Folk Classification System of Sediments?

[Nucleus]

 

 

Can someone explain this one im having a hard time with this. How to get the percentage?and also the ratio below what does it mean?

[studiot]

First you need to understand what is meant by the terms at the vertices

 

Gravel

Mud

Sand

Clay

Silt

 

What do you understand by these?

 

The first of these, (gravel) is made of coarse particles (small stones).

The rest are made of fine particles.

You can separate the sediment into coarse and fine particles by sieving

But you cannot always separate the fine particles this way because there is size overlap.

So the fine particles often come as a mixture say 50% sand and 50% mud, which corresponds to the 1:1 ratio line on the left hand diagram.

Note the 50% is not the % in the whole sample, just the ratio of sand to mud in the fines part.

 

The diagrams show the classification names for different mixtures of these components.

 

The classification depends upon the % of the component whose % is given along the left hand edge.

This percentage forms the horizontal lines in the diagrams.

 

So again in the left hand diagram, any sample containing above 80% gravel falls above the 80% horizontal line and falls into the light brown zone. It is then classified as gravel.

 

Similarly in the right hand diagram anything above 50% sand is called sand.

Anything with greater than 90% sand is just called sand.

That with greater than 2:1 ratio of clay to silt in the fines, but less than 90% sand, is called clayey sand.

Edited April 13, 2014 by studiot

[Nucleus]

is there a formula in getting the percentage?

[studiot]

 

is there a formula in getting the percentage?

 

 

It's a measurement,

Perhaps you would like to explain further what you mean.

[Nucleus]

 

It's a measurement,

Perhaps you would like to explain further what you mean.

 

How to measure? we will be using the folk classification to classify sediments and we are having a problem in understanding it since its complicated especially getting the percentage of the sediments inorder for us to classify the sediments

[studiot]

This is a very long term discussion, with one post per week or so.

 

Do you only have limited internet access?

 

Or do you have to translate replies?

 

I don't fully understand what course you are studying.

 

The folk classification is for a particular groups of sedimentary rocks, not sediments themselves.

What you have posted is more like a soil classification.

 

Are you studying the rocks or the sediments?

 

For what purpose?

 

Here is a good resource, it includes answers to your question about measurement.

 

Post again if you want more.

 

http://environment.uwe.ac.uk/geocal/SoilMech/classification/default.htm

[Nucleus]

This is a very long term discussion, with one post per week or so.

 

Do you only have limited internet access?

 

Or do you have to translate replies?

 

I don't fully understand what course you are studying.

 

The folk classification is for a particular groups of sedimentary rocks, not sediments themselves.

What you have posted is more like a soil classification.

 

Are you studying the rocks or the sediments?

 

For what purpose?

 

Here is a good resource, it includes answers to your question about measurement.

 

Post again if you want more.

 

http://environment.uwe.ac.uk/geocal/SoilMech/classification/default.htm

 

 

sorry for late replies

I am a bs-biology student a 3rd yr bs-biology student i am currently taking summer class thats why Im busy and sometimes i cant visit this forum and reply .

I dont need to translate replies because i can understand english

 

thank you site you post it gives me an idea about the classification of sediments but i think i cant use it as a reference since it not a published work but it helps.

[studiot]

What you should know is that there are similar classification schemes, for different purposes, for the mixed loose material lying above the bedrock.

 

Agricultural Scientists use one for soils for farming purposes. There is a United States and a United Nations standard for this.

 

Civil Engineers use another version for classification of this material for it's strength and bearing capacity.

This is supporting roads and buildings and other structures.

It is also for predicting its performance in earth structures such as embankments cuttings and slopes.

Finally their classification is used to describe the natural material for the purposes of extracting wanted material such as sand and aggregate or clay for making bricks.

 

Geologists use yet another one for recording what is there.

They also use their classification for understanding natural slope processes, weathering, erosion and so on.