NS3310 – Physical Science Studies

1. NS3310 – Physical Science Studies Rocks and Minerals

2. Rocks Tell Stories • Limestone • Basalt • Breccia • Gneiss

3. Key Questions • What is a rock? • What is a mineral? • What different kinds of rocks are there? • How do rocks and minerals form? • How can you tell them apart? • Can one type of rock change into another type of rock? • Can you tell the story of a rock by “reading” its characteristics?

4. The Story of Limestone • Limestone forms by the precipitation of CaCO3 from solution in ocean water • What is a solution? • What is a precipitate? • CaCO3 is an ionically bonded salt • What is an ion? • What is an ionic bond?

5. Ions • Ions are atoms with more or less electrons than protons • Complex ions can also form • Ionic bonds form between ions due to their electrostatic charges Let’s learn more:

6. Most elements in the natural environment exist as ions

7. The Story of Basalt • Basalt is formed from minerals crystallizing from lava at the earth’s surface • Basalt is dense and mineral rich • Basalt’s crystals are very fine-grained • Basalt is the most common rock in the ocean floor

8. Distribution of Elements in the Solar System • Elements in the Sun • Carbonaceous Chondrites • Elements in the Earth’s Core • Elements in the Earth’s Mantle • Elements in the Earth’s Crust • Elements in the Earth’s Hydrosphere and Atmosphere

9. Minerals • Minerals are naturally occurring solids formed through geological processes that have a characteristic chemical composition, a highly ordered atomic structure, and specific physical properties • Chemical Composition • Elemental Minerals • Carbonate Minerals (and others with ionic bonds) • Silicate Minerals (and others with covalent bonds) • Physical Properties • Crystal Structure • Cleavage and Fracture • Streak and Color • Luster • Hardness • Specific Gravity • Special Properties

10. What Holds Silicate Minerals Together? • We’ve already seen that carbonate minerals form from ionic bonds, but what holds silicate minerals together? • Silicate minerals are held together by covalent bonds Let’s learn more:

11. The Story of Granite • Granite is an intrusive igneous rock • Granite is composed of silicate minerals (feldspar, quartz, mica, and horneblende) • Granite is coarse-grained because the crystals formed slowly • Most of the earth’s continental crust is made of granite • Most of this granite formed as intrusions into the earth’s crust

12. Igneous Rocks • Intrusive • Granite • Diorite • Gabbro • Porphyry • Extrusive • Basalt • Andesite • Glass • Scoria • Obsidian • Pumice • Pyroclastic • Tuff • Rhyolite

13. The Story of Gneiss • Gneiss is a metamorphic rock • This means that it is altered from existing rock but was not completely melted • The minerals in a gneiss have re-crystallized and formed light and dark bands due to heat and pressure exerted on the rock • Gneiss has many stories

14. Rock Cycle • Igneous rocks are formed from magma cooling in the earth’s crust or lava cooling on the surface. • Sedimentary rocks are formed from the weathered pieces of existing rock. • Metamorphic rocks are formed by the recrystallization of existing rocks. • All rocks are susceptible to weathering and erosion. • All rocks are also susceptible to metamorphism. • All rocks can be subducted and re-melted (though the continents preserve rocks formed throughout earth’s history because they float higher in the mantle than do the oceans). • The rock cycle is a continuous process!

15. You can Use Texture and Mineral Composition to Identify Rocks • Igneous Rocks • Intrusive • Extrusive • Pyroclastic • Sedimentary Rocks • Clastic • Chemical • Bioclastic • Metamorphic Rocks • Foliated • Unfoliated

16. Types of Rocks • Igneous • Intrusive • Extrusive • Pyroclastic • Sedimentary • Chemical • Precipitates and Evaporites • Fossiliferous • Clastic • Sorted • Unsorted • Metamorphic • Foliated • Unfoliated

17. Sedimentary Rocks • Sediment Formation • Mechanical and Chemical Weathering • Sediment Transport • Water, Ice, Wind and Gravity • Sediment Deposition • Weathering and Erosion • Environment of Deposition

18. Clastic Sedimentary Rocks • Unsorted • Conglomerate • Breccia • Sorted • Quartz Sandstone • Arkose • Graywacke • Siltstone • Shale

19. Chemical Sedimentary Rocks • Precipitates • Limestone • Dolomite • Travertine • Chert • Evaporites • Gypsum • Halite

20. Metamorphic Rocks • Metamorphic Processes • Recrystallization • Rotation • Regional Metamorphism • Contact Metamorphism • Foliated Metamorphic Rocks • Slate • Phyllite • Schist • Gneiss • Unfoliated Metamorphic Rocks • Marble • Quartzite

21. Key Concepts • Minerals are naturally occurring elements and compounds in the earth. • Rocks are combinations of minerals (or in some cases a single mineral) that form the earth’s crust. • Rocks that form from magma, lava or pyroclastic material are igneous rocks. • Rocks that form from sediments produced by chemical and physical weathering are called sedimentary rocks. • Rocks that form by remineralization of existing rocks are metamorphic rocks. • Processes that form and change rocks comprise the rock cycle. • The characteristics of rocks tell their stories!