How are rocks made?

Rocks are found almost everywhere.  Very small rocks are called sand.  Rocks bigger than sand have other names, like pebbles, or stone.  Big rocks are called boulders.  In fact, almost all the earth – the mountains and the ground itself – is made of rock.

Rocks are made of minerals.  A few are made of just one mineral, but most rocks are made of many minerals, of magma, that lies under the earth’s crust.  As the magma pushes to the surface of the earth.  It cools and hardens into such rocks as granite, basalt and lava.

Some rocks are formed from bits and pieces of older rocks that pile up in layers and harden into rocks we know as sandstone and limestone.  Still other rocks began as one kind of rock and later were changed into other kinds of rocks.  Some limestone, for example, was changed by hear and pressure deep down in the earth into marble.

Why does the leaning Tower of Pisa lean?

The tower leans because it is slowly sinking in the soft ground.  The Leaning Tower of Pisa is a famous bell tower at Pisa, Italy.  The tower tips so far to one side that it looks as though it would fall over.  But it has been leaning for over 600 years!

Tower of Pisa

Why does it lean?  Of course, it wasn’t supposed to lean when it was built.  Yet it began to lean long before it was finished.

Builders began to work on the tower in 1174.  The stone foundation was not built on time enough ground to support the heavy marble tower and it began to sink unevenly into the soft soil.

But the builders went on adding story after story until the tower was 180 feet tall.  Since it was finished it has leaned a little more as the years went by.

Even today little by little the tower continues to tilt more each year.  It is now leans over 17 feet to one side.  Some people estimated that the tower will topple over within the next 100 years. – Dick Rogers