Lesson 25: Special text: The Earth’s crust, rocks, minerals Read and translate the text



Download 16.69 Kb.
Sana22.05.2021
Hajmi16.69 Kb.


LESSON 25:

Special text: The Earth’s crust, rocks, minerals

Read and translate the text.

What lies deep within the Earth? Our planet has a central core with several layers, or shells, surrounding it. The densest matter is at the center, and each layer above it is increasingly less dense.


THE EARTH’S INTERIOR


Our planet is almost spherical, with a radius of approximately 6400 km (about 4000 mi). Its central core is about 3500 km (about 2200 mi) in radius (Figure 11.1). We know that the outer core is liquid from measurements of earthquake waves passing through the Earth, which suddenly change behavior when they reach the core. But the innermost part of the core is solid and made mostly of iron, with some nickel. The core is very hot—somewhere between 3000°C and 5000°C (about 5400°F to 9000°F).

MINERALS AND ROCKS


Minerals are naturally occurring inorganic substances, often with a crystalline structure. They are composed largely of the most abundant elements in the Earth’s crust, silicon and oxygen, coupled with metals or the metallic elements of iron, calcium, sodium, potassium, and magnesium.

Rocks are usually composed of two or more minerals. Often, many different minerals are present, but a few rock varieties are made almost entirely of one mineral. Most rock in the Earth’s crust is extremely old, dating back many millions of years, but rock is also being formed at this very hour as active volcanoes emit lava that solidifies on contact with the atmosphere or ocean.

Rocks fall into three major classes: (1) igneous, (2) sedimentary, and (3) metamorphic rocks. The three classes of rocks are constantly being transformed from one to another in a continuous process through which the crustal minerals have been recycled during many millions of years of geologic time. 

Activity 1. Find the definitions and synonyms of the words which are given in bold in the text.



Activity 2. Complete the table.

Word

Definition

Synonym


















































































Download 16.69 Kb.

Do'stlaringiz bilan baham:




Ma'lumotlar bazasi mualliflik huquqi bilan himoyalangan ©hozir.org 2020
ma'muriyatiga murojaat qiling

    Bosh sahifa
davlat universiteti
ta’lim vazirligi
O’zbekiston respublikasi
maxsus ta’lim
zbekiston respublikasi
axborot texnologiyalari
o’rta maxsus
davlat pedagogika
guruh talabasi
nomidagi toshkent
pedagogika instituti
texnologiyalari universiteti
toshkent axborot
xorazmiy nomidagi
rivojlantirish vazirligi
haqida tushuncha
samarqand davlat
toshkent davlat
navoiy nomidagi
nomidagi samarqand
ta’limi vazirligi
vazirligi toshkent
Toshkent davlat
matematika fakulteti
tashkil etish
Darsning maqsadi
kommunikatsiyalarini rivojlantirish
Ўзбекистон республикаси
Alisher navoiy
bilan ishlash
fanining predmeti
Nizomiy nomidagi
pedagogika universiteti
таълим вазирлиги
vazirligi muhammad
fizika matematika
maxsus ta'lim
fanlar fakulteti
sinflar uchun
universiteti fizika
o’rta ta’lim
ta'lim vazirligi
Toshkent axborot
махсус таълим
haqida umumiy
Referat mavzu
ishlab chiqarish
tibbiyot akademiyasi
pedagogika fakulteti
umumiy o’rta
Samarqand davlat