Of to into of at in from for in into

1. The geology can then be traced … different levels underground. 2. … some cases, despite a high grade, the flotation process might be difficult. 3. The first check would be to look … an outcrop of the mineralization. 4. Sometimes special drifts are driven in order … explore the deposit. 5. Rock samples … trenches are sent to the lab for analysis. 6. The most widely used exploration technique is the drifting … probe holes. 7. Miners need proof … what minerals are there. 8. Exploration sounds similar … prospecting. 9. The mineralization can be divided … high- and low-grade sections. 10. It is not easy to define the point where prospecting turns … exploration.

14. Fill in the articles if necessary:

1. … prospector will identify the discovery. 2. … first check would be to look for an outcrop of the mineralization. 3. Rock …. samples from trenches are sent to the lab for analysis. 4. … trenching, for example, provides accurate near-surface data. 5. … miners need …proof of what minerals are there, and the metal grades 6. In this practice, … drill with a diamond-tipped bit cuts a narrow kerf of … rock. 7. The company's … Board of Directors must be convinced that the mine will yield an acceptable return on capital invested. 8. Where … ground cover is only … shallow layer of alluvial soil, trenches can be dug across the mineralized area. 9. … several exploration techniques are used, depending on the type of a deposit and its proximity to … surface. 10. … most widely used exploration technique is the drifting of probe holes.

15. A three-minute talk. Discuss these questions with your group mates:

a) jobs in mining;

B) deposit types.

Complete a project: “Prospecting Minerals”.

SUPPLEMENTARY READING

Mineral Prospecting and Exploration

Finding Orebodies

For a geologist in the mining business, exploiting an ore-body is the easy part of the job. The hardest part is to find the ore-body and define it. But how do you find these accumulations of metallic minerals in the Earth's crust? The mining company has to ensure that an ore-body is economically viable, and needs a guarantee of ore production over a very long period of time, before it will engage in the heavy investment required to set up a mining operation. Even after production starts, it is necessary to locate and delineate any extensions to the mineralization, and to look for new prospects that may replace the reserves being mined. Investigating extensions, and searching for new ore-bodies, are vital activities for the mining company.

Prospecting

Prospecting involves searching a district for minerals with a view to further operation. Exploration, while it sounds similar to prospecting, is the term used for systematic examination of a deposit. It is not easy to define the point where prospecting turns into exploration.

A geologist prospecting a district is looking for surface exposure of minerals, by observing irregularities in colour, shape or rock composition. He uses a hammer, a magnifying glass and some other simple instruments to examine whatever seems to be of interest. His experience tells him where to look, to have the greatest chances of success. Sometimes he will stumble across ancient, shallow mine workings, which may be what led him to prospect that particular area in the first place.

Soil-covered ground is inaccessible to the prospector, whose first check would be to look for an outcrop of the mineralization. Where the ground cover comprises a shallow layer of alluviums, trenches can be dug across the mineralized area to expose the bedrock. A prospector will identify the discovery, measure both width and length, and calculate the mineralized area. Rock samples from trenches are sent to the laboratory for analysis. Even when minerals show on surface, determining any extension in depth is a matter of qualified guesswork. If the prospector's findings, and his theorizing about the probable existence of an ore-body are solid, the next step would be to explore the surrounding ground. Exploration is a term embracing geophysics, geochemistry, and also drilling into the ground for obtaining samples from any depth.

Date: 2015-12-24; view: 639