Experts please. How do the processes of.......?

Question

weathering, erosion, and deposition contribute to the formation of rock layers in the Grand Canyon?

Answer 1

Just about every sedimentary process is represented in the stratigraphy of the Grand Canyon.

From bottom to top:
PreCambrian Vishnu Group: These are the deep basement rocks beneath the sedimentary rocks in the Grand Canyon and these are igneous intrusives and metamorphic schist. There are PreCambrian sedimentary rocks exposed in some sections of the Canyon, that consist of sandstones, shales, and some limestones.

Cambrian Tapeats Sandstone:
This is a sandstone formed by shallow marine deposition. It has spectacular examples of cross-bedding and other shallow marine characteristics. Hereford (1977) concluded the Tapeats was deposited as intertidal sand bars, beach, tidal flat and tidal channel sediments based on a variety of sedimentological features. More recent work by Chadwick and Kennedy (2001) has found evidence of deepwater breccia deposits that may have been in water depths of at least 200 meters. It is very possible that both descriptions are correct and that different parts of the Tapeats were in very different water depths. The well-defined hummocky cross-stratification I have observed in the Tapeats was formed most probably by storm-waves in shallow near-shore environments, representing upper, middle, and lower shoreface marine environments. These sands were eroded from older sandstones and igneous rocks that were exposed in nearby terrigenous environments and were carried by fluvial processes and ocean currents to their present depositional location.

Cambrian Bright Angel Shale:
My experience with the Bright Angel is that it is actually composed of thin bedded siltstones, mudstones, and sandstones. In some areas thin beds of limestone exist. The Bright Angel remains one of the least studied formations in the Grand Canyon. Recent work (Gallagher, 2003) suggests the Bright Angel was deposited in shallow water restricted marine embayments that may have been brackish water at times. These had to be low energy environments, likely tidally influenced, creating small scale wavy and lenticular bedding, ripple marks, and in confined channel area deposits of conglomeritic sandstones where water flow scoured the lighter clasts and carried them away. Trace fossils left by movements of living organisms, brachiopods, and trilobites can all be found.

Cambrian Muav Limestone
The Muav represents an offshore shoal environment that has some similarity to a sabkha, but may be better compared to modern environments such as Andros Island in the Bahamas. This type of environment is a combination of very shallow subtidal marine lagoons, tidal flats, and supratidal environments with no input of clastics such as sand, silt, and clay from streams or rivers. Wind may have carried some clastic particles to this area. Fenestral fabrics are seen that are evidence of algal mats, and desiccation cracks demonstrate that the surface was alternating between wet and dry. Dolomite formed within the Muav is also evidence of a hydrologic system where the near-surface sediment was strongly influence by both saltwater, freshwater, and high evaporation rates. Although not common, I have examples of stromatolites (algal mats) from the Muav. Storms in Muav time pushed waves over these shallow islands and created deposits of rip-up clasts as waves broke apart the carbonate sediments leaving behind layers of carbonate conglomerates.

Devonian-Cambrian Unconformity:
At the top of the Muav is an eroded surface where anything that was deposited during the Silurian, and possibly part of the Late Cambrian has been completely eroded away. This unconformity represents a significant period where at least for the later part of the time this area was above sea level and was being eroded and weathered away.

Devonian Temple Butte:
The Temple Butte is primarily limestone, with localized dolomite. It is one of the least understood of the Grand Canyon rock units, but the few fossils found in it suggest it is probably a depositional environment similar to the Muav. The dolomitic areas may represent supratidal areas while the rest of the limestone was probably a shallow subtidal zone. Rarely, corals, gastropods, and stromatoporoids have been found in the Temple Butte, suggesting it was a very shallow marine environment. The lack of siliciclastic deposits suggests it was offshore or in an coastal area distant from any mountains or other sources of siliciclastic sediments.

Mississippian Redwall Limestone:
This is one of the most dramatic formations in the Grand Canyon, forming large limestone cliffs throughout the canyon. This environment was a marine environment ranging from subtidal to tidal to supratidal. Deeper water zones were populated by carbonate producing algae and sea-grasses, and shallower zones had corals, bryozoans, and other carbonate producing life forms that all contributed carbonate sediment to the thick Redwall limestone beds. In some areas shallow marine environments produced beds of ooids, which are small round balls of carbonate formed by chemical and biological precipitation from seawater. Here are some pictures of ooids and other carbonate grains:
http://strata.geol.sc.edu/carbonateparti...

Surprise Canyon Formation:
At the end of the Mississippian the Redwall limestone was lifted above sea level and a series of river channels and marine estuaries eroded into the Redwall surface. At the same time an extensive system of caves developed across many parts of the exposed Redwall limestone. These channels were in some cases fed by water coming from the caves that drained the Redwall surface. With time the sea level rose again and the channels filled with deposits of sandstone, conglomerates, and silts. Many of these clastics came from the eroded Redwall limestone which contains large numbers of chert deposits. This chert gravel filled the base deposits of sediment in the Redwall caves and the lower sections of the Surprise Canyon channels. Eventually the channels filled completely and many of the caves filled with fine muds, although some remained open and later collapsed under the weight of sediments deposited during the early Pennsylvanian.

Pennsylvanian Wescogame, Manakacha, and Watahomigi Formations:
These are deposits of sand, silt, and mud, primarily in a shallow marine environment. Some areas have deposits of sand dunes that were deposited on dry land by windblown sand. This was a period of regressing sea levels leaving broad floodplains in an arid to semi-arid environment where drifting sand formed dunes, and rivers formed braided stream fluvial deposits of thin-bedded sands. In tidal zones these same sands were sorted and deposited by tidal flux, longshore currents, and wave action along beaches.

Permian Esplanade Sandstone:
The Esplanade is formed from eolian (wind-blown) sands. This was an arid environment. Also within the Esplanade are deposits of gypsum that were deposited by evaporation of confined bodies of water, possibly in coastal sabkha environments or in confined hypersaline lake beds.

Permian Hermit Formation:
Silt, sand, and mud make up the Hermit. Much of it was deposited as a fluvial deposit, which contains point-bars formed by meandering streams.

Permian Coconino:
This is an impressive deposit of eolian (wind-blown) sandstone. These were part of an enormous desert that extended as far north as present day Montana. The dunes are well preserved as cross-beds and are typically several meters high.

Permian Toroweap Formation:
This represents a complicated environment that includes laminated evaporites (gypsum) that formed in shallow marine waters, wavy-bedded sandstones that were deposited in a tidal flat environment, and eolian sand dunes. Other areas have carbonate rocks ranging from those composed of skeletal deposits of crinoids, bryozoans, brachiopods, trilobites and more. Desiccation cracks are found in some of the carbonates suggesting they were in very shallow environments that occasionally dried up.

Permian Kaibab Formation:
The Kaibab is primarily a carbonate unit, built by the deposition of carbonates by living organisms. Some parts of the Kaibab contain evaporites (gypsum) formed by evaporation of sea water in shallow confined areas. Cherts formed by the silicification of sponges that grew in the shallow marine environment are common in the Kaibab as fist-sized nodules. Other parts of the Kaibab that have sandstone deposits represent near-shore environments, both in and out of the water.

Younger sediments:
The story does continue, but on the southern side of the Grand Canyon most of the younger sediments have been eroded away, leaving the Kaibab at the surface. On the North Rim you can find Triassic Moenkopi (marine, tidal, fluvial) and Chinle Formations (fluvial & lacustrine), and Jurassic Navajo Sandstone (eolian & lacustrine), as well as younger Cretaceous, Pliocene, Miocene, and Holocene deposits.

As you can see every form of deposition is represented. Weathering is represented with examples such as wind, water, chemical, and probably everything but glaciation being present. Erosional processes such as karst (cave formation), wind-blown eolian erosion, fluvial erosion such as the Surprise Canyon channels, and marine erosion are represented as well.

Answer 2

the colorado river, which runs through the canyon was respnsible for eroding and deepening it through processes like attrition, abrasion, friction. these processes eroded sediments away and deposited them at the meander corners and at the mouth of the river.
weathering is the degradations of rocks in situ, that is, in an immobile state, without erosion. chemical and mechanical weathering are controlled by fluctuations in temperature and precipitation.
all these processes are explained in most geography text books.

Answer 3

You have a good one in "textbook". An alternate source would be the Grand Canyon website.

Answer 4

there are two kinds of weathering: chemical weathering attacks the rocks chemically or it had a chemical change, while the other one, physical weathering attacks the rocks physically or the rocks had a physical change.