Dataset:  rock_aquifer.dat

Source: C.E. Brown (1993). "Use of Principal-Component, Correlation, and Stepwise
Multiple Regression Analyses to Investigate Physical and Hydraulic Properties of
Carbonate-Rock Aquifers," Journal of Hydrology, Vol. 147, pp. 169-195

Variables related to porosity and log(permeability) in rock samples
from Central Penn
Potentiai Predictors:
Bulk Density (g/cm^3)
Insoluble residue (%)
Grain length of a-axis  (phi units)
Grain Length of b-axis  (phi units)
Calcite (%)
Dolomite (%)
Total Carbonate (%)

Variables/Columns
Sample    8  /* 1=Stonehenge Limestone, 2=Nittany Dolomite, 3=Axeann Limestone, 4=Bellefonte Limestone
Bulk Density   10-16
Porosity   18-24
Log Permeability   26-32
Insoluble Residue   34-40
Total Carbonate  42-48
Grain Length of a-axis  50-56
SD of a-axis length   58-64
Grain Length of b-axis   66-72
SD of b-axis length   74-80
Calcite  82-88
Dolomite   90-96