Test yourself

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

1. A path of the gas-rich magma moving up through a fissure is usually localized into a pipe.

2. A surface opening in the volcanic activity is called a vent.

3. A cone-shaped structure is usually called a crater.

4. Craters can also form when the summit area of a volcano collapses following an eruption.

5. Cinder cones are produced by the accumulation of fluid basaltic lavas and exhibit the shape of a broad, slightly domed structure that resembles a warrior’s shield.

6. Examples of the composite cones include the Canary Islands, the Hawaiian Islands, the Galapagos, and Easter Island.

7. Cinder cones are composed mostly of loose pyroclastic material.

8. The Andes in South America and the Cascade Range of the western United States and Canada are the examples of shield volcanoes.

9. Two of the most perfect cones—Mount Mayon in the Philippines and Fujiyama in Japan—exhibit the classic form of a composite cone.

10. The composition of volcanic gases is not that important because they do not contribute to our planet’s atmosphere.

11. Pyroclastic materials range in size from very fine dust and sand-sized volcanic ash to pieces that weigh several tons.

12. When the hot ash falls, the glassy shards often fuse to form a rock called lapilli.

13. Scoria is the name of vesicular ejecta - a product of basaltic magma.

14. When magmas with andesitic or felsic compositions erupt explosively, they emit ash and pumice.

Task 2. Fill in the gaps with the suitable words and word-combinations.

pyroclastic material, pahoehoe, gases, lapilli, aa

The materials associated with a volcanic eruption include (1) lava flows ( … flows, which resemble twisted braids; and … flows, consisting of rough, jagged blocks; both form from basaltic lavas); (2) … (primarily water vapor); and (3) … (pulverized rock and lava fragments blown from the volcano’s vent, which include ash, pumice, … , cinders, blocks, and bombs).

Unit 8

VOLCANIC STRUCTURES AND ERUPTIVE STYLES

Part 2

Task 1. Read and memorize the following words:

collapse pit – кратер вулкану	colossal - величезний
plug - пробка, заглушка; екструзивний бісмаліт	connect – з’єднувати
сaldera - кальдера	drainage - дренаж
weathering – вивітрювання, ерозія	lower – зменшуватись, знижуватись
squeeze – вичавлювати, видавлювати	pancake-like – подібний на млинець, оладку
steep-sided – той, що має круті або обривчасті сторони	piston - поршень
unconsolidated – пухкий, неущільнений	succumb – не витримати, поступитися
subterranean - підземний	toblanket - покривати
diatreme - діатрема	undergo - піддаватися
resistant – стійкий, міцний	vanish - зникати

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