The Goodness of the Badlands

In several arid and semi-arid places in the world one can encounter the bizarre-looking landscapes of clay and other sediments known as badlands. From French les mauvaises terres and closely resembling the Spanish word for a related but different landscape malpais, badlands are characterized by landscapes that look as though a clay bed sheet has been draped over many small hills and knolls, which sometimes rise into sharp knife-edged ridges and fins. There are usually rocks and boulders of sedimentary rock scattered about and sometimes these rocks end up as cap rocks on clay towers known as hoodoos. Badlands lack or have a very shallow regolith, which means there is little soil for vegetation to take root. The landscape is easily eroded by water and wind, and only hardy scrub plants such as sage brush and prairie grasses exist to a relatively moderate degree of abundance. Some flowering plants can also find a place to sprout in the cracks of rocks.

In the Province of Alberta, Canada is one of the most significant badland locations in the world. Sediments were laid down during the Late Cretaceous – from 75 to 65 million years ago – when the area was in a transition zone that was at times a shallow inland sea, a swamp, a river delta, or a flood plain. Over this period, prehistoric life left its remains in the sediments and the area is now said to be one of the two richest dinosaur fossil beds in the world, the other one being in China. Alberta’s badlands are at their most impressive and fossil-rich in Dinosaur Provincial Park, not far from the city of Calgary; however the Royal Tyrell Museum is located along the Red Deer River Valley just north of Drumheller. Farther south near Rosedale are the famous hoodoos with their cap rocks.

One interesting ingredient in the badlands clay matrix is the inclusion of a glassy igneous material resulting from volcanic ash fallout from the Yellowstone volcanoes. This material forms a crystalline clay-like mineral called montmorillomite and is the key ingredient in bentonite clay – a soapy, highly plastic clay which swells in water. When dry, bentonite clay is very hard. I once found a pencil sticking out of some dry clay but in spite of tugging with all my might I could not remove it. When wet, bentonite clay swells and becomes horrendously gooey. Walking on the stuff after a rain, I felt myself gaining height as the clay stuck to my boots. It is also terribly slippery and no fun to slide and fall down in. Easy to wash out with some serious scrubbing effort when wet, the clay cements itself to any surface when dry. If it gets between the fibres of the fabric of your clothes, it’s a futile effort to scratch it off with a fingernail, and a chisel is almost required to remove dried bentonite clay from a pair of boots.

The badlands are an exotic landscape to explore and rich in photographic landscape art potential. Go for the bones, stay for the photography!

Read more about the Alberta badlands

Read more about bentonite clay.

Tip of the Inselberg

It appears as a striking anomaly in a landscape of low dunes and flat horizons. The dome of Uluru looks unreal as it seems to be sitting as though it had been dropped from somewhere else onto the vast and flat desert of Australia’s Red Centre. Uluru is, however, not alone. A fraternal twin lies some 40 kilometres away – Kata Tjuta – quite different in appearance but born of the same mother, the Peterman Ranges.

As the geologists' story goes, the Peterman Ranges were much higher 550 million years ago, and erosion of these grand mountains produced two great alluvial fans, one of them consisting largely of river-rounded stones and the other of mostly sand. Over the next 50 million years, these fans built up layer upon layer, becoming kilometres thick. Then the whole area became covered by a sea and new layers of sediments fell on top of the fans. The weight of the new seabed turned the fans into rock – conglomerate for the rocky fan and sandstone for the other. Then some 400 million years ago, the Australian continent underwent considerable tectonic movement. The sea drained away and the layers of sediments were folded and tilted. The sandstone fan was tilted so that one end bent up at nearly 90 degrees. From 300 million years ago and on, the covering of sand and soil has slowly been blown away, exposing the harder rock of the ancient alluvial fans to the air. But what you see “sitting” on the landscape is just the tip of the iceberg, so to speak, or more accurately, just the tip of the inselberg.

Inselbergs are, according to the Encyclopaedia Britannica, an “isolated hill that stands above well-developed plains and appears not unlike an island rising from the sea.” Indeed, the name comes from German for “island” and “mountain” and was coined by early German explorers of southern Africa who were impressed by such landforms they encountered there. Inselbergs are often granite and other rocks of igneous origin, or other rocks that are more resistant and whose base lies well below the surface. While the surrounding soils and sands are gradually removed by the powers of erosion, the harder rock remains, slowly “rising” above the plains. As in the case of Uluru and its sibling Kata Tjuta, most of the petrified sediments still lie below the ground, possibly extending for several kilometres. Only a small portion of the total mass is exposed, making both landforms the lithological equivalent to an iceberg.

Incidentally, the sediments are not red in their unexposed state but rather light grey as the main components are feldspar and quartz, a type of sedimentary rock known as arkose. The exposed rocks turn reddish as their iron components oxidize with the air. This brings to mind the scene in the movie “The Hitchhiker’s Guide to the Galaxy” when for but a couple of seconds we see workers busy painting the grey rocks of Uluru red in preparation for the completion of the new Earth. Someone’s shot at a gag was not so far off from reality.

Hotspots and Large-body Impacts

The Kilauea volcano on the Island of Hawaii is one of the most active volcanoes in the world and visitors come to see the orange rivers of glowing lava that flow usually very peacefully – though sometimes aggressively and destructively – from the craters and vents and pours in dramatic cascades into the spitting and steaming ocean. The Island of Hawaii also includes two much higher volcanic peaks, Mauna Kea and Mauna Loa, whose eruptive activity has continued until fairly recently.

All the Hawaiian Islands are products of volcanism and the reason for their continued activity is a phenomenon called a hotspot. Hotspots are thought to be plumes of rising heat through convection currents within the mantle. The earth has 40-50 identified major hotspots and many minor ones, too. Hotspots remain in a relatively fixed position and so as the plates drift over them their product volcanic edifices are moved away from the up-welling magma and the volcanoes become extinct while a new volcano is born over the hotspot. The Hawaiian Islands form a chain of volcanoes with the Island of Hawaii comprised of the most recently active volcanoes, Maui’s Haleakala having been active until the recent past, and all islands becoming older as one moves northwest. On the ocean floor, a chain of extinct volcanoes and former islands extends across the Pacific, makes a change of direction halfway to Asia and continues on to its subduction zone at the far western end of the Aleutian archipelago. Other famous hotspots include the Yellowstone Caldera and Mount Etna.

What exactly are hotspots and what causes them? Two theories are that they are either deep mantle plumes or shallow plumes. But a new hypothesis is being tested that would suggest the origin of at least some of earth’s hotspots is large-body impacts. According to the paper by Johnathan T. Hagstrum, most of the earth’s major hotspots have antipodal hotspots or large igneous provinces (LIPs) of roughly the same age. The paper examines evidence that could suggest that a bolide of greater than 20km diameter striking the earth in an ocean could penetrate into the mantle and disturb it enough to create long-term volcanic activity where eruptive magma would cover any evidence of the impact crater. Furthermore, such a large impact would create Rayleigh shock waves that would spread around the globe and converge at the antipode of the impact. This convergence of seismic energy could fracture the crust sufficiently so as to lead to eruptive activity. One significant point is that most hotspots have antipodal LIPs, which suggests that if a large-body impact created the hotspot then the seismic energy focused at the antipode possibly triggered the basalt floods that created the LIPs. Another point is that in the case of continental impacts, the tensile strength of the thicker continental crust acted as a shield that prevented the creation of an antipodal hotspot or basalt flood. Only very large continental impact sites have antipodal hotspots. The paper offers a lot to consider.

So how about our Hawaiian hotspot? Its antipode is Lake Victoria in Africa; however, the research paper says that some antipodal hotspots are just coincidental and in the Hawaii/Lake Victoria case this seems to be the situation.

For further reading:

Hotspots

Antipodal Pair Impact Hypothesis

A post of mine about meteor craters

The Perito Moreno Glacier

Listed as one of the Seven Wonders of South America, the Perito Moreno Glacier is indeed a sight and sound to behold. From the viewing deck built up on the slope the view of the glacier is phenomenal. Between the mountain peaks emerges a 30-kilometre-long river of ice that stands on average 60 metres above the waters of Lago Argentina and stretches roughly 5 kilometres from side to side with a total surface area of about 250 kilometres squared. The view is nothing less than mind-boggling and at the same time both awe-inspiring and almost forbidding. It looks as though some frozen hell has breached its restraining barriers and has come flooding into our world. This incredible view has the air charged with sound as tremendous cracks and gunshot booms emanate from the seemingly static towers of ice that are actually slowly advancing forward into the frigid lake waters and bending under their own weight. Large chunks of ice break free and plunge into the lake with a splash that sounds like a semi-trailer truck was dropped in, and if you can watch long enough you might even see a huge section collapse into the lake with a thunderous rumble and a splash that sends tsunami-like waves rolling across the water.

The Perito Moreno issues from the Southern Patagonian Icefield, the third largest freshwater reserve on the planet. It is one of only three Patagonia glaciers that is still growing. Though the articles say that scientists are still not certain why the glacier is growing while most others are retreating, I think it may be a combination of factors such as proximity to the regions of the icefield that receive the most precipitation, wind direction in relation to the surrounding mountains, and the presence of self-produced cloud cover. Icefields tend to make their own climate, cooling the air over them creating clouds when the air is moist and causing rain or snow to fall while neighbouring mountains and plains remain dry.

Aside from its impressive visual appearance, the Perito Moreno glacier is also famous for its spectacular ruptures. The glacier’s trajectory pushes it against the rocky headland where Lago Argentina branches into the main lake and an arm known as Brazo Rico, and once the ice has built up against the rocks, the melt waters in Brazo Rico cannot escape into the rest of the lake. The water level rises and it can reach up to 30 metres before the water forces a way through in with a crashing collapse of ice and an explosion of ice-chocked water. The pent up waters surge through the opening sending icebergs swirling and bobbing into the main body of the lake. This extraordinary event may occur as frequently as once a year to as infrequently as once every several years.

The Primrose Terrace and the Wai-O-Tapu Geothermal Area

There are many places in the world where near-surface geothermal activity causes silicates to bubble up with hot water and then to be precipitated as the hot water trickles away or evaporates. Where these siliceous precipitates are deposited, impressive structures of delicate miniature pools and terraces are formed. Perhaps the most famous is the Mammoth Hot Spring terrace of Yellowstone National Park. In the southern hemisphere, New Zealand’s North Island has some of the most impressive geothermal features, particularly around Rotorua and Wai-O-Tapu.

The Wai-O-Tapu area includes a variety of natural features such as hot spring pools, bubbling mud pots, collapsed craters, and a sinter terrace known as the Primrose Terrace. This is the largest known sinter terrace (1.5 ha) in the Southern Hemisphere, since the Pink and White Terraces were destroyed in 1886 by the eruption of Mount Tarawera. The siliceous sinter flows in hot water from the Champagne Pool, which gets its name from the carbonic gases that bubbling out of the 73-degree water. Microbiolites and microstromatolites play an important role in the silicate precipitation by providing templates for silica precipitation. Around the Champagne Pool, various elements provide the colours of the rich pallet, including colloidal sulphur and ferrous salts (green), antimony (orange), manganese oxide (purple), silica (white), sulphur (yellow), iron oxide (red), and sulphur and carbon (black).

The Wai-O-Tapu area is associated with volcanic activity dating back to 160,000 years ago. The Champagne Pool is much younger, only about 900 years old, and the Primrose Terrace is believed to have been forming only for the last 700 years. 

Huangshan - Yellow Mountain

The granite towers of Huangshan in Anhui Province in China have attracted visitors for centuries, perhaps ever since their name was changed from Yishan to Huangshan in 747 AD by imperial decree. The name, which means “Yellow Mountain”, may have come from Huang Di, commonly thought to be the name of a legendary Chinese emperor. The towers, spires, and needles of granite and their crooked pines (pinus hwangshanensis) gazing over seas of clouds have inspired artists for ages. A well-developed tourist area, the mountain is etched by stone steps, sometimes augmented with concrete; the original steps carved out of the granite are said to be over 1,500 years old.

Huangshan formed over several periods of development. The first stage was a magmatic intrusion of granite that occurred about 143 Ma, followed by the formation of a batholith and stock formation of granite 96 Ma. The surface was covered by sedimentary deposits and was near a sea. About 65 Ma, the batholith experienced upheaval and the first granite mountains formed. The first Himalayan episode of uplifting took place about 54 Ma and the middle mountain and canyon were formed. This was followed by a long relatively stable period were shallow depressions of confluence basins formed on the paleo-gradational surface. Then came the long second movement of Himalayan uplifting followed by another stable stage. By the Quaternary, the granite was uplifted further as a fault block and as the granite cracked and split, streams cut their way deep into the rock. Exfoliation, sheeting, and frost weathering have also helped shape the fantastic metropolis of soaring stone.

I was very interested to read that ice age glaciation had contributed to the sculpting of the mountain; however, when I visited in December of 2004 I could not see any of the familiar tell-tale signs of former glacial occupation. In a paper called “Structural and Geomorphological Evolution of Huangshan (Yellow Mountain), Anhui Province, China” by Pei-Hua Huang, Robert F. Diffendal, and Ming-Qing Yang for the University of Nebraska, the authors point out that there is no determining evidence to support the claim that glaciers once existed on the mountain. This theory was originally proposed by J.S. Lee in 1936 but since the 1960’s P.H. Huang has studied the area and found non-glacial explanations for most of the formations previously believed to have been of glacial origin. You can read the paper by Huang et-al here. Interestingly, the article on Wikipedia adheres to Lee’s obsolete theories that glaciers once scoured the mountains. 

One question I personally have concerns the 7-ton boulder called Feilaishi. It rests atop a pedestal of granite which reputedly is of a different age or type from the boulder. It is said to be a glacial erratic, and usually this would be a credible deduction. But if not an erratic then how did this enormous boulder end up on its lofty precipice?

The Sanbagawa Metamorphic Belt

The Ara River flows down from the Chichibu Mountains in Saitama, Japan and works its way across the Kanto Plains to Tokyo Bay where it empties into the Pacific Ocean. During its journey through the mountains, Arakawa (its proper name in Japanese) incises its way through various ancient layers of rock, and at Nagatoro Town, the river has worked itself through a fault and carved out an impressive gorge in some very beautiful crystalline schist. The site is a popular scenic attraction, and the so-called Iwadatami (rock tatami) is a natural treasure.

The schist present at Nagatoro is part of Japan’s largest metamorphic belt. Known as the Sanbagawa Metamorphic Belt, this continuous strip of rock continues from the western shores of Kyushu Island, across the Island of Shikoku, past the Nanki Peninsula and along Honshu until it bends deep inland, arcs around and approaches the coast again. The metamorphic rocks here were once sediments on the ocean floor and located near the subduction zone of the oceanic plate. These sediments accreted over the period of about 130 to 120 Ma and the time of subduction is estimated at about 116 Ma. The sediments underwent metamorphism under high pressure and temperatures but were subsequently thrust toward the surface again at a relatively high speed at first, then gradually their ascent slowed down until they reached the surface about 50 Ma.

In more recent history, the Izu Peninsula, growing from the Higashi Izu monogenetic volcano field and colliding with the Island of Honshu, pushed its way into the island and bent the various belts of metamorphic rock northward. Thus the waters of Arakawa flowing north and far from the ocean cut through the metamorphosed sediments of Jurassic times. Depending on the type of protolith, the schist may appear a metallic blue/grey, smoky blue, light grey, greenish grey, or brown. Many of the rocks have crystalline bands running through them, giving them beautiful patterns.

Because of the abundance of exposed rocks here, Nagatoro is known as the birthplace of Japanese geological study.  

The Hopewell Rocks

The famous “flower pots” of the Hopewell Rocks are a natural treasure of Canada. Located in the Province of New Brunswick, on the shores of the Bay of Fundy, visitors can easily see how the erosion of the tides has worn away the sandstone and conglomerate bases of these sea stacks, creating slender columns supporting blocky-looking masses of rock. Trees and other vegetation sprout from the tops of many of these, making the rocks appear as giant potted gardens.

The history of the sediments present here goes back to over 600 million years ago when a colossal mountain range known as the Caledonia Mountains had formed in the region due to the collision of what are now the European and North American Plates. Though the mountain range stood higher than today’s Rocky Mountains, there were no eyes to view the lofty crags. The earth was in the Ediacaran Period, which lasted from 635-542 million years ago, and life had only just begun evolving complex multicellular organisms. Imagine that this grand mountain scenery was devoid of green vegetation and consisted solely of rock, snow, ice, and meltwater streams and rivers. As the mountains were eroded, sediments accumulated in the valleys. Further tectonic movement uplifted and tilted the sedimentary layers, causing them to fissure and split into blocks.

In the more recent geologic past, the glaciation periods of the ice age covered the region in glaciers that carved out a valley leading to the sea. When the last of the ice sheet retreated about 13,000 years ago, sea levels rose and flooded the valley, leaving us with the Bay of Fundy, famous for having the highest tides in the world. Rainwater and ice have worked through the fissures, widening the cracks in the ancient sedimentary layers.

I enjoyed a stroll between the towers of rocks at low tide in September of 2005. Many otherwise interesting landscape shots were spoiled by the yellow signs warning visitors to stay out of dangerous areas where unstable rocks might fall loose. I found most of my best photographs were of detailed sections of the ancient sedimentary rocks.

Painted Hills, Oregon

Photographers and painters cannot resist the sight of the colourful Painted Hills in Oregon, U.S.A. Located along Highway 26 near Mitchell, the hills are a part of the John Day Fossil Beds national monument and provide a visual record of nearly 40 million years of climate and ecological change in the area and are a rich library of knowledge regarding prehistoric plant and animal life.

The reddish layers of clay are laterite soil which are rich in iron oxides and typically form in tropical climates. The black parts are lignite, also known as brown coal. It is a very low grade of coal and formed from the remains of plants. The greenish and ochre layers formed later as the climate became drier. There are also layers of mudstone, siltstone, and shale.

All layers are mixed with volcanic ash from different eruption periods of different volcanoes, most notably volcanoes of the growing Coast Range Mountains. Prior to their formation, the region maintained a warm, humid climate. However, as the Coast Mountains grew in height, they created a rain shadow over the region and the climate gradually became drier.

I visited the Painted Hills in March of 2006. The day was overcast with light snow falling in the mountain pass. In spite of the flat light, I was enjoying exploring the area by myself as there were no other visitors while I was there. Then the clouds shifted and for about 20 minutes beautiful afternoon sunlight bathed the scene in warm light. How the hills came alive! A little later in the spring, yellow flowers bloom in the folds of the red slopes, adding one more dimension of colour and beauty to the landscape.

For a detailed report of the area's natural and human history check out this link.

This Is the Start of a Rocky Road

Welcome to my Geo-Files blog where I share my love of geology and photography. I have been interested in rocks and landforms since my elementary school days and once I started photography in my teens I was always keen on shooting subjects related to the lithosphere and the earth sciences. Nearly all of my photographs that have ever been published (over a hundred by now) featured rock formations (in the colloquial sense), volcanic landscapes, mountains, erosional features, and so on.

As my time permits, I will post about locations I have visited and photographed or projects I am working on, or have worked on, related to this field of earthly beauty. I am planning to feature several galleries and I will start with the following three: In Vulcan’s Garden (volcanic and related landscapes), pieces of eARTh (abstracts of rocks and landscapes), and High Light (mountain scenery). Later I expect I will add new categories as new photographs are added that don’t suit the initial three categories.

So stop by when you can and watch the collection grow.

Peter Skov

February 27, 2013