How can a rock have high porosity and low permeability?

How can a rock have high porosity and low permeability?

A good example of a rock with high porosity and low permeability is a vesicular volcanic rock, where the bubbles that once contained gas give the rock a high porosity, but since these holes are not connected to one another the rock has low permeability.

How can a rock have high porosity and low permeability quizlet?

Porosity is the amount of open space in a rock or sediment. Permeability is the extent to which pores are interconnected. A rock can have high porosity but low permeability. An aquifer must have both high porosity and high permeability.

Why do some soils have high porosity but low permeability?

Since the soil/rock type has high porosity and permeability, water may move downward from gravity through the rock layer into lower layers. Some surface soils in the area have a high clay content (very small particles), so they have high porosity but low permeability.

Which material has a high porosity but low permeability?

clay
A good example of an aquitard is a layer of clay. Clay often has high porosity but almost no permeability meaning it is essentially a barrier which water cannot flow through and the water within it is trapped.

How are porosity and permeability related?

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.

How do porosity and permeability affect the flow of groundwater?

Porosity ultimately affects the amount of water a particular rock type can hold and depends on a couple of different factors. The ability of the ground water to pass through the pore spaces in the rock is described as the rock’s permeability. Permeable layers of rock that store and transport water are called aquifers.

What kind of rock is most likely to have both high porosity and high permeability?

In contrast, well-sorted sandstone closely replicates the example of a box of marbles cited above. The rounded sand grains provide ample, unrestricted void spaces that are free from smaller grains and are very well linked. Consequently, sandstones of this type have both high porosity and high permeability.

What does porosity and permeability mean?

Porosity and permeability are related properties of any rock or loose sediment. Mathematically, it is the open space in a rock divided by the total rock volume (solid and space). Permeability is a measure of the ease of flow of a fluid through a porous solid.

How do porosity and permeability differ?

What does it mean if a rock is said to have a high permeability?

High permeability means that water moves easily through the rock or sediment. Low permeability means that water moves very slowly through certain rocks and sediments.

Why does porosity affect permeability?

Does permeability depend on porosity?

The permeability of a medium is related to the porosity, but also to the shapes of the pores in the medium and their level of connectedness.

What rock would have the greatest porosity?

Of the consolidated rocks, well-fractured volcanic rocks and limestone that has cavernous openings produced by dissolution have the highest potential porosity, while intrusive igneous and metamorphic rocks, which formed under great pressure, have the lowest. Porosity is a measure of how much water can be stored in geological materials.

What rock is porous and permeable?

Porous and Permeable Rock (3) Metamorphic. These rocks are either igneous or sedimentary rocks, which have been metamorphosed or transformed by extreme heat and/or pressure.

Can you distinguish between porosity and permeability?

Porosity and permeability are both properties of rocks and soil. The main difference between porosity and permeability is that porosity is a measurement of space between rocks whereas permeability is a measurement of how easy it is for fluids to flow between rocks. Porosity measures how much space is between rocks.

Which Rock is more porous?

Still, marble is more porous, softer and less durable when compared to granite. Marble is especially vulnerable to household acids like vinegar, mustard, catsup, citrus and numerous food-related products. Acidic substances can cause etching when they come into contact with marble.