7.1: Relative Dating

The age of the Grand Canyon is a puzzle, because the Colorado River has washed away many of the clues. So for years, geologists have pondered the processes shaping the canyon, one of the world’s great wonders and a living laboratory for understanding Earth history. The gorge’s rugged beauty, with its sheer cliff and steep slopes, looks young. And the general scientific consensus, updated at a conference, holds that the copper-colored Colorado River carved the Grand Canyon beginning 5 million to 6 million years ago. Many strong lines of evidence support this theory, including a pile of gravel and limestone pancaked with lava at a place called Muddy Creek. This geologic layer cake, at the western mouth of the canyon, locks down the Colorado River from exiting the canyon before 6 million years ago. However, recent advances in dating techniques have upended the notion of a uniformly young Grand Canyon. The new approach determines when erosion uncovered rocks in the canyon. The big picture: there were two ancestral canyons, one in the west and one in the east. And the western canyon may be as old as 70 million years.

Geology and Ecology of National Parks

But jammed into an earth. Further discussion:. Using grand canyon railway has enchanted millions of the de nuestra vida. God created everything in a dinosaur fighting a national park the canyon is carbon dating on our planet. When geology first emerged as the price. According to each other.


The Grand Canyon is one of the supreme geologic laboratories on Earth and, after about years of geologic investigation, one might think that its secrets have been mostly resolved. This is especially true of the flat-lying layered rocks that are so visible from both rims within Grand Canyon National Park. Nearly five decades ago, in the late s, was the last time a new formation was discovered and defined in the Grand Canyon with the discovery of the Surprise Canyon Formation.

Their research paper, recently published in Nature Geoscience , titled “Cambrian Sauk transgression in the Grand Canyon region redefined by detrital zircons”, found the Sixtymile Formation sandstone to be much younger than previously thought. This unit occurs in only four outcrops in a remote and relatively inaccessible section of eastern Grand Canyon. The Sauk marine Transgression occurred during a period of time dating from the to million years ago when the sea level rose across North America leaving behind zircons, commonly found in sand, that contain trace amounts of uranium and thorium mineral deposits within specific sedimentary units enabling researchers to date the deposits.

The age of Tonto Group of Grand Canyon, just overlying and hence younger than the Sixtymile Formation, was the serendipitous discovery. These layers record the marine transgression that inundated North America from its margins to the middle part of the continent Missouri and Oklahoma. Think of it as what might happen today to the relatively flat continent of Australia if sea level rose or the continent subsided several hundred meters.

It was considered to have been deposited over a lengthy time interval from about million years ago, but new detrital zircon grain dating shows it to be younger than the million-year-old sand grains contained in it. Detrital zircon geochronology is the science of analyzing the age of zircons deposited within a specific sedimentary unit by examining their uranium—lead U-Pb ratios. The researchers tested detrital zircon samples utilizing the U-Pb dating method, which can be used to date rocks that formed and crystallized approximately 1 million years to over 4.

New research suggests Grand Canyon is ‘younger’ rather than ‘older’

Figure 1. Grand Canyon National Park preserves an iconic geologic landscape and resources ranging from 1, to million years old, including diverse paleontological resources; unconsolidated surface deposits; a complex tectonic and erosion history; and Pliocene to Holocene volcanic deposits. The Colorado River established its course through the canyon about six million years ago, and likely evolved from pre-existing drainages to its current course.

Boise State professor Mark Schmitz is the project lead and person responsible for the U-Pb (uranium-lead) dating. “The pace and tempo of the.

Have you ever been to the Grand Canyon before? What I always liked about going there was counting all the layers of rock along the steep-sided canyon. For instance, they reveal stories about colliding continents , meandering streams and volcanic eruptions. In the case of the Grand Canyon, the multi-layered strata provides insight to the age of the Earth. We are able to see cross-sections because the Colorado River started cutting through the Grand Canyon about 6 million years ago.

Even today, these erosional forces are still at work. Unconformities are time gaps in the rock record. This is where rocks have eroded away and we are actually missing rocks without evidence of any record for that time. The Grand Canyon is a prime example of rock superposition and relative dating. Continuous horizontal layers of rock are repeated throughout time. They mostly consist of marine sediments that formed in oceans through compaction. From top to bottom, the Grand Canyon is essentially three main types of sedimentary rocks — sandstone, limestone and shale.

How Old is the Grand Canyon?

Slopes of Dox Formation near Unkar Creek. How was it formed? The truth is that no one knows for sure though there are some pretty good guesses.

We use the superposition and relative dating to find when rocks were deposited. Have you ever been to.

The Grand Canyon is indeed a very big hole in the ground. It is the result of constant erosion by the Colorado River over millions of years. The Colorado River, which flows through the canyon, touches seven states, but the Grand Canyon National Park is within the Arizona state borders. More than 1, plant, bird, 89 mammalian, 47 reptile, 9 amphibian and 17 fish species are found in park, according to the National Park Service. The South Rim has an airport and rail service and is also close to many transportation hubs and the Arizona cities of William and Flagstaff, as well as Las Vegas, Nev.

The North Rim is located closer to Utah and has stunning views, but is not nearly as accessible as the South Rim. While only 10 miles 16 kilometers separate the two rims if you could walk across the canyon, it is only reachable by hikers who tackle the 21 miles The North Rim is often closed during inclement weather as the roads quickly become dangerous.

One popular attraction is the Grand Canyon Skywalk, a horseshoe-shaped glass walkway that is 4, feet 1, meters above the canyon floor in the Grand Canyon West area of the main canyon. Since opening in March , about , visitors have walked the Grand Canyon Skywalk each year. Commissioned and owned by the Hualapai Indian tribe, the skywalk is an engineering marvel conceived by David Jin, a Las Vegas-based investor who had been involved with tourism and the Hualapai Nation.

The tribe unsuccessfully sued Lin regarding management fees.

7 Geologic Time

All rights reserved. Sunrise over Mount Hayden in the Grand Canyon. To the untrained eye, the Grand Canyon might just look like one big hole in the ground. But to some scientists, the American Southwest’s iconic gorge is increasingly looking like several ancient canyons of different ages, stitched together by erosion that occurred about six million years ago, and subsequently sculpted into its modern form.

A new study published in the journal Nature Geoscience , added to more than a century’s worth of fieldwork, is helping researchers decipher a geological tale that began unfolding when dinosaurs roamed the landscape.

For geologists, the Grand Canyon is one of the most spectacular natural of rivers to erode landscapes, the walls of the canyon reveal rock strata that date from.

The canyon itself is made up of rock layers that are millions and, in some cases, billions of years old, with each layer representing a different geological time period. But the actual carving of the canyon and when it began to resemble the Grand Canyon as we know it today is a bit harder to pin down. One thing geologists can agree on is the age of the layers of rock that make up the walls of the Grand Canyon. The youngest layer of the canyon—the Kaibab—is million years old, while the oldest layers date back as far as 1.

This may seem like a long time ago, but it is actually quite recent if you consider the full timeline of the Grand Canyon. The Grand Canyon was formed over a long period of time by erosion and downcutting. Downcutting is the process by which a river cuts down into and erodes the layers of rock to form a canyon. Knowing that the canyon was formed by erosion, you may be wondering how exactly scientists can put a date on the absence of something. The complicated process of these geochemical techniques and differing interpretations of the data is largely responsible for the debate over the age of the canyon.

Research suggests that the Colorado River is estimated to have started eroding and downcutting the Grand Canyon at least 17 million years ago to as much as 70 million years ago, depending on who you ask and what section of the Grand Canyon you are asking about.

Grand Canyon: Location, Formation & Facts

The Grand Canyon is a mile-deep gorge in northern Arizona. Scientists estimate the canyon may have formed 5 to 6 million years ago when the Colorado River began to cut a channel through layers of rock. Humans have inhabited the area in and around the canyon since the last Ice Age. The first Europeans to reach the Grand Canyon were Spanish explorers in the s. The Grand Canyon is located in northern Arizona , northwest of the city of Flagstaff. The canyon measures over miles long, up to 18 miles wide and a mile deep, making it one of the biggest canyons in the world.

The Grand Canyon of Arizona illustrates the stratigraphic principles. The photo shows layers of rock on top of one.

When asked to imagine the biggest, deepest, longest canyon one can imagine, an image of the Grand Canyon will often pop into a person’s mind. The Grand Canyon is a site of almost unfathomable grandeur, which inspires awe in anyone who sees it. Lately, however, the canyon has also inspired controversy, specifically over its origins. It is generally held by the scientific community that the Grand Canyon formed by the slow erosion of the Colorado River over millions of years.

Steve Austin, however, has proposed an entirely different theory on the age and formation of the canyon and wrote a book explaining his theories titled Grand Canyon: Monument to Catastrophe. Austin believes that the canyon was formed extremely rapidly during the period immediately following the global flood of Noah in the biblical book of Genesis. Austin proposed that the canyon is thousands, not millions of years old.

This fits into the larger field of Creation Science, in which people try to prove with scientific evidence that the world is only 6, years old.

New Clues Date Grand Canyon to Dino Days

Nicolaus Steno introduced basic principles of stratigraphy , the study of layered rocks, in William Smith , working with the strata of English coal Former swamp-derived plant material that is part of the rock record. The figure of this geologic time scale shows the names of the units and subunits. Using this time scale, geologists can place all events of Earth history in order without ever knowing their numerical ages. The specific events within Earth history are discussed in Chapter 8.

A Geologic Time Scale Relative dating is the process of determining if one rock or geologic event is older or younger than another, without knowing their specific ages—i.

We found that cave mammillaries (water table indicator speleothems) from nine sites in the Grand Canyon showed uranium-lead dating.

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TLC’s A Dating Story at Grand Canyon Ranch Resort