Transportation

Alright class, today we will be talking about how soils are formed from rocks. Can anyone tell me what processes contribute to this formation?

Isn't it mainly through weathering?

Exactly! Weathering is crucial. We can categorize it into physical and chemical weathering. Physical weathering breaks down rocks into smaller pieces without changing their composition. Can anybody give me an example of physical weathering?

Freezing and thawing in winter can cause rocks to crack.

Correct! And what about chemical weathering?

That would involve changing the rock's minerals, right? Like when rainwater reacts with rocks?

Yes! Rainwater can form new compounds through reactions. This is important because fine soils typically come from chemical weathering.

So the original rock can change completely during this process?

That's correct! Remember, these processes directly relate to the properties of the soil we use in engineering.

Now, let's discuss transportation. How do you think soil moves from one place to another?

I guess water would carry soil away from rivers and streams?

Yes! Water is a major agent. It can carry soil suspended in it or allow it to roll along the bottom. What else can transport soil?

Wind could carry fine soil particles as well.

Exactly! Wind erodes and transports finer soils, often leading to uniform deposits. And what about glaciers?

Glaciers move slowly and can grind and carry a lot of material.

Right! The movement of glaciers results in well-graded deposits due to grinding and crushing. Factors like gravity also play a role.

So each of these agents affects the soil's structure and composition differently?

Exactly! The nature of soil varies drastically based on how it's transported and deposited.