GEOS 220: Environmental History of Southwest
Outside Activities
Outside activity #1:
Crossdating Tree Rings by Skeleton PlottingAccess this activity on the web through this page.
First, read the explanatory pages that lead up to the fun page: Try skeleton plotting for yourself.
When you succeed at crossdating a virtual sample:
- Make it obvious that you succeeded:
- Line up your winning skeleton plot with the master chronology
- Put the plots as far right as possible, but still visible
- Show the answer box
- Set the core magnification at 1x
- Put a part of the core that has highly variable ring growth in full view
- Capture an image of the crossdating applet:
- For PC users, do an "alt-print screen" to take a snapshot of the screen.
- For Macintosh users with OS X, there are two options for importing a screen shot into your word processor.
- Press this combination of keys: crtl+cmnd+shift+4. This will turn the mouse icon into a cross hairs with which you can select the portion of the screen which you wish to capture.
- Use the "grab" application. The easiest way to locate it is to open spotlight and type grab. Since this is an application, it will be separated from documents that contain words, etc.
- Open your favorite word processor.
- Edit-Paste Special into a document.
- Re-size the image to be reasonable.
- Fill in page with text (should be about ½-page typed) about dendrochronological crossdating.
- The explanatory pages have many pearls of wisdom in this regard.
- For example, in what cases might a tree-ring sample not be crossdateable?
- Writing tip #1: Avoid first-person sentence subjects:
- Instead of: I or we (also the vague subject, "one") can crossdate tree-ring samples.
- Try: Tree-ring samples can be crossdated.
- Writing tip #2: Avoid superfluous third-person subjects doing stuff:
- Instead of: Dendrochronologists (or English majors) can crossdate tree-ring samples.
- Try: Tree-ring samples are crossdateable.
- One page total (with your figure).
- Due Tuesday, Sep. 16, 2025, in D2L.
Outside activity #2:
Arizona State MuseumThe University of Arizona has many museums, most of which are on the main campus and are free of charge to students. In this activity, please visit the Arizona State Museum in order to learn about human-environment interactions in the Southwest.
2022 Note: The Paths of Life exhibit at the Arizona State Museum is now permanently closed. See below for new suggestions for what to focus on for this activity.
2024 & 2025 Note: The Arizona State Museum itself is now closed, for the foreseeable future. See below for how to view the Paths of Life exhibit by video and thereby complete this activity for Geos. 220.
For this activity:
Watch this short video created in 1993 describing the Paths of Life exhibit.
Write an essay comparing facets of modern life of Indigenous people of the Southwest that can be gleaned from this video version of the Paths of Life exhibit with what was covered in Part II of EHSW about the lifeways of early Indigenous people of the Southwest. Focus on human-environment interaction. For example:
- Do modern tribes practice agriculture?
- If not, how is food obtained?
- How is water obtained and managed?
- Is land used differently on a seasonal basis? How so?
- Include a compare/contrast statement with an early culture as discussed in lecture.
- Briefly, how did first contact with Spanish change environmental history of the American Southwest?
1-page, single-spaced, prose (i.e., not bullet points). Use more than one paragraph; three paragraphs would be about right. Start each paragraph with a topic sentence, as was done for the wolf script. As usual in this course, try writing completely without any first-person "I" or "we." One more time: No quoting in this class, ever. Graded on depth and writing.
Due Thursday, Nov. 20, 2025, in D2L.
Laboratory of Tree-Ring Research, University of Arizona
Tucson, Arizona 85721 USA
Copyright © 2001-2025, Laboratory of Tree-Ring Research, University of Arizona
Revised — November, 2025
