ROCKS Made of Minerals

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Verity Barber
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1 ROCKS Made of Minerals There are many types of minerals and most of them are used by organic creatures or by industry in some way or another. Some minerals are rare and very costly. Rock cycle This should actually be call a rock web and many of the parts are interconnected in many ways. It is the process by which all rocks are formed and can form other rocks. Takes millions of years Igneous rocks are formed under a lot of heat from the core of the earth. It takes solid rock and turns it into liquid rock called magma. When magma leaves the volcano or mantle it is called lava.

As it cools it forms crystals and solid masses Intrusive (inside) igneous rocks, like granite, form when magma cools inside the Earth: SLOWLY. Crystals are LARGE.

2 As it cools it forms crystals and solid masses Intrusive (inside) igneous rocks, like granite, form when magma cools inside the Earth: SLOWLY. Crystals are LARGE. Extrusive igneous rocks, like the basalt lava flow in this photo, form at the Earth's surface COOL QUICKLY: Fine grains. Volcanic rocks are extrusive (outside) igneous rocks. Crystals are small

3 When magma cools VERY fast that the ions can not line up glassy texture Photograph by Steve Mattox, July As it cools it forms crystals Picture of Mt Rushmore is granite

4 . Granite obsidian Mount Rushmore.

5 Carved granite into the southeast face of a mountain in South Dakota are the faces of four presidents, a memorial to American history. The faces of George Washington, Thomas Jefferson, Theodore Roosevelt and Abraham Lincoln look down from their stony heights and remind everyone that even the impossible is possible. South Dakota state historian Doane Robinson conceived the idea in 1923 to attract more people to the Black Hills of South Dakota with colossal carvings of western heroes After trying to get another sculptor to do the work, Robinson contacted Gutzon Borglum. Borglum, who agreed to come out to the Black Hills in 1924 to look at the area and see if the carving was possible It was the highest peak in the immediate vicinity, and the granite was very resistant, eroding one inch every 10,000 years.

6 On October 4, 1927 the first actual work of carving began. Dynamite was used to remove rock from the mountain until there was only a thin, three to six inch layer of granite left. With fanfare Washington's face was dedicated on July 4, " Abraham Lincoln was dedicated on September 17, 1937, In March of 1941 Borglum died suddenly of an embolism (burst blood vessel in the brain). His son, Lincoln, took over the project for the next seven months, until funding ran out. The carving of Mount Rushmore was shut down and the presidential faces were complete as they stood.

7 Sedimentary rock These are horizontal layers of compressed material NEVER HEATED that has been worn away from the mountains. Weathering: both chemical and mechanical breaks them apart. Erosion - moves the material to low lying areas where they pile up and become compacted over time. Sometimes, these areas are also worn away and redistributed in other areas.

9 The weight from the top layers gradually compress the lower layers and minerals have time to grow between the large layers. This type of

10 cementation holds the layers even tighter

11 Clastic sedimentary rocks are those that have been

12 broken apart and stuck together again. You can see large and small pieces Compressed

15 Chemical sedimentary rock are those that have minerals precipitate (come out) from solution and redistribute. The minerals may also be undissolved from water and form fine layers.

16 Organic sedimentary rocks are made from once living bones, shells, bodies and layers of plant material. Usually it is dark gray/black

17 Organic sedimentary rocks form from the build up and decay of plant and animal material. This usually forms in swamp regions in which there is an abundant supply of growing vegetation and low amounts of oxygen. The vegetation builds so quickly that new layers of vegetation bury the dead and decaying material very quickly. The bacteria that decay the vegetation need oxygen to survive. Because these decaying layers are buried so fast the bacteria use up what oxygen there is available and can not finish the decomposition of the vegetation. The overlaying layers become so heavy that they squeeze out the water and other compounds that aid in decay. This compressed vegetation forms coal. The longer and deeper that coal is buried makes it of higher quality.

18 Metamorphic rock This is formed deep in the earth where the heat from the core and the pressure from above turns the rock very soft. Minerals may

19 have time to concentrate.

21 Foliated metamorphic rock is ones where the mineral grains flatten and line up in parallel bands or layers. When

22 the minerals are heated and pressed they have time to migrate to other areas and concentrate. Slate Lime (shells of animals) -> sedimentary rock limestone -> metamorphic rock slate

23 foliated metamorphic non-foliated

24 Mineral grains grow and rearrange, they do not flatten or line up but still may migrate. They will grow MUCH larger than the foliated ones. Marble

25 Mica is added to paint and makeup to provide sheen, to drywall compound to make it sandable, is used as window 'glass' in stoves and furnaces, used in electronics to make capacitors and insulators, in the plastic industry as an extender, filler, and reinforcing agent, and in the rubber industry as a filler.

Chapter 9 : Rocks and Minerals

Table of Contents Chapter 9 : Rocks and Minerals Section 2: Igneous and Sedimentary Rocks Section 3: Metamorphic Rocks and the Rock Cycle Section 2 and 3: Rocks and the Rock Cycle There are 3 different