Weathering and Erosion
Name_______________________________
The Sand Lab
Date_____________________Period_____
The Task
What you will do.
a) Observe sand grains sampled from different locations and environments.
b) Sketch what you see, paying attention to grain size, shape, and sorting.
c) You will deduce the distance to the source of the sand grains based on your observations in part (b) above.
Purpose By looking at sediment samples such as sand, you can determine the mineral makeup, source rock, distance from the
source, and transportation characteristics of your sample.
Procedure In this lab, you will observe samples of sand using a microscope. Do the following:
1) Observe the sand grains through the microscope.
2) On the data sheet sketch what you see through the eyepiece. Be sure to use color and to fill the entire circle on your
data page with what you see in your field of vision through the eyepiece of the scope.
3) Make sure that you pay attention to the following features while sketching:
a) Grain size (small, medium, large)
b) Sorting (Note the different size and shape of grains)
c) Shape (Are the grains angular or rounded)
4) In a complete sentence, write a conclusion about each sand type.
Definitions
Sorting: The uniformity of the sample. If all the grains are the same size the sediment is said to be well sorted. If they
are not the same, it could be mixed or poorly sorted.
Poorly
Sorted
Mixed
Well
Sorted
Shape: The shape of the grains helps us to determine how far the sample was transported from its source rock. If the
sand grains are rounded, then they have traveled a long distance from the source rock. More distance equals
more time and more erosion. This makes the grains round. If the sample has grains that are angular, they have
not traveled far from the source rock.
Angular
Rounded
Rounded
Example Conclusion Sentence: A sample that is sand having all small grains with a very rounded edges can be
described as: “This sample from Saudi Arabia is a well-sorted, small-grained sand that was deposited far from its source
rock.” What do you think the presence of seashells indicates?
Sample Name: _________________________________________________
Grain Size: small medium large
Grain Shape: rounded angular
Sorting: poor mixed well
Distance from the Source: near
far
Conclusion Sentence
____________________________________________________________________________________________________________
Sample Name: _________________________________________________
Grain Size: small medium large
Grain Shape: rounded angular
Sorting: poor mixed well
Distance from the Source: near
far
Conclusion Sentence
____________________________________________________________________________________________________________
Sample Name: _________________________________________________
Grain Size: small medium large
Grain Shape: rounded angular
Sorting: poor mixed well
Distance from the Source: near
far
Conclusion Sentence
____________________________________________________________________________________________________________
Sample Name: _________________________________________________
Grain Size: small medium large
Grain Shape: rounded angular
Sorting: poor mixed well
Distance from the Source: near
far
Conclusion Sentence
____________________________________________________________________________________________________________
Sample Name: _________________________________________________
Grain Size: small medium large
Grain Shape: rounded angular
Sorting: poor mixed well
Distance from the Source: near
far
Conclusion Sentence
____________________________________________________________________________________________________________
Sample Name: _________________________________________________
Grain Size: small medium large
Grain Shape: rounded angular
Sorting: poor mixed well
Distance from the Source: near
far
Conclusion Sentence
____________________________________________________________________________________________________________