ASSIGNMENT I-2  Skeleton Plotting & Crossdating

GRADING RUBRIC

The assignment is worth a total of 18 pts plus the "Top Two" (2)  points (for the complacent core) =  a total of 20 points

In addition to these 20 points, 2 Bonus Points are possble for successfully crossdating a core with Absent (Missing) and/or False Rings.  (See the Tutorial on:  Skeleton Plotting Absent and False Rings  to learn how to do this and then follow the directions under BONUS POINTS below.
                                  (Note that the bonus opportunity this year is not the one described in Class Notes on p 134.).  

• Skeleton Plot and Cross Dating  (total of 8 pts)
  ( graded on the basis of the image(s) that you pasted into you document, showing your successful match with dates from the answer visible)
  
  
  • (5 pts) Skeleton Plot:  Your copied image should show an accurately plotted graph that lines up with the master chronology, showing a clear match. 
    
    IMPORTANT: Students must follow the step-by-step sequence of the assignment in the order given:   first plot the core; second, find the match with the master; third assign the begining and ending dates to the core based on this match; and last, check the answer (and make a copy of this final image).  No shortcuts!  You will be required to draw a skeleton plot by hand on graph paper for a question on Test #2, so the purpose of this online assignment is to train you for doing it on your own manually.
         
  • (3 pts) Cross Dating: The Answer Box should be displayed in your image showing that the beginning and ending dates match your skeleton plots.  These dates may also be included in the text of your write up.
    
    
• Write Up    (total of 10 pts)
  • (2 pt) Explanation of skeleton plotting  in your own words
  • (2 pt) Explanation of pattern matching  in your own words
  • (2 pt) Explanation of cross dating in your own words
  • (2 pts) Master chronology:  Explanation of what it is and how it is used in cross dating.
  • (2 pts) Complacency and Sensitivity: Description (in your own words) of what these two types of ring patterns look like, followed by an explanation of which type is better for cross dating and why.
    
• "Top Two" (total of 2 pts)   Crossdating a complacent core
  
  Directions:  Repeat the skeleton plotting exercise, but this time with a complacent core and write a paragrph describing how it differed from the sensitive core exercise.  Here's the step-by-step:
   
  • After you've saved your previous crossdated image, change the SENSITIVITY from 1 (very sensitive) to 5 or 6 (more complacent). 
  • Then click "Restart a New Core" and try to plot, match, and crossdate the more complacent core. 
  • If you are successful, save the image as above and
  • Write a "Top Two" paragraph (200 -300 words) describing (a) the challenges of crossdating a complacent core and (b)explaining the specific techniques you used to meet this challenge and successfully get your plot to match the master (e.g., paid more attention to subtle changes in ring width, compared each ring to its adjacent rings to decide if it was "narrower" enough to draw a line, etc.)
    
    
    
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• Bonus Point Opportunity (up to 2 additional points)  Crossdating with absent or false rings
  
  Directions:  Repeat the skeleton plotting exercise again, but this time plot a core which may have absent rings and a core which may have false rings and write a paragrph describing your experience with this challenge compared to the previous plotting exercises.  Here's the step-by-step:
  
  • Study the tutorial  on:  Skeleton Plotting Absent and False Rings
  • After you've saved your previous crossdated images, select ABSENTS or FALSES to indicate which type of rings you want embedded in the next core you'll look at (it is suggested that you don't try to do both absent and false rings in the same core -- do them one at a time).
  • Then click "Restart a New Core" and try to plot, match, and crossdate the core, inserting the absent ring notation(s) or the false ring notation(s) in the proper place(s) on the skeleton plot
  • If you are successful, save the image as above and
  • Write a Bonus Opportunity parapgraph (200 - 300 words) describing your experience with absent and false rings!  What did you have to do differently?  What made this so difficult?,  etc. etc.