What are Caves

A roofed rock cavity of natural origin, accessible from the surface and large enough for human entry. Caves occur in all kinds of rocks and in every geographical region. The scientific study of caves is called speleology; spelunking is the exploration of caves as a hobby. Lava tube caves, an important minor class, are formed by channelled outflow of molten lava in congealing flows. Sea caves most commonly result from erosion by waves. Most known caves, including the largest, longest and deepest, are created by subsurface waters dissolving passageways in soluble rocks, principally limestone. Limestone caves develop along or down natural rock partings, such as joints or bedding planes. Over time, subsurface water may enlarge the diameter of passages in the partings from micrometers to meters or tens of meters. The natural beauty of caves is greatly enhanced by their secondary mineral deposits, principally stalactites, stalagmites and flowstones of calcite, a reprecipitate of dissolved limestone.

Longest Caves. The Mammoth Cave-Flint Ridge System in Kentucky, US, is the longest known. More that 500 km of interconnected passages are mapped there. Other caves in Switzerland, the US and Ukraine exceed 100 km. Canada's longest known, Castleguard Cave in Banff National Park, has 23 km of galleries passing far beneath the Columbia Icefield.

Deepest Caves. Several caves in the Alps, Caucasus, Pyrenees and Mexico have now been explored to a depth of over 1500 m. Arctomys Cave, in the Rocky Mountains, is Canada's deepest, at 560 m underground.

Life in Caves. Caves trap sediment, flora and fauna, thus preserving natural historic records. Most of our knowledge of human cultural evolution before the last 10 000 years comes from cave dwellings. Many varieties of insects, fishes, birds and mammals live in caves, some adapting to the total darkness by losing their eyes and pigmentation.

Author D.C. FORD

http://www.thecanadianencyclopedia.com

Vocabulary Drill:

Task 1. a) Translate the following words and collocations into Russian. Restore the situations in which they are used in the texts1-3:

bowels of the earth, concern for health, demand for outdoor experiences, the thrill of original discovery, the remotest corners of the globe, investigation of caves, to enjoy the solitude, the underground wilderness, technical challenges, lack of experience, to live unforgettable experience, complete safety, rock instability, light failure, uneven floors, falling rocks, advanced caving, hands-and-knees situations, negotiation of vertical drops, outside assistance, RCMP detachment, introductory courses, equipment hire, first aid kit, a headlamp, backup flashlight, waterproof, a long loop, emergency, of battery-operated light, bulb, roofed rock cavity, lava flow, parting, interlinked passages and shafts, sediment

b) Find in the texts translation of the following words and collocations:

искать новые ходы, товарищество, слаженная работа команды, случайный посетитель, «дикий» спелеотуризм, полная безопасность, риск, переохлаждение, истощение, заблудиться, деятельность, требующая усилий, запасной источник энергии, опора для ноги, низкий свод (пещеры), вертикальный ход (дыра), предполагаемый исследователь пещер, прокат снаряжения, аптечка, кодекс поведения, ручной электрический фонарь, свет подводит, быть под рукой, дополнительный набор батареек, gas lantern, вяленое мясо, сладкая плитка, мусорить, жаждоутоляющее, прочный, выбраться из узкого места, поток раскаленной лавы, вторичные минеральные образования, натечные камни, горизонтальный ход, вертикальный ход

Task 2. a) Match the words from two columns to make collocations.

b) Translate the collocations into Russian:

remote unforgettable introductory equipment concern for find complete necessary get strenuous advanced negotiate prospective thrill

caving health corner a drop a new extension experience of original discovery safety precautions activity cavers course lost hire

Task 3. Fill in the gaps in the sentences with the collocation from part a). Put the words in proper forms:

1. Caving enthusiasts want to investigate every ….. of the cave.

2. Spirit of adventure is not the only reason for people to start traveling. …… and fitness made many people move to nature.

3. When a caver ……, it is often named after him.

4. Caving is a ……, but rewarding one. If you take all the …… , you’ll have a chance to …… of getting into bowels of the earth in …… .

5. …… are recommended to take an …… to acquire necessary skills.

6. He didn’t accept the offer to undertake a caving trip because even the idea of …… in the darkness terrified him.

7. …… made them…… . And not in vain. When they squeezed themselves through the narrow drop they entered into a picturesque grotto. It was … .