Figure F63. Comparison of physical properties from core and log measurements. Small blue solid circles = data from whole-round core measurements; open red circles = data from split core measurements; and solid green lines = data from log measurements. A. Bulk density. B. Porosity. C. P-wave velocity in vertical direction. D. Natural gamma radiation (NGR) activity. cps = counts per second, gAPI = gamma-ray American Petroleum Institute.