Category Archives: Geology

Visible Changes

2023 Grand Finale Tour, Arizona, Arizona Photos, Geology, Natural History, New Attitude to Nature

 

 

 

There is no doubt about it, the Grand Canyon is grand. It is one of the most beautiful places on earth. I is also fascinating because it makes long history visible before your eyes. We did not visit it this  year when we were in Arizona, but we have visited it many times. Some places brag about being worth the trip even though the claims are dubious. The Grand Canyon has a right to brag.

You can see some of the history of such astounding changes in places like the Grand Canyon of Arizona. The geological history of the American Southwest revealed there makes visible what has happened in the last 1.7 billion or so years. That is long before there was any human life on the planet.

Each layer of rock is displayed in different colours. It may be the best record of the earth’s formation anywhere in the world. Almost 2 billion years of history are recorded there although the most dramatic changes occurred recently about 5-6 million years ago when the mighty Colorado River began to carve its astonishing path through the canyon walls. Even that  relatively recent history, includes no history of human life, because there was none.

The fossils found in each layer tell the story of the development of life on earth. The Vishnu Schist which is one of the oldest layers, near the bottom of the canyon, was formed when the first life on the planet, bacteria like creatures and algae first emerged.

Many of the other layers were created by billions of small marine animals, when this area was submerged by ocean. Their shells eventually accumulated to such an extent over hundreds of millions of years that they built up into thick layers of limestone that we can see today from the top of the canyon, looking a mile down. I am always amazed to think that a sea covered this incredible land.

 

 

As far as plant life goes, since I self-identify as a flower guy, they have been around for at least a 125 million years or so.  During that time, they evolved astonishingly from tiny barely visible flowers to glorious huge dahlias, from nearly inconspicuous grasses to majestic Redwood trees. All of those are flowering plants!

Life really is grand.  We must learn to appreciate all life. Not just human life. That is part of what I call a new attitude to nature.

 

White Sands National Monument

2019 Trip to Southwest United States, desert, Geology, New Mexico, Wild Flowers

 

Chris is not standing barefoot in snow. This is sand–incredible sand!

For years I have wanted to visit White Sands National Monument. There is nothing like it on the planet.  The main geological feature here is sparkling white sand about the color of sugar. I had heard about it, but nothing really prepared me for it. This is the largest white gypsum dune field in the world. The glistening sand dunes are found in the Tularosa Basin at the northern end of the Chihuahuan Desert in New Mexico north of Las Cruces and south of Alamogordo.

It covers about 800 sq. km. (300 sq. mi). Gypsum, which is also found in Manitoba in a completely different form, is a water soluble mineral that is not often found as sand.  Because there is no drainage from the Tularosa Basin surrounding the white sand dunes  the sediment from the mountains that is washed by rains, even though infrequent, gets trapped in the basin. When the rain evaporates dry lakes form and strong winds blow the white gypsum up into huge fields of rippling white sand dunes.

Sand dune never remain in place. They are constantly on the move. At one point we saw dunes about to climb over the State highway we had driven to get here.   What surprised me is that the water table here  is very shallow and water can actually rise to the surface after heavy rains turning the interdune area into temporary large ponds.

Geology is always interesting. There is a lot of history in rocks. Millions of years ago, an ancient sea covered most of the southwestern United States and during this time layers of gypsum were deposited on the floor of the sea. Of course that sea was never static either. It rose and sank many times over millions of years. This started the process of the creation of gypsum.

Gypsum is created within layers of sedimentary rock often found in thick beds or layers. It forms in lagoons where ocean waters that are high in calcium sulfate content slowly evaporate but are regularly replenished with new sources of water. This is precisely what happened at White Sands.

Massive gypsum rock forms within layers of sedimentary rock, typically found in thick beds or layers. It forms in lagoons where ocean waters high in calcium and sulphate content can slowly evaporate and be regularly replenished with new sources of water. Because gypsum dissolves over time in water, gypsum is rarely found in the form of sand. That is why White Sands is unique.

Many factors led to the creation of this astonishing ecosystem.   280 to 250 million years ago (‘mya’) the continents of the world were welded together in one massive mega-continent now called Pangea. Part of what we today call the United States in the southwest, including the southern part of current New Mexico, were covered by what we now call the Permian Sea.  When the sea rose and fell repeatedly thick layers of the mineral, gypsum, were left behind along with other minerals that were also dissolved on the seafloor.

About 70 mya when the earth’s tectonic plates started to shift they collided into each other. In some places the pressure from such movement pushed up land and created many mountain ranges including the Rocky Mountains and the mountains that now surround the Tularosa Basin.

30 mya ago the tectonic plates began to pull apart in the opposite direction creating many fault zones. Large portions of mountains were sometimes split apart causing sections of the Earth’s crust to drop thousands of feet, forming basins along the faults. At that time 2 distinct mountain ranges were formed in this region—the San Andres Mountains to the west that are shown in my photographs and the Sacramento Mountains that we could see to the east. Between the two mountain ranges, where we stood, the Tularosa Basin was formed.

About 2 to 3 mya the Rio Grande River flowed along the southern edge of the Tularosa basin bringing sediments and minerals into the basin. This eventually blocked the basin’s outlet to the sea.  Water that was trapped at the blockage started to collect at the lowest point and eventually formed Lake Otero. This lake was about 1,600 sq. miles and covered much of today’s basin.

24,000 to 12,000 years ago the climate was much colder and wetter then it is today. About 12,000 years ago when the climate changed and the last ice Age ended, Lake Otero began to evaporate and when conditions became dryer a playa or dry lake bed was formed. Around 11,000 years ago, the rain and snowmelt carried dissolved gypsum from the surrounding mountain ranges into the Tularosa Basin. Much of that gypsum runoff settled in Lake Otero.

As the climate became even warmer and dryer the sun and winds combined to transform this area into the Chihuahuan Desert and almost all of Lake Otero dried up completely. The dry portions of the lakebed became what today is called Alkali Flat. When Lake Otero’s water disappeared selenite crystals formed on the bottom of the Alkali Flat. Small pieces of gypsum crystal were broken down by strong winds leaving small grains of white sand that were polished into a brilliant white color unlike anything I have ever seen anywhere. These Sands, unlike the white sand beaches of the Caribbean are really white. The sands were consistently pushed to the northeast by the prevailing winds from the west accumulating into massive dunes forming the white dune fields that we saw today.

Of course not all geology is old. Geology is today too. At the present time change occurs as well. Rain and snow melt from the surrounding mountains and even upwelling from the deep water within the basin from time to time fills Lake Lucero with water that contains gypsum. When the water in the lake evaporates again small selenite crystals (2cm to 3cm) are again formed on the surface of the temporary lake and Alkali Flat in the same was they have for thousands of years. It is usually when large floods concentrate the mineralized water about every 10 to 14 years that crystal formations again occur. After that the relentless forces of wind and water again attack those crystals of gypsum creating ever smaller particles of white sand until they are as fine as the sand we walked on today.

Of course it is not just the geology that is interesting in White Sands National Monument.  A plant guy like me must pay some attention to the plants. One of the more interesting ones is Soaptree Yucca (Yucca elata). The plants and animals of White Sands are special because they must  have special attributes to survive the harsh and changing conditions of the desert.  The desert is not place for wimps. The landscape here is constantly changing, even more than most other environments.  The sand moves. It never stays for long in one place. That is a characteristic of all dunes.

The Soaptree yucca adapts to these changing conditions by growing rapidly. Yucca first take root in the interdunal soil. Then when the sand piles up as it inevitably does, it elongates its stem to keep it’s leaves above the sand so that they can continue the important work of photosynthesis whereby light is miraculously turned to energy. What looks like a yucca of 4 to 6 feet, as many of those I saw, are actually much taller with a long stem that connects to the roots in the interdunal soil. Plants are smart!

Lac Pink

2018 Trip to Ottawa, Geology, Natural History, photography

 

 

 Lac Pink

 

Gatineau Park is beautiful–that is actually a pitiful understatement–but it is much more than that. It is fascinating. The same goes for my favorite lake in the park.

There are more than 50 lakes in Gatineau Park, including Lac Pink, (or Lake Pink as it is more prosaically called in English),which is  my favorite. It is one of only 58 known meromictic lakes in North America.  A meromictic lake is a lake where the upper and lower layers of the water in it never mix. That seemed very strange to me.  Normally a lake’s waters mix all the time especially during spring and autumn when the water density and air temperature distribute nutrients and oxygen throughout the lake, more or less evenly.

The water of Lac Pink doesn’t  mix like most lakes because it has a relatively small surface surrounded by steep cliffs that protect it from the wind which would otherwise mix the waters. As a result there is no oxygen in the deepest 7 metres of the lake. The deepest part of the lake has not has not been in contact with the air since the last Ice Age 10,000 years ago. That amazed me.

The lake is beautiful but it is not pink. It is named after the Pink family which were the first non-indigenous owners of it. The lake is actually green, not pink. The reason it is green, a gorgeous green in fact, is because of the presence of microscopic algae. The beautiful green colour is actually a bad sign. The green algae gradually takes over the oxygen in the lake suffocating the life in it. This is a natural process called “eutrophication” which ordinarily takes thousands of years.

However eutrophication can be affected by human activities. For example, Lake Winnipeg is suffering from it because of runoff from agricultural lands, sewage deposit by the City of Winnipeg as well as other municipalities  into the Red River, and other causes.

Because Lac Pink is so popular (I am not the only one who loves is), people have sped up the natural process of eutrophication. At one time eutrophication was  happening so fast it was estimated it would be complete within decades rather than a thousand years. As a result the lake has been rehabilitated. Humans caused the problem and now have come to the rescue of the lake. We can be a force for good or ill. The choice is ours. Conservation efforts have included building platforms and a trail to limit damage by erosion. Volunteers have also helped to plant 10,000 small trees.

Since there is no oxygen at the bottom of Lac Pink there is really only one organism that is able to live there without oxygen. This is a a prehistoric anaerobic organism. It is a pink photosynthetic bacterium, which uses sulphur instead of oxygen to transform sunlight into energy. Imagine that. It transforms light into energy even though it does not photosynthesize. This lake is endlessly fascinating.

Higher up in the lake resides the three-spined stickleback fish, a saltwater fish left behind from the Champlain Sea, which used to cover the region. This little saltwater fish adapted to the lake’s gradual desalination and today lives in the lake’s fresh water.

The Champlain Sea was a temporary inlet of the Atlantic Ocean that was created by retreating glaciers just after the last Ice Age. The Champlain Sea once included much of the land that is now part of Quebec and Ontario and even parts of New York and Vermont. The huge continental ice sheet that covered much of North America during the last Ice Age was so heavy that it depressed much of the rock beneath it. When the Ice Age ended the St. Lawrence and Ottawa River valleys were so low that they were actually below sea levels. These areas flooded with sea water when those massive continental ice sheets from around the world melted and raised sea levels substantially, once those ice sheets no longer dammed the oceans back.

Then the land gradually rose as the Ice sheets were removed. This is called isostatic rebound and is still happening to this day all over Canada, including for example, Lake of the Woods where we have a cottage. The Champlain Sea lasted for about 3,000 years from 13,000 to 10,000 years ago. As a result the sea coast gradually retreated to its current location. Of  course, since the process of isostatic rebound is not yet complete, those coastlines will continue to change. This process will now also be affected by rising sea levels due to climate change. This area, as so many others around the world, will be in for interesting times, not all of which will be benign.

The remaining glaciers fed the Champlain Sea making it more brackish than typical sea water. It has been estimated that the Champlain Sea was as much as 150 metres (490 ft.) higher than the level of the St. Lawrence and Ottawa River valleys today. Scientists are so smart to figure all of this out.

There is much evidence of this former sea including the clay plain deposited along the Ottawa and St. Lawrence Rivers that have resulted in such interesting forest types that I travelled through on this trip as well as large wetlands that are home to amazing vegetation, including my favorite, orchids. Other evidence of the sea includes whale fossils and marine shells that have been found near Ottawa and Montreal.  There are also fossils of other oceanic fish such as capelin.

This entire notion of an ocean in this area is astonishing. About 11,000 years ago when the land was so low after the Ice sheets were gone from southern Canada, the Atlantic Ocean rushed into the St Lawrence River Valley filling even the area of current Ottawa with ocean water. In other words, a mere 11,000 years ago there would have been bowhead whales and seals swimming above where we were standing today. I am always amazed that much of Manitoba at one time was the bottom of an ocean, but that was 450 million years ago! Comparatively, 11,000 years ago is just a blink of an eye ago.

Nature constantly astounds! Gatineau Park is an example of that.

Rocks and Trees

2018 Trip to Ottawa, Geology, photography, waterfall

Rocks and Trees and waterfalls in the Canadian Shield

Often when we tell people that we are headed to the east people ask, “Why would you do that?  All you will see are rocks and trees and more rocks and more tree.” Then often, they add, “Boring!”  I would say if you think Northwestern Ontario is boring that you are probably boring.

Shortly after heading east down the Trans-Canada Highway we saw evidence of something that intrigues me.  That is the Canadian Shield. I kept thinking about this as I travelled east.  I love to see it, but my viewing pleasure is enhanced by what I have learned about this astonishing Canadian Shield.

We experienced snow on day 1 and 2 of our trip to the east

When I was at the Grand Canyon we were amazed that the oldest rocks at the bottom of the canyon  were 1.7 billion years old. That seemed like a lot, but those rocks are youngsters compared to the rocks in the Canadian Shield!

The shield contains some of the oldest rocks on the planet.  Many are 2 billion years old. Some are nearly 4 billion years old! The Shield goes well beyond Canada’s borders. Nearly 2/3 of North America is part of the shield.  It stretches from the Arctic to Mexico.

To geologists rocks seem to be alive since they tell us so much about where we and our world came from.  The earliest mountains on our planet are about 3.9 billion years old. The continents of our planet  have always been migratory. They travel like rafts on the surface of the earth. This is part of the system of tectonic plates. When continental plates collide parts of one plate can be added to the other. This is referred to as continental accretion. The plate tectonic process began soon after the earth was created. The Shield was assembled over billions of years. Since then many successive mountain ranges have been created and worn down over deep time. As a result geologists often look for ghosts of ancient mountain ranges. The Shield is one of these ghosts–the worn down stumps of very old mountains.

Colliding continents created immense volcanic activity which in turn created many rocks including  gneiss.  Gneiss is a highly metamorphosed rock that is composed of distinct bands of alternating pinkish granitic rock and darker more iron rich rock. It is very common in Canada. This rock shows the intense deformation of rock that occurred at great depths under the surface of the planet when crustal rocks collided to create the crustal mosaic that constitutes the oldest part of our country.  Where it is now exposed at the surface over large parts of the country these rocks are evidence of deep erosion of mountains and the removal of vast volumes of rock over the millions of years that followed these collisions creating a relatively flat Shield surface with which we are familiar.  The rocks we see are often the very deep roots of what were at one time very high mountains.  Contemplating such immense erosion gives one a profound sense of the power of time.

Gneiss is produced when 2 plates squeeze against each other and the igneous rocks are heated to extreme temperatures as a result of the friction and the pressures are enough to create mountains. The rock at that point is as soft as toothpaste.  The heat is so intense and so extreme that rocks are dehydrated  and produce water streaming from a burning rock.  The rock that is forced out is mineralized water.

Even though the Canadian Shield contains some of the oldest rocks on the planet, from time to time sojourner rocks have arrived from far off places. Some of these have even arrived from other worlds. For example, at Sudbury about 1.8 billion years ago a meteorite rocked the earth, digging deep beneath the surface at that time to create what we now call the Sudbury Basin.  The Basin is so deep it can be seen from space.

The force of that blow was awesome.  In fact it exceeded the force of all of our nuclear weapons combined!  The Sudbury Basin close to where we travelled is the second largest known impact crater on our planet. It is 62 km long and 30 km and 15 km deep.  To consider the force that created such an impact is a humbling task. Railway engineers who were constructing the Canadian Pacific Railway discovered it accidentally in 1885.   Another surprise meteoric visitor from outer space created the crater that later filled with rock. We now call that crater West Hawk Lake.

The last two million years in the Shield have produced great fluctuations in climate. From time to time, this generated massive continental ice sheets that came and went over the continent wearing down mountains, depositing rock materials, and retreating again, only to arise again later.  The changes created by these forces were also awesome.  These ice sheets were HUGE.  Imagine ice sheets 2 km. deep above where we were driving. It really was difficult to comprehend.

I love these little islands of rocks and trees

         My friends probably think I’m nuts, but I was thinking about such things as we drove through the Shield. It is much more than rocks and trees.

Golden Circle Tour

2018 Trip to Iceland, Geology, Nature, religion, waterfall

 

Our last day of the Iceland tour was something called the Golden Circle Tour. This has nothing to do with Trumpian hijinks. The Circle Tour is a famous one-day trip around many sites within a couple of hours of Reykjavik. That is all most tourists see of Iceland. Don’t get me wrong, it is a a wonderful part of Iceland, but it is only a small part. We were very fortunate to be able to see large part of the  island from west to east and north to south.

Skálholt, which is Iceland’s first Bishopric (that is not Bishop’s prick). Christianity in Iceland  has been a powerful religious force for more than 1,000 years. This power was carefully built up over hundreds of years by an influential dynasty of chieftain priests. Naturally, like the rest of Europe no one believed in the separation of church and state. The first of the bishops was Gissur the White a bombastic priest who led the pro-Christian faction at the AD 1,000 Alpingi where the people’s leaders decided to convert to Christianity mainly to improve their chances of trade with Europe rather than out of any sincere religious convictions. The people of course had no say in their conversion to Christianity, not unlike the princes of Germany in the German Reformation. Commerce was more important than religion. Sort of like it is now.

Often the best part of church interiors is the stained glass. This was one of those churches.

 

On the Circle Tour was Geysir which has lent its names to all water spouts around the world. Actually Great Geysir started erupting in 1294 and reached heights of 60 metres (200 ft.) but it has not kept up for decades.  In the 20thcentury, eager (read stupid) tourists tipped gravel and garbage into its mouth hoping to cause an explosion. They also used soapy water on special occasions such as Independence Day but that did not help either. As a result of this abuse, the geyser became nearly dormant. Surprisingly, in 2000 it sprang back to life spouting 40 metres (130 ft.) into the air. It is no longer that robust but still lifted off impressively.

I am supposed to be the orchid guy, but while we were looking at the geyser and some hot pots of water, Chris spotted an orchid with her eagle eye. According to a German tourist near us it is called Knabenkrautin German. I think the common English name is marsh orchid or Common twayblade.  I tried to photograph it, but we were too far away and were not allowed to walk closer.

 

After that we drove to Gullfoss(Golden Falls). No this was not a golden shower either. This is one more spectacular waterfall. Actually, it is a double water fall. First the River Hvítá tumbles 11 metres and then the lower falls drops 21 metres. The rock of the riverbed was formed during an interglacial period. Apparently it has flowed for thousands of years. It was a very impressive falls.

We learned that at one time Iceland was planning to build a hydro electric dam and plant here, but a heroic protester led the opposition. She said, “I don’t sell my friends.”  Now it is a UNESCO world heritage site, one of two we visited today on our golden circle tour. No doubt Iceland has earned more money from tourists visiting the site than they would have from the electrical power from one more damn dam. I promise this is the last waterfall I will show from Iceland.

Our last stop on our Golden Circle Tour was Thingvellir National Park the historical heart of Iceland and now the second UNESCO world heritage site we saw in one day!  It is a fantastic natural site as well as the site of the Viking Parliament, the first in the world. The National Assembly was established there by the Vikings in 930 AD and was regularly convened there until 1798. As well the geology there is incredibly important because one can see the continental tectonic plates pulling apart.

This was the end of our tour around the island of Iceland. we finished our visit with a  couple of days in Reykjavik.

 

 

Arches National Park

2016 Trip to Southwest USA, Geology, Nature, Utah

 

I remember well a day 2 years ago when we visited Arches National Park in Utah. It was an extraordinary day. It was one of those travel days that I will never forget. It was not a long day. Sadly, our visit was all too brief.

The Geology of Arches National Parkis as fascinating as the arches. It is history told in the language of stone and rock.         The story of the area now contained with Arches National Park (“Arches”) began approximately 65 million years ago.  At that time this area was a most improbable sight for what we see today. At that time it was a dry seabed that spread from one horizon to the other.  For example, if you stood in Devils Garden 65 million years (‘mya’) ago the red rock features that make up this fantastic landscape would not have been visible at all. Everything would have been buried thousands of feet below the surface. Like the marble that lay in front of Michelangelo, all would have been uncarved raw material.

65 mya geological forces started to work on this rough landscape.  The first geological step was for geological forces to wrinkle and fold the buried sandstone.  This process has been compared to a person with a giant rug gathering the two edges toward each other. Such a process would make lumps across the middle. Geologists call these lumps Anticlines. As the sandstone warped, fractures tore through it establishing the patterns for rock sculptures of the future.

The great uplift of the Colorado Plateau occurred about 200 million years after that some 40 million years ago.   The entire region began to rise thousands of feet above sea level.  That happened for much of the American Southwest. As the Colorado Plateau rose up, layers of sedimentary rock were presereved in tact. Now, as a result,  scientists can read those rocks like a geological book. The Grand Canyon is one of the places where this geological book is most readable. The entire region, though particularly the Grand Canyon of course, is famous for its multicolored layer cake geology where each layer tells a distinctive story about a particular historical epoch that began in the Precambrian nearly 2 billion years ago and ended 570 million years ago.

Our first stop in the park was near to Park Avenue. There is a short trail that is referred to as Park Avenue because of the many rocks that resemble city skyscrapers. We also saw some rocks that appeared to be balancing on pillars. These were starkly unlike. We did not walk far down the trail as we had little time for hiking. That was a shame. Next time I hope we have more time. Nearby I also stopped for some photos of the wonderful snowcapped La Sal Mountains to the east

We next drove around the trail and stopped at the rock that is referred to as Courthouse Towersbecause it does look like a classic American courthouse. These reminded me of some of the rock formations I had seen a few years ago in Monument Valley, still my favorite place in the American Southwest. Of course, I was compelled to take some more shots with my camera.

 

 

Of course, nothing ever stays the same in geological terms. What was lifted up fell subject to the forces of erosion over long periods of time. Specifically, the forces of erosion carved layer after layer of rock away from the surface. One it was exposed, the deeply buried sandstone layers rebounded and expanded, like a sponge expands after it is squeezed. Of course this process takes a very long time. This created even more fractures in the rock and that permitted water to seep into the rock and break it down even further.

It seems odd because this region is so dry, but today water is the force that shapes the environment here more than any other force. Rain erodes rock and carries sediment down and washes that sediment down washes and canyons into the Colorado River. In winter snowmelt pools in fractures and other cavities and often it freezes and then it expands as all water does when it freezes. This breaks off chunks of sandstone. Small recesses develop and grow bigger with each storm.  Little by little over thousands of years, this process turns fractured rock layers into fins and in time, fins turn into arches.

 

 

Delicate Arche

Over very long periods of time the forces that created these arches will continue to widen them to such an extent that they become unstable and collapse. That happened just a few years ago.  In 2008, Wall Arch collapsed reminding us that these rock forms are not permanent. Noting is permanent, except change. Someday Delicate Arch will collapse too. Of course most of these arches will remain much longer than I will. After all this landscape took 65 million years to be sculpted. It really is an improbable landscape.

Like a fingerprint, every arch in the park is unique. Each arch tells its own distinct story of rock, water, erosion, time and change. Yet there are some interesting categories of arches. The free-standing arch is the most obvious type of arch. It stands alone, independent of other rock walls or fins. It seems to stand proud spanning an opening. Some arches of this kind have been called Windows. Often they frame a scenic view. Of course, in Arches,everyopening frames a scenic sight. It is entirely unavoidable. The most popular arches in the park, such as Delicate Arch belong in this category of arches.

 

Delicate Arch

Chris and I both saw Delicate Archfrom the lower viewpoint area. She stayed behind while I walked to the Upper Arch viewpoint, but I did not walk all the way up to the Arch. It would have taken me about 45 minutes to walk up to it but I felt we did not have enough time. This is the most famous of the park’s arches.

More than 2,000 arches have been identified in the park. That is an astounding number. Arches National Park has the densest concentrations of natural stone arches in the world ranging in size from sliver thin cracks to spans of more than 300 feet.

The rock layers that are frequently visible in the park today, were once buried by over a mile of other rock. This overlying rock first had to erode to expose the sandstone beneath, for arches to have formed. Arches National Park is a wonder of nature. It truly is. I am convinced there can’t be anything like it anywhere else in the world.  Wall Arch, the 12thlargest arch in the park, completely collapsed overnight in August 2008. Wall Arch fell on August 4, 2008 while people were sleeping at Devil’s Garden Campground not far away. Many reporting hearing the sound of thunder, but the skies overhead were clear. Yet thousands of tons of sandstone came crashing to the ground. The sound was deafening.

For most of the history of what we now call Arches National Park there were no red rocks here at all. Salty inland seas, braided river systems, coastal plains, and sand dunes were what we would have found during most of the history of this park. Geologists know this because they are smart and they know what to look for. The clues are there for the discerning eye to see and interpret. Geologists interpret clues such as fossils, ripple marks and cross bedding to understand the history of each geological layer to compose their picture of what happened here.

It is worth remembering that every arch, spire or other rock shape for that matter is a remnant of ancient massive layers of rock that once covered the entire region. Over time the layers of rock bulged, cracked, and then began to erode. Of course, over time every arch will collapse and crumble. That is entirely inevitable.       Although every arch will fall, collapses are actual rare occurrences. I was surprised to learn that there is no good way to predict when an arch will be pulled to its grave by the irresistible force of gravity.

Balanced Rock

 On our too brief drive through the park, we stopped at Balanced Rock with the La Sal Mountains in the background. This was an improbably and acutely precarious balanced boulder sitting on top of a sandstone spire. Together with the arches this is one of the signature rock formations of the park. It looks like it is ready to fall off at the next summer breeze. It has been estimated to weight 3,577 tons, the weight of an ice-breaker ship or 27 blue whales.

Balanced Rock

We had spent about 4 hours in the park and travelled right to the end of the self-guide tour. Not nearly enough time, yet this concluded one of my best days sight seeing ever! This was right up there with my experiences at Monument Valley, Yellowstone National Park, Sedona, Canyon de Chelly, Plitvice Lakes Croatia, Saguaro National Park, Churchill, and a few others.  My camera shutter got hot from over use. I used the word “Wow” far too often to count. If I had shot film images at the rate I shot digital images, I would have had to declare personal bankruptcy.  Thank goodness digital “film” is “free.”  Long live digital photography.

I still have one of Utah’s 5 National Parks to see–Canyonlands. Next year I hope to see it.

Bryce National Park: “Poetry in Stone”

2017 Trip to Southwest USA, Geology, Nature, Travel, Utah

Bryce Canyon National Park in Utah has been described as “Poetry in Stone.” I loved that description.  Each of us who visits Bryce has to remember that the landscape is never static. It is always dynamic and changing. Change is the only constant. The forces of weathering never get fatigued and exert a relentless force on the rock. Bryce Canyon consists of a series of deep amphitheaters filled with a variety of colored rock formations. Some of them are called hoodoos and they are what Bryce Canyon is most famous for.   Hoodoos are eroded columns of sandstone.  They were formed when wind, rain, and ice eroded “fins” of harder rock that eventually being columns and then further eroded into strangely shaped hoodoos. When those windows grow larger, their tops eventually collapse.  Everyone wonders why do they appear here and not in many other places of the world, though I have seen them in Alberta. Frank Decourten wrote a book called Shadow of Timeabout Bryce and its hoodoos “the grand icons of erosion.’ He also pointed out that “Hoodoos are ephemeral–new columns form while older ones are destroyed–and erosion is both their creator and, eventually, their executioner.”  They are created by differential erosion, the cap is harder and does not erode as fast, protecting the column underneath.

 

We loved the views at the various look offs. Each was spectacular in its own unique way. The spires of pink, orange, and red spires were breathtaking. The Paiute Indians who used to hunt here described them as “red rocks standing like men in a bowl-shaped recess.” The image above is a panorama. That means I combined a number of photos into one image. If you click on it, I hope it gets bigger.

 

Of course in the world of geography nothing is forever. As Decourten said, “Inevitably, even the pillars, protected to some degree by dripstone and caprock , succumb to the relentless attack of the elements and the hoodoos begin to crumble.”   Bryce really is a phantasmagorical funhouse made of stone. Bryce is one of the few places where people notice–really notice–the rock. That is because it is so strange. There is no place like it. But they are not only beautiful, they are fascinating if you dig into the geology of Bryce. As Decourten pointed out, “The vibrant colors, the intricate patterns of erosion, and the infinite variations in the surface textures of these rocks are both enchanting and mystifying.”

 

If you look closely at this picture of me you might be able to see Fear.

Bryce was affected by the Cretaceous Period is one of the most interesting periods in the history of our planet. It lasted approximately 79 million years, 145.5 million years ago 65.5 million years ago when the dinosaur disappeared. Decourten said “The Cretaceous was perhaps nature’s greatest excursion into mayhem. It was a time when the gradual, steady, geological processes of the planet went haywire.  For example, the slow spreading of the ocean basins which results in continental drift was proceeding at a rate up to three times greater than the rate at which such spreading occurs today!  During the Cretaceous, the plates of the Earth’s brittle crust were dashing around the planet at a geologically reckless speed–as much as 8 inches per year–about five times faster than your fingernails grow (the normal speed of the tectonic plates). Partly as a result of the high rate of seafloor spreading, great quantities of magma were produced and volcanoes erupted on an unprecedented scale with astonishing intensity.  More igneous rock formed worldwide during Cretaceous time than in any other period of geologic history (except perhaps the period just after the formation of the Earth). Ash and gases erupting from the Cretaceous volcanoes seem to have created a natural “greenhouse effect” which profoundly changed the global climate. It was warm 100 million years ago, very warm.  Tropical forests grew as far north as Alaska. The arctic zones disappeared and temperate conditions at eh poles caused the icecaps to melt. Water released during this great thaw lifted the world’s oceans onto the low borderlands of all the Cretaceous continents.

On land and in the swollen seas, a riot of evolution, induced by the rapid and profound environmental changes, produced bizarre life forms: giant seagoing lizards (mosasaurs); flying reptiles the size of small jet aircraft; the horned, armored, and duck-billed types of dinosaurs (not to mention the fearsome predators, such as Tyrannosaurus, which fed on them); tree-sized ferns and other primitive plants. Finally, there is some good evidence the Cretaceous might have been punctuated, 66 million years ago, by a collision between the Earth and an asteroid, an appropriately violent end to a turbulent period. A great extinction followed this event resulting in the extinction of vast amounts of life on earth, including, the dinosaurs.  Much of that ancient history is told in the rocks and fossils of Bryce. The story is endlessly fascinating.

 

An inland sea divided North America east to west 90 million years ago (‘mya’). During this time sediments were deposited at the bottom of that sea, forming the oldest rocks in the park. Before the canyon was filled with hoodoos it was filled with water. I am particularly interested for some reason in the fact that much of North America was at one time split by an ocean seaway. How can that possibly be? How weird is that desert regions like the American southwest were at one time inundated by this interior seaway? This has been called the Cretaceous Western Interior Seaway. When this interior seaway covered much of North America, including Manitoba, coal, sandstone, and mudstone accumulated along the western edge of this seaway. If it had accumulated on the eastern edge we might be richer here in Manitoba today. What a pity. During this time what we now call the Gulf of Mexico penetrated north across the low plains of central North America and joined the waters that were advancing from the northern Arctic Ocean. This incredible seaway in time submerged the entire region where the Rocky Mountains are now found (though they were not in existence yet at that time). This great interior seaway divided North America into two island continents!

Between 55 and 40 mya years ago much of Utah was a basin of water encircled by mountains.  That seems impossible now because it is so dry. Yet for millions of years rivers deposited sediments –mainly dissolved limestone—into a system of large lakes at the top of the Plateau . 20 mya ago, as the Colorado Plateaubegan to be uplifted the lakes dried up and their mixtures of sediments became the muddy limestone that geologists now refer to as the Claron Formation. Then massive tectonic plate activity from 20 to 15 mya began to push up an incredible part of the Earth’s crust. Eventually this uplifted the region by an astonishing 2 miles, creating the 130,00 sq. mile Colorado Plateau that I have come to know a little bit and love a lot.

If one stand on the rim of one of the amphitheaters in Bryce Canyon and thinks about things like this one’s mind is expanded to near stretching limits. The world is and has been a very strange place and much of that strangeness can be detected right here at Bryce.  This ancient world has been recorded in stone. That stone of course was subject to what Decourten called “Water, wind, gravity—nature’s wrecking crew—worked in concert to efface and obscure. He also said, The erosion which removed much of the younger layers created this glorious shrine to the dynamic artistry of geologic processes. Whatever else Bryce Canyon National Park may be, it is certainly a monument to erosion.

What we saw today was the product of massive rock layers that had been uplifted and fractured over millions of years and then submitted to the relentless never-ending forces of erosion. Those forces are not at sleep today. They never sleep. What we see tomorrow will also be the product of those same forces.

 

I have fallen in love with geology the study of how these forces have shaped our wonderful planet.  That is to me an astonishing admission. I would never have dreamed this were possible when I was a liberal arts student as an undergraduate at the University of Manitoba. I despised all science. I was enamoured of the arts and humanities. Science was irrelevant. Now I know how foolish I was. Science is critically important to understanding our world. If we understand it, even if we don’t solve all of its mysteries, we can’t help but love it and if we love it we will try to care for it. That is why science—just like arts and humanities—is vitally important.

 

Our next stop was one of my favourite—i.e. Natural Bridge formed through the erosion of rock by streams or rivers. This window or arch formed from a combination of processes. First, frost wedging, which is the expanding of cracks in rock as water turns to ice, weakened the rock. Then over time, dissolution occurred as a result of chemical dissolving of the rock by rainwater that cut away at the top and sides of this wall of rock. Over time the relentless force of gravity pulled loose the weakened pieces of rock at the center and that created a hole in the wall that we could clearly see and photograph today. That is why the “bridges” of Bryce Canyon, such as Natural Bridge, are spectacular examples of arches that, like the hoodoos, are constantly at risk of destruction as the never ending forces of erosion chip away at the rock. Nothing stands in the way of time. Everything changes.

Capitol Reef National Park

2018 Trip to Southwest USA, Geology, Nature,

 

Capitol Reef National Park was the 4thof the “Big 5” National Parks that we have seen.  The Park is most important geological feature is a wrinkle in the earth’s crust that extends for nearly 100 miles from Thousand Lake Mountain to Lake Powell. It was created over a long period of time by 3 gradual but powerful forces: deposition, uplift, and erosion. The result is a stunning example of what geologists call a monocline, or one-sided fold in the crust of the earth in what are otherwise largely horizontal rock layers. This fold runs north and south through the Utah desert. Waterpocket foldwas form about 65 million years ago when the earth’s surface buckled upwards. This was around the time the dinosaurs went extinct.

The climate in the region changed fantastically over millions of years. During the past 280 million years ago this region changed from ocean to desert to swamp and river bed. During this time 10,000 feet of sedimentary rock consisting of limestone, sandstone, and shale was deposited.

That was followed by uplift between 50 and 70 million years ago when an ancient fault was reactivated during tectonic activity. This lifted the land to the west up by 7,000 feet higher than the land in the east. The land did not crack, rather the layers folded over the fault line. 20 million years ago it was uplifted again.

After that erosive forces shaped the landscape. Much of this sculpture work occurred between 1 and 6 million years ago. Moving water and gravity were the main erosive forces. Powerful rains, flash floods and awesome freeze/thaw cycles loosen and crack the rock after which much of it is washed away. Often this left behind stunning canyons, cliffs, domes, and natural bridges or arches made of rock.

The original European explorers thought it looked like an ocean reef and thought its white domes looked like the American capitol and hence gave it the name Capitol Reef.

People have lived here for long periods of time.  As a result the park contains Ancestral Puebloan petroglyphs and a preserved Mormon homestead.

Charles Dutton the famous geologist who first scientifically explored much of the American Southwest in the 1880s described it like this, “…the light seems to flow or shine out of the rock rather than to be reflected from it.”