Put the facts in the correct order which shows how sea floor spreading develops.
Date: 2015-10-07; view: 549.
Compose sentences, using the following words and phrases
Look through the text and pick out the terms, which have the following definition.
1. to include / to be part of
2. stress that pulls a solid body apart
3. to fill up
4. a lump
5. insertion of sedimentary material into a crack
6. horizontal normal separation
7. downward movement
8. part of the continental crust above sea level
9. oceanic crust forms along the Mid-oceanic ridge and spreads out laterally
10. subsurface water is transported toward the surface
| 1.to creep outward | 6. to plug |
| 2. to subside | 7. to be tugged apart |
| 3. to thin away | 8. to stick |
| 4. to rise from beneath | 9. to sink |
| 5. to well up | 10. to create |
3.1.3. Spreading ridge evolves several stages. Put the words according to the stages. Compose sentences to describe the process. (R.P – 8.1.2, 8.1.3)
Stage 1
Stage 2
Stage 3
Stage 4
| mantle | new | rise through | molten |
| upwelling | blocks | rock | plug |
| melt | subside | molten | gap |
| partly | cracks | cracks | rock |
| oceanic | crustal | block | pull apart |
| crust | fresh | rim | old |
| push up | appear | plate | tension |
| above | bulging | crust | |
| subside | |||
| block | |||
| central |
1. Fresh cracks appear.
2. Mantle upwells.
3. It partly melts.
4. Molten rock plugs gaps.
5. Tension pulls old crust apart.
6. New crustal blocks subside.
7. Mantle pushes up the oceanic crust.
8. Molten rock rises through cracks.
9. Bulging plate splits.
10. The process is repeated.
11. A central block subsides.
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| After-reading tasks. | | | Fig. 45 Three types of plate boundaries |