This file contains stiff diagrams for the 2003 and 2004 sampling events of the Oak Openings
groundwater quality study.  The file also contains jpeg images of the stiff diagrams.

A stiff diagram is a graphical means of presenting the chemical analysis of the major cations and 
anions of a water sample.  Ion concentrations in milligrams per liter (mg/L) are converted to 
millequivalents per liter (meq/L).  Cations (positively charged ions) are plotted on the left 
side of the diagram, with anions (negatively charged ions) plotted on the right.  The length of 
the diagram vertices are proportional to ionic content.  The diagrams were created with GeoStiff, 
a program that produces stiff diagrams as GIS ArcInfo polygon coverages.  In this shapefile, all 
Stiff diagrams will have sodium plus potassium (Na+K), calcium (Ca), and magnesium (Mg) plotted 
on the left, with chloride (Cl), bicarbonate plus carbonate (HCO3+CO3), and sulfate (SO4) plotted 
on the right.