The Coconino Sandstone formed as the area dried out and sand dunes made of pure quartz sand invaded a growing desert some 260 million years ago (see 6b in figure 1). Today, it is a 375 to 650 ft (115 to 200 m) thick golden white to cream-colored cliff-former near the canyon's rim.
What type of rock is the Coconino Sandstone?
An unconformity marks the top of this formation. The Coconino Sandstone formed as the area dried out and sand dunes made of pure quartz sand invaded a growing desert some 260 million years ago (see 6b in figure 1). Today, it is a 375 to 650 ft (115 to 200 m) thick golden white to cream-colored cliff-former near the canyon's rim.
How did the Coconino sand form?
If sand blows on top of dry, cracked river mud, it slowly fills the cracks with thin, horizontal layers of sand. Creation geologists did field research and found evidence that the Coconino sand was wet and forcefully injected into the mud below. They could not find any evidence of horizontal layering. Photo by JHW.
What is the name of the Sandstone Formation in Arizona?
Coconino Sandstone is a geologic formation named after its exposure in Coconino County, Arizona. This formation spreads across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah . This rock formation is particularly prominent in the Grand Canyon,...
Is the Coconino Sandstone evidence for the Genesis flood?
The Coconino Sandstone ( Figure 1a ), whose buff-colored sand piles up as thick as 300 feet (90 m) in the Grand Canyon area and 1,000 feet (300 m) in other areas, is one of the most common evidences raised against the Genesis Flood. The arguments sound pretty compelling.
What kind of rock is Coconino Sandstone?
eolian sandstoneThe Coconino is often regarded as something like a “type” of the many similar Permian cross-bedded sandstones that occur around the world. It is generally accepted that the Coconino is an eolian sandstone and that its sand grains are well-sorted and well-rounded.
What is the depositional environment of the Coconino Sandstone?
The Coconino Sandstone, the origin of which is conventionally attributed to desert sand dunes, was deposited by water. Evidence for this (in addition to the character of fossil footprints therein) includes cross-bedding angles of only 25 degrees, not the 30-34 degrees one expects from desert dunes.
How thick is the Coconino Sandstone?
51.6 feetCoconino Sandstone. Chiefly a cliff-forming, white, fine- to medium-grained, cross-bedded sandstone. Thickness 51.6 feet (15.7 m).
How old is the Coconino Sandstone in the Grand Canyon?
about 260 million years oldCoconino Sandstone - This layer averages about 260 million years old and is composed of pure quartz sand, which are basically petrified sand dunes.
Is Coconino a sedimentary sandstone?
It consists primarily of fine well-sorted quartz grains, with minor amounts of potassium feldspar grains deposited by eolian processes (wind-deposited) approximately 275 million years ago....Coconino SandstoneStratigraphic range: PermianTypeSedimentarySub-unitsHarding Point Sandstone Member, Cave Spring Sandstone11 more rows
What is the name of the geologic formation that makes up the Coconino Plateau?
Toroweap Formation (slopes and cliffs) crops out between massive cliffs the Kaibab Formation (above) and Coconino Sandstone (below) on Grand Canyon's South Rim.
Are there dinosaur fossils in the Grand Canyon?
Not at Grand Canyon! The rocks of the canyon are older than the oldest known dinosaurs. To see dinosaur fossils, the Triassic-aged Chinle Formation on the Navajo Reservation and at Petrified Forest National Park is the nearest place to go.
Why is sandstone a sedimentary rock?
Sandstone is a type of rock made from sediment — a sedimentary rock. The sediment particles are clasts, or pieces, of minerals and fragments of rock, thus sandstone is a clastic sedimentary rock.
Why is the Redwall Limestone Red?
The Redwall Limestone has a gray color, but almost everywhere it is stained red by iron oxide washed from the red, iron-rich layers above (Supai and Hermit Formations). Like most limestones, the Redwall is formed mostly of the calcium carbonate shells of sea creatures.
Was Arizona underwater at once?
Arizona was still covered by a shallow sea during the ensuing Cambrian period of the Paleozoic era. Brachiopods, trilobites and other contemporary marine life of Arizona left behind remains in the western region of the state. The sea withdrew from the state during the Ordovician and Silurian.
What was the continental formation at the time of the Kaibab toroweap and Coconino formations?
Cliffs of the Toroweap Formation can be found in Walnut Canyon National Monument, about 70 mi southeast of the Grand Canyon, and east of Flagstaff, Arizona. Marine transgression, and continental wind-blown sand, laid down the three units of Kaibab, Toroweap, and Coconino....Toroweap FormationTypeGeological formation10 more rows
What is the oldest body of rock in the Grand Canyon?
The oldest known rock in Grand Canyon, known as the Elves Chasm Gneiss, is located deep in the canyon's depths as part of the Vishnu Basement Rocks and clocks in at an ancient 1.84 billion years old.
What is the most conspicuous layer of sandstone?
Look for a white or light colored cliff below the Toroweap slopes: the Coconino Sandstone is one of the most conspicuous layers. In the top of the layer, especially, there are shapes like frozen sand dunes. Tilted south, these ancient dunes reveal that the prevailing winds blew from the north.
What are the grains in the Coconino dunes?
Tilted south, these ancient dunes reveal that the prevailing winds blew from the north. Coconino grains are quartz, a mineral both abundant and durable. When rocks weather and erode, many minerals may be present in the resulting sediment. Some of these minerals dissolve; others erode to dust.
What is the glue that turns sediment into rock?
To turn a sediment into rock requires a natural glue: silica and calcite cements are most common. Groundwater introduces these dissolved cements into the sediment. The more cement, the harder the rock. There are numerous reptile and invertebrate tracks in the Coconino, but no bones.
What is the name of the sandstone that stretched from Arizona to Canada?
The Coconino Sandstone was a Sahara-like sand sea, called an erg. It was a wind-blown dune desert that stretched from present-day Arizona all the way to Canada. Looking west from the summit of the tallest dune, perhaps you could have seen the distant shimmer of Panthalassa, the world ocean of the time of Pangaea.
What are the characteristics of a dune quartz?
These dune quartz grains are very mature: uniform composition, small sand size, very well rounded, and all grains about the same size. Those features demonstrate the grains’ origin in blowing dunes.
How thick is Coconino Sandstone?
The Coconino Sandstone ( Figure 1a ), whose buff-colored sand piles up as thick as 300 feet (90 m) in the Grand Canyon area and 1,000 feet (300 m) in other areas, is one of the most common evidences raised against the Genesis Flood. The arguments sound pretty compelling.
What is the myth of the Coconino Desert?
Myth #4—The Coconino Desert Spread Over a Huge Floodplain and Filled Open Mud Cracks on that Floodplain. Secular geologists assume that the Coconino sand formed on top of dry, cracked mud. Underneath the Coconino Sandstone are the brown siltstones of the Hermit Formation, made of mud turned into rock.
What is the avalanche in desert sand?
In modern deserts, dry sand avalanches down the back sides of desert sand dunes at a steep angle of repose (about 32˚). As the windblown sand becomes too steeply piled, it avalanches again down the slope to make a distinctive tongue-like deposit ( Figure 2a ). This process produces “cross-bedding” as seen in Figure 3.
Why are sand grains in the desert dunes so similar?
Sand grains in desert dunes are usually very similar in size, or “well sorted,” because the wind carries only select sizes. But Coconino sand grains are best described as moderately or poorly sorted. Creation geologists carefully studied over 100 thin sections, widely spaced in the Coconino, to determine this.
What causes sand grains to froze?
In deserts, the wind picks up sand grains and forcefully throws them against each other. This causes small imperfections on the surfaces of the quartz sand grains and gives them a “frosted” appearance when viewed with magnification. The same thing happens to glass when sand is blown against it. This is known as mechanical frosting, since physical (or mechanical) forces produce it.
Why do sand grains turn round?
In modern deserts, sand grains (especially the larger ones) become rounded as wind blows them about. Sharp angular corners get broken off during grain-to-grain collisions, and the grains become spherical or “round” in shape.
What did the Coconino Desert blow in?
Subsequently, the Coconino desert blew in, filling the cracks with sand. The observable facts. If wind gradually filled the deep cracks with sand, layer after layer, the fillings should have horizontal layers in them.
How long has the Coconino Sandstone been around?
The Coconino Sandstone in Grand Canyon has long been interpreted by the secular scientific community as an ancient desert that blew across western North America some 250 million years ago.
What did Brand find about Coconino Sandstone?
As Brand poured over many slabs of Coconino Sandstone, he also found that the trackways sometimes went “sideways.”. This was intensely interesting because, although the animal walked sideways across the dune, its toes were always pointed to the “top” of the dune (see the trackways that go sideways across the image below).
How did Coconino Sandstone form?
The Coconino Sandstone formed as the area dried out and sand dunes made of pure quartz sand invaded a growing desert some 260 million years ago (see 6b in figure 1). Today, it is a 375 to 650 ft (115 to 200 m) thick golden white to cream-colored cliff-former near the canyon's rim.
How thick is the shale in the canyon?
It is a soft, deep red shale and mudstone slope-former in the canyon that is 160 to 175 feet (49 to 53 m) thick.
When was Kaibab limestone deposited?
A prominent ledgy cliff-former, the Kaibab Limestone was laid down in middle Permian time an average of about 225 million years ago in the deeper parts of the same advancing warm, shallow sea that deposited the underlying Toroweap Formation.
How thick is the Toroweap Formation?
An unconformity marks the top of this formation. Next in the geologic column is the Toroweap Formation, 200 to 250 feet (60 to 75 m) thick (see 6c in figure 1).
How old is the Coconino?
1 It is dated by evolutionists as within the Permian system, some 250 million years old.
What is the most difficult formation to reconcile within the Flood model of Earth history?
Standard thinking cites the Coconino Sandstone as perhaps the most difficult formation to reconcile within the Flood model of earth history. The conventional view is that the Coconino Sandstone represents ancient wind-blown desert sand dunes, which would have been impossible to form during the global Flood.
What is the National Creation Science Foundation?
Basic research sponsored by the Institute for Creation Research and funded by its research division, the National Creation Science Foundation, continues to investigate subjects crucial to the creation/evolution question. Many of the currently funded projects are in the field of geology under the umbrella research initiative FAST ...
Is sand dune angular?
Its sand grains are poorly sorted and somewhat angular, not at all like desert sands with well-sorted and rounded grains. We suspect the research will demonstrate that the sand dune interpretation can be confidently rejected in favor of a better supported sub-aqueous interpretation.
Is Coconino a marine rock?
According to Whitmore's reports, the deposit interfingers with other formations of unquestionable marine origin, implying that the Coconino is also marine. It bears fossil trackways and burrows best understood as being related to underwater activity, not to a dry, sand dune environment.
Abstract
The cross-bedded Coconino Sandstone (lower Permian, Arizona) is often used as a “type” ancient eolian sandstone. Previous field and laboratory work by the author have revealed data that instead support a marine origin for this sandstone.
Introduction
In the first chapter of his insightful book, The Nature of the Stratigraphical Record, Derek Ager (1981) discusses a concept which he refers to as the persistence of facies. What Ager means by this is that during certain periods of geologic time, specific facies inexplicably appear around the world over and over again.
Methods
Stratigraphic charts and electronic data sheets compiled for the COSUNA project by the AAPG in the 1980s were used to gather the primary data for this project (Adler 1986; Ballard, Bluemle, and Gerhard 1983; Bergstrom and Morey 1984; Hills and Kottlowski 1983; Hintze 1985; Kent, Couch, and Knepp 1988; Mankin 1986).
Results
It was found that the Coconino could be correlated with sandstones occurring on both the east and west sides of the Rocky Mountains and into the Great Basin of California, Nevada, and Utah. Units could be traced from California to the Dakotas and from Texas to Idaho (fig. 5).
Discussion
The author has been part of a team that has been studying the Coconino Sandstone. In our studies we have examined many dozens of outcrops, have collected hundreds of samples (cutting corresponding thin sections for microscope work), and have studied numerous samples with XRD (X-ray diffraction) and SEM (scanning electron microscopy).
Conclusions
The Coconino Sandstone of Arizona is one of the most well-known cross-bedded sandstones and historically has formed the basis for comparison for all other ancient “eolian” deposits.
Acknowledgments
Ray Strom, Paul Garner, and others have been significant contributors to the Coconino project that we started so many years ago. This paper is just a small part of the larger project. Countless hours have been spent in the field, the lab, and in the office— of which Ray and Paul have been an integral part.
