A core plug has 21% porosity as determined using a Boyle’s Law porosimeter. When it was dry, the core weighed 238.00 g. When the outside of the dry core was lightly coated with paraffin, it weighed 249.51 g. The density of the paraffin was 0.896 g/ cm3 . When the coated core was immersed in distilled water, it displaced 124.87 cm3 of water. What is the probable lithology of the core?