GLY 105 Sedimentary & Metamorphic Rocks Lab Assignment

GLY 105 Sedimentary & Metamorphic Rocks Lab Assignment is a 82 points assignment that covers various topics related to rocks and their formation. The lab assignment covers topics like sedimentary rocks, weathering, sediment transport, sedimentary rocks deposition, metamorphism, and effects of heat and pressure.

Name: _________________________________ TA: _____________________________________
Date: ______________________ Section Number: ________________ Lab ( / 82 pt
GLY 105 Sedimentary & Metamorphic Rocks
As for every assignment you do in the class: all answers must be in your own words. Plagiarism will not be tolerated - do
not copy directly from internet or textbook – you will be given a zero for the assignment.
From Rocks to Sediment – Weathering
Sedimentary rocks form from surface processes that break down preexisting rocks. Sedimentary rocks therefore
hold clues to how they formed and the environments where they may have formed.
1. Sediment size, shape and degree of sorting may indicate the energy, rate, and/or duration of deposition as well
as the transport process (river, debris flow, wind, glacier, etc.). A poorly sorted sediment will contain a large
variation in grain sizes while a well sorted sediment indicates that the sediment sizes are very similar. On the
diagram below: (3pts)
a. Draw an arrow indicating the trend of grain size. (Use the terms: large and small).
b. Draw an arrow indicating trend of grain shape. (Use the terms: rounded and angular)
c. Draw an arrow indicating trend sorting. (Use the terms: well sorted and poorly sorted)
2. Sample A and B are the before and after effects of putting glass filled with water in the freezer overnight.
Figure A is a close up of a fracture in a rock. Figure B shows the talus slope (rock debris pile) that is often
found on the slopes of tall mountains. Propose a theory as to how this mountain might be weathering down.
(1pt)
Plate tectonic theory of weathering.
3. Using Figure C, D and E, describe the sediment size, shape and degree of sorting commonly produced by
this type of weathering. (3pts) Circle one for each
1
s

Size: Large / Small
Shape: Angular / Rounded
Sorting: Well sorted / poorly sorted
4. Has this sediment traveled far from its source? (1pt) Yes or No
5. Describe how the rocks are being weathered in Figures F & G, and where this most likely will occur. (1pt)
The rocks are weathering by mechanical weathering since weathering is occurring through abrasion of the
particles.
6. Examine the two examples of weathering illustrated in Figures A/B and F/G.
a. This type of weathering ( does not change ) the chemical makeup of the minerals in the rock
itself (1pt)
b. These would be examples of (Physical Weathering). (1pt)
7. Some minerals dissolve in water and some in acidified water, this dissolving is a form of weathering. The way
materials react in different conditions may help in identification. (3 pts)
a. Identify the minerals Halite, Calcite and Quartz.
What happens when water is
applied to the sample? (0.5pts
each)
What happens when dilute
Hydrochloric Acid is applied to the
sample? (0.5pts each)
Name that Mineral
(1pt each)
Mineral A Dissolves in water
Reacts with hydrochloric acid to
produce carbon dioxide gas, water, a
dissolved metal ion, and dissolved
chlorine
Halite
Mineral B No reaction No reaction
Quartz
Mineral C No reaction
Reacts with an acid to produce
bubbles on the surface of the crystal
Calcite
b. What type of weathering would the reaction to water or dilute hydrochloric acid represent? (1pt)
Circle one: Mechanical (Physical) Weathering Chemical Weathering
c. Write down what the main mineral component of the following sedimentary rocks and describe how they would
react to water and how they would react to acidified waters. (Quartz, Calcite or Halite) (3pts)
2

Main mineral
component
How would the rock react in water?
If none write “no reaction”.
How would the rock react in acidified
waters?
If none write “no reaction”.
Halite
Rock Salt
Sodium
Chloride
Dissolves in water Reacts with hydrochloric acid to
produce carbon dioxide gas, water, a
dissolved metal ion, and dissolved
chlorine
Quartz
Sandstone
Silicon
dioxide
No reaction No reaction
Calcite
Limestone
Calcium
Carbonate
No reaction Reacts with an acid to produce bubbles
on the surface of the crystal.
Rates of Reaction
Not all materials weather at the same rate. As you saw above some minerals weather chemically faster than others
based on their composition. In this next section we will explore how grain size affects the rates of weathering.
8. The rate of a chemical reaction is affected by the physical size of the reactants. (3pts)
a. Drop 1 whole Alka-Seltzer tablet into beaker #1 the water. Measure and record the time to
dissolve. 37.2 seconds
b. Take an Alka-Seltzer tablet that has been broken into approximately 3-4 pieces of about equal
size. Drop broken tablet into beaker #2. Measure and record the time to dissolve. 31.1 seconds
c. Take an Alka-Seltzer tablet that has been ground to a fine powder. Transfer powder into beaker
#3. Measure and record the time to dissolve. 8 seconds
9. As particle size is reduced through (Physical ) weathering the rate of chemical weathering: ( increases )
(circle one) (1pt)
10. As particle size decreases, the total surface area of a reactant (_increases _) As a result, the probability of
interactions between atoms/ions (increases), and the rate of reaction (increases). (1pt)
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Sediment Transport – Erosion
11. After a rock is weathered, broken down into pieces or components, the sediment produced is often transported
some distance from its original location in a process called erosion. In your group come up with at least 3 ways
that sediment is transported (do not include humans or animals :) and what grain size(s) you expect that agent
of erosion to move. (3pts)
Agent of Erosion Grain size
Wind Clay and Silt
Water Sand and Gravel
Glacier Sand
Sediment to Sedimentary Rocks – Deposition
12. All sediment does not settle at the same water velocities. Shake the jar of sediment labeled “Question 12” and
observe. Describe what you observed. (1pt)
After shaking the jar, the sediments with different sizes settle with varying velocities. The large particles settle
first followed by the medium particles. The clay and silt takes time to settle. Hence, this experiment provides a
proof that sediments of different sizes settle at different velocities.
13. Some sediment is deposited on land and some in water. Before you are several settling tubes; one containing
water and one is just air. Pour some of sediment into each of the tubes. What is the major difference between
sediment deposited in air vs. in standing water? (1pt)
The sediments deposited in air settle faster compared to the sediments deposited in standing water. This is
because the sediments deposited in air are bombarded by random moving air particles. Unlike the sediments
deposited into still water.
14. Make a connection between what you see in the tube with the rock Sample 1. Was sample 1 deposited in air or
water? Cite supporting evidence. (1pt)
The experiment above shows that weathering and deposition of rocks occur faster in rapid activity areas compared
to areas that are not active.
15. If the sediment became lithified what type of sedimentary rock would it become? (1pt)
Circle one: Clastic Chemical
16. Acidic groundwater may dissolve the limestone bedrock it moves through.
a. Study Figures 1-4 what often happens to some of this dissolved material? (1pt)
Some of the dissolved material turn to carbon IV oxide, water and dissolved salt.
4

Sediment to Sedimentary Rocks – Depositional Environments
17. Take a jar and 6 sugar cubes, (Labeled Question 17), remove one cube and set it aside as a control cube.
Shake the remaining cubes in the jar for 30 shakes. Remove one cube and set it next to your control
cube. Repeat this cycle until all the cubes are out of the container. Sketch & Describe the pattern
progression you see in the sugar cubes. (2 pts)
18. This sediment colliding together is an example of abrasion. What type of weathering would abrasion
represent? (1pt) Mechanical (Physical) Weathering Chemical Weathering
19. What are the two major environments on the planet where sediment grains would constantly colliding with one
another and producing a similar pattern to the one you saw in the sugar cubes above. (2pts)
Beach Coral Reef Swamp Sand Dunes Floodplain Lake
Lagoon River Glacial Deposits Deep Sea Fan Salt Flat Tidal Fat
20. On the diagram below: (6pts)
a. Indicate on the sketch below where erosion and deposition are most likely to take place?
b. Place the rocks in the most likely depositional environment:
i. Coquina – Limestone family, made primarily of broken calcareous shells. Number :4_
ii. Conglomerate – Clastic rock made of rounded, gravel sized sediment. Number :2_
iii. Shale – Clastic rock made of clay sized particles, breaks into sheets. Number :5_
iv. iv. Breccia – Clastic rock made of angular gravel sized sediment. Number :1_
v. Quartz sandstone – Clastic rock made primarily of sand sized quartz grains. Number: 3
5

Metamorphism – Effects of Heat and Pressure
21. Identify the igneous rock sample 3: Basalt_(1 pt)
On the hotplate your instructor will simulate 2 very common metamorphic environments: high
temperature/high pressure and high temperature/low pressure. Since we cannot take a sample like #3 and do
this experiment we will simulate this using clay as our rocks with pennies representing elongated minerals.
22. If a rock were caught up in a continental-continental collision it would experience (low) temperatures and
(high) pressures. (1 pt)
23. Under the conditions above which of the following do you think might occur to the minerals within this rock?
(1 pt)
a. They will all dissolve.
b. They might recrystallize and/or reorient themselves (line up)
c. Nothing will happen to them.
24. Which of the following is true regarding magma rising from below. (1 pt)
a. Rising magma exerts great pressure on the surrounding rocks forcing the grains to reorient
themselves.
b. Volatile components within rising magma often interact with surrounding rock causing minor
explosions that fracture the rocks around.
c. Rising magma will bake the rocks it comes into contact with causing metamorphism?
25. If a rock comes into contact with rising magma it would experience (high) temperatures and (high) pressures.
(1 pt)
For this next part a hot plate will be used. Do be careful not to burn yourself or others!!!
26. Your TA has 2 clay samples that have 4-6 pennies embedded into each. The pennies will represent
minerals within your clay “rock”. The clay “rocks” will be placed on a hotplate. A brick will be placed
on top of only one of the two clay “rocks”. Fill in the table below: (4pts)
“Rock” with the Brick. “Rock” without the Brick.
6

Write “High” or “Low” for the pressures and temperatures
the “rock” with the brick is experiencing:
____ Pressure _________ Temperature
Write “High” or “Low” for the pressures and temperatures the
“rock” without the brick is experiencing:
____ Pressure _________ Temperature
Sketch what you think will happen to the “rock” the brick is
on.
Sketch what you think will happen to the “rock” the brick is not
on.
27. Observe samples 4, and 5. Before it was changed, sample 5 looked like sample 4. Was the pressure that
created sample 5 equal in all directions or unequal in all directions? (Support your claim.) (1pt)
The pressure was unequal in all directions. The change of the shape was due to uneven exertion of pressure on
the sample.
28. After watching the video describe what happened to form sample 5? (1pt)
29. Observe rock samples 6 and 7. One is sedimentary and one is metamorphic. Which is which and what
connection can you make from the video, the Styrofoam cups and the formation of these rocks? (1pt)
30. What metamorphic texture is represented here? (foliated )(1pt)
31. Water exerts the same amount of force in all directions. What type of force is this an example of? (1pt)
Circle one: Confining Pressure Directed Pressure Atmospheric Pressure
32. What type of pressure would the “rock” with the weight applied be experiencing? (1pt)
Circle one: Confining Pressure Directed Pressure Atmospheric Pressure
33. Sketch and describe what happened to the clay “rocks”. (2pts)
7

“Rock” with weight applied. “Rock” without weight applied.
34. Make a connection between this activity and samples 8 and 9 (one is igneous and one is metamorphic). Which
is which and how did you determine this? (1pt)
35. What metamorphic texture is represented by this activity? ( non-foliated )(1pt)
Name that Rock
8
36.On the diagram below indicate which region each of the three different rock types would form. (3 pts)
A
D B C

37. Using the Sedimentary Rock Classification Chart, identify the following sedimentary rocks. (8 pts)
Sample
Number
Reacts
to Acid
(Y/N)
Visible description of rock Rock Name Depositional
environment
10
11
12
13
38. Using the Metamorphic Rock Classification Chart, identify the following metamorphic rocks. (8 pts)
Sample
Number
Reacts
to Acid
(Y/N)
Description of rock Metamorphic
Texture Rock Name Parent Rock
14
15
16
17
9

10