Caves Are Unique (And Spooky) Treasure Chests Of Prehistoric Life

Caves have always fascinated people. Tales of strange or extraordinary large bones found in them may have also inspired legends that referred to caves as gateways to an underground world of fear, perhaps still inhabited by monsters and demons...Read On

Of Dragons and Geology

Johann Jakob Scheuchzer (1672-1733) was a Swiss physician, but also quite interested in travels and natural sciences. He published his observations on the culture and natural world of the Alps as “Itinera per Helvetiae alpinas regiones facta annis 1702-1711“.

In the introduction by the editor we read:

“The name of Scheuchzer will be famous …[] The author was in the best conditions to make valid discoveries during his explorations. He worked with incredible determination.., [] no danger, no costs, no difficulty were too large for this great man.“

Despite the work was intended to dispel of myths and superstitions so common in the Alps, Scheuchzer, like many other naturalists of his time, did not see a contradiction in publishing own and exact observation and rumors... Read On

The Geology Of Star Trek: From Extraterrestrial Minerals To Alien Life-Forms

August 19, 1921: Happy Birthday to Eugene Wesley „Gene“ Roddenberry - creator of Star-Trek Universe, where you can find some fascinating geology, from extraterrestrial minerals to silicon life-forms !! Read on...

What's in a name? - Mineralogy

It may seems strange, but Romans didn´t know minerals, despite crystals of quartz were well known and various famous mines of gold, silver and lead date back to these times, but so they didn´t know "mines". Roman naturalist used the term "metallum", derived from the Greek language, to describe both real metals as non-metallic minerals like salt, sulphur or gemstones. “Ad metallum damnare” was therefore the punishment to work in mines to extract rocks and metals. Only in medieval times the term “metalliarum” or “metallum”/“metullum” refers in specific to real metallic elements, like gold and iron, as mines where such ores are found.
 

The modern term and use of the word "mine" derives probably from the celtic word “meini”, may referring to both the ore as the mine, as still in medieval Latin the word “minera/minora” can be used to describe the metal as the galleries where it´s found. For sure the word “minae” referring to mining activities, can be found in documents dating back to 1143.

From medieval mines the word will later give to "the minerals" their name and finally to the "study of minerals" - mineralogy.

Fig.1. Lecture in mineralogy, from Bartholomäus Anglicus "Über die Eigenschaften der Dinge" (1390-1400) - "On the Properties of Things".

Bibliography:

GRUBER, F. (2004): Einige Ausdrücke des Montanwesens in etymologischer - sprachgeschichtlicher Sicht. Res Montanarum. Nr. 34: 101-112

How Charles Darwin Classified His Minerals And Rocks

In an autobiographic note Charles Darwin remembers a childhood wish:

“It was soon after I began collecting stones, i.e., when 9 or 10, that I distinctly recollect the desire I had of being able to know something about every pebble in front of the hall door–it was my earliest and only geological aspiration at that time.“

Also during later school years Darwin remains interested in chemistry and minerals, however he laments that “I continued to collecting minerals with much zeal, but quite unscientifically – all that I cared was a new named mineral, and I hardly attempted to classify them.” As a medicine student at Edinburgh University (1825-1827) Darwin frequented various courses on natural sciences, also lectured by mineralogist Professor Robert Jameson, however he considered Jameson´s lectures as „incredibly dull“. Nevertheless Darwin seems to have used frequently Jameson´s „Manual of Mineralogy“ for his private studies, as it is one of the most heavily annotated books in his library. Jameson´s manual uses physical properies, like color and especially the degree of hardness, introduced by German mineralogist Carl Friedrich Christian Mohs in 1822-1824, for mineral identification. Darwin adopts this “visual characterization” approach, so he often describes rocks based on the well visible physical properties, referring to mineral texture or colors, using terms like “porphyry”, for rocks with large, well visible, crystals, "greystone" or “greenstone”, a general name for greenish-dark magmatic rocks (today classified as dolerite-basalt).

In summer of 1831 Darwin joined a field trip of professor Adam Sedgwick, geologizing in Wales. Darwin was interested in acquiring the basics of geological field work, structural geology and rock classification. Twenty pages of notes made by Darwin during this tour are still today preserved – in his autobiography he will later remember: “This tour was of decided use in teaching me a little how to make out the geology of a country...”

When Darwin returned to Shrewsbury, August 29th, a letter from Captain Robert FitzRoy was offering him a position as gentlemen companion on board of the brig Beagle, ready to set sail from Plymouth in December 1831. 

Darwin used the remaining time to exercise mineral identification with the blowpipe (heating a mineral you then observe the chemical redactions and modifications of the specimen to identify it or its composing elements) and muriatic (hydrochloric) acid, useful to distinguish between carbonatic and siliceous rocks

On board of the Beagle Darwin could rely on a complete library for mineral identification, like "A selection of the Geological Memoirs" (1824), including a mineral chart by French geologist A. Brongniart. These manuals use properties like color, hardness, form, but also taste and odour for mineral identification. Darwin got for himself a goniometer, to measure angles of crystal-faces, a not easy to use tool in the field but Darwin proudly remarks "Hornblende determined by myself with goniometer".
Especially interesting are classification charts based on the color of a specimen. "Werner's nomenclature of colors”, published in 1821 by Patrick Syme (1774-1845), is a book displaying a chart and description of various colors to be compared with the colors of minerals, animals and plants. Darwin used this book to describe snakes, rocks and even the "beryl blue" glaciers.

Fig.1. Page from "Werner's nomenclature of colors”, the book was brought on board of the Beagle by Darwin himself.

It is curious to note that Darwin not only used a mineral classification scheme based on the work of German mineralogist Mohs. He adopted also the geological terms used mostly by German geologists, like Alexander von Humboldt, to describe the rocks observed in the field. Darwin will become especially interested in volcanic rocks.

Darwin´s final advice published in 1839 for collecting rocks has value still today (even if Darwin himself admitted he didn´t follow it always):

"Put a number on every specimen, and every fragment of a specimen; and during the very same minute let it be entered in the catalogue, so that if hereafter its locality be doubted, the collector may say in good truth, “Every specimen of mine was ticketed on the spot." Any thing which is folded up in paper, or put into a separate box, ought to have a number on the outside (with the exception perhaps of geological specimens), but more especially a duplicate number on the inside attached to the specimen itself."

Fig.2. Page with rock-classification from Jameson 1821 (influenced strongly by the work of German geologists), Darwin will himself adopt "German" terms like "Amygdaloid" to describe basaltic lava flows observed on the volcanic islands visited during the voyage of the Beagle.

Bibliography:

HERBERT, S. (2005): Charles Darwin, Geologist. Cornell University Press: 485
ROBERTS, M. (2001): Just before the Beagle: Charles Darwin’s geological fieldwork in Wales, summer 1831. Endeavour Vol. 25(1): 33-37

Ancient Stories Provided An Early Warning About Potential Seattle Earthquakes

Oral tradition played – and still plays – an important role in many societies. The subjects of these stories range from fantastic fairy tales to myths, tales based on real persons, places or historic events. But interestingly enough, these stories may also represent attempts to record and transfer knowledge of past geological catastrophes as a warning from generation to generation. Read On...

How Volcanic Eruptions Inspired Artists

As diplomat in France, from 1776-1785, Benjamin Franklin noted in 1783 a strange, grey-bluish mist covering the sky above Europe. Franklin speculated that the cloud was some sort of volcanic dust, may transported from the wind from the Katla, famous Icelandic volcano,  to the European mainland. In fact in June 1783 the Laki on Iceland had erupted, one of the largest volcanic eruptions in historic times with worldwide effects on earth´s atmosphere, climate and history. 

But volcanic dust also influenced art and poetry.

A surprisingly colourful sunset inspired Norwegian artist Edvard Munch (1863-1944) to his famous painting “The Scream”. A distorted figure seems to be petrified screaming in pain, the red background reinforces the despair and agony. Munch himself noted:

"I was walking along the road with two friends - then the Sun set - all at once the sky became  blood red - and I felt overcome with melancholy.  I stood still and leaned against the railing,  dead tired - clouds like blood and tongues of  fire hung above the blue-black fjord and the city. My friends went on, and I stood alone, trembling with anxiety. I felt a great, unending scream piercing through nature."

Exceptional sunsets were observed above Oslo and in many other cities worldwide in the years 1885-92. The New York Times reports on November 28, 1883:

"Soon after 5 o’clock the western horizon suddenly flamed into a brilliant scarlet, which crimsoned sky and clouds. People in
the streets were startled at the unwonted sight and gathered in little groups on all the corners to gaze into the west.  Many thought that a great fire was in progress
....People were standing on their steps and gazing from their windows as well as from the streets to wonder at the unusual sight. The clouds gradually deepened to a bloody red hue,  and a sanguinary flush was on the sea…"

 

Fig.1. Sunset seen in London in the year 1883, from SYMONS, G.J. (1888): The Eruption of Krakatoa, and subsequent phenomena.

The red-glowing sunsets were caused by volcanic ash, dispersed in the higher atmospheric layers the fine particles scattered the sunlight especially effective during sunset.

August 1883 the volcanic island of Krakatoa in Indonesia had annihilated itself in a gigantic eruption. Ash, volcanic dust and gases were send in the higher atmospheric layers, high above clouds and rain the particles would stay for years there, inspiring artists and poets, like English poet Alfred, Lord Tennyson (1809-1892):

"Had the fierce ashes of some fiery peak
Been hurl’d so high they ranged about the globe?
For day by day, thro’ many a blood-red eve...
The wrathful sunset glared..."

Munch however was not the first painter to be inspired by the range of sky-colors caused by a volcanic eruption. Famous English landscape painter William S. Turner (1775-1851) was so impressed by the sunsets in the years 1815-16 that he produced an entire series of paintings, showing the changes observed in the sky for almost one year (Turner will also go on painting more volcano-related paintings). 
In April 1815 the Tambora, also on Indonesia, had erupted, the largest volcanic eruptions in modern times. Also here volcanic particles and dust were injected in the stable stratosphere, scattering for years to come the sunlight and painting the sky in wonderful reddish, orange, bluish-violett colors, an inspiring and haunting view.

Bibliography:

OLSON, D.; DOESCHER, R. & OLSON, M. (2004): When The Sky Ran Red - The Story Behind The Scream. Sky & Telescope, February: 28-35