Text 22. Alexander karpinsky

Alexander Karpinsky is an outstanding Russian scientist who described the geological past of the European part of our country including the Donetz Basin. This tireless scholar studied the past history of the earth in order to help people to explore its wealth. He founded the Russian school of geology, which has won the leading position in the world science. His “Essays on the Geological History of European Russia” was of great importance in the development of geology and coal-mining in the Donetz Basin.

Alexander Karpinsky followed M. V. Lomonosov’s idea that rocks and minerals undergo constant changes, and that there are continuous physico-chemical processes in the earth’s crust.

He personally drew up paleogeographical maps showing the distribution of land and sea at prehistoric times. These geographical maps afforded a graphic picture of European Russia 500, 300, 250 and 200 million years ago.

According to his theory an enormous sea covered nearly the entire territory from the Urals to the Caspian and the Black Sea, and as far as the present Baltic Republics.

The territory of the present Donbass was once a bay of this sea. Giant plants and trees grew on its shores. These plants and trees fell into the marsh of the bay and were covered by sand and silt. The compressed deposits of trees and other plants underwent decomposition, and deposits of coal were formed.

(1160)

Part II Text 1. Apatite

Apatite (Greek apate, "deception"), is a mineral so named because it resembles various other minerals for which it might be mistaken. It consists chiefly of phosphate of lime. Apatite is a distinct mineral of composition Ca5(PO4)3F in which some or all of the fluorine may be replaced by chlorine (chlorapatite). The mineral crystallizes in the hexagonal system and has a hardness of 5 and a specific gravity of 3.2. When pure, apatite is colorless and transparent, but it may exhibit various degrees of color and opacity. These mineral phosphates of lime were often used in the preparation of fertilizers, but they have been replaced by phosphate rock.

(550)

Text 2. Granite

Granite, igneous rock of visible crystalline formation and texture, is composed of feldspar (usually potash feldspar and oligoclase) and quartz, with a small amount of mica (biotite or muscovite) and minor accessory minerals, such as zircon, apatite, magnetite, ilmenite, and sphene. Granite is usually whitish or gray with a speckled appearance caused by the darker crystals. Potash feldspar imparts a red or flesh color to the rock. Granite crystallizes from magma that cools slowly, deep below the earth’s surface. Exceptionally slow rates of cooling give rise to a very coarse-grained variety called pegmatite. Granite, along with other crystalline rocks, constitutes the foundation of the continental masses, and it is the most common intrusive rock exposed at the earth’s surface.

The specific gravity of granite ranges from 2.63 to 2.75. Its crushing strength is from 1050 to 14,000 kg per sq cm (15,000 to 20,000 lb per sq in). Granite has greater strength than sandstone, limestone, and marble and is correspondingly more difficult to quarry. It is an important building stone, the best grades being extremely resistant to weathering.

(970)

NOTES:

• potash feldspar - калиевый полевой шпат;

• sphene – титанит.