Continental Volcanic Arc Hot Craton Ocean Basin Spot MAFIC Divergent Convergent basalt scoria, etc. rhyolitic Plate Boundary Plate Boundary e….

1.Chert is a key rock that tells us about the history of rocks typically found around San Francisco. 

According to the web pages provided above, where did the chert form?

https://www.nps.gov/goga/learn/education/chert-faq.htm

https://pubs.usgs.gov/bul/b2188/b2188ch3.pdf

Select one:

a. It formed at the bottom of the ocean, in a region where sea surface temperatures were warm. It was then transported on land by plate movements.

b. It formed in a region where sea surface temperatures were cold. It was then transported on land by plate movements.

c. It formed at the bottom of the ocean, along a mid-ocean ridge.

d. It formed 

Read over your Chapter on Igneous Rocks. Magma cools quickly when it is not insulated beneath Earth’s surface. 

Cooling at this rate produces rock that:

Select one:

a. Is glassy, like obsidian

b. Has very small crystals, like basalt

c. Has large crystals, like granite 

d. Has a mixture of large and small crystals

3.Refer to the video on Classifying Igneous Rocks. 

Which of the following statements best describes a volcanic igneous rock?

An example of an igneous volcanic rock called rhyolite is pictured below:

Select one:

a. It cooled slowly, so it is coarse grained (has large-sized crystals). 

b. It cooled relatively quickly, so it is fine grained (has small-sized crystals).

c. It cooled so quickly that no crystals formed (it is a glass).

d. It cooled slowly and then quickly, so it is porphyritic (has small and large-sized crystals).

4.Which of the following statements best describes a plutonic igneous rock?

Remember that rocks can consist of bits that aren’t minerals… for example: teeth, bones, glass, coal, etc.

Select one:

a. It cooled slowly, so it is coarse grained (has large-sized crystals).

b. It cooled relatively quickly, so it is fine grained (has small-sized crystals).

c. It cooled so quickly that no crystals formed (it is a glass).

d. A and B

e. B and C 

5.Carefully study the cross-section below after reading your text! 

This is a simplified example that shows all types of plate tectonic boundaries that can be found around the globe. 

Geologists find specific igneous rocks associated with specific types of plate tectonic boundaries. The igneous rock is labeled in the lithosphere below, so just take a peak at whether rocks are felsic, intermediate, or mafic igneous rocks when close to a divergent, convergent, or transform plate tectonic setting.

Which of the following statements is most true?

c.  

d. 

e. Subduction of felsic oceanic crust produces intermediate rocks on otherwise mafic continental lithosphere.

f. Subduction of intermediate oceanic crust produces mafic rocks on otherwise felsic continental lithosphere.

6.Read or check out the video on metamorphic rocks… How does regional metamorphism occur?

Select one:

a. By hot water circulating through mafic igneous rocks.

b. By high pressure conditions in a subduction zone.

c. By heat from the magma of an adjacent igneous intrusion. 

d. By high temperatures and high pressures during burial.

7.Many mountain ranges consist of metamorphic rocks that once formed deep underground.

Which of the following is NOT a viable explanation for why we now see these rocks at the surface of the Earth?

Select one:

a. Strike-slip faults slide them around.

b. They float to the surface due to low density.

c. They are uplifted or exhumed by vertical movement on faults. 

d. They are exposed at the surface by erosion of the overburden of rock.

8.Serpentinite is the state rock of California, and widely abundant in the Bay Area. Visit the following website to read about serpentinite.

https://www.nps.gov/goga/learn/education/serpentinite-faq.htm

https://www.conservation.ca.gov/cgs/Pages/Publications/Note_14.aspx

What environment is NOT associated with formation of serpentinite?

Select one:

a. A fracture or fault zone that transmits thermal fluids

b. A black smoker That’s right, the steam from black smokers travels through the oceanic lithosphere and metamorphoses the Peridotite.

c. A mid-oceanic ridge

d. A continental collision zone

9.Describe the igneous rock type and texture shown in the photo

c. 

d. Plutonic and aphanitic, with fine crystals not visible to the naked eye

e. Plutonic and phaneritic, with coarse crystals visible to the naked eye

f. Plutonic and porphyritic, with fine and coarse crystals visible to the naked eye 

10.Describe the igneous rock rock type and texture that you can see below in the photo

b. 

c. 

d. Plutonic and aphanitic, with fine crystals not visible to the naked eye 

e. Plutonic and phaneritic, with coarse crystals visible to the naked eye

f. Plutonic and porphyritic, with fine and coarse crystals visible to the naked eye

11.Identify the type of rock forming in the photo of a Hawaiian lava flow below.

Select one:

a. Basalt pahoehoe

b. Basalt a’a

c. Basalt lava 

d. Pele’s tears

e. Basalt pumice

f. Pele’s hair

12.Given the Principle of Original Horizontality, what event must NOT have occurred to produce the stack of rock layers in the picture below?

Original Horizontality: https://www.youtube.com/watch?v=mbQ8AIUJ7rg

For more on numerical and relative dating in general:

Select one:

a. Strike-slip faults slide them around.

b. They floated to the surface due to low density.

c. They are uplifted or exhumed by vertical movement on faults. 

d. Natural gas pushes them up gradually.

e. Deposition of sediments or volcanic flows in planar, inclined layers

13.Refer to the sequence of events shown below, which explains the development of an angular unconformity (gap in the record of geologic time). 

Which geologic principle clarifies that Layers F-H are youngest?

Unconformities: https://www.youtube.com/watch?v=DNcYBLG3TBo

Select one:

a. Principle of Cross Cutting Relations

b. Principle of Original Horizontality

c. Principle of Lateral Continuity

d. Principle of Superposition

e. Principle of Angular Unconformity 

f. Principle of Faunal Succession

14.Examine the geologic cross-section below. The view is “from the side” or across the earth’s surface. 

The cross-section view is useful to geologist because it shows the layers, faults, and other cross-cutting features (such as intruding igneous rocks) as if we’ve sliced open the earth’s crust. 

Take plenty of time and please decide which statement is true… Note that feature (F) is a fault.

Understanding Geologic Time:

Earth’s History: https://www.youtube.com/watch?v=Z6k3NRy-YWs

Law of superposition: https://www.youtube.com/watch?v=EadTLGMu3LI

Original Horizontality: https://www.youtube.com/watch?v=mbQ8AIUJ7rg

Geologic Principles: https://www.youtube.com/watch?v=rc3da3-znK4

Unconformities: https://www.youtube.com/watch?v=DNcYBLG3TBo

Select one:

a. Fault F is older than Unit A

b. Unit A is younger than Unit C.

c. Unit C is older than Unconformity E 

d. Unit D is younger than Unit C.

e. Fault F is younger than Unit C

15.Serpentinite is California’s state rock. It is oceanic crust that was altered by thermal waters.

https://www.conservation.ca.gov/cgs/Pages/Publications/Note_14.aspx

As you already learned, Chert is a sedimentary rock… see links in earlier questions for more info on Chert!

Choose the statement below that is most correct:

Select one:

a. Serpentinite is younger than radiolarian chert based on the Principle of Original Horizontality 

b. Serpentinite is older than radiolarian chert based on the Principle of Superposition

c. Serpentinite is older than radiolarian chert based on the Principle of Original Horizontality

d. Serpentinite is younger than radiolarian chert based on the Principle of Superposition

e. Serpentinite is younger than radiolarian chert based on the Principle of Lateral Continuity

f. Serpentinite is older than radiolarian chert based on the Principle of Lateral Continuity

• Attachment 1
• Attachment 2
• Attachment 3
• Attachment 4
• Attachment 5
• Attachment 6
• Attachment 7

ContinentalVolcanic ArcHotCratonOcean BasinSpotMAFICDivergentConvergentbasaltscoria, etc.e.g. rhyoliticPlate BoundaryPlate Boundarye.g. andesitespillow basaltssea levelgabbroFELSIC Igneous RocksVtrenchMAFICigneous rocksINTERMEDIATEe.g. various granites,igneous rockse.g. diorite, grano-syenites, monzonites,diorites, plagiogranitesgranodiorites, etc.VN T VN7basalt/gabbrofractionalmeltingULTRAMAFICSubduction Zone(Igneous rocks of upper mantle)fractionationresidueplume ofe.g. peridotite/dunitee.g. dunitehot mantleperidotitemagma