Name________________ Soc. Sec. #__________________

Geology 111G, Section 2--Survey of Geology Spring 2003

Exam 1

Multiple Choice (2 points each; 50 points total). Circle the letter of the correct answer.

1. Which of the following is probably not an attribute of metal that results from the metallic bond?

a. Electrical conductivity;

b. Malleability

c. Thermal conductivity

d. Tremendous hardness.

2. Which of the following igneous textures indicates that a rock cooled slowly, so that there large, visible minerals present?

a. Aphanitic;

b. Phaneritic;

c. Porphyritic;

d. Glassy.

3. The type of pluton that might be found under the deep root of the Andes Mountains in South America is:

a. Dike;

b. Sill;

c. Batholith;

d. Stock.

4. Na+ and Cl- (note excess electrical charge) are examples of _____________.

a. Ions;

b. Polymorphs

c. Atoms;

d. Isotopes.

5. The relative durability of a mineral, or its ability to scratch other minerals or substances, is termed:

a. Fracture;

b. Hardness;

c. Cleavage;

d. Dislocation.

6. Oceanic crust and continental crust differ primarily in terms of their

a. Strength;

b. Age;

c. Composition and thickness;

d. Temperature.

7. Ionic charge is determined by changes in the number of __________ in a particular atom.

a. Electrons;

b. Protons

c. Neutrons

d. Anions.

8. Which of the following is the best example of a process or event that we might use in support of the doctrine of Catastrophism?

a. Meteorite impact at the end of the Cretaceous;

b. Very slow steady deposition of mud in the deep ocean;

c. Subduction of oceanic lithosphere at 5 cm per year;

d. Gradual erosional carving of the Grand Canyon by the Colorado River.

9. Gold, Au, is an example of which of the following classes of mineral?

a. Native element;

b. Halide;

c. Oxide;

d. Sulfide.

10. A ferromagnesian silicate that consists of double chains of silicon-oxygen tetrahedra is ___________.

a. Biotite;

b. Amphibole;

c. Pyroxene;

d. Olivine.

11. Minerals that consist of an ion in combination with an oxygen anion, such as Hematite, Fe2O3, are classified as:

a. Native elements;

b. Halides;

c. Oxides;

d. Sulfides.

12. A high-silica intrusive or phaneritic rock, with greater than 70% silica, generally light gray or pink, is:

a. Granite;

b. Gabbro;

c. Rhyolite;

d. Diorite.

13. Which of the following igneous textures indicates that a rock cooled slowly at first, after which it cooled rapidly?

a. Aphanitic;

b. Phaneritic;

c. Porphyritic;

d. Glassy.

14. Which of the following layers of the earth is rigid, forms the outer shell about 100 km thick, and is divided into the fabled plates of plate tectonics?

a. Lithosphere;

b. Asthenosphere;

c. Mesosphere;

d. Inner core

15. A dike is

a. A tabular (sheet-like)discordant pluton;

b. A tabular concordant pluton;

c. A complex of plutons (stocks) of great dimensions;

d. A massive concordant pluton.

16. Low-silica or basaltic magmas can be formed by which one of the following processes?

a. Partial melting of asthenosphere by decompression at a mid-ocean ridge

b. Subduction-related melting of asthenosphere by volatile release from a subducted slab;

c. Partial melting of overthickened continental crust;

d. Degassing of the core.

17. A subduction zone, where an oceanic plate descends beneath another plate, is considered which of the following types of plate margin or boundary?

a. Divergent;

b. Convergent;

c. Transcurrent;

d. It's not a plate boundary.

18. Rocks composed of fragments, like ash and cinders, ejected from the vent of a volcano are:

a. Volcanic or extrusive rocks;

b. Plutonic or intrusive rocks;

c. Pyroclastic rocks;

d. Lava rocks.

19. The core of the earth is made up mostly of

a. Nickel and Iron;

b. Silicon and Oxygen;

c. Olivine and Pyroxene;

d. Unknown materials.

20. Isotopes that change their atomic mass or number with the passage of time are __________ isotopes.

a. Stable;

b. Unstable;

c. Radioactive;

d. Ionic.

21. Why are intermediate magmas likely to cause violent eruptions?

a. Their very high temperature;

b. Their low viscosity and low temperature;

c. Their moderate viscosity and significant volatile content;

d. Their complete lack of volatiles.

22. Diamond is very hard and fails to cleave because it is composed of a network of this strong bond type:

a. Covalent;

b. Ionic;

c. Metallic;

d. Van der Waals.

23. The following elements are important constituents of all ferromagnesian silicates:

a. Fe and Mg;

b. K and Na;

c. Ca and Na;

d. S and Ni.

24. Which of the following substances, in its pure form, lacks minerals?

a. Diorite;

b. Volcanic glass;

c. Granite;

d. Basalt.

25. Which of the following is not a pyroclastic deposit or process?

a. Ash fall;

b. Ash flow;

c. Lava flow

d. Lahar.

Matching. Arrange the following minerals in their proper order of hardness, labeling the softest 1 and hardest 5. (2 Points Each; 10 Points Total).

26. _______ Quartz

27. _______ Talc

28. _______ Corundum

29. _______ Calcite

30. _______ Gypsum
Short Answer (5 Points Each; 10 Points Total)

31. Explain the difference between continental crust and oceanic crust in terms of their composition (or density) and thickness. Which of these crustal types rides higher (forms the higher topography) on the asthenosphere?

32. Explain how volcanoes are classified according to the composition of the edifice and the resultant shape of the edifice. Name and describe two different types of volcano discussed in class using this classification system. Sketches will work if they are properly labeled.

Term Recognition (3 points each; 30 points total). Fill in the missing term (the blank) using one of the terms from the following list. Each answer is used only once.

hypothesis cinder cone caldera

laccolith catastrophism earthquakes

dike silicates temperature

sill rock paradigm

lahar amphibole chert

crust theory uniformitarianism

volcanoes pyroclastic pressure

ash flow asthenosphere lithosphere

mineral tectonics cleavage

33. The study of the deformation and large-scale architecture of the earth's crust is termed

__________________.

34. A large, steep-sided volcanic depression known as a ____________ results when roof rocks collapse into the magma chamber and displace molten material.

35. The doctrine that the Earth is shaped or formed in part by gradual, day-to-day events, is termed ____________________. This doctrine may be summarized as "The present is the key to the past."

36. A scientific idea that can be rejected or retained by testing or experimentation is termed a ________________.

37, 38. Plate boundaries are not visible as lines on the globe. Their locations are defined by aligned features that result from the interactions of the plates, such as _______________ and _______________.

39. The outer 40 km of the Earth that makes up the continents, composed dominantly of minerals containing silicon and oxygen, is termed the _____________.

40. A _______________ is an aggregate or collection of minerals.

41. A _______________ is a volcanic mudflow formed by the mixing of pyroclastic debris with snow on the flank of the volcano.

42. A ______________ is a naturally occurring, solid crystalline substance, generally inorganic, with a specific chemical composition.