Earth Materials, Processes and Environments

GEOL-1121 Fall 2015

Practice for Lecture Test #2

 

Name ________________________

 

Part I ‑ Multiple Choice (50 pts. ‑ 2 pts. each question).

  *Circle the letter of the best answer.

1) Which of the following magma compositions is characterized by higher silica contents and high viscosities?

      a) Andesite

      b) Rhyolite

      c) Peridotite

      d) Basalt

 

2) Which of the following is the most abundant volatile (dissolved gas) in magma?

      a) CO2

      b) NO2

      c) H2O

      d) SO2

 

3) Which of the following is a typical characteristic of a pahoehoe lava?

      a) A ropy or contorted upper surface

      b) They commonly grade into aa lava.

      c) Basaltic composition

      d) All of the above

 

4) Which of the following are examples of shield volcanoes?

      a) Mt. St. Helens and the surrounding Cascade Volcanoes

      b) Nevada del Ruiz and most other active volcanoes in the Andes Mountains

      c) Volcanoes that form the Hawaiian Islands

      d) All of the above

 

5) The Cascade volcanoes are associated with which of the following plate tectonic features?

      a) Subduction Zone

      b) Oceanic Ridge or Rise

      c) Rifted continent

      d) Mantle Hot Spot

       

6) Which of the following best describes a cinder cone?

      a) A moderate sloping volcano underlain by burnt Earth material

      b) A small steep-sided volcanic landform composed of pyroclastic material

      c) A large low-sloping volcanic landform composed of pegmatite

      d) A low-sloping volcanic landform composed of tuff and lava

 

7) Which of the following is used in calculating the Volcanic Explosivity Index (VEI)?

      a) Amount of uranium and thorium in the magma

      b) Height of the erupted column and the volume of material erupted

      c) Amount of magma below the surface

      d) All of the above

 

8) In which of the following locations has there been super volcano eruptions in the recent geologic past?         

      a) Yellowstone National Park

      b) Mid-Atlantic Ridge

      c) Hawaiian Islands

      d) All of the above

 

9) Lava that is erupted under water will form:

      a) Fissures

      b) Columnar joints

      c) Pillow lavas

      d) All of the above

 

10) Which of the following is a characteristic of a composite or stratovolcano?

      a) Formation along mantle hot spots

      b) Low slopes

      c) Both violent and passive eruptive histories 

      d) All of the above

 

11) Which of the following is commonly associated with volcanism along mid-oceanic ridges and rises?

      a) Basaltic compositions

      b) Passive eruptions

      c) Pillow structures

      d) All of the above

 

12) Acidic solutions that aid in the production of soils are most commonly produced by which soil horizon?

      a) A-horizon

      b) O-horizon

      c) B-horizon

      d) All of the above

 

13) Which of the following is not a typical characteristic of the A-horizon of a soil profile?

      a) Measurable organic content

      b) Elevated or higher content of sand

      c) Enrichment in iron oxide minerals

      d) Depletion or lower content of soluble minerals and clays.

 

14) In which of the following locations is frost wedging most important?

      a) Polar regions with colder temperatures

      b) Desert areas with limited moisture

      c) Middle latitude areas with adequate rainfall

      d) All of the above

 

15) The two most abundant minerals or components in clastic sediments and sedimentary rocks are:

      a) Feldspars and quartz

      b) Feldspars and amphibole

      c) Quartz and clay

      d) Calcite and quartz

 

16) The chemical precipitate sediments and sedimentary rocks are classified according to:

      a) Grain Size                                                  

      b) Composition

      c) Fossil content                                                                                                       

      d) All of the above

 

17) Which of the following is a clastic (detrital) sedimentary rock?

      a) Shale

      b) Chalk

      c) Chert

      d) All of the above

 

18) Physical (mechanical) weathering allows chemical weathering to occur at a much faster rate because:

      a) Physical weathering increases the surface area of the rock material.

      b) Physical weathering breaks down the feldspars into clays.

      c) Physical weathering dissolves some of the minerals.

      d) All of the above

 

19) Bodies or deposits of sediment that have distinct chemical, biological and physical characteristics resulting from the depositional environment are called:

      a) Facies

      b) Horizons

      c) Depolayers

      d) Strata

 

20) In which of the following environments would you commonly find mud deposits?             

      a) Deep marine

      b) Lakes

     c) Deltas                                                

      d) All of the above

 

21) If weathering was not an active geologic process on the Earth, which of the following would best describe the surface of the planet?

      a) Lacking the plant and animal life that is so abundant on the surface today.

b) Very few sediments and sedimentary rocks on the Earth's surface.

      c) Covered with ancient meteorite craters like the Moon's surface.

      d) All of the above.

 

22) Which of the following is a clastic (detrital) sedimentary rock that forms along near surface faults?

      a) Mylonite

      b) Chert

      c) Conglomerate

      d) Breccia

 

23) Which of the following statements about atmospheric air is not correct?

      a) It is composed of mostly nitrogen.

      b) Oxygen makes up approximately 18% of the volume of air.

      c) Carbon dioxide is only a minor component of air.

      d) The composition of the Earth’s atmospheric gases have not changed much since

            the formation of the planet.

 

24) Which of the following is a chemical sedimentary rock composed of microcrystalline quartz?

      a) Chert

      b) Rock gypsum

      c) Chalk

      d) Shale

 

25) Which of the following is a characteristic of limestone?

      a) It commonly forms in deltas and lakes.

      b) It is a detrital or clastic sedimentary rock.

      c) It is composed of calcite.

      d) All of the above

 

Part II ‑ Fill in the Blank (50 pts. ‑ 2 pts. each number) 

 

26) The major focus of this course is the study of: ____________________________ _______________________________________________________________

 

27-28)( 4 pt.) Explain how hydrothermal deposits form and why they are economically important.  _________________________________________________________      __________________________________________________________________

 

29) Large fragments of lava that are ejected and cooled in the air are called _______________________.

 

30) Explain why the release of volcanic gases is considered a major benefit of volcanism.

      __________________________________________________________

 

31-32)(4 pt.) A low-temperature mixture of volcanic debris and water that moves down river valleys and low-lying areas along the flank of a volcano is a/an ______________. Name a location where one of these occurred. _________________________

 

33) Explain how a volcanic eruption can cause measurable climatic changes. ________________________________________________________________

 

34) A volcanic rock formed by the consolidation of hot volcanic ash and debris is called a/an _______________.

 

35) Explain why basalt lava more commonly displays vesicular textures than andesite.       __________________________________________________________________

 

36) A/An _______________________ is a steep-sided, bulbous mountain or hill that forms as a thick viscous magma is forced passively toward the surface.

 

37) Symmetrical polygonal fractures that form in thick lava and thin intrusions are called ____________________________.

 

 

38-39) Our local soil is called: _________________________.  Red clay that is typical of south Georgia is seen at the surface when_________________________________ ________________________________________________________

 

40) Water expands ________% causing rocks to break during the process of frost wedging. 

 

41-42)(4 pt.) A type of physical weathering that results from the expansion of crystalline igneous and metamorphic rock bodies due to erosion and removal of the overlying             rocks is called __________________.  This commonly allows plants to grow along the fractures and further break the rock material through the process of _______________.

 

43) Sedimentary rocks are classified according to ______________________ and ________________________.

 

44-45)(4 pt.) Name two methods by which an unconsolidated sediment is converted to a sedimentary rock through lithification ___________________________ and

_____________________________.

 

46) Name a mineral that commonly forms by hydrolysis.  ____________________

 

47) A solution that contains an excess of free hydrogen atoms is a/an _____________.

 

48) Clastic or detrital sediments that are larger than 2 mm. are called  _____________.

 

49) A chemical-precipitate sedimentary rock that commonly forms in desert lakes is ______________________.

 

50) __________________________ are the remains or traces of ancient life forms that are commonly preserved in sediments and sedimentary rocks.

 

 

 

 

 

 

Extra Credit (2 pts.): Name a sedimentary rock that commonly forms in swamps that is economically important. __________________