Download Analysis of Glacial Soils pbog

Name: _________________________
REGENTS EARTH SCIENCE
Glacial Sediments Lab
Date: _______________
Per: ______ Lab # _________
Analysis of Glacial Sediments
Glaciers deposit material in two different forms – as till and as outwash. Till consists of material that was
carried by the glacier and deposited directly by the glacier as the ice melted. A till deposit contains
particles of all sizes in an unsorted and unlayered mass. Outwash is material that is eroded and
deposited by streams flowing away from the melted ice - it is sorted by size and often layered. The
running water sorts the materials as it deposits so that, in an outwash sample from any given area, one
particle size is much more common than any of the other sizes.
Goals of this Activity: To identify a sample of glacial sediment based the characteristics of its
sediment sizes it contains. The sample you will analyze was collected from an area that has been
affected by glaciers moving over the area. Essential Question – Is the sample of sediments we have
glacial till or glacial outwash?
Materials:
 safety goggles
 unknown glacial sediment (either till or outwash)
 sieve set consisting of four screen sizes (#6, #20, #40, and #100 or similar), pan, and lid
 electronic balance
 250 mL glass beaker to contain sample
 100 mL plastic beaker to use as a pedestal for massing the screens
Procedure:
1. Put on your safety goggles.
2. Determine the mass of the empty glass beaker and record the value in Table 1.
3. Disassemble the screen sieve set and ensure that there are no sediments stuck in the screens.
Place the plastic beaker on the balance and tare it to zero it out. Balance the parts on the beaker
and determine the mass of each empty screen and the pan. Record each of these masses in
Table 1.
4. Use the glass beaker to obtain a sample of the glacial sediment. Limit your sample to about half
of the beaker’s volume.
5. Determine the total mass of the beaker with glacial sediment and record this mass in Table 1. To
find the mass of the sediment alone, subtract the mass of the empty beaker from the mass of the
beaker plus the sediment. Record this value in Table 1. Note that this mass is the total mass of
the original sediment sample, so the percent of this total is equivalent to 100% of the sediment
analyzed.
6. Stack the sieves and the pan in the correct order of their screen sizes, so that the smallest mesh
in on the bottom (above the pan) and largest is on the top.
7. Pour all of the glacial sediment from the beaker onto the top screen. Place the sieve cover on the
top. Shake the set of sieves horizontally for about a minute to sift the sample through the
screens.
8. When the shaking is completed, remove the cover and carefully separate each screen from the
one below it. This may require teamwork – one person holds it down while the other lifts…
9. Determine the mass of each screen/pan together with the sediment it contains. Record each
value in Table 1.
10. Subtract the mass of each empty sieve/pan from the mass of the screen/pan with the sediment
determined in procedure step 9. The total mass of sediment from all of the sieves and the pan
should equal the total mass of the original sediment sample obtained in procedure step 5. If the
difference in the two values is more than 3 grams, discard all parts of this sample and return to
the procedure step 4 and repeat to obtain new data.
11. To find the percent of the total mass, divide the mass of the sediment alone retained in each
screen or pan by the total mass of the original sediment sample. Multiply each of these answers
by 100 to change to a percentage. Record this information in Table 1.
12. Plot the percentage values as a bar graph on Figure 1 to show the relative percentages retained
on each screen.
13. Find out from your teacher the screen size of each sieve. Record each of the screen sizes on the
lines provided in Table 2.
Table 1 – Mass Analysis *
Object
Mass of Empty
Container (0.1 g)
Mass of Container
plus Sediment
(0.1 g)
Mass of
Sediment
(0.1 g)
Percent of Total
Mass of Sediment
(0.1%)
Grand Total
Sieve
Sediment
Masses
Grand Total
Sieve Sediment
Percentages
Beaker
Top, or largest,
screen
Second screen
from top
Third screen
from top
Bottom, or
smallest, screen
Pan
* Record all values to the nearest tenth of a unit.
Table 2 – Mesh Sizes
Top screen
= ___________________ mm
Second screen
= ___________________ mm
Third screen
= ___________________ mm
Bottom screen
= ___________________ mm
Pan
Figure 1
Analysis and Conclusions:
1. Which screen retained the largest percentage of sediments?
______________________________________________________________________________
2. Did each screen contain a portion of the sample? ___________
What does this tell you about the sample? _________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
The grid below shows sizes (in millimeters) and names of the major sedimentary particles. Locate
each of the screen sizes on the grid below. At the correct location of each size, draw a vertical line
through the strip below the sediment size names. Write the name of each layer (from the diagram on
P. 1) in the area between the vertical lines you just drew. For example, since the top screen size is
0.5mm, the vertical line separating medium sand from coarse sand should extend down across the
strip and “top screen” is written in the space to the right of the line you just drew.
0.01
0.0625
Fine
Silt
Medium
Silt
Coarse
Silt
0.125
Very
Fine
Sand
0.25
Fine
Sand
Medium
Sand
0.5
1.0
Coarse
Sand
2.0
Very
Coarse
Sand
4.0
Granules
8.0
Small
Pebbles
3. On which screen were particles 0.6 mm in diameter retained?
______________________________________________________________________________
4. On which screen was very coarse sand retained?
______________________________________________________________________________
5a. List the particles sizes that were retained on the bottom screen by name:
______________________________________________________________________________
5b. Now list them by their size range: ______________________
6. On which layer did the silt-size particles end up on?
______________________________________________________________________________
7. Only rarely does the total mass on the screens exactly equal the total mass of the original
sample. Did your total mass increase or decrease? What is a possible explanation of why it
increased/decreased?
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
___________________________________________________________________________
CER Question: Are the glacial sediments you analyzed a sample of
outwash or till?
Draft your answer using the CER graphic organizer on the following page.
Then, use this graphic organizer to type up your final response in a clear,
well-written CER. Your goal is to stay in the far right-hand column of the
rubric provided!!!
Reminders:
 Reread the introduction and the directions carefully before you
construct your write-up.
 All questions require complete sentences; remember to incorporate
quantitative and qualitative data in the response.
 Double space your writing!
 Staple your completed, printed CER to the back of this lab.
Claim, Evidence and Reasoning Writing Organizer
Claim
What is the claim you can make based on your evidence?
(The answer to the question being asked that you believe is the correct answer based on what you’ve learned
from the evidence that you will present!) This should NOT start with “Yes” or “No”!!
Evidence:
What is the evidence you collected?
(Specific Data – Qualitative and Quantitative – list and compare/contrast the data. Use your ELA transition
words in your writing!)
Reasoning:
Explain why you can make the claim from the evidence you collected.
(This is the explanation. Incorporate/restate the claim, and state the scientific principle(s) that connects your
claim to your evidence!)
Rubric for Glacial Sediments Analysis
Claim, Evidence and Reasoning (CER)
Directions: Use this rubric to ensure that your CER is well-written!
Getting
Started
Keep
Trying
Getting
There
Nicely
Done!
0
1
2
Typed but multiple
Write-up
Not typed
spelling/grammatical
errors are present.
0
Claim
Claim is incorrect
0
1
Typed and proper
grammar and spelling
are present. Few, if any,
errors present.
1
2
Claim is correct but
Claim is correct and is
not well-written and
well-written in a clear
not expressed well.
manner.
3
5
Provides appropriate
Doesn’t provide
any quantitative
Evidence
Does not provide
any evidence.
evidence to
support claim.
Poorly
written/didn’t
apply ELA skills.
but not sufficient
Provides appropriate
evidence to support
and sufficient
claim. Incomplete
evidence to support
evidence. Does not
claim. Both
include both
quantitative and
quantitative and
qualitative evidence is
qualitative evidence.
provided. Well-written
Writing needs
and organized.
improvement.
Provides some
reasoning that
Reasoning
Reasoning
Does not provide
any reasoning.
provided is not
appropriate and
does not explain
the evidence.
connects the evidence
to the claim, May
include some scientific
principles for why the
evidence supports the
claim, but not
sufficient. Not wellwritten/organized.
Provides clear, wellwritten reasoning that
connects all evidence
to the claim. Includes
appropriate and
sufficient scientific
principles to explain
why the evidence
supports the claim.