Friday February 17, 2012

1. FridayFebruary 17, 2012 (Quiz 20)

2. Launch Pad Friday, 2-17-12 No Launch Pad Today.Please turn in your Launch Pads for the week.

4. Announcements • I will be available after school today until 4:45.

5. Latest News None Today

6. Quiz 20

7. The Carbon Cycle and Sedimentary Rocks

8. The Carbon Cycle and Sedimentary Rocks

9. Stages in the Formation of Coal

10. Lithification of Sediment Sedimentary rocks are produced through the processes of lithification. Lithification occurs when loose sediments are transformed into solid sedimentary rock. Common lithification processes include: • compaction • cementation by calcite, silica, or iron oxide

11. Features of Sedimentary Rocks At the Earth’s surface, layer upon layer of sediment accumulates. Each layer records the nature of the environment at the time that layer was deposited. These layers, called sedimentary strata, or beds, are the most characteristic feature of sedimentary rocks. Separating the strata are bedding planes, flat surfaces along which rocks tend to separate or break. Each bedding plane marks the end of one episode and the beginning of another.

12. Fossils in Sedimentary Rocks Fossils are the traces or remains of prehistoric life, and are perhaps the most important inclusions found in some sedimentary rocks. Fossils help to determine past environments, are used as time indicators, and are useful for matching rocks from different places.

13. Worksheet Sedimentary Rocks (Part 2)

14. The Launch Pad Thursday, 1/27/11 • Define the terms “sedimentary strata” and “bedding plane.” • Each layer records the nature of the environment at the time that layer was deposited. These layers, called sedimentary strata, or beds. • Separating the strata are bedding planes, flat surfaces along which rocks tend to separate or break. Each bedding plane marks the end of one episode and the beginning of another.

15. Lab Sedimentary Rocks

16. The Launch Pad Friday, 1/28/11 • Name the following sedimentary rocks. Coal Conglomerate Coquina Sandstone Shale Breccia

17. Metamorphic Rocks Metamorphic rocks are those that have changed their form due to external environmental issues. Metamorphic rocks are produced from preexisting igneous, sedimentary, or even other metamorphic rocks. Metamorphism takes place where preexisting rock is subjected to temperatures and pressures unlike those in which it formed. There are different degrees of metamorphism which can be seen in the rock’s texture and in its mineralogy. An example of low-grade metamorphism is shale becoming slate. In high-grade metamorphism, obliteration of the rock’s original features occurs.

18. Metamorphic Rocks Most metamorphism occurs in one of two settings: When rock is intruded by a magma body, contact, or thermal metamorphism may take place. Here, change is driven by a rise in temperature within the host rock surrounding a molten igneous body. During mountain-building, great quantities of rock are subjected to directed pressures and high temperatures associated with large-scale deformation called regional metamorphism.

19. What Drives Metamorphism? The driving agents of metamorphism include heat, pressure (stress) from burial (confining pressure) or from differential stress during mountain building, and chemically active fluids (mainly water and other volatiles.)

20. Pressure as a Metamorphic Agent

21. Metamorphic Textures The degree of metamorphism is reflected in the rock’s texture and mineralogy. When rocks are subjected to low-grade metamorphism, they become more compact and more dense (like slate.) Under more extreme conditions, stress caused certain minerals to re-crystallize. Consequently, many metamorphic rocks consist of visible crystals, much like coarse-grained igneous rocks.

22. Metamorphic Textures The crystals of some minerals will recrystallize with a preferred orientation, essentially perpendicular to the direction of the compression force. The resulting mineral alignment usually gives the rock a layered or banded appearance termed foliated texture

23. Metamorphic Textures Some metamorphic rocks have a nonfoliated texture. Metamorphic rocks composed of only one mineral that forms equidimensional crystals are, as a rule, not visibly foliated (examples: limestone and marble.)

24. Common Metamorphic Rocks

25. Classification of Metamorphic Rocks

26. Worksheet Metamorphic Rocks

27. The Launch Pad Monday, 1/31/11 • Name the following metamorphic rocks. phyllite slate schist foliated gneiss anthracite marble quartzite nonfoliated

28. Lab Metamorphic Rocks

29. Classification of Metamorphic Rocks