Here is a link to Mrs. Watson and class's brilliant soil study post...
Soil Investigations
Dear Mrs. Watson and class,
Your soil investigation techniques are wonderful and I see you have discovered soil isn't as simple as it might seem. The soil around my house is mainly a clay/sand mix but we have improved the soil in our garden by adding to our natural soil. We help build the humus layer.
Let's have a quick look at the story of soils...
Rocks
Formed from lava flows.
This photo is from my collection of photos but was unmarked and so I am not certain of its source.
Location: Kilaeua, Hawaii, U.S.A.
Blown out by volcanic eruptions.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Mount Tarawera, New Zealand
Can build up in layers.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Rock cutting, Yellowpinch, Australia
Eroded by wind and rain to form sands.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
Shells can add to the mix.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
In time some hardy plants can grow.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
Other plants take hold as the soil builds up. Dying plants build the humus layer.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
Fires can add ash to the mix making soils richer and help plants grow
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Royal National Park, N.S.W., Australia
Sometimes drought can take away the plants...
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
...but water can make the plants burst into life again.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: Bournda National Park, N.S.W., Australia
The process goes on as layers form and erode away, sometimes sharing beautiful colouring with us as they do...
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: North Tura Beach, Bournda National Park, N.S.W., Australia
and looking more like the work of an artist's brush.
Schools and students have permission to use this graphic for non-commercial, educational purposes.
Location: North Tura Beach, Bournda National Park, N.S.W., Australia