Field Methods

ESC-4931  Spring 2015

Review for Lecture Final

 

Describing Sediments and Sedimentary Rocks (Chapter 6)

1) What are the three major types of unconformities?  Describe how they form.  Describe how       unconformities are commonly recognized in the field.

2) Name and describe the characteristics (sediment type/characteristics, fossil content, sed. structures, etc.) for the common marine, terrestrial and transitional sedimentary environments.

 

Describing Igneous Rocks (Chapter 7)

1) What are the basic stratigraphic units used in mapping volcanic rocks?  Why is mineral and whole rock composition important in recognizing volcanic units? 

2) Why are interbedded sedimentary rocks important in mapping volcanic rocks?  Give examples.  Describe how paleomagnetic and radiometric data are used in recognizing igneous units. 

3) Describe some of the problems in mapping volcanic rock units.

4) List and describe the important characteristics of lava flows. 

5) How can subaqueous and hyaloclastic rocks be recognized in the field?  List and describe the characteristics of these rocks that can be used to distinguish them from lava and tuff erupted on land.  What is palagonite and how does it form?

6) Compare and contrast the following: ash falls, ash flows, and lahars.  Describe the field characteristics that can be used to distinguish these different types of deposits.

7) What are the basic stratigraphic units used in mapping plutonic rocks?  List and describe the important characteristics used in recognizing these units.

8) What is the IUGS Classification?  Describe the end members used in the classification.  Be able to determine the name of an igneous rock based on its composition. 

9) Define the following: xenolith, restite, xenocryst, pegmatite, aplite and orbicular. 

10) How do layered intrusions form?  What are Schlieren Structures?

11) List and describe the common secondary features observed in intrusive igneous rocks.

 

Rock Structures and Structural Information (Chapter 8) 

1) List and describe some of the reasons that geologic structures and deformation should be studied and described in the field.

2) Compare and contrast faults and joints.   Define and describe the origin of the different types of faults and joints.  List and describe the common surface features associated with joints and what they indicate about the origin of the fractures.

3) Describe how the orientation of faults are recognized and mapped.  How is the offset of faults measured and described?  List and describe the common surface features or textures associated with faults and what they indicate about the faulting.  How are faults age dated?

4) Define and describe the following types of movement indicators: slickensides, slickenfibers, and gash fractures.

5) Define and describe the following types of foliation: slaty cleavage, fracture cleavage, mylonite, schistosity, and crenulation cleavage.

6) List and describe all of the commonly-used sense-of-shear indicators.  Draw examples and show sense of shear for the following: augen tails, sheared grains, S-folds, and Z-folds.

7) Define a fold.  List and define the major types of folds.  Describe the measurements used in describing folds?  Compare and contrast bending and buckling folds. 

 

Describing Metamorphic Rocks and Deformation (Chapter 9) 

1) Describe how each of the following are used to determine the protolith of a metamorphic rock: mineralogy, whole-rock geochemistry, and porphyroclasts (or paleoblast). 

2) Name and describe some primary textures and structures that are observed in metamorphic rocks.  Why are these also called relict textures?

3) Name and describe the major types of foliation.  What can be inferred from each type? 

4) Describe how metamorphic rocks are mapped.  What features are used in distinguishing these metamorphic rock units.

5) Define, compare and contrast the following terms: metamorphic grade, metamorphic facies and metamorphic zone.  How are each of these used?  What is the problem in mapping metamorphic zones in most areas? 

6) Compare and contrast ortho- and paragneiss.  Describe the different textures of gneissic rocks.

7) What is a migmatite and how does it form?  Why are the igneous rocks associated with migmatite commonly granitic?

8) How are nonfoliated metamorphic rocks classified?  Do all nonfoliated metamorphic rocks form in an absence of directed pressures?  Explain.

9) Describe how age relationships in metamorphic rocks are commonly determined.  Define and give examples of the following features: pre-, syn- and post-tectonic.

 

Geologic Maps (Chapter 10)

1) Give the definition of a geologic map.  Describe the different uses of geologic maps.

2) Describe some of the different types of reference and base maps that are used in making a geologic map.  Which map type is most commonly used as a base map?

3) What is a formation?  Why is it the basic unit in geologic mapping?  What is a marker bed?

4) Define, compare and contrast the following mapping techniques: traverse, contact, and exposure mapping. 

5) In addition to outcrops and exposures, list and describe the other field data that is used in recognizing and mapping bedrock geology.

 

Water Quality  (Adopt-A-Stream Handouts and Lectures)

1) What is a watershed?  Where is the best location to collect water samples in a stream or river?

2) What is dissolved oxygen and why is it important in streams and rivers?  What is the minimum amount of dissolved oxygen needed for aquatic life forms?  How does temperature and decaying organic material affect dissolved oxygen levels?

3) What is conductivity?  How is it measured?  What causes high conductivity in surface waters. 

4) What is pH?  How is it measured?  What is the typical range of pH in streams?  Why is the pH much lower in some south Georgia streams?  Why are the problems associated with low pH? 

5) What is alkalinity?  Why is it important relative to surface waters?  What are some of the factors that determine the alkalinity of surface waters?

6) What is turbidity?  How is it measured?  Why is it important relative to surface waters?  Compare and contrast turbidity and settleable solids?

7) Why are phosphate and nitrates considered nutrients?  How can these affect water quality?  What are some of the most common sources of these nutrients?

8) Compare and contrast titration and colorimetric measurements. 

9) What are macroinvertbrates?  Why are they important to streams and rivers?  Describe how both the diversity and abundance of macroinvertebrates are used to determine water quality.

10) How often should biological testing be completed at a site?  Why?  What is a kick seine and how is it used?  What is a D-frame net and how is it used?

11) Compare and contrast rocky and muddy stream bottoms.  Where do these stream types occur in Georgia?  Why are different sampling techniques used for each type?

12) Would recent heavy rains affect biological sampling in a stream?  Explain.

13) What are bacteria?  What are indicator bacteria?  What risks do bacteria pose to humans?

Please Note:  The final exam will be comprehensive.  Approximately 25% of the questions will come from the first test.

14) How does E. coli bacteria get into streams and rivers?  What is the relationship between E. coli and fecal coliform? How does weather and seasonal changes influence bacteria?