Department of Earth Science |Northeastern Illinois University

AQUEOUS GEOCHEMISTRY
ESCI 406
Spring, 2005
Homework #6: Due Monday, April 18, 2005                                                                     Sanders

Portfolio of Analyses

* The objective of this assignment is to analyze the chemical composition of water samples from one of your analysis sets, using PHREEQCI as a tool.  In this assignment, you will take one of your analysis sets, and for each sample in the set, use PHREEQCI to analyze it.  (To download PHREEQCI, go to the course home page and click Links).  Then, you will compare and contrast the analyses, commenting on the differences and similarities between and among the analyses, and trying to explain them in terms of the hydrogeochemical processes that are or could be taking place.

This homework assignment will form the fourth entry in your Portfolio of Analyses.  Please hand it in with the whole portfolio.  I will look at and potentially comment on the whole portfolio, but only this week's assignment will be graded.

The Assignment Cover page: Create a cover page for this section. Introduction: Describe the basic principles and concepts used in this exercise. Methods: Explain how you used PHREEQCI to analyze the equilibrium conditions of each sample.  Results: Make a simple statement to the effect that results of the PHREEQCI analyses are given in Appendix B.  (Appendix A should be the five analysis sets themselves.)  If you decide to extract any information from the results, summarize it in a neat table that you put within the body of the paper itself (not in an Appendix).  For example, you might decide to pull out all of the saturation indicies for a particular mineral, for all of the analyses, and summarize them in a single table to show a trend along a flow path or through time.  This would be a small table and would not need to go in the Appendix, so just put it within the Results section, along with a sentence that "points" to it, for example, "Table 3 shows saturation indicies for calcite for all samples, listed in increasing distance from the headwaters of the stream." Discussion: This week, the Discussion is the most important section!  Discuss what the results showed.  Be sure to put the results in the geologic context.  Think in terms of trends through time, or along flow paths, or variations related to geologic settings.  Look for differences and similarities, and explain them. Appendices: Appendix A should include your five analysis sets, and Appendix B should include your PHREEQCI output.  Please label each one carefully and neatly so the reader can tell what it is. References Cited: This should be updated to include all citations you have made. The Portfolio Overall:  Make sure you include all the components to the portfolio that are listed below.

Things to Check Before Handing in the Portfolio

* Cite the source of every piece of information that is not taken from your own brain.  Use standard citation format!  (e.g. "Eby, 2005")
* Check your "References Cited" page, and make sure it includes all of the sources you have cited thus far, in proper format. 
* Make any corrections to previous versions of the portfolio (based on my comments on previous assignments, or your own edits/corrections.)
* Hand in the whole portfolio with all the components listed here:
    - cover page for the whole portfolio
    - the current assignment, including its cover page
    - each of the previous assignments, including the cover page for each one
    - Appendix A (include a cover page saying "Appendix A" and giving the title of the Appendix): the five analysis sets, including the cover page for each one
    - Appendix B (include a cover page saying "Appendix B" and giving the title of the Appendix): the PHREEQCI output for your samples.
    - References Cited (make sure it is updated this week to include all sources cited throughout your entire portfolio).
* Use dividers, tabs, or colored pages between sections.

© 2005 Laura L. Sanders.  Last updated April 11, 2005.