Lesson 3. Differences between rocks

DIFFERENCES BETWEEN ROCKS

Rock textures

If ever you look at a piece of rock you can be sure that it will fall into one of these two groups

a) NON-POROUS, SHINY, HARD b) POROUS, DULL, CRUMBLY,

In (a) the grains are interlocking; they fit tightly together with no spaces between thegrains.

In (b) the grains can’t interlock because of their shape. They don’t fit tightly together and there are spaces in between the grains.

Remember the words

difference – різниця shiny – блискучий dull – тьмяний crumbly -- крихкий granite – граніт slate – сланець sandstone – пісковик limestone – вапняк properties – властивості

Answer the questions:

1. What are the properties of granite and slate?

2. What are the properties of sandstone and limestone?

3. What is the reason for the difference between these two groups of rocks?

4. How are the grains arranged in the rocks of group (a)?

5. Why can’t the grains interlock in the rocks of group (b)?

6. What is there in between the grains in the rocks of group (b)?

Lesson 4

Grammar: the Past Indefinite Tense