1 / 16

GEOL 108 - Crises of a Planet Lab 5 - Rocks, Weathering, and Minerals

GEOL 108 - Crises of a Planet Lab 5 - Rocks, Weathering, and Minerals. Oct. 2 - 5, 2012. Department of Earth Sciences. QUIZ 3 REVIEW. Solid Bedrock. Unconsolidated sediments.

etoile
Download Presentation

GEOL 108 - Crises of a Planet Lab 5 - Rocks, Weathering, and Minerals

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GEOL 108 - Crises of a PlanetLab 5- Rocks, Weathering, and Minerals • Oct. 2 - 5, 2012 Department of Earth Sciences

  2. QUIZ 3 REVIEW Solid Bedrock Unconsolidated sediments A large earthquake occurs with the epicenter at point C. Is there likely to be more damage at point A or at point B, and why? Bonus: Name these 3 cartoon dogs (1 pt). REVIEW | 2 Department of Earth Sciences

  3. LAB 5 - ROCKS, WEATHERING, AND MINERALS • Identify minerals • Compare clay properties • Relate weathering of rocks to clay formation ROCKS, WEATHERING, MINERALS | 3 Department of Earth Sciences

  4. WHAT IS A MINERAL? • Definition of a Mineral: • naturally occurring • inorganic • solid • characteristic crystalline structure • definite chemical composition steel plastic sugar table salt mercury ice coal no, #1 no, #1 no, #1,2 YES! no, #3 YES! no, #2 basalt obsidian mica gold paper chalk coral no, #5 no, #4 YES! YES! no, #1,2 no, #2 no, #2 Source: www.sci.uidaho.edu/geol111/Geology%20101/minerals_II_jh.ppt • ROCKS, WEATHERING, MINERALS | 4 Department of Earth Sciences

  5. LUSTER • Metallic • Non-metallic • Glassy (vitreous) • Waxy • Silky • Greasy • Earthy (dull and powdery) • Pearly Shiny ≠ metallic! • ROCKS, WEATHERING, MINERALS | 5 Department of Earth Sciences

  6. COLOR • In general, color is not a diagnostic property • Impurities in the crystal can change the color • Color is less variable for minerals with metallic luster http://nature.berkeley.edu/classes/eps2//wisc/jpeg/l15s32.jpeg • ROCKS, WEATHERING, MINERALS | 6 Department of Earth Sciences

  7. STREAK • Streak is the color of a mineral’s powder • A mineral’s streak is the same for all specimens regardless of apparent color. Example: Metallic and earthy hematite (Fe2O3) both have red-brown streaks. • ROCKS, WEATHERING, MINERALS | 7 Department of Earth Sciences

  8. CLEAVAGE • A specific type of breakage • Occurs because bonds between atoms are weaker in some directions. • There may be up to 6, but usually 1-3 • Angles between cleavage directions 1 direction 2 directions 3 directions (90°) 3 directions (not 90°) • ROCKS, WEATHERING, MINERALS | 8 Department of Earth Sciences

  9. CLEAVAGE • One direction of cleavage Example: Mica • ROCKS, WEATHERING, MINERALS | 9 Department of Earth Sciences

  10. CLEAVAGE • Two directions of cleavage feldspar hornblende • ROCKS, WEATHERING, MINERALS | 10 Department of Earth Sciences

  11. FRACTURE • No planes of weakness • leads to irregular or • conchoidalfracture • ROCKS, WEATHERING, MINERALS | 11 Department of Earth Sciences

  12. CRYSTAL HABIT • A crystal’s habit is the shape it takes when it grows unimpeded by other grains (somewhat rare). • Commonly confused • with cleavage. Two intergrownStaurolite crystals “St. Andrew’s Cross” twinning • ROCKS, WEATHERING, MINERALS | 12 Department of Earth Sciences

  13. HARDNESS • What can a mineral scratch and what is it scratched by? It will only be scratched by harder material. • Please don’t test samples on each other! • ROCKS, WEATHERING, MINERALS | 13 Department of Earth Sciences

  14. OTHER PROPERTIES • Specific Gravity (density compared to water) • Magnetism • Reaction to acid (Carbonate minerals –CO3) • ROCKS, WEATHERING, MINERALS | 14 Department of Earth Sciences

  15. THE ROCK CYCLE Clays • ROCKS, WEATHERING, MINERALS | 15 Department of Earth Sciences

  16. CLAYS • Group of minerals, commonlyfound in sedimentaryrocks • montmorillonite • kaolinite • illite (Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2·nH2O Al2O3·2SiO2·2H2O (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,(H2O)] • ROCKS, WEATHERING, MINERALS | 16 Department of Earth Sciences

More Related