Regarding porosity this report might be relevant to you: http://www.isws.illinois.edu/pubdoc/CR/ISWSCR-351.pdf

Check this

https://www.google.com.ng/url?q=http://www.aqtesolv.com/aquifer-tests/aquifer_properties.htm&sa=U&ved=2ahUKEwjCov-dnJHZAhUPKFAKHQVYCrwQFjAAegQIExAB&usg=AOvVaw3_i8REDIQfasnIb5369kTk

I agree with the answer of Dr. Boriana Tchakalova ,and support this link.

Both consolidated and unconsolidated geological materials are important as aquifers. Of the consolidated materials (ie. bedrock), sedimentary rocks are the most important because they tend to have the highest porosities and permeabilities.

Sedimentary rock formations are exposed over approximately 70% of the earth’s land surface. These sedimentary formations are typically hundreds to thousands of metres thick, and they are underlain by the igneous and metamorphic rocks that make up the rest of the crust.

Although most bedrock aquifers are within sedimentary rock, in some

areas igneous or metamorphic rock can be important as aquifers.

Bedrock aquifers

Much of the bedrock is also covered with tens to hundreds of metres of

unconsolidated sediments (a.k.a. surficial deposits or drift). These

include colluvial materials (deposited from mass wasting) alluvial materials

(deposited by flowing water), glacial deposits and eolian (wind-blown)

deposits. They are “unconsolidated” because they have not been around

long enough, and have not been buried deep enough to have become

lithified.

Surficial deposits that are more than a few metres thick can be very

important sources of groundwater, partly because they tend to have quite

high porosities and permeabilities, and also because they are amenable for the development of wells.

We will discuss the aquifer properties of specific types of rock and surficial

materials in more detail later in the curse.