Empirical Relation Between Carbonate Porosity and Thermal Maturity: An Approach to Regional Porosity Prediction: REPLY TO RAY DISCUSSION

I thank Ray (1985) for the interest shown in my paper (Schmoker, 1984). His analysis illustrated mathematical relations not specifically addressed in my manuscript. 1 do not believe, however, that these results are significant or that they weaken my arguments. He demonstrated only the obvious point that if two variables correlate with a third variable, they will correlate with each other. Further­ more, his analysis and conclusions are based on the assumption of an exponential porosity-depth relation. I would argue that such a relation is an effect of subsurface diagenesis that does not explain the cause, and that Ray has approached the problem backward. The proper con­ clusion would be that, for certain simple basins, an expo­ nential porosity-depth relation follows logically from the idea that porosity decreases in the subsurface as a function of thermal maturation. Perhaps the point that should be emphasized here is that depth (z) in and of itself does not affect or control geologic