1.Identify this rock.

A. Gabbro

B. Quartz

C. Biotite

D. Granite

E. Rhyolite2. What would be a place to expect to find this rock. A. HawaiiB. Cascade Mountains in WashingtonC. Great Barrier ReefD. Texas Hill CountryE. East Texas Pineywoods

3. What rock is this?

A. Orthoclase

B. Biotite

C. Granite

D. Rhyolite

E. Rose Quartz

4. Which rock was exposed by erosion long after it had cooled

deep in Earth’s crust?

A. Olivine

B. Pumice

C. Basalt

D. Rhyolite

E. Granite

5. What kind of rock might form from this lava once it cools?

A. Magma

B. Granite

C. Rhyolite

D. Basalt

E. Pyroxene

6. Use the Bowen’s Reaction Series to predict what kind of rock

would form from a magma that crystallizes at a high temperature

deep in Earth’s crust.A. GraniteB. PeridotiteC. PumiceD. ObsidianE. Rhyolite

7. Identify this rock.(Hints: it’s silica-rich and floats on water.)

A. Pumice

B. Basalt

C. Scoria

D. Granite

E. Peridotite

8. Which kind of magma would most likely form obsidian?

A. A silica-rich magma that’s cooled instantly.

B. A silica-rich magma that’s cooled slowly.

C. A silica-poor magma that’s cooled instantly.

D. A silica-poor magma that’s cooled slowly.

E. None of the above

9. This is Enchanted Rock, northwest of Fredericksburg. What kind of igneous rock

would you most likely find here?

A. Arenite

B. Basalt

C. Rhyolite

D. Granite

E. Peridotite

10. What process could have formed this rock?

A. Volcanic eruption

B. Evaporation

C. Plankton being buried & compacted

D. Mountain-building as two continents collided.

11. What would NOT be considered a type of coal?

A. Anthracite

B. Bituminous

C. Lignite

D. Peat

E. Carbide

12.Identify

A. Andesite

B. Basalt

C. Pumice

D. Diorite

E. Granite

13. Which formation would most likely contain columnar basalt?

A. Composite

volcano B. Cinder

cone

C. Laccolith

D. Volcanic Neck

14. This metamorphic rock – made up entirely of quartz - was once…

A. Shale

B. Slate

C. Sandstone

D. Schist

15. Which texture best describes this rock?

A. Fine-grained

B. Coarse-grained

C. Volcanic Glass

D. Porous

16. Use the Bowen’s Reaction Series to predict what kind of rock

would form from a magma that crystallizes at a low temperature at

Earth’s surface.A. GraniteB. PeridotiteC. PumiceD. ObsidianE. Rhyolite

17. Identify

A. Gabbro

B. Granite

C. Obsidian

D. Andesite

E. Rhyolite

20. Use the Bowen’s Reaction Series to find which mineral is the first to come out of solution in a

magma? A. Quartz

B. Olivine

C. Na-Plagioclase

D. Orthoclase

E. Muscovite

21.Which rock would most likely be ejected from this eruption?

A. Pumice

B. Basalt

C. Granite

D. Diorite

E. Gabbro

22. What element is present in scoria that makes it darker and

heavier than pumice?A. Al

B. Na

C. Ca

D. K

E. Fe

23. This is a sketch of a geological cross-section nearby, in Washington County. At what elevation would one be sitting on a pile of volcanic ash?

A. 1 meter

B. 10 meters

C. 15 meters

D. 24 meters

E. 30 meters

24. Which situation would produce rocks with a fine-grained texture?

A. B.

25.What sedimentary rock would most likely form from this

environment? A. Sandstone

B. Breccia

C. Coal

D. Dolomite

26. This is a sketch of a geological cross-section nearby, in Washington County. At what elevation would one be sitting on an ancient sand dune?

A. 1 meter

B. 10 meters

C. 15 meters

D. 24 meters

E. 30 meters

27. Where on this geologic map might metamorphic rocks be

expected to be found?

C.

A.

B

D.

28. This rock was found in Central Texas. It indicates the existence of

_____________ in Texas’ geological past.

A. Plutons

B. Lava Flows

C. Violent eruptions

D. Hydrothermal vents

29. This is Pilot Knob, an extinct volcano located just southeast of Austin. The volcano is composed of basalt. What does this indicate about this part of Central Texas at

the time this volcano was active?

A. It was a desert area.

B. It was covered in glaciers.

C. It was at the bottom of the sea.

D. It was rainforest

30. This is Sideling Hill in Maryland.

Which of Steno’s Laws is BEST demonstrated here?

A. Law of Superposition

B. Law of Original Horizontality

C. Law of Cross-cutting Relationships

D. Principle of Unconformities

31. What geologic process is being depicted here?

A. MetamorphismB. VolcanismC. ErosionD. Deposition

32. The series of yellow, brown, green, & blue bands represent different types of …

A. GraniteB. GneissC. Slates &

SchistsD. Basalts

33. These are photos of fresh lava recently erupted along the East

Pacific Rise. What rock might it be? A. Rhyolite

B. Gabbro

C. Peridotite

D. Basalt

Obsidian Butte Obsidian Butte is a single dome of rhyolite. At the coordinates, the dome is made up of gray to black rhyolite pumice and obsidian. Pumice is a light air-filled volcanic glass. It can be described as a rock sponge because of the rock is filled with frozen gas bubbles. Pumice forms during explosive eruptions when volcanic gasses that were dissolved in the magma suddenly come out of solution and the magma cools quickly to trap the shape of the bubbles. The effect is similar to the results of a shaken carbonated drink after you open it and the foam instantly freezing. Other types of magma will also form pumice. Elsewhere on the dome you will find rhyolitic breccia.

Some areas of the dome have obsidian. Obsidian is a dense volcanic glass. Obsidian forms under similar situations as pumice, but there is not as much gas dissolved in the magma, so the glass form a dense mass. Obsidian usually forms from rhyolitic lava. The black color comes predominantly from tiny minerals of magnetite trapped with in the glass. Obsidian fractures easily and forms very sharp edges, so be careful.

34. What accounts for the differences between Obsidian and Pumice?

A.Mineral ContentB.Metal ContentC.Cooling timeD.PressureE. Gas Content