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 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.

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.

Пояснения к тексту:

ü adit - n горизонтальная под­земная выработка, штольня

ü angle – n угол

ü approximate - а при­близительный

ü bit - n режущий инструмент; буровая коронка, коронка для алмазного бурения; головка бу­ра, сверло; carbide bit - армиро­ванная коронка, армированный бур; diamond bit - алмазная буро­вая коронка

ü borehole - n скважина, бу­ровая скважина

ü crosscut - n квершлаг

ü dip - n падение (залежи); уклон, откос; v падать

ü enable - v давать возмож­ность или право (что-л. сделать)

ü exploit - v разрабатывать (месторождение); эксплуатиро­вать; exploitation – n разработка; эксплуатация

ü measure - n мера; мерка; кри­терий; степень; pl свита, плас­ты; v измерять

ü overburden – n покры­вающие породы, перекрываю­щие породы; верхние отложе­ния, наносы; вскрыша

ü pit – n шахта; карьер, разрез; шурф

ü reliable - а надежный; до­стоверный

ü rig - n буровой станок, буровая вышка; буровая каретка; буро­вое оборудование

ü sample – n образец; проба; v отбирать образцы; опробовать, испытывать

ü section - n участок, секция, отделение, отрезок, разрез, про­филь, поперечное сечение; geo­logical ~ геологический разрез (пород)

ü sequence - n последова­тельность; порядок следования; ряд

ü sink (sank, sunk) - v проходить (шахтный ствол, вертикальную выработку); углуб­лять; погружать; опускать; sink­ing - n проходка (верти­кальных или наклонных выра­боток); shaft sinking - проходка ствола

ü slope - n наклон; склон; бремсберг; уклон; v клониться, иметь наклон; sloping - а наклон­ный; gently sloping - с небольшим наклоном

ü steep - а крутой, крутопадаю­щий, наклонный

ü strike – n зд. простирание; v простираться; across the strike - вкрест простирания; along (on) the strike - по простиранию

ü trench – n траншея, канава; котлован; v копать, рыть, шур­фовать

ü to make use (of) – использовать, применять

ü to take into consideration принимать во внимание; syn take into account

2. Определите по словообразовательным элементам (суффиксам и префиксам), какой частью речи являются следующие слова. Переведите их письменно:

а) known — unknown;

б) differ — different — difference;

в) found — founder — foundation;

г) mean — meaning — means;

д) difficult — difficulty;

е) extract — extractive — extraction;

ж) improve — improvement

3. Прочитайте следующие сочетания слов и письменно переведите их:

1) preliminary exploration

2) shape, dimensions and quality of a deposit

3) properties of the surrounding rock and overburden

4) analyses and tests of samples

5) core drilling

6) drilling rigs

7) to measure bed thickness

8) to facilitate the planning of current production

9) to make use of exploratory openings

10) general size of a deposit

11) exact estimation of ore reserves

12) exploratory pits, crosscut and boreholes

13) reliable information on the angle of dip

14) to determine the industrial importance of a deposit

15) to take into consideration detailed estimates of the ore reserves of individual sections

4. Укажите, какие предложения соответствуют содержанию текста. Подтвердите свои ответы фактами из текста.

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 explora­tion.

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.

5. Письменно ответьте на следующие вопросы по тексту:

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 deter­mined?

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?

6. Найдите в правой колонке:

а) русские эквиваленты следующих сочетаний слов:

б) английские эквиваленты следующих сочетаний слов:

7. Заполните пропуски в предложениях, используя приведенные слова:

Bed bedded bedding

а) 1. Exploration of gently dipping ... deposits is performed by vertical pits.

2. The principal indicator of the economic importance of combustible shales is the persistence (постоянство) of the ...s in thickness and grade.

3. As is known, any change in the normal ... of a seam is called a disturbance.

Work workable working

б) 1. The term «prospecting» covers the whole range of geological ... aimed at discovering ... deposits.

2. Naturally, the prospector also finds non-... mineral con­centrations more often than economic ones.

3. Many countries have their own classification system of ... deposits.