The Marvel Of The Nature

The Grand Canyon

The Grand Canyon is one of the most identifiable and remarkable landscapes on earth and the most internationally recognized symbol of nature in North America.  But this oversized natural wonder is much more than a sight to behold. It is a cultural landscape that has been lived in, traveled through, feared, marveled at, exploited for profit, utilized for education, and praised as inspiration by a diverse array of people over a very long time.  

Colorado River 

This unique place has influenced American science, art, environmental values, popular culture, tourism, and leisure.  It provided life and salt for Native Americans, thwarted early Spanish explorers, confounded prospectors and evoked poetry from the pens of scientists. From the early travelers to today’s five million annual visitors, everyone reacts differently - but everyone reacts.  As these reactions have been captured in oral histories, books, photographs, paintings, poetry, news articles, and movies, the relationship between people and place in this iconic American landscape has grown to shape our nation’s history and values. 

The Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile (6,000 feet or 1,800 meters). Nearly two billion years of the Earth's geological history has been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted. While the specific geologic processes and timing that formed the Grand Canyon are the subject of debate by geologists, recent evidence suggests the Colorado River established its course through the canyon at least 17 million years ago.Since that time, the Colorado River continued to erode and form the canyon to its present-day configuration.

Grand Canyon Map

Grand Canyon Mountains 

History

The Grand Canyon has been home to Native Americans for thousands of years. About 10,000 years ago, paleo-hunters were known to have hunted big game throughout the area. More recently, hunter-gathers lived in the area until about 1000 BC. Archaeological findings, such as pottery found in the canyon, have been carbon dated to 4000 years ago.

Ancestral Puebloan people moved in around 500 AD. They cultivated corn, hunted bighorn sheep, rabbits, and deer, and made intricate baskets. Their basket making skills lead archaeologists to call these people “basket makers.

The park contains nearly 2,000 ancestral Puebloan sites including the impressive Tusayan Pueblo which was built in 1185 AD. By the late 1200s, the early Grand Canyon Native Americans abandoned their homes. Some speculate that an extended drought prompted this mass exodus.

In the 1300s, the Cerbat (ancestors of today’s Havasupai and Hualapai Tribes) people moved in along with the Southern Paiutes. A century later would see the Navajo and the Dine (relatives of the Apache) people settling in and around the canyon. Today, the Navajo’s reservation is located along the eastern section of the Grand Canyon.

Native Americans

Early Explorers.

In September 1540, under orders from the conquistador Francisco Vásquez de Coronado to search for the fabled Seven Cities of Cibola, Captain Garcia Lopez de Cardenas, along with Hopi guides and a small group of Spanish soldiers, traveled to the South Rim of the Grand Canyon between Desert View and Moran Point. Pablo de Melgrossa, Juan Galeras, and a third soldier descended some one third of the way into the Canyon until they were forced to return because of lack of water. In their report, they noted that some of the rocks in the Canyon were "bigger than the great tower of Seville. It is speculated that their Hopi guides must have been reluctant to lead them to the river, since they must have known routes to the canyon floor. Afterwards, no Europeans visited the Canyon for over two hundred years.

Fathers Francisco Atanasio Domínguez and Silvestre Vélez de Escalante were two Spanish priests who, with a group of Spanish soldiers, explored southern Utah and traveled along the North Rim of the Canyon in Glen and Marble Canyons in search of a route from Santa Fe to California in 1776. They eventually found a crossing, formerly known as the "Crossing of the Fathers," that today lies under Lake Powell.

Also in 1776, Fray Francisco Garces, a Franciscan missionary, spent a week near Havasupai, unsuccessfully attempting to convert a band of Native Americans to Christianity. He described the Canyon as "profound".

In the mid 1800s, an army survey party explored the region led by Lieutenant Joseph Ives. Ives came to the conclusion that the area was “altogether valueless” and a “profitless locality.”

John Wesley Powell became one of the first to raft the Grand Canyon in 1869. He and his party of nine traveled 1,000 miles through the Grand Canyon on wooden boats. Three men were lost during this dangerous expedition through rapids and overwhelming heat. A second journey in 1871 provided a wealth of information about this unexplored part of the U.S. Powell is also known for founding the U.S. Geological Society. Lake Powell is named after John Wesley Powell.

“The Mountain Lying Down” was a term once used by the Paiutes to describe the area. John Wesley Powell later began using and publishing the term “Grand Canyon” in the 1870s and the name has stuck.

Formation and Geology 

 The truth is that no one knows for sure though there are some pretty good guesses. The chances are that a number of processes combined to create the views that you see in todays Grand Canyon. The most powerful force to have an impact on the Grand Canyon is erosion, primarily by water (and ice) and second by wind. Other forces that contributed to the Canyon's formation are the course of the Colorado River itself, vulcanism, continental drift and slight variations in the earths orbit which in turn causes variations in seasons and climate. 

 Water seems to have had the most impact basically because our planet has lots of it and it is always on the move. Many people cannot understand how water can have such a profound impact considering that the Canyon is basically located in a desert. This is one of the biggest reasons that water has such a big impact here. Because the soil in the Grand Canyon is baked by the sun it tends to become very hard and cannot absorb water when the rains to come. When it does rain the water tends to come down in torrents which only adds to the problem. The plants that grow in the Grand Canyon tend to have very shallow root systems so that they can grab as much water as possible on those rare occasions when it does rain. Unfortunately these root systems do nothing to deter erosion by holding the soil in place. Now you've got lots of water, no place for it to go, but down to the Colorado River, and nothing holding the soil and rock in place. The result is frequently a flash flood roaring down a side canyon that can move boulders the size of automobiles, buses and even small houses. If automobiles, buses and small houses are in the way then it will take them too. Luckily no one builds houses in the Grand Canyon so that's not a problem but there are a few autos, vans and buses sitting at the bottom of the Colorado. This mass that moves down a side canyon during a flash flood is more like a fast flowing concrete than water and it can be very dangerous. You should always be well informed of weather conditions when you are hiking through side canyons in the Grand Canyon. 

 After erosion by liquid water the next most powerful force is probably its solid form, ice. In the colder months, especially on the north rim, water seeps into cracks between the rocks. These cracks can be caused by seismic activity, or by the constant soaking and drying of the rocks. When the water freezes it expands and pushes the rocks apart and widens the cracks. Eventually rocks near the rim are pushed off the edge and fall into the side canyons. These rocks sometimes hit other rocks and are stopped but on occasion one fall by a large rock will cause a cascading effect and create a rock fall that will alter the landscape drastically in the side canyon. Debris from rock falls piles up at the bottom of the side canyons and is then carried down to the Colorado River the next time there is a flash flood. Rock falls frequently take out sections of trail in the Grand Canyon requiring the Park Service to close these trails until they can be repaired. 

 Once the ice had pushed the rocks off the edge and the water in the flash floods has carried them down to the river, then the Colorado itself takes over. The erosive action of the Colorado has been severely constrained by the building of the Glen Canyon Dam, which ended the annual spring floods, but there is still a lot of water flowing relatively quickly through a very narrow gorge. Before building the dam the Colorado River had spring floods that would exceed a flow rate of 100,000 CFS. All of that snow melting in the Colorado Rockies came pouring down through the Grand Canyon in May and June, every year, like clock-work. These spring floods were considerably larger than todays "trickle" of 8,000-10,000 CFS at low water and even the 20,000 CFS peak flow rates. 

 The Colorado's spring floods used to carry away all of the debris that was deposited in the main channel by the flash floods, but todays mediocre flow rates have a tough time doing the job. It still gets done to some extent, it just takes a lot longer. In the process of moving the rocks and sediment down the river to the Pacific Ocean the bed of the river is scoured by all of this fast moving debris which slowly eats away at the banks and bed of the river. This causes the river to widen and cut down deeper into the lower rock layers. Another cause for the slowing of the erosive force of the Colorado River is the fact that it is now trying to cut through harder granites and schists found at the bottom of the Canyon instead of the softer limestones, sandstones and shales near the top. This rock takes a lot longer to erode and a slower moving river means it takes even longer.

Wavy layers

Geology

The Grand Canyon is part of the Colorado River basin which has developed over the past 40 million years. A recent study places the origins of the canyon beginning about 17M years ago. Previous estimates had placed the age of the canyon at 5–6 million years. The study, which was published in the journal Science in 2008, used uranium-lead dating to analyze calcite deposits found on the walls of nine caves throughout the canyon. There is a substantial amount of controversy because this research suggests such a substantial departure from prior widely supported scientific consensus. In December 2012, a study published in the journal Science claimed new tests had suggested the Grand Canyon could be as old as 70M years.However, this study has been criticized as "[an] attempt to push the interpretation of their new data to their limits without consideration of the whole range of other geologic data sets.

The result of all this erosion is one of the most complete geologic columns on the planet.

The major geologic exposures in the Grand Canyon range in age from the 2-billion-year-old Vishnu Schist at the bottom of the Inner Gorge to the 230M-year-old Kaibab Limestone on the Rim. There is a gap of about a billion years between the 500M-year-old stratum and the level below it, which dates to about 1.5 billion years ago. This large unconformity indicates a period of erosion between two periods of deposition.

Many of the formations were deposited in warm shallow seas, near-shore environments (such as beaches), and swamps as the seashore repeatedly advanced and retreated over the edge of a proto-North America. Major exceptions include the Permian Coconino Sandstone, which contains abundant geological evidence of aeolian sand dune deposition. Several parts of the Supai Group also were deposited in non–marine environments.

The great depth of the Grand Canyon and especially the height of its strata (most of which formed below sea level) can be attributed to 5–10 thousand feet (1,500 to 3,000 m) of uplift of the Colorado Plateau, starting about 65M years ago (during the Laramide Orogeny). This uplift has steepened the stream gradient of the Colorado River and its tributaries, which in turn has increased their speed and thus their ability to cut through rock (see the elevation summary of the Colorado River for present conditions).

Weather conditions during the ice ages also increased the amount of water in the Colorado River drainage system. The ancestral Colorado River responded by cutting its channel faster and deeper.

The base level and course of the Colorado River (or its ancestral equivalent) changed 5.3M years ago when the Gulf of California opened and lowered the river's base level (its lowest point). This increased the rate of erosion and cut nearly all of the Grand Canyon's current depth by 1.2M years ago. The terraced walls of the canyon were created by differential erosion.

Between 100,000 and 3M years ago, volcanic activity deposited ash and lava over the area which at times completely obstructed the river. These volcanic rocks are the youngest in the canyon.

layers sequence

Tourism 

Grand Canyon National Park is one of the world’s premier natural attractions, attracting about five million visitors per year. Overall, 83% were from the United States: California (12.2%), Arizona (8.9%), Texas (4.8%), Florida (3.4%) and New York (3.2%) represented the top domestic visitors. Seventeen percent of visitors were from outside the United States; the most prominently represented nations were the United Kingdom (3.8%), Canada (3.5%), Japan (2.1%), Germany (1.9%) and The Netherlands (1.2%).[60] The South Rim is open all year round weather permitting. The North Rim is generally open mid-May to mid-October.

Tour through Grand Canyon

Mining the Grand Canyon.

The 1870s and 1880s yielded the discovery of lead, zinc, asbestos, and copper which prompted many to stake mining claims. However, actually mining the canyon proved difficult and treacherous. Instead of getting dollars through mining, many miners turned to a more profitable venture: tourism. Buildings, railroads, lodging, and new trails along with fabulous photos and paintings depicting the canyon and eventual National Park status in 1919, beckoned tourists from all over the world with promises of a sight unlike any other in the world. They were right.

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