I. Porosity (P)

100P

T

VP

V Where VP is the total volume of pore space

and VT is the total volume of rock or sediment.

The proportion of any material that is void space, expressed as a percentage of the total volume of material.

In practice, porosity is commonly based on measurement of the total grain volume of a granular material:

100T G

T

V VP

V

Where VG is the total volume of grains within the total volume of rock or sediment.

P T GV V V