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Author Topic: How to work out where samples of sand came from ?  (Read 5497 times)

Offline Makiyo781

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a geologist discovered a sandstone that contained very fine particles of sand. The sand was well sorted , had rounded edges, and composed mostly of quartz. When she looked at the sand grains more closely through a magnifier, she observed that the sand grains were covered with tiny nicks and scrapes that made the grain look frosted.
1.what inferences can you make about the origin of the sand??
2.what type of depositional environment can you infer??


 

Offline Bass

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Re: How to work out where samples of sand came from ?
« Reply #1 on: 04/04/2005 04:25:10 »
This type of sand is most commonly windblown sand.  The nicks and scrapes are caused by minute abrasions as the wind blows the sand grains into like sized grains and is commonly called "frosting".  The sand is well sorted, because the wind can only blow sand of a certain size- once it gets larger, the wind can no longer move the grains.  Beach and river sands are usually not as well sorted and/or will have larger grain sizes due to more active environment.  As to depositional environment-- well let's just say I would be looking for camel teeth as a possible fossil.

Prediction is difficult, especially the future.  -Niels Bohr
 

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Re: How to work out where samples of sand came from ?
« Reply #1 on: 04/04/2005 04:25:10 »

 

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