B. destruction of sedimentary rocks

C. consolidation of sedimentary rocks

3. Listen to the dialogue. Sediments are cemented by:

A. water

B. pressure

C. minerals

You will hear short conversations between two people. At the end of each conversation, a third person will ask a question about what the two people said. Each conversation and each question will be spoken only one time. For this reason, you must listen very carefully to understand what each speaker says. After you hear the conversation and the question, read the three selections and choose the one that is the best answer to what the speaker asked.

1.How are the main ingredients of sedimentary rocks called?

A. clasts

B. clay minerals

C. grains

2. What is the size of grains forming shales?

A. large

B. medium

C. fine

3. What substance refers to orthoquartzite?

A. shale

B. siltstone

C. arenite

5. DISCUSSION: Classification of sedimentary rocks (R.P – 6.1, 6.2)

5.1. Situational games: use the following key words and communicative formulas

KEY WORDS	COMMUNICATIVE FORMULAS
sediment	I image that
chemicals	we tend to think
dissolve	it is (was) a common view that
oolites	I wish I could agree with you that
evaporates	I partially agree with you that
gypsum	unfortunately
offshore (waters, basin)	could you comment on
weathering	the words
diagenesis	it may have disappointing results
bedding plane	a great advantage is
swampy vegetation
acid conditions
extract
include

A. Discuss the following statements, discussing them with your group mates (agree / disagree / doubt)

· When parent rock breaks up its minerals behave in similar ways

· Coal types vary according to the processes involved

· Three main minerals tend to settle in a sequence-

- gypsum

- sodium chloride

- calcium carbonate

B. You are going to take your exam in geology. There is one difficult question that you don’t understand – HOW THICK EVAPORATE LAYERS WERE FORMED.

C. Image that you are sediment. Your group mates are minerals. Act out the processes of converting sediments into a rock.

5.2 You have to give a lecture on sedimentary rocks. Use the following diagram.

Sedimentary Rocks

mechanical sediments chemical sediments organic sediments

destructive mechanical destructive chemical action of the decay

action of water, wind, etc. action of water of the remains of

organisms

unconsolidated consolidated rock salt, gypsum coal, peat,

(uncemented (firmly

particles) cemented

particles)