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What aspects of an ancient sandstone would you study to show that it was originally a desert sand dune?
Wiki User
∙ 13y ago
The nature of the sandstone may be indicative of a desert sediment. You would expect an arkose or similar sandstone (roughly 25% feldspar and the rest quartz). You would expect there to be very little clay as the environment should be dry which would not cause the breakdown of feldspar minerals to form clay. This is not conclusive evidence but when combined with other information it all helps to build a picture of the depositional environment.
The grains in desert sandstones tend to be well sorted and rounded due to abrasion caused by wind action.
Desert sands grains tend to become stained by iron oxide minerals forming a yellow to red colour (although this does not always happen so an absence of staining does not prove the material is not a desert sandstone).
The presence of cross-bedding may be indicative of a desert formed sandstone. Wind formed (aeolian) dunes in a desert produce larger sets of cross beds than those found in water deposited (fluvial) cross bedding.
Sandstones deposited by aeolian rather than fluvial environments have a unique feature known as pinstripe laminae. These are very narrow stripes only a few grains wide consisting of finer grains than are found in grainfall laminae (which is formed by fluvial processes).
Finally if fossils are found in the rock, they should only be of land animals or land vegetation. No marine fossils should be present.
For some good examples of large scale aeolian cross bedding, please see the related link.
Wiki User
∙ 13y ago
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Where can you find sandstone?
Sandstone is a clastic sedimentary rock composed of sand sized minerals, found in and near sand. Limestone is a sedimentary rock made up of the minerals calcite and aragonite, found in and near water.
Sedimentary rocks can't be dated?
Sedimentary rocks cannot be given an absolute date by radiometric testing, but they can be given an estimated date from a few geological laws, for example if a bed of desert sandstone ins under a bed of limestone there is a law that says that the sandstone is older.
What is sandstone made of?
•Sandstone retains only a small part of the intergranularpore space that was present before the rock was consolidated. • •Compaction and cementation greatly reduce the primary pore space. • •Secondary openings, such as joints and fractures, along with bedding planes, typically transmit most of the groundwater in bedrock sandstone aquifers.• The hydraulic conductivity of cemented sandstone aquifers is low to moderate. • •Transmission is primarily through fractures although primary porosity may continue to contribute to storage. • •Because bedrock sandstones extend over large areas, these aquifers can often provide large amounts of water.
What materials are sandstone made out of?
When the waves erode cliffs, large pieces of rock(BOULDERS) fall off and crash down to the beach below. Pieces break off the boulders until they eventually are worn down to pebbles.. The pebbles are then eventually worn down to sand due to the force of the waves. Sandstone(sometimes known as arenite) is a clastic sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow, red, gray, pink, white and black. Since sandstone beds often form highly visible cliffs and other topographic features, certain colours of sandstone have been strongly identified with certain regions. Rock formations that are primarily composed of sandstone usually allow percolation of water and other fluids and are porous enough to store large quantities, making them valuable aquifers and petroleum reservoirs. Fine-grained aquifers, such as sandstones, are more apt to filter out pollutants from the surface than are rocks with cracks and crevices, such as limestone or other rocks fractured by seismic activity.Sandstone is mined by quarrying. It is sometimes found where there used to be small sea areas. It is usually formed in deserts or dry placeslike the Sahara Desert in Africa, the Arabian desert in the Middle East and the Australian desert. In the western United States and in central Australia, most sandstone is red.[1]
Where in the world can you find limestone and sand stone?
There are MANY places. The types can also vary greatly. For examplelime stone is quarried in Iowa. It also makes the underlying strata in Mexico south of Cancun. The stone is soft and over MANY years holes form called cynotes and caves. In England, the white cliffs of Dover are white primarily because of the limestone content. Sandstone is also a relatively soft rock. Much sandstone is located in the desert area of the Southwest US. There are some interesting rock formations formed by the wind eroding the sandstone.
What is desert sand eroded from?
sandstone
Are there mountains made of sandstone?
Yes, many of the mountains in the desert southwest are made of sandstone
What plants are in the ice desert?
sagebrush,sandstone
Where was the Red Stone brought from for building the Red Fort?
The red stone is sandstone and sandstone and India's source of sandstone is the Thar desert
Is De Long Shale older or Desert Sandstone?
NO
Why does the sand in the Painted Desert not mix and become a uniform color?
The sand does blend and form uniform colors. However, most of the 'sand' in the Painted Desert is not loose but bound to form sandstone. The different colors of the sandstone are what give the Painted Desert its name.
What part of the desert is made from Sedimentary rocks?
Sandstone and compacted dunes.
Where is sandstone mined?
Sandstone is typically mined in very dry places. For example, the Sahara desert is one of the most known areas where sandstone is mined. This is because the Sahara produces sand sized minerals.
What type rock will most likely found in a desert?
Sedimentary rock like sandstone
What is the sandstone landmark in Australia called?
A major sandstone feature in Australia is Uluru, or Ayers Rock. It is located in the central Australian desert, and is a popular place for tourists to visit.
What is the huge sandstone rock in the middle of the Australian desert called?
Ayers Rock - aka 'Uluru' - is the famous landmark in the Australian desert.
Where can you mine sandstone on RuneScape?
There are 32 rocks of sandstone in the western desert mining site. This is south of the bandit camp in the Kharidian Desert and on the runescape map will be labeled as "Quarry". If you want to mine there though you should where desert robes and bring waterskins so you do not lose health due to the heat. Also you will need a shantay pass in order to enter the desert which can be bought at the entrance for a small fee.
