Magmatic, igneous, vein deposits, metal-rich, hydrothermal solutions, disseminated deposit

Some of the most important accumulations of metals, such as gold, silver, lead, and copper, are produced by … processes. The best-known and most important ore deposits are generated from … . Hydrothermal deposits are thought to originate from hot, … fluids that are remnants of late-stage … processes. These ion-rich solutions move along fractures or bedding planes, cool, and precipitate the metallic ions to produce … . In a … (e.g., much of the world’s copper deposits), the ores from hydrothermal solutions are distributed as minute masses throughout the entire rock mass.

Test yourself

Task 1: Tell whether the sentences are true or false. Correct the false ones.

1. When magma rises through the crust, it forcefully displaces host or country rock.

2. The structures that result from the emplacement of magma into preexisting rocks are called saturns.

3. Plutons can have a tabular or a massive shape.

4. If igneous bodies cut across existing structures, they are discordant.

5. Dikes closely resemble buried lava flows.

6. Sills are nearly horizontal, concordant bodies that form when magma exploits weaknesses between sedimentary beds.

7. Large granite batholiths consist of no plutons.

8. Plutons which are less than 100 square kilometers are termed stocks.

9. Laccoliths can lift the sedimentary strata they penetrate.

10. Pegmatites are composed of unusually large crystals.

11. Many of the most productive deposits of gold, silver, and mercury are hydrothermal vein deposits.

12. Accumulation generated by hydrothermal activity is called a disseminated deposit.

Task 2. Choose the best word to complete the text.

Massive, concordant, shape, discordant, tabular, the country or host rock.

Intrusive igneous bodies are classified according to their … and by their orientation with respect to … , generally sedimentary or metamorphic rock. The two general shapes are … (sheet-like) and … . Intrusive igneous bodies that cut across existing sedimentary beds are said to be …; those that form parallel to existing sedimentary beds are … .

UNIT 6

Volcanic eruptions

Task 1. Read and memorize the following words:

cone-shaped - конічний	congeal - замерзати
dissolved – той, що є розчиненим	contain - містити
erupt - вивергатися	halt - зупиняться
extrude - виштовхувати	impede – ускладнювати, перешкоджати
picturesque – мальовничий, яскравий	influence by – підлягати впливу
bond – хімічний зв’язок	polymerization - полімеризація
perceive - розуміти	viscosity – в’язкість, липкість, тягучість
explosive - вибуховий	reduce – зменшувати, знижувати, послабляти

Task 2. Read the following text, translate it into Ukrainian.