Exam 3

Question 1

What is a water table?

Answer 1

• boundary between unsaturated and saturated zone

- not constant, it varies from season to season

Question 2

What is porosity?

Answer 2

Total volume of pore (void) space in sediment or rock. May be fractures within rock or spaces between grain.

Question 3

What is permeability?

Answer 3

a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it.

Question 4

What is compaction?

Answer 4

Increased pressure from burial compresses the particles and the excess water is squeezed out.

Question 5

What is sorting?

Answer 5

Materials with poor sorting general have less porosity and permeability than a well sorted materials for the same grain size.

Question 6

What is cementation?

Answer 6

Cement fills the pores so it decreases porosity and permeability.

Question 7

What is an aquifer?

Answer 7

material )(sediment and rock) that stores and transmits groundwater un sufficient quantities. High porosity and high permeability.,

Rock types:
Unconsolidated: gravel, sand
Consolidated: sandstone, conglomerate, limestone

Question 8

What is an aquitard?

Answer 8

also called confining beds- rocks/beds through which water cannot move, or moves very slowly. Low permeability (porosity varies).

Rock types:
Unconsolidated: mudstone, clay
Consolidated: shale, slate

Question 9

What are the two types of aquifers?

Answer 9

Unconfined: open to the surface (not confined under any aquitard)

Confined: sandwiched between two aquitards and is not open to the surface at that location

Question 10

What are springs?

Answer 10

Where the surface intersects the water table

Question 11

What is the cone of depression

Answer 11

excessive pumping draws down the water table into a cone shaped depression around a pumping well