The ability of a rock or sediment to let fluids pass through its open spaces, or pores. For a ROCK to be PERMEABLE, the open spaces must be connected. The larger and better sorted the particles are, the more permeable the rock or sediment is.
What is the difference between porosity and permeability?
More specifically, porosity of a rock is a measure of its ability to hold a fluid. … Permeability is a measure of the ease of flow of a fluid through a porous solid. A rock may be extremely porous, but if the pores are not connected, it will have no permeability.
What is the difference between porosity and void ratio?
Void ratio is usually defined as the ratio of the volume of voids to the total volume of soil solid. … Porosity is defined as the ratio of the volume of voids to the total volume of the soil.
Is sand or silt more permeable?
For example, a sandy soil will have larger porosity than silty sand, because the silt will fill in the gaps between the sand particles. But it would a lower permeability because the water would have a “harder” time getting through because there would be less space for it to maneuver.
Is the volume of pore spaces in a rock or soil?
Porosity is the percentage of void space in a rock. It is defined as the ratio of the volume of the voids or pore space divided by the total volume. It is written as either a decimal fraction between 0 and 1 or as a percentage. For most rocks, porosity varies from less than 1% to 40%.
Which term refers to the void spaces in soil which can be filled by water or air?
porosity. The ratio of the volume of void or air spaces in a rock or sediment to the total volume of the rock or sediment. The capacity of rock or soil to hold water varies with the material. (
Is the volume of voids or open space in a rock or unconsolidated material group of answer choices?
Porosity is a measure of the volume of open space in rocks and unconsolidated, geological materials like alluvium and soils.
Is an aquitard permeable?
An aquitard, also known as a confining bed, is a much less permeable geologic unit. … In general, gravel, sandy materials, limestone, or highly fractured rocks make good aquifers, whereas clay-rich, poorly sorted sediments, and unfractured rocks often form aquitards.
When a stream is in av shaped valley running on bedrock the stream?
When a stream is a v-shaped valley running on bedrock, the stream is? Well above base level. A stream meanders across a broad, flat valley with numerous swamps and lakes.
Is the percentage of rock or sediment that consists of voids or openings?
What is porosity? The percentage of rock or sediment that consists of voids or openings. It is the measurement of a rock’s ability to hold water.
What is the difference between an aquifer and an Aquitard?
Aquifers are underground layers of very porous water-bearing soil or sand. Aquitards, by contrast, are compacted layers of clay, silt or rock that retard water flow underground; that is, they act as a barrier for groundwater. Aquitards separate aquifers and partially disconnect the flow of water underground.
What are the two zones of groundwater?
Groundwater is found in two zones. The unsaturated zone, immediately below the land surface, contains water and air in the open spaces, or pores. The saturated zone, a zone in which all the pores and rock fractures are filled with water, underlies the unsaturated zone.
What is pore volume?
The pore volume is the total volume of very small openings in a bed of adsorbent particles. … When drying of a sorbent bed is necessary, a large pore volume will hold a large amount of water, and slow the drying process. The pore volume is the total volume of very small openings in a bed of adsorbent particles.
What is pore space in rocks?
Porosity is a measure of volume of the free space in a rock. Most rocks contain empty space, called pore space, between the mineral grains that make up the rock. You can think of porosity like the holes in a sponge.
What is total pore space?
Pore space is defined by porosity of a material possessing free space between the mineral grains, expressed as percentage (Rebollo et al., 1996), and depends on size and sorting of the particles as a cubic or hexagonic package.
What is the layer that has open space between sediments?
aquifer. a body of rock or sediment that stores groundwater and allows the flow of groundwater. porosity. the percentage of the total volume of a rock or sediment that consists of open spaces.
Is the open space for groundwater?
The total volume of open space in which the groundwater can reside is porosity. Porosity determines the amount of water that a rock or sediment can contain. In sediments or sedimentary rocks the porosity depends on grain size, the shapes of the grains, and the degree of sorting, and the degree of cementation.
What is the percent of open space called in an aquifer?
In a set volume of rock or sediment, the percentage of the rock or sediment that consists of open spaces is porosity. One factor that affects porosity is sorting.
Does silt have a high porosity?
Silt particles are smaller than sand, but larger than clay particles. Likewise, there is less pore space between silt particles than between sand particles, but more than between clay particles. Clay, the smallest particle, has the least amount of pore space.
Are rocks impermeable?
Fine-grained sedimentary rocks, like clay, although having gaps between the grains (and so being porous), like sandstone, have gaps that are so small that water can’t flow through, so they are impermeable.
Do aquifers have high porosity?
An aquifer is a term for a type of soil or rock that can hold and transfer water that is completely saturated with water. … Good examples of aquifers are glacial till or sandy soils which have both high porosity and high permeability. Aquifers allows us to recover groundwater by pumping quickly and easily.