has slowly been changed. On the change of the surface of the earth I plan a book, etc.

During his travels in Tuscany, Steno had studied outcrops of layered rocks, and he had recognized that the sedimentary layers were petrified shores and marine sediment of an ancient, now vanished sea.

He also noted that fossils are found only in layered rocks and never in recent soils. If fossils were of inorganic nature, like many naturalists argued at the time, we should find them in every kind of soil and rock. By combining his observations in the field and the results of the shark’s dissection, Steno formulated a surprisingly modern geo-theory:

The layers were formed by deposition in water. The now hard rock was once a soft mud.
An animal living in the sea would, after its death, sink slowly into the soft mud. Mud and water would petrify the animal and preserve it.
Collapsing cavities in earth´s crust would tilt layers along the borders of the forming crater upwards. Exposed to air the mud – with the fossils still inside – dries and becomes hard rock.
Eventually the crater fills with water and a new layer is deposited above the old ones.

In the end, Steno argued, all the layers were uplifted again, this time high enough to form a mountain, where a curious naturalist can find the fossils eroding from the rocks. Unfortunately Steno’s work, like the work of many others before him, was soon forgotten and ignored.

In 1695, amateur physician and naturalist John Woodward published An Essay toward a Natural History of the Earth. This book, intended to prove the veracity of the Biblical account of a large ancient flood, was not well written and mostly based on work copied from other naturalists. Woodward argued that fossils are the remains of animals killed by a flood, and cited Steno to support this idea. However, reading Steno’s original considerations makes it clear that a single flood was not sufficient to explain the thick layers of sedimentary rocks found everywhere. Woodward’s book was therefore mostly dismissed by contemporary scientists, but it made Steno’s ideas popular again. Scientists then began to actively study and discuss sedimentary rocks and fossils – and the rest is history.

Used References:

KARDEL, T. & MAQUET, P. (eds.) (2013): Nicolaus Steno – Biography and Original Papers of a 17th Century Scientist. Springer Publishing: 739

The Geology Of Jules Verne’s Journey To The Center of the Earth

Figure from the novel “Journey to the Center of the Earth” published by Jules Verne in 1864.

“Well gentlemen, at one point at least I agree … the materials of the geologists are not charts, chalk and chatter, but the earth itself. We should never know the truth until we are able to make that journey and see for ourselves.”
from “Where Time Began,” a 1976 film based on Jules Verne’s novel Journey to the Center of the Earth.

Novelist Jules Verne was born on February 8, 1828, in the French city of Nantes. Today he is known as a pioneer of the science-fiction genre, imagining a submarine traveling twenty thousand leagues under the sea, a space projectile heading to the moon and a fantastic journey into the depths of our world. One hundred and fifty years after Verne’s visions, humans have walked on the moon, nuclear submarines can travel under the sea and we have started to explore the mysteries of the deep earth.

Journey to the Center of the Earth was published in 1864 and was immediately a critical success, and has remained in publication in both French and English to this day. In the opening chapters of the novel, the German Professor Otto Lidenbrock and his nephew Axel discover an ancient document, written by Snorri Sturluson. This (fictional) 16th-century alchemist described a journey into a large system of volcanic conduits, accessible from the crater of the Icelandic volcano Snæfellsjökull. So Lindenbrock and his nephew traveled to Iceland, employed a local guide, and following the document’s coded directions, entered the volcanic crater.

There, they descended through the sedimentary layers of the crust into its foundation. About 140 kilometers beneath the surface they discovered an underground sea occupying a cavern, roughly the size of Europe, hollowed in the granite of the lower crust. The travelers ventured upon the “Lidenbrock Sea”, as they name the newly discovered ocean, in a raft built out of the logs of “great palm-trees of species no longer existing” growing along the shores.

At sea, they witnessed a battle between Jurassic sea monsters and disembarked on an island with a geyser. Venturing inland they discovered living mastodons and primitive hominids. Verne’s bestseller was a product of rich imagination and research. He likely based his fictional travel account on the works of geologists like Alcide d’Orbigny, who classified rock strata by their fossil content, Elie de Beaumont, who worked on the origin of mountain ranges, and Charles Sainte-Claire Deville, who studied volcanoes.

Geological section, published by German geophysicist August Sieberg in 1914, showing the anatomy of a stratovolcano, with a main conduit, various lateral dikes and a large sill connected to the magma reservoir. In contrast to the sketch, the conduits for magma are in reality only a few meters wide.

An important source of inspiration to Verne were the books by the French scientist and writer Louis Figuier. In 1864 Figuier published La Terre avant le déluge, a popular science book discussing geology and paleontology. From Verne’s surviving correspondence with his publisher, we know that he started to work on his novel sometimes between January to August 1864. Some passages and scenes in Verne’s novel, like the battle between an ichthyosaur and a plesiosaur witnessed by the travelers, was likely inspired by an illustration in Figuier’s book. Verne’s imaginary forest growing along the “Lidenbrock Sea” was similar to the fossil forests of the Carboniferous period. The heat necessary to keep the forest alive comes from “the excessive heat of the globe. The Earth was still so hot in itself that its innate temperature dominated” as Figuier writes in his textbook. Before the discovery of radioactive decay, geologists believed that earth’s inner heat was the residual heat of its formation from a molten ball. Over time earth cooled down and a solid crust formed.

Verne’s explorers used the hollow volcanic conduit of Snæfellsjökull as a gateway to earth’s interior. Many geologists at the time believed that volcanic conduits, empty once the volcano erupted, connected a volcanic crater to magma chambers deep underground. Today we know that such conduits are far too small (and obstructed by solid rock) for humans to move through.

However, Verne was right when he described a chamber full of gigantic crystals found deep underground. For crystals to grow, they need the right conditions and a lot of time. In theory, there are no limits to how large a crystal can become, however, perfect conditions for crystal growth are rarely met. That said, such perfect conditions are found in the Cueva de los Cristales, located in the Naica Mine, Chihuahua, Mexico.

The mine of Naica was opened in 1828 to mine for lead, zinc and silver ore. In 1910 a natural cave was discovered, named later Cueva de las Espadas. The name derives from the three-foot long blade-like gypsum (calcium-sulfate) crystals covering the walls of the cave. However, what the miners discovered almost 90 years later, during the construction of a tunnel 0.2 mile below ground, is even more astounding. The Cueva de los Cristales hosts the most incredible crystals ever discovered, mirroring Verne’s fantastic description. Almost perfect conditions made it possible to grow gypsum crystals more than 10-meters in length and with an estimated weight of 40 to 50 tons.

The enormous gypsum crystals of Naica. Note person at bottom right for scale. Credit: Wikipedia/Alexander Van Driessche. CC BY 3.0. Van Driessche

Maybe Verne was right in even a more spectacular way. The largest crystal possible on earth could be indeed found at its center. Earth’s core is a solid ball of superhot iron and nickel alloy about 760 miles in diameter. Modern research suggests that it displays a crystalline structure. Unfortunately, at the moment, there is no way to be sure and visit this place as Verne imagined.

Carl Linnaeus’s Systema Naturae And An Early Attempt of Mineral Classification

18th Century Swedish physician, botanist, and zoologist Carl von Linné – latinized Carl Linnaeus – is today famous for his binomial nomenclature, a hierarchical classification scheme for every living organism.

But he was also interested in mineralogy and tried to include minerals in his system. Curiously enough, fossils, now recognized as the petrified remains of ancient organisms, were of no interest to Linné.

During his early travels in Sweden and Norway, Linné became interested in mining activities. During his time, mineral identification and classification were quite a messy thing. Only the most common minerals, like feldspar and quartz, and minerals of some economic value, like ore minerals or gemstones, even had specific names.

Basic mineral identification often relied on easy to observe properties, like color, adding to the general confusion. For example, distinct minerals like ruby and garnet were classified based on the same red color as one mineral, but color variations of the same mineral – like quartz – were all seen as different minerals.

Linné classified plants (and later animals) based on their sexual reproduction organs. The system worked, so he also adopted the idea of sexual reproduction for the classification of minerals.

Of course, minerals don’t mate or have genitals, but Linné imagined that minerals formed by the mixing of various salty fluids, acting as male parts, with different kinds of rocks, acting as female parts. His more practical approach included minerals classified by the shape of the crystal, number of crystal faces, and the observed behavior if exposed to great heat.

The 1770 edition of Linné’s Systema Naturae.

In contrast to his biological classification system, Linné’s mineralogical system never really became popular.

Today, minerals are defined by a specific mineralogical composition and their regular crystalline structure. Linné lacked the technology to accurately identify the chemical composition of a given mineral, and also lacked the knowledge of the physical laws that control the symmetry of crystals.

It wasn’t until the beginning of the 19th century that the first modern mineral classification books were published, such as naturalist Abraham Gottlob Werner’s Short classification and description of the various rock types and The genetic-geological classification and an attempt to introduce a mineral-system based on superficial properties by mineralogist Carl Friedrich Christian Mohs.

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Geological Star Trek Review – “Arena”

Captain Kirk fights a Gorn in the 1967 TOS episode “Arena” – you can see Vasquez Rocks in the background.

Sulfur, niter (saltpeter) and carbon, as coal and as crystalline diamond, save Captain Kirk’s life in the 1967 TOS episode “Arena.”

When a remote outpost of the Federation is attacked by an unknown enemy, the Enterprise pursues the fleeing vessel, inadvertently entering a sector of space controlled by the Metrons, a race with powerful psychic powers. Kirk, transported by the Metrons to a desolate planetoid, is forced into a battle against the captain of the Gorn ship – a reptile-like creature protected by an almost indestructible armored skin.

The planetoid displays a rich geologic diversity. Kirk mentions finding ruby corundum. He uses niter (saltpeter), sulfur, and coal he finds to make gunpowder for use in a primitive cannon, and diamonds as projectiles (here – judging from the crystal shape – likely quartz was used as film prop). After injuring the Gorn, Kirk spares his life to the surprise of the Metrons.

There are almost 5.000 known mineral species, yet the vast majority of rocks are formed from combinations of a few common minerals, like feldspars, quartz, amphiboles, micas, olivine, garnet, calcite, and pyroxenes. We still know little about other worlds. Over 300 minerals have been identified in meteorites, 130 minerals were discovered so far on Mars and 80 on Earth’s Moon.

By convention, the names of terrestrial minerals (a crystalline combination of one or various elements) end with the suffix -ite, the denominations of elements with the suffix – ium, -um, -on, -gen, or -ine. This nomenclature is not always applied in Star Trek.

References:

De FOURESTIER, J. (2005): The Mineralogy of Star Trek. Axis, Vol.1(3): 1-24

Sagenhaftes Südtirol: Die Magie des Karfunkelsteins

“Nach einer Tiroler Sage erfahren wir folgendes über die Erschaffung der Gemse. Der Teufel bekam eines schönen Tages, nach ständigem Drängen an den Herrgott, die Erlaubnis dem Schöpfer ein Tier nachzubilden und ein “Viech” zu schaffen. Nun war es seine erste Tat eben diesem “Viech” schöne nach rückwärts gewundene Hörner zu geben, wie er selbst sie trug als Wahrzeichen seiner höllischen Macht. Da der Teufel aber für die Gestalt der Ziege sowohl des Bockes als auch der Geiß eine besondere Vorliebe hatte, mußte auch sein Tier so aussehen, nur daß er Bock und Geiß aus Übermut gleichermaßen mit Hörner, richtiger gesagt, mit der “Krucke” ausstattete. Damit es aber noch ein besonderes Aussehen erhalte, setzte er den Bart nicht an diese Stelle, wo ihn die Ziegen haben, sondern boshafterweise über das Waidloch. Dazu tat er noch einen langen buschigen Fuchsschwanz. Als die “Viecher” so fertig waren, hatte er eine richtige Teufelsfreude und gab ihm das Gebirge zum Wohnort, dort wo die Felsen und Grate am gefährlichsten sind, weil er wußte, daß dieses von ihm geschaffene sonderbare Wild die Jäger und Wildschützen besonders reizen würde und so mancher infolge seiner blinden Leidenschaft Leib und Leben daransetzen werde. Als sie aber so im Gebirge dahinsausten, die Teufelstiere, da sah er zu seinem Ärger, daß sie ständig mit ihren wunderbaren Fuchsschwänzen in Latschen und Zuntern hängen blieben und er, der Teufel, mußte hinterher sein und sie wieder aus ihrer unbequemen Lage befreien. Das ermüdete nicht nur sehr, sondern kostete vor allem auch sehr viel Zeit und außerdem ging ihm dabei manches “Viech” zugrunde, was ihn sehr verdroß. Als er eben wieder daran war, so ein “Viech” loszulösen und es im Augenblicke nicht gelang, biß er kurzerhand den Fuchsschwanz ab und machte es sogleich auch an allen anderen Gemsen, so daß an Stelle des buschigen Langschwanzes nun nur mehr das kurze Stutzer! zu sehen ist, das der Jäger mit dem Namen “Wedel” bezeichnet. Den wertvollen Bart aber, den Schmuck jedes Tiroler Schützenhutes, tragen die Gemsen noch heute dort, wo er nicht hingehört, nämlich über dem Hintern.”
R. Rothleitner “Volkstümliches über die Gemse” (1937)

Die Gämse oder Gams spielt in den Sagen, Brauch und Geschichten aus den Alpen eine kleine, aber feine Rolle. Sie ist eines der Symboltiere der Berge und Flur- und Bergnamen beziehen sich auf sie. Allein sieben Berge in den Alpen heißen Gamskogel und die Ortschaft Kitzbühel in Tirol hat eine Gams im Wappen. Auch viele traditionelle Lieder behandeln die schwierige und gefährliche Jagd nach ihr.

Gamsjäger waren einige der wenigen Alpenbewohner, die sich in die hohen Gipfelregionen vorwagten. Sie kannten die Berge, wie man sich zwischen Fels und Geröll bewegen kann, und wussten auch wenn sich das Wetter verschlechtern würde.

Gamsjäger wurden bewundert, aber da sie sich so oft in die Berge vorwagten, hatten sie auch einen eher zwielichtigen Ruf. So soll die Gams, mit ihren hakenförmigen Krucken und schwarzen Fell, eigens vom Tuifl geschaffen worden sein, um die jungen Jäger ins Gebirge und so in ihr Verderben zu locken. Sogar der große Naturforscher Saussure schreibt in seinem Buch Voyages dans les Alpes (1786-1796), dass Gamsjäger, “in den Wildnissen mit dem Teufel Umgang, der sie dann endlich in den Abgründen stürze”, hätten.

Doch der Tuifl kennt auch viele Geheimnisse der Berge.

Im Jahre 1745 entdeckt der Bauer Andrä Kreidl auf der Gamspirsch am Roßrücken im hintersten Zillertal die ersten Granate, und beginnt zwei Jahre später mit dem Abbau für Schmucksteine.

Rote Granatkristalle im Glimmerschiefer aus der Sammlung Giuseppe Garbari (1863-1937).

Die Granatvorkommen Südtirols liegen hauptsächlich im Bereich von kristallinen Schiefern und Gneise der Zentralalpen, doch kommen Granate auch in Kontaktzonen, in magmatische Intrusionen und Resten ozeanischer Kruste vor.

Das Passeiertal ist ein bekanntes Fundgebiet für Granate. Der Granatkogel, der seinen Namen dem ungewöhnlichen Almandinreichtum verdankt, ist von der Timmelsjochstraße über das Seebertal hin erreichbar. Die herabgestürzten Felsblöcke und Moränenmaterial rund um den kleinen Seebersee sind ergiebige Fundstellen. Begleitmineralien sind Hornblende in schwärzlich-grüne, bis 20 Zentimeter langen Büscheln (genannt Garben) sowie Disthen. Wie in anderen Gebieten der Ostalpen (Zillertal) wurde auch hier einst Granat für Schmuckzwecke gewonnen. Im letzten Krieg fand das Material auch als Schleifmittel Verwendung.

Eine weitere wichtige Fundstelle ist das berühmte Bergwerk St.Martin am Schneeberg.

Das Pfitschtal biegt bei Sterzing vom Eisacktal in Richtung Osten hin ab. Es handelt sich um ein geologisch höchst interessantes Gebiet, das auch in der Geschichte des Mineraliensammelns eine bedeutende Rolle spielte. Im Talgrund ist die Gesteinsabfolge des Tauernfensters aufgeschlossen. Auf der nördlichen Talseite ragen die älteren, hellen Gneisformationen des europäischen Kontinentalplatte auf, die von einem weißen Quarzitband, das sich vom Talboden bis zum Pfitscherjoch hinzieht, überlagert werden. Meeresboden des Penninischen Ozeans, der ursprünglich aus Tiefseesedimente, basaltischen Tiefseelava und Peridotiten bestand, wurde hier metamorph in bräunliche Kalkschiefer, grüne Chloritschiefer und Serpentinit, die auf der südlichen Talseite aufgeschlossen sind, umgewandelt. Spessartin kommt in Millimetergroße, gelbliche bis rötliche Kristalle, sowie Grossular als Millimetergroße, rote Kristalle, im Grüngestein vor. Berühmt ist die Fundstelle auf der Burgumer Alm.

Literatur:

FRUTH, L. (1975); Mineral Fundstellen – Band 1 Tirol Salzburg Südtirol – Ein Führer zum Selbersammeln. Christian Weise Verlag: 208 Seiten
Gartner et al. (2002): Burgum im schönen Pfitschtal. Mineralogie – Geologie – Archäologie. Geschichte und Geschichten. Eigenverlag Arthur Gartner, Sterzing: 128 Seiten
GARTNER, A. (2010): Im Reich der Bergkristalle. Die Mineralien des Pfitschtales. Erker
Glas et al. (1997): Zillertal: Das Tal der Gründe und Kristalle. extraLapis Nr. 12: 96
HOSSFELD, J. (1977): Die Mineralien im Sterzinger Gebiet – Einige Hinweise zu den Fundorten Alpiner Mineralien im Gebiet um Sterzing. Klub Eisacktaler Mineraliensammler, Athesiadruck Brixen: 75 Seiten

Stoanklauber in Tirol

„Es ist fast nichts in dem Mineralreiche, wovon Tirol nicht etwas besitzt.“
Josef v. Sperges, 1765

Das Tauernfenster auf der “Geognostische Karte Tirols“, um 1849. Das Zusammentreffen von verschiedenen Gesteinsarten – Sedimente und Lavagestein des Penninischen Ozeans und Gneise des europäischen Kontinents – verbunden mit der Metamorphose durch die Auffaltung der Alpen vor 60 bis 30 Millionen Jahre, führte zur Bildung vieler verschiedener Minerale, die heutzutage in den Tiroler Bergen gefunden werden können.

Die „Stoansucherei“ ist ein steinaltes Gewerbe. Bereits vor 9.600 Jahren suchten die Menschen die Gipfelregionen der Tiroler Alpen auf, um Bergkristall zu sammeln und aus diesen Steinwerkzeuge herzustellen. Abbau von Kupfererz ist in Südtirol ab ungefähr 1.300 v.Chr. nachgewiesen. Bei St. Lorenzen wurden Hinweise auf Kupferverarbeitung in der Frühen und Mittleren Bronzezeit gefunden. Vom Ternerbühel stammt eine steinerne Gussform für Kupferbeile und auf der Kleinen Pipe bei St. Georgen ist ein Stück eines Gusskuchens erhalten geblieben. Welche Kupfererzlagerstätte zwischen Pfundererberg, dem Tauferer- und Ahrntal genutzt wurde ist allerdings unbekannt. Im späten Mittelalter und der frühen Neuzeit erlebte der Bergbau hier eine Blütezeit.

In 1558 verfasst Georg Rösch v. Geroldshausen die älteste bekannte Aufzählung von Tiroler Mineralien. Er listet hauptsächlich Erze und Gesteine auf, die in den verschiedenen Bergwerken abgebaut werden, erwähnt aber auch Minerale die auf den vergletscherten Gipfeln der Tauern gefunden werden können.

„Granaten, Talggen, Kobolt, Federweiss: Die Malochiten haben ihren Preyss; … Crystallen darbey, durchsichtig weiss. … der edle Lapis Armenus [hier vermutlich Azurit], Den man sunst bringt aus fernen Landten, Der ist auch in Tyrol vorhandten.“

Um 1581 berichtet Ladurner, dass die Bewohner des Zillertals mit dem Abbau von Federweiss (Asbest und Talk vom Hollenzen, Greiner und Rotkopf) etwas Geld dazuverdienen. In 1745 entdeckt der Bauer Andrä Kreidl auf der Gamspirsch am Roßrücken im hintersten Zillertal die ersten Granate und beginnt zwei Jahre später mit dem Abbau für Schmucksteine.

Der Roßrücken im hintersten Zillertal teilt den Gletscher in Hornkees und Waxeggkees. Alle drei Bereiche sind bekannt für ihren Mineralreichtum, insbesondere für die Granate. Die Almandine finden sich im Bereich des Roßrückens in lauchgrüne, feinkörnige Chlorit-Biotitschiefer. Im Bereich der Gletscher handelt es sich bei dem Muttergestein hingegen um einen Granitgneis.

In 1738 beschreibt Anton Reschmann in seinem “Regnum animale, vegetabile et minerale medicum Tyrolense” die “Carbunculi calcedoni” – vermutlich Granate – im Tauferer Tal. In 1777 beschreibt Ritter Erenbert von Moll die Mineralien die in Tirol gefunden werden können:

„Gold in Quarz und Schiefer mit goldischem, silberhältigen Marcasit … Silber in Bleyglanz … Bley …. Eisen in Schiefer … Kobald … Granaten … Grüner und schwarzer Störl [und] Sinectis (Talk) vom Greiner.“

Im Sommer 1777 wurden in herabgestürtzten Talk-Chlorit-Blöcken vom Greiner schwarze, wirrstrahlige angeordnete Kristalle bis über 10 Zentimeter Länge gefunden. Der kaiserlich-königliche Direktoratsrat in Tirol und Naturforscher Franz Joseph Müller vermutete, dass es sich um Turmalin handeln könnte und führte weitere Untersuchungen durch. Das Vorkommen von “Störl oder Schörl” am Greiner ist auch der erste Fund von Turmalin in Europa überhaupt (vorher nur von Ceylon und Brasilien bekannt).

Abbildung von Turmalin-Kristallen vom Greiner (Zillertal) aus “Nachricht von den in Tyrol entdeckten Turmalinen oder Aschenziehern“, Franz Joseph Müller von Reichenstein (1778).

Turmalin Kristall in Chloritschiefer vom Pfitschtal. Es handelt sich um dieselbe Gesteinsformation die zum Greiner ins Zillertal hinüberzieht. Etikette von der Brendler Sammlung, um 1923.

Ein weiterer Forscher der in 1784 ins Zillertal reiste ist Belsazar Hacquet. In “Hacquets Mineralogisch-botanische Lustreise von dem Terglou in Krain zu dem Berg Glokner in Tyrol” (1784) berichtet er von einem Jäger, der ihm in Breitlahner Stufen mit Granat und “Strahlschörl” (wohl Aktinolith) verkauft.

Die ersten Mineralien wurden bereits im 16. Jahrhundert an den Fürstenhöfen Europas als Kuriositäten gesammelt. In Tirol legt Erzherzog Ferdinand II. (1529-1595) auf Schloß Ambras eine bedeutende Sammlung an, die auch Kristalle aus dem Zillertal umfasst. Aber erst im 19. Jahrhundert wird das Mineraliensuchen und -sammeln auch für weniger begütete Sammler erschwinglich. Um 1796 werden die ersten “Stuffenhändlern” erwähnt, Leute die in den Bergen nach Mineralien und Gesteine suchen und nach Augsburg und München verkaufen. Selbst Johann Wolfgang von Goethe besitzt eine “Suite” mit 37 Tiroler Mineralien – darunter schöne Diopside, Granate, Bergkristall, Cyanit, Tremolith, Pyroxen, Eisenglanz, Apatit und Idiokras (Vesuvianit) – die er von seinem Gönner Großherzog Carl August geschenkt bekommen hat.

Wäre der von Alois Pfaundler in 1803 vorgeschlagene “Mineralogisch-geognostischen Vereins in Tirol” auch tatsächlich gegründet worden, wäre Tirol auch das erste Land mit einem eigenen Mineralienverein geworden. So aber wird der erste Mineralienverein in 1807 in London gegründet, gefolgt in 1830 von Paris, in 1836 von Tirol und in 1848 von Berlin. Das Mineraliensammeln ist von einem einfachen Zusammentragen von Naturkuriositäten zu einem wissenschaftlichen Hobby geworden.

Es werden auch die ersten Mineralienführer veröffentlicht. In 1821 veröffentlicht Wilhelm, Edler von Senger das erste Mineralienbüchlein mit dem Titel „Versuch einer Oryctographie der gefürsteten Grafschaft Tyrol“, gefolgt in 1852 von Karl Doblickas “Tirols Mineralien” und Leonhard Liebeners “Die Mineralien Tirols.” Der Südtiroler Naturhistoriker Georg Gasser veröffentlicht in 1913 sein umfassendes Standardwerk über „Die Mineralien Tirols.”

Und wo es eine Nachfrage für immer neue Mineralstufen gibt, da gibt es auch einen Markt.

Um 1850 öffnen die ersten Mineraliengeschäfte, die Stufen und Mineralien-Partien an interessierte Sammler anbieten. Der Mineralienhändler Kassian Mayr aus Straß bietet zum Beispiel “grünen Augit, Granat, Turmalin, verschiedene Quarzkristalle, Chalcedon, Prehnit, Zeolith, Analcim, Adular, Periklin, Apatit, Liebenerit, Egeran” und andere Minerale an. Um 1870 erlebt der Handel mit Tiroler Mineralien und Edelsteine eine Hochblüte.

Literatur:

FRUTH, L. (1975); Mineral Fundstellen – Band 1 Tirol Salzburg Südtirol – Ein Führer zum Selbersammeln. Christian Weise Verlag: 208 Seiten
Glas et al. (1997): Zillertal: Das Tal der Gründe und Kristalle. extraLapis Nr. 12: 96
HOSSFELD, J. (1977): Die Mineralien im Sterzinger Gebiet – Einige Hinweise zu den Fundorten Alpiner Mineralien im Gebiet um Sterzing. Klub Eisacktaler Mineraliensammler, Athesiadruck Brixen: 75 Seiten

Giovanni Arduino And The Geology Of The Dolomites

» [I worked] still young in the mines of Klausen and elsewhere in Tyrol, in order to learn Metallurgy; I went there by chance, and I was urged to stay by my natural very strong inclination for the universal Mineralogy, and for all the matters concerning the Science of the Fossil Kingdom. «
Venetian scientist Giovanni Arduino worked at an early age as a mining assistant in the iron mines of Klausen in South Tyrol.

Italian mining engineer Giovanni Arduino (1714-1795) is considered nowadays the spiritual father of the modern chronostratigraphic chart. Based on his observations in the Venetian Dolomites and Tuscany in 1759 Arduino proposed “a series of layers forming the visible crust of earth … ” subdivided “in four generalized units following each other.” He named them primary, secondary, tertiary, and quaternary, speculating that they formed at various times and under different environments.

Arduino used a section of rocks exposed in the Val dell´Agno (Venetian Dolomites) to explain his classification. The numbers refer to the thickness of the strata, the letters to the description in the accompanying text. The extremely tattered state of the original drawing suggests that Arduino showed it repeatedly to the many naturalists who visited him.

Primary Layer: Pebbles formed by the erosion of underlying “primitive or primeval” – considered to be the earliest – rocks. Fossils were rare, if not absent. This unit includes unstratified or poorly stratified rocks, like porphyry, granite and schist, of the crystalline basement of the Dolomites. Arduino’s rock unit survives into modern chronostratigraphic charts as the Paleozoic Era (rocks older than 252 million years) and Precambrian Eon (541 million years to about 4.6 billion years ago).

Mica shist as crystalline basement rock of the Dolomites, Arduino’s Primary Rocks.

Secondary Layer: A well-stratified succession of marl- and calcareous rocks with marine fossils, making up the characteristic peaks of the Dolomites. In 1841, English geologist John Phillips, based on the correlation of fossils in rock strata worldwide, renamed this sedimentary succession the Mesozoic Era (252 to 66 million years ago).

Sas de Pütia showing Arduino’s Secondary Rocks, the well-stratified red Gröden-Sandstone, grey Bellerophon limestone and fossil-rich reef limestone.

Tertiary Layer: Poorly consolidated sediments like gravel, clay, fossiliferous sand, and also younger volcanic rocks. Our modern Cenozoic Era (66 to 2 million years ago).

A conglomerate of the Tagliamento catchment, dating into the Pleistocene to Miocene according to our modern stratigraphic system (2-23 million years). Similar deposits were Arduino’s Tertiary Rocks.

Quaternary Layers: Unconsolidated sediments found in valleys. Our modern Quaternary Period (2 million years ago to modern age).