1. Ответьте на следующие вопросы по тексту:

   1. What is magma?

   2. Where does magma take its origin?

   3. How are intrusive and extrusive rocks formed?

   4. What does the igneous rocks classification take into consideration?

   5. What does the classification of the rocks depend on?

   6. What rocks are known as plutonic (hypabyssal, volcanic)?

   7. How were the rocks originally classified?

   8. What is the size of plutonic rocks (hypabyssal rocks, volcanic rocks)?

   9. What is groundmass?

   10. What texture do plutonic rocks have?

   11. What texture do hypabyssal and the volcanic rocks have?

   12. What other texture is common?

   13. What texture do lavas have?

2. Найдите в тексте предложения, содержащие словосочетания из комментариев и переведите их письменно. Составьте свои предложения с этими словосочетаниями.

3. Вставьте следующие слова в текст:

grains extrusive occurrence large ferrous

size economical classifying magma

Igneous Rocks

Igneous rocks form a … group of minerals. Igneous rocks have crystallized from … . They are classified in different ways. The first classification depends on their … . The rocks texture and composition is also important when …. Igneous rocks occur as intrusive or … rocks. The rocks grain … depends on their occurrence place. The intrusive rocks have larger grain size while extrusive rocks have finer … . Igneous rocks are rich in minerals that have … importance. These rocks are rich in iron, nickel, gold, zinc and other … metals.

4. Закончите предложения подходящими по смыслу словами из текста:

   1. The igneous rocks have assumed a crystalline structure …

   2. Magma is usually formed …

   3. Extrusive rocks are the result of …

   4. Intrusive rocks are the result of …

   5. The igneous rocks classification takes into consideration …

   6. The classification of the rocks depends on …

   7. Plutonic rocks are …

   8. Hypabyssal rocks are …

   9. Volcanic rocks are …

   10. Plutonic rocks have an average grain size of …

   11. Hypabyssal rocks display grain size from …

   12. Volcanic rocks are with grain size less than …

   13. Granitic texture is …

   14. Porphyritic texture is …

   15. Ophitic texture is …

   16. Vesicular texture is …

5. Перефразируйте следующие предложения, используя слова, данные в скобках:

   1. As it is known the igneous rocks have assumed a crystalline structure from magma. (have crystallized)

   2. Magma takes its origin in the earth crust. (has)

   3. The igneous rocks classification takes into consideration two characteristics. (is carried out, twofold basis)

   4. The classification of the rocks depends on the percentage of silica. (are classified)

   5. Silica surplus is made known by the presence of quartz. (excess, is shown)

   6. Originally the rocks were classified under these three headings. (Formerly, divided, heads)

   7. Plutonic rocks have an average grain size of more than 0.5 mm. (are those with)

   8. The hypabyssal and the volcanic rocks are given to having large crystals set in a finer grained groundmass. (are liable to have)