Metamorphic Rocks: Recycled Rock(Exploring Science: Earth Science)

Metamorphic rocks, like the name suggests, morphed from rocks that already existed. These rocks form through changes in conditions like heat and pressure. The type of metamorphic rock that forms depends on how much heat or pressure is involved. During the transformation, metamorphic rocks can change properties such as shape and texture. In ancient Greece, pillars, sculptures, and cities were built from marble, a type of metamorphic rock. Today, marble and other types of metamorphic rock are still used in construction.

Review :
A trickle of melted rock creeps down the side of a volcano... and with that, youngsters 10 to 12 years of age are on a path of finding out how the world works. Earth is continuously recycling its crust, producing three basic types of rock: igneous, sedimentary, and metamorphic. The long story of how rocks form, change structure under heat and pressure, and then re-form is told in this set of three small, beautifully illustrated books. Igneous Rocks opens the trilogy wit ha double-page spread of volcanoes. The red glow of a volcanic eruption on the slope of Mt. Etna stands out against the dark night sky behind the soft lights of Catania, Italy. On the facing page, lava pours into the blue Pacific Ocean off Hawaii, raising huge clouds of steam. Lava runs rapidly if large quantities of gas are dissolved in it, but if the gas content is low, eruptions can be explosive, as at Mt. St. Helen's. Geology is a descriptive science. Rocks are classified by color, texture, composition, rate of cooling, etc. Pages 36 and 37 show pleasing designs with faint lines. Granites and other slow-cooling rocks form the bases of continents. Mt. Rushmore was carved out of granite rock. Sedimentary Rocks opens with a picture of deeply entrenched meanders of San Juan River in Arizona cutting through horizontal beds of beige sandstone. On the facing page is a contrasting blue photo of ripple marks on the floor of a settlig basin in which sedimentary rocks are forming, perhaps eventually to be lifted up, become incised, and form canyon walls. Physical and chemical weathering break down mountains, and the particles move downstream. The wonderful humorous section titled "Sedimentary Journey" may be lost on the young, but not the old. Metamorphic Rocks opens with a surprise, for here the sculptor is the hand of humans, not nature. In creating his Pieta`, depicting Jesus being cradled in his mother's arms after the descent from the cross, Michelangelo has added warm humanness to a block of cold marble. On the facing page, the stern curlyheaded marble figures with long, flowing robes adorn St Peter's Basilica. Marble is limestone that has been subjected to heat and pressure and restructured into rock that can take a polish. A section head reminds us that "Rocks Are Not Forever" Earth recycles.-- "SB&F" This set of books has clear text that explains the scientific topic while discussing the social and historical significance of each. Using recent research, these books show scientists at work in their fields and answer the questions posed by every curious science student.-- "Science Books & Films "Science Series for Every Library""