Grammar focus Modals in English

Task 1. Translate the sentences into Ukrainian paying special attention to the underlined modals.

1. Data of this type led them to examine the possibility that magma might change (evolve) and thus become the parent to a variety of igneous rocks.

2. Although the interiors of plates may experience some deformation, all major interactions among individual plates (and therefore most deformation) occur along their boundaries.

3. In addition, magma can originate far from plate boundaries.

4. It should be noted that not all minerals produce a streak when rubbed across a streak plate.

5. Not all minerals have cleavage, but those that do can be identified by the relatively

6. smooth, flat surfaces that are produced when the mineral is broken.

7. However, colour should not be used to distinguish these groups.

8. Conversely, changing economic factors can turn a once profitable ore deposit into an unprofitable deposit that can no longer be called an ore.

9. The Sierra Nevada batholith, for example, must be a continuous granitic structure that forms much of the Sierra Nevada in California.

Task 2. Choose the best modal to complete the sentences and translate them.

1. By definition, a plutonic body must/is to have a surface exposure greater than 100 square kilometers to be considered a batholith.

2. A 19th century study by G. K. Gilbert of the U.S. Geological Survey in the Henry Mountains of Utah produced the first clear evidence that igneous intrusions can/ are able to lift the sedimentary strata they penetrate.

3. Not all pegmatites contain such large crystals, but these examples emphasize the special conditions that must/have to exist during their formation.

4. Because of their mobility, the ion-rich solutions can/must migrate great distances through the surrounding rock before they are eventually deposited, usually as sulfides of various metals.

5. Because these accumulations contain only 0.4 to 0.8 percent copper, between 125 and 250 kilograms of ore must/should be mined for every kilogram of metal recovered.

6. However, the lava is usually able to / can move forward by breaking through the hardened surface.

Discussion

Task 1. Read and memorize the following words:

olivine - олівін, хризоліт, перидот	soil - ґрунт
biotite - біотит	garnet - гранат
coating – шар, покриття	luster - блиск
conchoidal – конкоїдальий, раковистий (про злам)	augite - авгіт
high-gloss – глянцевий	pyroxene - піроксен
kaolinite - каолініт	feldspar - польовий шпат
muscovite - калієва слюда, мусковіт	clay - глина, глинозем
microcline- мироклин	amphibole – амфібол, рогова обманка
opaque - матовий, без блиску; темний	hornblende - амфібол, рогова обманка
orthoclase - ортоклаз

Task 2. Read the text. Translate it into Ukrainian. Talk about light and dark silicate minerals. Use the following names of minerals in your story: olivine, augite, hornblende, orthoclase, microcline, biotite, quartz, garnet, kaolinite.