Accretionary Wedge 24: Heroes VS Cartoons

Callan Bentley at Mountain Beltway will be hosting the next edition of The Accretionary Wedge and he is searching heroic earth scientists.

I was influenced by many people in my approach to geology, contemporary parents, friends and teachers, but also by historic personalities in form of their biographies and achievements in science.
Nevertheless I wouldn't speak about them only as heroes - they were after all men, and displaying them as infallible scientist seems somehow to put them on an unattainable podium.
Let's also remember the words of the theoretical physicist Philippe Blanchard

"The scientist should take the science seriously, but they should not take themselves to seriously."

People that propose revolutionary ideas, ahead of their time, often get misunderstand, even attacked verbally and ridiculed. William Smith for example, considered a pioneer of stratigraphy, was nicknamed "Strata-Smith" after his proposal that the earth is organized in defined layers. And the caricatures of Charles Darwin and Thomas Henry Huxley are today part of history.
On the other hand, some personalities gather such a reputation, that no critic is allowed or tolerated. Criticism can only be addressed in a indirect way, for examples by caricatures or satiric drawings. Even if it's exactly not the gentlemen's way (or perhaps it is - the best known examples are made by Victorian gentlemen in the golden age of geology in the years between 1780 and 1900) satirical drawings, in a certain manner, are a funny way to criticise - both in a fair or unfair manner.
A caricature can refer to a portrait or a behaviour that is exaggerated or distorted, the sense of a satirical drawing is to capture the essence of a person or thing to create an easily identifiable visual likeness - the drawing should be simple, but unmistakable for someone that has some background information (for example knows the depicted person or the context) and transport as much meaning as possible. Although this kind of satire is usually meant to be funny, its deeper purpose is often an attack on something strongly disapproved by the satirist, using the weapon of wit. But these prerequisites make the drawings also a source of information's to explore the history of earth sciences, the caricatures carry a lot of information, not only about the depicted person or geological model, but also how new theories are accepted or refused by society, and as last but not least, the personal opinion of the caricaturist on the matter.

The first geologists had to face many prejudices and hostilities, like James Hutton (1726-1797), facing the many critics of his ideas on deep time and rock formations. One of the most famous caricatures, depicted many times in books dealing with geology and palaeontology, was produced by the English geologist Henry De la Beche (1796-1855) to lampoon the theories of Charles Lyell.

Fig.2. "Awful Changes.", see also the Ichthyosaurus installment at ART evolved.

The prominent "Professor Ichthyosaurus" was considered first to represent William Buckland (1784-1856), but the geologist and dedicated earth-science historian Martin J.S. Rudwick realized the connection of this scene with some drawings produced in 1831 by De la Beche in his diary, where he ridiculed the uniformity-principle of Lyell.
Lyell proposed that even if earth is much older then previously thought, and the forces that sculpt the planet are inexorably but slow, these forces follow a eternal circle of climate and fauna - so in a distant future, after our recent ice age, it is may possible that after mammals again reptiles live in a greenhouse (note the palms in the background), following as highest "social class" the human race.

In the other drawings of De la Beche diary a lawyer (the reference to Lyell seems obvious) is carrying a bag with "his" theory around the world, or he is shown wearing particular glasses to see the world in a personal view, and offering this "theoretical approach" to a geologist carrying a hammer, a reference to the applied working researcher. It's obvious that De la Beche could not overcome his prejudice against Lyell as a lawyer, that he considered much more a theory foreigner then a real researcher (considering how much Lyell travelled and how much geological phenomena he visited this is a very unfair insinuation).
In a second cartoon (brought to light by Haile 1997) De la Beche is mocking on the effects of present causes, operating at the same slow magnitude and rate throughout geologic history. We see a vast U-shaped valley, and in the foreground a nurse with a child.

Fig.3. De la Beche´s cartoon of 1830-1833 mocking the effects of present causes. The cartoon is entitled "Cause and Effect".

The child is peeing into the huge valley and a caption has his nurse exclaiming, 'Bless the baby! What a valley he have made.!!!'

On the 24 July of 1837 the Swiss geologist Agassiz was to be thought to hold a lecture about his studies on fossil fishes - instead the members of the venerable Swiss Society of Natural Sciences heard from their young president a theory, emerged some years before, to explain the origin of erratic blocks and scratches on rocks in the Alps. "O Sancte de Saussure, ora pro nobis!" - O holy de Saussure, pray for us, was the only comment of the German geologists Leopold von Buch (1774-1853) as he left the room. Another proposed great idea caused disbelief in the public and gave cartoonist much to work on. Agassiz showed in his study "Études sur les glaciers" (1840) that glaciers were the explanations of erratic blocks and scratches on rocks in the Alps, the idea of a large ice cap covering the Alps, and the Ice Age was ready to meet the broader public.

Agassiz introduced with his former mentor Buckland in the autumn of 1840 the glacial theory to the British Isles.
Professor Buckland, was a highly respected scientist, but also eccentric and very perky, and in a first moment struggled with the idea of his friend Agassiz, but became convinced after he saw the spurs of glaciers and moraine deposits in the Alps and Scotland. Maybe the public was anyway chuckling over the debate about the importance that highly respected men gave to this apparently tiny marks on rocks, in every case the well-known mining engineer Thomas Sopwith (1803-1879) thankfully poked fun on his fellow countryman and on the subject of the dispute.

Fig.4. Costumes of the Glacier.

The cartoon sketch that he scratched/draw of the Professor, titled "Costumes of the Glaciers", shows Buckland dressed for fieldwork. The numerous captions are difficult to read, but the lines at Buckland's feet are noted to be "Prodigious Glacial Scratches" produced by "the motions of an IMMENSE BODY, not allow to change its course upon Slight Resistance" (we ignore if this is referred to the glacier or the appearance of Buckland). Buckland holds - like all true geologist do - a geological map under his arm, a "Map of Ancient Glaciers". On the erratic stones scattered around his feet's captions tell, that this stone was scratched 33.333 years ago, but on a other rock this prodigious age is relativated, claiming that a similar looking stone was just scratched by the wheel of a passing cart, just the day before yesterday, and in the background it's seems that some new scratches are just in the making by a passing carriage.

Caricatures and cartoons can bring science and scientific discussion to the attention of a broader public, but to appreciate them, they have to be understood.
What I choose, are only two examples and theories, and many others were worth to be told, but they show us how certain geologists and their support of new ideas have influenced society, and how they were seen by their contemporaries, and how society understand (sometimes wrongly) the work of the researchers.

We are only humans - and maybe that’ s the most important teaching that cartoons can give to us.

BIBLIOGRAPHY:
BROWNE, J. (2001): Darwin in Caricature: A Study in the Popularisation and Dissemination of Evolution. Proceedings of the American Philosophical Society 145(4): 496-509
CLARY, M.R. & WANDERSEE, J.H. (2010): Scientific Caricatures in the Earth Science Classroom: An Alternative Assessment for Meaningful Science Learning. Sci & Educ 19:21-37
GORDON, E.O. (1894): The Life and Correspondence of William Buckland. John Murray, London
LEEDER, M.R: (1998): Lyell's Principles of Geology: foundations of sedimentology. Geological Society, London, Special Publications 143: 95-110
MACDOUGALL, D. (2004): Frozen Earth - The once and future story of Ice Ages. University of California Press, Berkely-Los Angels.
RUDWlCK, M. S. (1975): Caricature as Source for the History of Science: DE LA BECHE'S Anti-Lyellian Sketches of 1831. Isis, Vol. 66 (234): 534--560
RUDWICK, M.J.S. (2005): Bursting the Limits of Time. The Reconstruction of Geohistory in the Age of Revolution. The University of Chicago Press.

Introduction Image: The Trilobite, cartoon from The Punch 1885

Accretionary Wedge #23: That is not dead which can eternal lie

The March 2010 Accretionary Wedge is being hosted by Ed at Geology Happens, and here's the proposed theme:

"This AW is to share your latest discovery with all of us. Please let us in on your thoughts about your current work. What you are finding, what you are looking for. Any problems? Anything working out well?"

Well, considering even only the Holocene of the Alps there is a major hiatus of knowledge, and I can provide only a humble, but maybe interesting piece of considerations on the problem:

"That is not dead which can eternal lie,
And with strange aeons, even death may die"
H.P. Lovecraft (1890-1937)

A major unknown factor in rock glacier research is the formation age of these features. But for the understanding of climatic significance, and possible reaction of permafrost in a warmer climate, these information's are very important. Rock glacier develop mostly well about the tree-line, and in areas with strong debris accumulation, a difficult habitat for plants to growth. So in the rubble of rock glaciers organic matter, which would allow a 14C dating, is mostly missing.
Exceptions are known from the Swiss Alps, in the rock glacier "Murtèl" HAEBERLI et al. (1999) were able to date moss remains, and in an actual paper BOMMER et al. (2010) describe the discovery of wood fragments of larch in the front of an (in)active rock glacier.
Sometimes active rock glaciers override peat deposits, that can be dated, (EVIN & BEAULIEU 1985). Exposure age determinations of boulders on the surface, for example by cosmic rays or OSL are problematic because of the unstable surface that reworks constantly the material.
Evidence for a relative age can be supplied by the weathering of rocks, and lichen vegetation on blocks, but also here the moving surface cause troubles, the conditions of lichen growth and surface alteration change with time, so that the final date will be a mixture of different ages or at beast only an extreme value.

All these methods may provide only a maximum or minimum age, and are connected with a number of methodological problems; also an important question is what reflects these dates? The original rock wall exposure to erosion, the formation and deposition of the rock fragments in the talus, the mobilization of the talus by permafrost creep? And what if rock glaciers experience phases of inactive and active periods?

So it's no wonder that estimated ages of rock glaciers range from recent times, or formation during the last glacier high stands in the 16. and 19. century to interpretations of late glacial relics with ice 1.000 of years old (PALACIOS & VAZQUEZSELEM 1996; HUMLUM 1996; KÄÄB et al. 1997).

The rock glacier that I studied in the last years reaches with his front the Lazaun pasture (Ötztaler Alpen) and it is a possible good candidate for an extensive research on internal structure and dynamics of permafrost in the Alps.

Fig.1. The Lazaun pasture with the bog and in te background the active rock glacier. From the front of the rock glacier a glacial river flow from the left to the right, exposing a sequence of peat deposits and sand/pebble layers.

An extensive survey was carried out, geomorphological mapping, GeoRADAR, GPS and hydrological measurements. Also I tried to get some information's about the age of, so local legends tell, this petrified dragon.

A connection of the rock glacier with the glacier high stand of the alpine Little Ice Age is supported in part by lichenometry and moraine stratigraphy, which suggests an age of several hundred years. If, however, the measured GPS velocities are used to derive an age estimation (considering the length and the velocities of creep) the age ranges from 2.200 to 1.300 years. These observations relative the published ages of rock glaciers inferred simply by creep velocities (HAEBERLI et al. 1997), rock glaciers don't creep always at the same rate; reacting to climate change they display a complex behaviour.

A tentative approach to determinate the long term behaviour of the rock glacier is the interpretation of a stratigraphical column in peat deposits in front of the rock glaciers. The outcrops created by a glacial river expose a peat-sediment sequence in an alpine fen.

Fig.2. Outcrop, GeoRADAR measurements and soundings showed that the peat is pretty deep, up to 3m.

There were several peat layers (at least four) alternating with clastic sediments (sand and pebbles), also, as a small sensation, wood fragments where found and recovered (the actual tree line is lowered by climatic and anthropogenic influence by some hundred meters).
Similar sequences are known in the Austrian part of the Ötztaler Alpen, where they were interpreted as a glacier advance - glacier retread cycle. (BORTENSCHLAGER 1984). I myself observed similar sediments in the Rieserferner mountain group, so such records are not rare, and have much potential for future research on the Holocene history of the Southeast-Alps.

The sediments so maybe represents the varying climatic conditions in front of the rock glacier, during climatic favourable conditions moss and peat plants flourished and build up the peat layer, during cold periods the glacier and rock glacier advanced, providing more erosion and a source of clastic sediments that form the sand and pebble layers.

And because finally the wintertime is over, I hopefully soon will go back to the rock glacier and dare to interfere in his sleep...

Fig.3. Peat layers in transition to grey mud and pebbles.

REFERENCES:
BORTENSCHLAGER, S. (1984): Beiträge zur Vegetationsgeschichte Tirols I. Inneres Ötztal und unteres Inntal. Berichte des Naturwissenschaftlich-Medizinischen Vereins in Innsbruck. 71, 19 - 56.

EVIN, M. & BEAULIEU, J.L. (1985): Nouvelles données sur l´age de la mise en place et les phases d´activite du glacier rocheux de Marinet 1 (Haute-Ubaye, Alpes de sud francaises). Mediteranee. 4: 21-30
HAEBERLI, W.; KÄÄB, A.; WAGNER, S.; VONDERMÜHLL, D.; GEISSLER, P.; HAAS, J.N.; GLATZELT-MATTHEIER, H. & WAGENBACH, D. (1999): Pollen analysis and 14C-age of moss remains recovered from a permafrost core of the active rock glacier Murtèl/Corvatsch (Swiss Alps). Journal of Glaciology 45: 1-8
HUMLUM, O. (1996): Origin of Rock Glaciers: Observations from Mellemfjord, Disko Island, Central West Greenland. Permafrost and Periglacial Processes 7: 361-380
KÄÄB, A.; HAEBERLI, W. & GUDMUNDSSON, G.H. (1997): Analysing the Creep of Mountain Permafrost using High Precision Aerial Photogrammetry: 25 Years of Monitoring Gruben Rock Glacier, Swiss Alps. Permafrost and Periglacial Processes 8(4): 409-426
PALACIOS, D. & VAZQUEZSELEM, L. (1996): Geomorphic effects of the retreat of Jamapa glacier, Pico de Orizaba volcano (Mexico). Geografiska Annaler 78A(1): 19-34
SCAPOZZA, C.; LAMBIEL, C.; REYNARD, E.; FALLOT, J.-M.; ANTOGNINI, M. & SCHOENEICH, P. (2010): Radiocarbon Dating of Fossil Wood Remains Buried by the Piancabella Rock Glacier, Blenio Valley (Ticino, Southern Swiss Alps): Implications for Rock Glacier, Treeline and Climate History. Permafrost and Periglac. Process. 21: 90-96

Accretionary Wedge #20: Why?

Asked for the ultimate answer to the Ultimate Question of Life, the Universe, and Everything, Deep thought, the supercomputer created by the imagination of the science-writer Douglas Adams, asked the far more important question: What is the ultimate question itself?

An wise man once said, a fool can ask more then ten men of science can possibly answer, but a problem and a good question is the first step of scientific research.
Geologist and earth scientists in the past centuries where observing rocks, relationships between them, superposition, unconformities and many other features, and came to ask themselves the apparent simple question: how came this marine limestone on the top of the mountain, why the coasts of the continents resembles the conjunctions of a gigantic jigsaw, where all rocks deposited by volcanic eruptions or sedimented in a quiet ocean basin? Today a part of these questions seems trivial, but still some of them are not conclusively answered. And even if we assume a question is answered, changing also slightly the problem can open the ways to a bunch of new issues.

In a survey carried out on 753 scientist from different nations around the globe , the german magazine "Spiegel" asked for the greatest - still unresolved problems in geosciences, and not so surprisingly the results fit quite well with the ultimate questions that trouble the Geoblogosphere:


Lockwood asks directly from Outside The Interzone one of the most important question from a slightly different perspective, not why earth enabled the existence of life, but why life enabled the existence of earth? Without life, this planet wouldn't be "Earth." Or we can ask ourselves, would nonexistings men be concerned about nonexisting earth?


Today Humans were concerned about Earth, especially when geological phenomena threaten their lives and their property - like volcanoes. It seems today elusive, that once volcanoes and their products where considered by earth scientists only as local features, with no significance for the geological evolution of earth - living in quiet central Europe they underestimated the power of this fire mountains - or asked they simply the wrong questions?

Not so Tuff Cookie, introducing us in the burning question how Magma reaches the surface of Earth, and how to study it´s path without X-ray powers and invulnerability. To understand the mechanism of volcanic eruptions may helps to predict and mitigate the impact on our society - a very important question with even more important answers.


And Hypo-theses proposes the ultimate hypothesis: With ongoing research we realized that earth is a complex systems, with factors like the interior structure, the outer crust, the liquid and the frozen hydro- and atmosphere and the biosphere (and humans) interacting among themselves, so ... what would be, if we really understand earth?


Many thanks to all participants for the content and the questions of this edition of the Accretionary Wedge. But don´t panic - at least one important question can be answered now - who is hosting the next Accretionary Wedge?

Accretionary Wedge: The Iceman story

The December Accretionary Wedge is hosted by Kenneth Clerk in his “Office of Redundacy”. He is asking – which scientific advancements have directly affected your interests? As first point I choose a discovery that happened not far away where I worked for my thesis. It is also mentioned in it, even is it not strictly geological, but as second point, I like to think interdisciplinary (or at least try) – and so even a archaeological discovery can be useful to understand the glacial history of a research areas:

Location of the discovery point (black rectangle) of the bronze-age mummy in the Ötztaler Alps. Blue areas represents the glacier extends in 2003, the red line the glacier extends during the Little Ice Age (ca. 1850).

The finding in the late summer 1991 of a prehistoric mummified corpse at the upper edge of the accumulation area of an alpine glacier, together with its unique set of artefacts, provided new information on the cultural development of bronze-age cultures, but also insights on the glacier dimensions during the little-known phases of major glacier shrink age that characterized the warmest parts of the Holocene. This phase is practically undocumented by glacial sediments, and is only recognizable by proxy-data like changes in pollendiagrams or dating organic materials, over- or underlying glacial or proglacial sediments.

The sudden burial of the corpse in a permanent snow cover occurred 5300–5050 cal yr B.P., indicating a significant climatic change that induced glacier expansion at the beginning of Neoglaciation.

The "Similaun" as highest peak (3597m a.s.l.) with his two glaciers, the "Similaun" in foreground, and the "Niederjoch"in background. Until ca 1970 the glaciers flowed together, but the shrinkage in the last years was notable.

The marked ablation during the summer 1991 (helped by a pronounced sunny weather and the deposition of saharian dust on the glacier ice, that diminished the albedo) of the small glacier near the Similaun Hut, in the Tyrolean Alps, brought the corpse to the surface. The preservation of the corpse was possible thanks to its location in an almost horizontal gully in the bed rock, in which it remained motionless, frozen to the ground in cold ice. This corpse is the highest prehistoric find (ca. 3280m a.s.l.) in the Alps. The discovery is also notable by the presence of a rich collection of several exceptionally preserved items of clothing and equipment. The mummy was dated by the C14-method to 4.500+-30 to 4580+-30 yr B.P., that corresponds to a calibrated age of 5300-5050 yr B.P., and resulted older then a first relative dating by the accompanying tools, especially by the bronze-axe.

The snowfield on the right of this picture represents the depression in which the corpse was found.

The small glacier that revealed the mummy lies on the northern slope of the alpine divide, east of the Finail-Spitze-mountain (3514m a.s.l.). Until the 1970, the glacier was part of the much greater Niederjoch Glacier, a composite alpine glacier that descends northward in the Nieder Valley. But only in the last 5 years the Niederjoch-glacier lost 60-100m length.
During the last glacial maximum (LGM, ca. 18.000 yr), the entire area was completely ice-covered, only narrow and steep arêtes and horns protruded from the ice. In the area of the Similaun Hut sharp trimlines in a height varying from 3060m NW of the Similaun Hut to 3400m on Finail-Spitze divides the uppermost frost-shattered crests from the lower slopes, smoothed by glacial erosion. The trimline can also recognized locally as marked weathering line that separates different oxidized surfaces (the bed rock consists of Fe-rich gneiss and schist).
A second trimline is marked by an abrupt change in lichen diameter (from 100mm above to 40mm below) and density. The dating by lichenometry attributes this glacier stand to the Little Ice Age (LIA), which generally corresponds to the maximum Holocene glacier elevation.
Some soil horizons were found in depression between 3000 and 3215m a.s.l. and dated to 5615+-55 yr B.P. (6450-6300 cal yr B.P.) and 3885+-60 yr B.P. (4416-4158 cal yr B.P.). Similar recent soils needed at least 5 to 12 centuries for development, suggesting that the climatic conditions on the site were for a long time relative favourable and constant.
The Iceman and his site reveal that between 9000 and 5000 yr B.P. the mountain glaciers were smaller than in the second half of the Holocene. About 6400 cal. yr B.P. and for several centuries after, an ice-free peripheral belt allowed the accumulation of organic matter and developments of relatively thick soils. The Iceman was killed on the site during summer, and covered by snow soon after. Until 5300 to 5050 cal yr B.P. ago, a rapid climatic change took place, producing a persistent snow cover and a glacier expansion, which conserved the body until his discovery in modern times.

The valley of Tisa, on the italian side of the Alps, the Iceman came from the Valley of Schnals (in the background the modern artificial lake on the bottom of the valley) and passed the relict rockglacier in the foreground. The modern trail passes on the left side.

Detailed information about the lifestyle and environment of the Iceman is based on both on-site and off-site data. The on-site data are represented by his clothing, the wooden artefacts, plant macro remains recovered during two archaeological excavations at the discovery site in 1991 and 1992, as well as the micro and macro fossil content of the food residue from the mummies intestines. They provide information about Neolithic edible and otherwise useful plants, the making and suitability of his equipment, prehistoric diet, the season of his death, his social status, palaeo-environment and the taphonomy of the find assemblage. Off-site data are represented by palynological and macroremains analyses of peat deposits from mires in the nearer and wider vicinity of the discovery site, which reveal the vegetation and climate history as well as human impact on the vegetation during the time of the Iceman.
Both the axe shaft and the long bow were found in the vicinity of the corpse and were made of yew (Taxus baccata). The quiver was made of caprine skin and was stiffened with hazel wood (Corylus avellana). The 14 arrows were made of the wood of the wayfaring tree (Viburnum lantana). One is repaired, the front end being restored with dogwood (Cornus). The dagger handle is made from a piece of ash (Fraxinus excelsior). Its sheath was knotted from the bark of linden (Tilia).
He also had with him two containers made of birch (Betula) bark, in one were found charcoal pieces wrapped in Norway maple (Acer platanoides) leaves.

Several wood species could be identified from the charcoal remains, which are interpreted as cold embers: probably spruce (Picea/Larix-type), pine (Pinus mugo-type), green alder (Alnus viridis), some Pomoideae which were probably Juneberry (cf. Amelanchier ovalis), dwarf willow (Salix reticulata-type) and elm (Ulmus). A backpack was constructed from a thick branch of hazel (Corylus avellana) bent into a U-shape, together with two coarsely-worked laths of larch (Larix decidua).
All in all, the majority of wood species found with the Iceman thrive in the montane regions (valley bottoms to 1,800 m),although some subalpine (1,800-2,500 m) and alpine (above 2,500 m) species are also represented. Their ecological requirements point to the transition zone between thermophilous mixed-oak forest communities (Quercetalia pubescenti-petreae) and the montane spruce forest (Piceetum montanum). Norwegian maple (A. platanoides), European yew (T. baccata), ash (Fraxinus sp.), lime (Tilia sp.) and elm (Ulmus sp.) allow to infer a humid habitat with a mineral rich, free-draining soil and a mild winter climate. All that is similar to the present-day conditions in the woodlands found on the slopes and in gorges in the lower Schnalstal and Vinschgau in South Tyrol, where it is assumed he lived.

The Schnals-valley and his entrance in a narrow gorge - the steep walls are very exposed and sunny, so that very dry-tolerant plant species can be found here, like cactus species (Opuntia ficus-indica), yew and shrubs communities and steppe-like grass patches. On more humid slopes a larch or spruce forest develops.

So the botanical evidence seems to confirm a climate comparable to modern conditions, and implies a glacial extent similar, if not slightly minor to the present.
This has very important influence on the reconstruction of past, and modern climatic and glacial development, and at last the actual discussion about climatic change.

BARONI, C. & OROMBELLI, G. (1996): Short paper – the alpine “Iceman” and Holocene Climatic Change. Quaternary Research 46: 78-83

MAGNY, M. & HAAS, J.N. (2004): Rapid Communication - A major widespread climatic change around 5300 cal. yr BP at the time of the Alpine Iceman. Journal of Quaternary Science 19(5): 423-430

OEGGL, K. (2009): The significance of the Tyrolean Iceman for the archaeobotany of Central Europe. Veget. Hist. Archaeobot. 18:1-11

Geology of the "Pale Mountains"

Dave Schumaker at Geology News is asking "What is your favorite place to do field work?"

Maybe it’s the variety on rocks that can be found on a place – from crystalline basement, to permo-mesozoic marine and terrestrial sediments to the quaternary cover:

"Once, all mountains in the reign of the Dolomite Mountains were dark peaks, with sheer rock walls, belted by dark forest and rich pastures.

Then one day, the prince of this kingdom encountered a beautiful girl, and felt in love with her. So did the girl. After some time, they decided to marry. The first time they were very happy, and when the old king died, they become king and queen. But one day the girl went sick and weak. The prince worried, and asked her was happened. The girl explained, that she was the daughter of the moon, and were missing the vast and white plains of her native kingdom – and if she did not return, she surely will die by this desire. So the prince decided to go with her and they returned to the moon. But the light on the moon blinded the poor prince, and he had return to earth. Sad and hopeless - missing his beloved- he wandered into the forest, and encountered dwarf. He told the dwarf his problem, and the dwarf responded:” Listen carefully, young prince, I’m the king of dwarfs, and my people was banished long time ago from his land, and we are searching for a new home. If you will promise, that we can live on the peaks of your kingdom, we will solve your problem.”
The king gave his word. In the night the dwarf people climbed the peaks of the mountains, and begun to weave the moon light, and cover the dark peaks, so it seemed that they were covered by snow.

The next day, the king, seeing the white peaks, enjoyed, and his queen returned to earth. And so the Pale Mountains - the Dolomite-Mountains - between dark peaks came to being."

This old ladinian (from the old folks living in the valleys of the Dolomites) myth tries to explain the variety of landscapes and rocks found there. But even the geological (his)story is fascinating, ranging from sunburned deserts to swallow lagoons to a frozen wasteland.

The Alps on a geological basis comprises rocks originating from two continents: The European continent to the north with the subsequently separated Penninic units (aquamarine blue and pink in the One Geology cartography project map); and to the south the Adriatic or Apulian microcontinent, a fragment of Africa, with its Austroalpine (dark red) and Southalpine units (violet). Due the Alpine orogenesis, the various units today lie side by side in a very confined space. The diversity of rocks also causes their strongly differentiated reactions against weathering and erosion, as well as against glacial abrasion during the Ice Age – and so a reason for the pronounced diversity of the alpine landscape.

An approximate bipartition in the eastern Alps is caused by a mayor fault system, the Periadriatic Line, separating the Austroalpine in the North, predominated by metamorphic rocks, from the Southalpine, mainly magmatic and sedimentary rocks.
The basement of the Southalpine unit consists predominantly of a monoton succession of quartz phyllites of the Paleozoic era.
Towards the end of the Paleozoic increasing magmatic activity started, one part of the melts remained struck in 12 km depth where it solidified; the other part reached the surface and covered enormous areas with volcanic deposits. This “Permian Athesian Volcanic Group” forms a solid fundament for the Mesozoic sediments that build up the “Pale Mountains”.

Cooling joints in ignimbrite deposits of the Auer-Formation (276-274 Ma).

Accredtionary Wedge #13: Geologeeeeee in Spaaaaaaaace

The last years have seen a new kind of exploration, robots and space probes have given us insights in the (in part) icy geology of the “rest” of the solar system. But there are also fire worlds, strange tectonic settings, gas giants, where the laws of geology don’t rule no more, eternally frozen worlds… So it was only a matter of time, until the Accretionary Wedge has conquered the deep space, where no geologist is gone before… on goodSchist.com

Silver Fox takes a look on the possible future Gold-Iron-Nickel rush in the frontier asteroid rim. But asteroids, and their impacted counterparts’- meteoroids, are not only good to delivery elements trough space, but also create important geomorphic features on the planets of the solar system, like shown by ed.
And speaking from amazing geomorphic features, ever seen a reversed fluvial topography on Mars?
Space can be a very hot place, so hot that new elements can formed, but still so cold that all geology is based on ice or liquid gases, like on Titan 1 e 2.
A often forgotten world of ice is Pluto, the declassified planet. On the other side there is the hell (tectonic) on Venus, or the molten small moon Io.

(This is just a selection of the submissions on the Accretionary Wedge - for the complete list visit the side of Chris I´m still ongoing reading ...)

Rockglaciers from Mars !!!

"No one would have believed in the last years of the 20th century that this world was being watched keenly and closely by intelligences other than martians's and yet as mortal as his own. Yet across the gulf of space, minds that are to our minds as ours are to those of the beasts that perish, intellects vast and cool and unsympathetic, regarded this mars with envious eyes, and slowly and surely drew their plans against us. "

From all planets and minor objects of the solar system, most similarities to features of periglacial regions on Earth can be found on the red neighbour - Mars.
The term periglacial refers here to immediate results of frost as climatic factor acting on soil substrat/detritus (geologic component).

Even if the terminus is mostly debated and in part imprecise, he can be summarized as “conditions, processes and landforms associated with cold, nonglacial environment”.

Permafrost – perennially frozen soil- is one diagnostic criteria for a periglacial environment, that can, but mustn’t contain ground ice. In the last case it can be called “dry permafrost”, but it plays a minor role in the development of characteristics or spectacular landforms of the periglacial realm.
The most spectacular forms of permafrost imply the presence of water and ice. Pingos (or hydrolaccolith), literally small mountains, contain a core of pure ice, and can reach up to 50m high. Other features that imply frozen water are ice-wedges or ice-lens and bodies.
Important macroscale features of permafrost are rockglaciers. Rockglaciers can best be defined by their morphology, saying that a rockglacier is “an accumulation of angular rock debris that contains either interstitial ice or an ice core and shows evidence of movement through creep and deformation of the ice-part”.

The presence of ice on Mars was never questioned. Even the first modern geographical maps by american astronomer Richard Antony Proctor from 1867 located two huge icecaps on both the poles. Today we know that the polar ice caps of Mars contain at least a part of water-ice, but it seemed not so extraordinary much, in ever case lesser, then some author speculated needed for a civilisation on Mars.

The question still remaining –even today- is, how much ice, and so water exist on Mars, and where else it can be found, in an atmosphere with so less pressure that it is prohibiting that water can exist in liquid form (at least for a longer period)? Models showed that a cover of detritus could prevent the ice to sublimate, so allowing in theory in some regions great amounts of subsurface ice, and maybe even liquid water. But how to prove the existence of this modelled ice?

Landforms indicative of ground ice on Mars have known since the first flyby missions of the 1960s. Images from Viking orbiters provided an overwhelming list of permafrost and ground ice indicators.
Mars resembles an astounding variety of landforms that on Earth can found in recent glacier covered, and/or in past glaciated areas, like patterned ground, thermokarst, mass movement phenomena, cirques and horns, grooves and valley troughs filled with morain-like material. On earth they are declared to prove glacial to periglacial conditions and glacier ice. On the other side, on Mars there exist a lot of forms that have no counterpart on Earth.

The most recent space probes measured the emission of neutrons from the surface of Mars. Water ice adsorbs more neutrons that dry detritus, so mapping the amount can be used to map and estimate the presumed water ice content of the first meters of the surface detritus, the so called regolith.

Fig.1. Watercontent in percent of weigth of the martian regolith, ranging from 3% (light blu) to 11% (dark blue). The presence of water ice is correlated with latitude, radiation and elevation/temperature. Red zones are areas with dense numbers of "debris aprons" (after KERR 2003).

The Phoenix Mission finally discovered subsurface ice covered only by centimeters of some dust and detritus on the high latitude (ca. 70°N) of the northern hemisphere. But still they prove only an ice content up to 6-11% in the first 1 to 2 meters of the regolith.

On Mars there are different types of features whose morphology certainly indicate the presence of deep buried ground ice - rampart craters, debris flows, lobate debris aprons, terrain softening and collapsing and patterned or polygonal terrain.

Many martian craters have a unique morphology - they are surrounded by lobes or tongues with layered ejecta, terminating in a low ridge or escarpment. This “rampart craters” are unique for Mars in our solar system, and probably represents refrozen ejecta from an impact that melted the subsurface ice-rocks mixture.

Most curious and debated are very large features, up to hundreds of kilometres long, that shows ridges and furrows on their surface, and seem to flow along rock walls and follow valleys.

Three main forms can be distinguished

- linear valley fills – long features, that resembles lava flows that fill the valleys

- pancake-like crater fills (like found in the hourglass crater)

- and lobate to tonguelike shorter mass movements, that initiate from a rock wall, shows a pronounced ridge and furrow morphology, and end with a gently slope on flat terrain.

Fig.2. Infrared MOC-image, east of the Hellas-basin, Mars. A typical association of debris aprons, debris tongues and crater fills. Note the superimposed features in the center of image. Scale in 100 kilometers.

Interpretations range from lavaflows, that some features resemble, to vast mass-movements and rockfalls deposits.
The huge aureole deposits, that form a ring extending up to 1.000km around the basal escarpment of Olympus Mouns, were also interpreted to represent immense submarine landslides.

Studies on (primarily mentioned) terrestrial rockglaciers and debris-covered glaciers in recent years offered a new explanation – the rockglacier like features on Mars are - according to the duck test … rockglaciers.

Fig.3. Terrestrial rockglaciers, Alps. Scale in 100 of meters. Showing a tongue like rockglaciers, and two "lobate debris aprons".

A rockglacier can be active - containing enough ice to show creep and deformation, inactive – still containing ice, but to less to show movement, and relictic – containing no more ice, but still displaying the morphology of past movement

Under modern climatic conditions on Mars, and assuming a behaviour comparable with terrestrial rockglaciers in Antarctica, the rockglaciers on Mars can possibly be active containig both water as CO2-ice in a belt stretching approximately on the 30° latitude (Fig.4).

Fig.4. Martian rockglaciers. Mean elevation data map (blu - deep, red - high) showing areas with high density of lobate debris aprons, like east of the Hellas basin, the chaotic terrain from Deuteronilus and Protonilus Mensae, the west escarpment of Olympus Mons and the Argyre basin.

MOC (Mars Global Surveyor Camera) Orbiter images of lineated valley fills and lobate debris aprons show that the surface of this features are practically uncratered, indicating likely emplacement and formation within the past several million years. With this method, the lobes of Olympus Mons were dated to be polygenetic with ages ranging between 280-130, 60-20, and -surprisingly- 4 million years and younger.

Fig.5. The west escarpment of Olympus Mons, with pronounced lobes (note the ridges)expanding for more then 200 km (scale) - some authors interpreted the morphology as deposits from glaciers, or remanents of debris covered glaciers. It is unclear however if they still contain ice.

However at current Mars surface temperatures, and very low accumulation rates of material, flow rates large ice masses would be so slow, that they could not be younger then 1 to 10 millions of years, but still much older then the crater counting let conclude. But assuming higher past temperatures in geologically speaking recent times, a young age became more convincing.
Overlapping tongues seen on some lobes even let assume that they were periodically active, implying possibly glacial and interglacial periods on Mars, driven by the steep tilted axis of Mars (15-35°).

The distribution of the presumed activ and relict rockglaciers seem to support this hypothesis, they only occur in a narrow belt of 30 to 50° of latitude on both hemisphere, region that in past “passed trough” the climatic zone that enables the formation of great amounts of ice and activity of rockglaciers (Fig.4.).

Discovery of microbial activity inside of active terrestrial rockglaciers give room for speculation that rockglaciers on Mars can be a habitat for primitive live forms. Pressure of the overlaying rockdetritus, with an average thickness calculated from thermodynamic constrictions of 200 up to 300 meters, maybe melt some waterice, or some water pentrates from deeper zones of the martian crust on the base of the formations and create pockets of liquid water.

And so we are (re) arrived to new frontiers...

P.S.

Until today, rockglaciers are only known from Earth and Mars. Mercury and Venus are much to hot to possess water, or even ice. The gas giants lack a surface, and the minor objects in the solar system seemed to small or to cold to enables creep and deformation of material.
But the Voyager in 1979, and the Cassini-Galileo in 1997 mission have provided some images from one of the moons of Jupiter, Callisto.

The high resolution image from the Galileo space probe shows a crater with a lobate deposit, protruding from the craterrim to the centre for 3 to 3.5 kilometers.

The nature of this morphology is still unknown, possible interpretation includes landslides or creep of ice-detritus mixture. The morphology, tonguelike to lobate with a low surface angle and a steep escarpment at the end resemble a rockglacier. But the very low temperature on the surface of Callisto of -180°C does not support creep of water ice. Alternately a different ice component, like methane or other gases, maybe is still capable to deform and so creep along the inner craterrim.

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