The Rock Cycle
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The document describes the rock cycle, which is the process by which rocks are formed at the Earth's surface and within the Earth over geological time. It involves several steps: weathering and erosion of existing rocks, transportation and deposition of sediment, burial and compaction of sediment into sedimentary rock, deformation and metamorphism of existing rocks due to heat and pressure, melting of rocks to form magma, crystallization of magma to form igneous rock, and uplift and exposure of rocks at the surface through tectonic activity. The major rock groups - sedimentary, metamorphic, and igneous rocks - are formed through this continuous process.
The Rock Cycle
- 1. Earth & Space ScienceEarth & Space Science The Geosphere II The Rock Cycle Science is Organized Knowledge
- 2. In your l ab not ebook, pl ease answer as best you can: 1. What would many, close-together contour lines on a topographic map indicate? • Steep or rapid change in elevation 1. What does the map scale display? • Approximate distances between map locations 3. True or False? Parallels (lines of latitude) indicate north-south location on a globe. • True 4. Which continent(s) does the Prime Meridian run through? • Europe (UK, France, Spain) and Africa (Algeria, Mali, Burkina, Faso, Tongo, Ghana) 4. Name the four layers of the earth and give one fact about each. • Inner Core – solid, very dense iron and nickel • Outer Core – liquid iron & nickel, spins around inner core to produce magnetic field • Mantle – semi-solid, hot molten rock, thickest layer • Crust – very thin, outer rocky layer Bonus Question: Which of Earth’s Poles is coldest? The South Pole (Antarctica) . Week 3 Review Quiz
- 3. What Are Rocks? ...and Where Do Rocks Come From?
- 4. Minerals Minerals: naturally occurring, solid, inorganic substances with a definite chemical composition and an ordered internal structure. • Naturally occurring: not man-made, they can be found in nature • Solid: not liquid or gas at room temperature • Inorganic: not from living or dead organisms • Definite chemical composition: made from specific elements found in nature • Ordered internal structure: atoms arranged in a repeating patter
- 5. The Rock Cycle We'll start here
- 6. Experiment 3 Physical & Chemical Weathering Day Seed Observations Sprouted? (Y/N) Rock Observations 1 Hard, shriveled No Solid, no cracks 2 3 4 5 6 7
- 7. Weathering The breakdown of rocks into smaller pieces (sediment). • Physical (mechanical) – Size change • Chemical – Composition change • Biological – Physical & chemical
- 8. Frost Heaving Physical Weathering from Freezing and Thawing Frost Wedging
- 9. ExfoliationPlant Roots Burrowing of Animals Friction and Repeated Impact
- 10. Oxidation (rust) Living Organisms Acid Rain Chemical Weathering Water/Carbonic Acid
- 12. Erosion & Transport – sediment is carried away
- 13. Erosion The process by which water, ice, wind or gravity moves fragments of rock and soil.
- 14. Glaciers Rivers, Oceans & Runoff Wind and Storms Landslides and soil creep
- 15. Deposition – sediment is laid down
- 16. Deposition of Sediment Along with erosion, rocks and rocky particles (such as shell and bone) are transported and/or deposited in layers by: • Icebergs (former glaciers) melting • Settling of biogenic ooze • Earthquakes • Volcanic eruptions • Floods and Hurricanes • Evaporation
- 19. Burial & Compaction – sediment pressed down
- 20. Burial and Compaction • Layers of sediment are laid down on top of one another (usually on the ocean floor) by erosion and deposition • Buried layers are pressed together by the weight of the water and sediment on top • Minerals form between sediment particles, holding them together • “Recycled” sedimentary rock is formed (also known as lithification)
- 22. Sedimentary Rocks exhibit the following: • Stratification: the deposition of sediment into horizontal layers or “strata” • Lamination: several thin layers (< 1cm) • Superposition: deeper layers are older • Cross-cutting Relationships: intrusions younger than the strata they cut through • Fossils: evidence of life trapped in rock layers
- 23. Sedimentary rocks: soft, grainy or powdery, and may contain fossils. Breccia Coal FlintLimestone Sandstone Shale
- 24. Deformation – rocks folded & split
- 25. Deformation • Rapid surface movement along fault lines (earthquakes) • Slow, deep folding as tectonic plates collide/separate (at higher temperatures) The movement of Earth’s crust that causes physical transformation of igneous and sedimentary rocks.
- 26. • Experiment using layered sheets of wax – shows how rock layers tend to bend and fold before they break.
- 28. Metamorphism – chemical change of rocks
- 29. Metamorphism A change in mineral composition of igneous and sedimentary rocks due to extreme pressure and/or heat deep within the Earth’s crust. • Regional: large area such as mountain range in subduction zone where rocks are pulled/pushed • Contact: due to physical proximity of heat, usually from magma intrusion
- 30. Metamorphic rocks: hard and may have thin layers (straight or wavy), shiny specks or sparkly crystals. Schist GneissMarble SlateQuartzite Amphibolite
- 31. Uplift – rocks pushed up to surface
- 32. Uplift The movement of Earth’s tectonic plates can cause a lifting up of previously buried rock layers. • Rapidly (during earthquakes) in those same areas
- 33. Uplift The movement of Earth’s tectonic plates can cause a lifting up of previously buried rock layers. • Slowly where tectonic convergence occurs
- 34. Melting – rocks heated into semi-solid magma
- 35. Crystallization – magma cools into solid rock
- 37. Fig. 2.9 Crystallization Magma cools at different rates, but always with regularly repeating (lattice) structure to form igneous rocks. • Intrusive: under- ground • Extrusive: above ground
- 39. Igneous Intrusions • Dike: “veins” that run perpendicular to (cut through)the strata • Sill: sheets that run in the same direction (between) the strata • Batholith: huge, bulbous mass intruding surrounding strata deep underground
- 40. Batholith: Yosemite’s Half Dome • Different rock types weather at different rates • Sedimentary racks are soft/crumbly and weather very easily • Metamorphic rocks are very hard and resist weathering & erosion • Granite pluton
- 43. Igneous Rock Formation Type of rock is determined by mineral composition and environment of formation.
- 44. Scoria ObsidianBasalt Igneous rocks: varied in texture, color & density. Granite Pumice Gabbro
- 46. Review: Major Rock Groups • Sedimentary – Form in layers at Earth’s surface, usually under water – Contain fossils • Metamorphic – Rocks changed by pressure and temperature • Igneous – Formed from magma (molten rock) – Intrusive (plutonic): slowly cool underground – Extrusive (volcanic): quickly cool at the surface
- 47. What Type of Rocks Are These?What Type of Rocks Are These?
Editor's Notes
- #4: Rocks are inorganic, naturally occurring solid substances made of two or more minerals that come from (and form) Earth&apos;s outer layer (crust).
- #7: Experiment 3Date: Chemical & Physical Weathering Observation – what do you know about the weathering of rocks? - Weathering = breaking down into smaller pieces - A chemical reaction may be happening if there is/are: A change in color or (gets cold or hot) or precipitate (indicates new compound) Release of (sound, light, or heat) QUESTION: How can rocks be weathered by an acid & plants? Hypothesis – what do you think will happen and why? A: If rocks and steel wool are placed in vinegar (an acid), then , because . B: If a seed is “planted” in sandy plaster and kept moist, then , because . Experiment 3A Materials: vinegar, 50 ml & 100 ml beakers, rocks, steel wool sample Procedures: Place several rocks in the 100 ml beaker. Fill the beaker to the 80 ml line with vinegar. Watch the rocks for a few minutes. Record what you see: Place a sample of steel wool in the 50 ml beaker. Fill the beaker to the 25 ml line with vinegar. Let the steel wool sit for at least 30 - 45 minutes. Then swirl the beaker and record any changes you see: Experiment 3B Materials: Plaster of Paris, sand, paper cup, measuring spoon, seeds, stirring stick, water, paper towels Procedures: Place 15 ml of sand into the paper cup. Mix in enough wet plaster to fill the cup about 3/4 full. Right away, press a few seeds into the plaster. Allow the plaster to dry, then place a damp, folded paper towel inside the top of the cup. Take your “plaster sprouts” home and place the cup near a window, checking to make sure the paper towel stays wet all day long. Every day, pull the paper towel up and record what you see in a chart on the next page. Bring your sprouts back to class with you next week, along with your lab notebook.
- #10: Which of these would be considered “Biological” weathering? Exfoliation is most common in granite (intrusive igneous); because of it&apos;s lattice structure (due to crystallization), sheets will fracture and &quot;peel&quot; parallel to the rock surface.
- #11: Any Biological weathering here? Rust = a chemical reaction where iron reacts with water and/or oxygen to form ferric iron oxide (hematite).
- #14: Wind erosion (like that of the dust bowl of the 1930s). Water erosion (roadway is washed away). Glacial erosion (rocks embedded in ice are carried slowly downhill with the weight of the glacier).
- #17: Sedimentation rates vary from place to place, and at different times. Rates can range from .2cm to 1 m per 1000 year span.
- #18: Can you guess how each of these was formed? Shoreline ripples, evaporation, conglomerate of river rock, estuary deposit.
- #19: What do you notice? How much “sediment” do you think was laid down because of this blast? (25 feet thick, with many layers “sifted” by the water)
- #23: Sedimentary rock is the only type of rock to contain fossils! WHY?
- #37: Gravity: a result of Earth&apos;s MASS Magnetism: a result of the LIQUID outer core spinning around the SOLID iron inner core ~4,000 miles to center of Earth&apos;s core
- #41: Why don’t we see metamorphic rock formations like this? **metamorphic rocks don’t form when blobs of magma cool inside sedimentary rock layers like plutons do *while metamorphic rocks are “harder” than igneous rocks, you don’t find them as spherical “intrusions” but rather as warped layers/sheets of rock below sedimentary (and sometimes igneous) layers.
- #45: They may have tiny holes or a glassy surface, can be dense or frothy, or either solid-colored, streaked, or speckled.
- #48: Anybody know what type of rocks these are?