Say whether the following statements are true or false

1 Geology is the science that deals with the origin, history, and physical structure of the earth and its life, as recorded in rocks.

2 Geologists try to answer such questions as how old the earth is, where it came from, and what it is made of.

3 Astronomers and physicists think today that the earth was formed at least 14 billion years ago out of a cloud of cosmic dust.

4 It is considered that the core has two parts: an inner, solid core and an outer liquid core.

5 Mantle around the inner core is formed by heavy minerals.

6 Geologists distinguish between oceanic crust, which lies under the oceans, and continental crust, of which the continents are made.

7 They believe that the tallest mountains in the world, the Himalayas, formed when Japan smashed into Asia.

8 Fossils of marine organisms found in some of the highest mountains and in the deep­est oilwells prove that the rocks there were formed in ancient seas and then rose or fell to their present positions.

9 Rock strata that have crumpled and buckled into wavelike structures are called faults.

10 Sedimentary rocks are rocks formed in verticalal layers.

5 Fill in the gaps

Near the surface of the ____________ (1), at atmospheric temperatures and pressures, rocks tend to break when subjected to great stresses such as earthquakes. However, deeper into the crust, _____________ (2) rising from the mantle raises the rocks' temperature, and the pressure of overlying rocks compresses them. At these higher __________ (3) and pressures, the rocks become somewhat flexible. Instead of breaking, they tend to warp or fold when stressed. _______________ (4) occur when broad areas of the crust rise or drop without frac­turing. The rock strata in these areas appear to be horizontal but, on closer inspection, are actually slightly tilted, or dipping

Rock strata that have crumpled and buckled into ______________(5) structures are called folds. Folds are the most common structures in mountain ________________ (6), ranging in size from wrinkles of less than an inch to great arches and troughs many miles across. The upwarps or arches are called _______________ (7); the downwarps or troughs are synclines. Geologists further divide anticlines and synclines according to how the folds tilt. A short anticline with its crest plunging downward in all direc­tions from a high point is called a ___________________ (8). Many domes are almost perfectly circular. Some of them have a core of one type of rock that has pushed up into the surrounding rock and lifted it, such as the salt domes along the U.S. Gulf Coast. A syncline that dips down toward a common center is called a _______________ (9) Anticlines and synclines are important to petroleum geologists because they often contain petroleum.