Exploration of Mineral Deposits

Exploration is known to include a whole complex of investiga­tions carried out for determining the industrial importance of a deposit. The main task is to determine the quality and quantity of

Unit 7_____________________________________________ 177

mineral and the natural and economic conditions in which it oc­curs. The exploration of the deposit is divided into three stages, namely preliminary exploration, detailed exploration and exploita­tion exploration.

The aim of preliminary exploration is to establish the general size of a deposit and to obtain an approximate idea of its shape, dimensions and quality. At this stage the geological map of the de­posit is corrected and a detailed survey of its surface is completed.

The information on the preliminary exploration is expected to give an all-round description of the deposit which will enable the cost of its detailed exploration to be estimated.

The following points should be taken into consideration: 1) the shape and area of the deposit; 2) its depth and angles of dip and strike; 3) its thickness; 4) the properties of the surrounding rock and overburden; 5) the degree of uniformity of distribution of the mineral within the deposit and the country rock, etc.

Preliminary explorations can make use of exploratory openings such as trenches, prospecting pits, adits, crosscuts and boreholes. They are planned according to a definite system, and some are driven to a great depth.

All the exploratory workings are plotted on the plan. These data allow the geologist to establish the vertical section of the deposit.

The quality of the mineral deposit is determined on the basis of analyses and tests of samples taken from exploratory workings.

The method of exploration to be chosen in any particular case depends on the thickness of overburden, the angle of dip, the sur­face relief, the ground water conditions and the shape of the min­eral deposit.

The task of the detailed exploration is to obtain reliable informa­tion on the mineral reserves, their grades and distribution in the different sectors of the deposit. Detailed exploration data provide a much more exact estimate of the mineral reserves.

Mine or exploitation exploration is known to begin as soon as mining operations start. It provides data for detailed estimates of the ore reserves of individual sections. It facilitates the planning of current production and calculating the balance of reserves and ore mined.

The searching and discovering of new mineralized areas are based on geological survey and regional geophysical prospecting. The results of these investigations provide data on iron-bearing formations and new deposits for commercial extraction.

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In detailed exploration both underground workings and bore­hole survey are used. Core drilling with diamond and carbide bits is widely used. Non-core drilling is also used in loose rocks in combi­nation with borehole geophysical survey.

One of the main methods to explore coal deposits is also core-drilling. Modern drilling equipment makes it possible to accurately measure bed thickness and determine structure of beds, faults and folds. Recording control instruments are attached to drilling rigs which allow the geologists to get reliable samples good for nearly all parameters of coal quality to be determined.

УПРАЖНЕНИЯ

25. Уважите, какие предложения соответствуют содержанию текста.
Подтвердите свои ответы фактами из текста Б.

1. The purpose of preliminary exploration is to determine the
mineral reserves and their distribution in the different sectors of the
deposit.

2. The properties of the surrounding rock and overburden
should be taken into consideration during the preliminary explora­
tion.

3. The purpose of the detailed exploration is to find out the
quantity (reserves) of the deposit.

4. Exploitation exploration facilitates the planning of current
production.

5. Both core drilling and non-core drilling are widely used.

6. Recording control instruments allow geologists to get reliable
ore samples.

26. Ответьте на следующие вопроси:

1. What stages does exploration include?

2. What is the main purpose of preliminary exploration?

3. What should be taken into consideration by geologists during
preliminary exploration?

4. What exploratory openings do you know?

5. Do you know how the quality of the mineral deposit is deter­
mined?

6. What is the aim of a detailed exploration?

7. Is core drilling used in prospecting for loose rocks?
8.What is drilling equipment used for?

Unit 7

27. а) Найдите в правой колонке русские эквиваленты следующих сочетаний слов:

1. bedded deposits

2. core drilling

S.the angle of dip of the seam

4. the thickness of overburden

5. exploratory workings

6. composition of minerals

7. pits and crosscuts

8. to exploit new oil deposits

9. sampling

10. geological section

а) мощность наносов

б) разрабатывать новые место-

рождения нефти

в) шурфы и квершлаги

г) пластовые месторождения

д) опробование (отбор) образцов

е) угол падения пласта

ж) колонковое бурение

з) геологический разрез (пород)
и) состав минералов

к) разведочные выработки

б) Найдите в правой колонке английские эквиваленты следующих сочетаний слов:

1. буровые скважины

2. по простиранию пласта

3. равномерность распределе­
ния минерала в залежи

4. водоносность пород

5. карбидные и алмазные коронки

6. детальная разведка

7. использовать новые поисковые
методы

8. проникать в залежь

9. коренная порода

10. свойства окружающих пород

а) ground water conditions

б) detailed exploration

в) boreholes

г) along the strike of the bed (seam)

д) carbide and diamond bits

е) the uniformity of mineral distri-

bution in the deposit

ж) the properties of surrounding rocks

з) to make use of new prospecting
methods

и) country rock

к) to penetrate into the deposit

28. Заполните пропуски в предложениях, используя приведенные слова:

bed

Bedded