The Galesville Sandstone (Cambrian) of south-central Wisconsin was studied as an example of porosity reduction in a shallow buried quartz arenite. The Galesville is a clean, well-rounded, well-sorted quartz arenite and probably has had a maximum overburden of 900 m.
Porosity of the samples in thin section ranges from 15 to 28%. Minus-cement porosity averages 24%. Differences in porosity according to orientation are not statistically significant, and the percentage of pressolved quartz is similar for all outcrops, averaging 0.8%.
Reduction in porosity owing to mechanical repacking of grains after deposition may have reduced porosity from about 45 or 50% to a minimum of 33%. Intergranular pressure solution of approximately 0.8% of the Galesville resulted in a minimum porosity reduction of 9% below the value established for maximum mechanical compaction.