Earth History Dating geologic events like volcanic eruptions
- Slides: 54
Earth History Dating geologic events like volcanic eruptions, uplift, subsidence, deposition, impacts, intrusion, ice ages, etc
Geologic Age Dating • Relative Age Dating – Places events in a sequence – Only indicates one is older than other • Absolute Age Dating – Also called: Radiometric/Radio- active Dating – Identifies actual age
Relative Age Dating rules/laws to follow when dating rocks • • • Uniformitarianism Law of Original Horizontality Law of Superposition Law of Cross-cutting Relationships Law of Include Fragments Unconformities
Relative Age Dating • Uniformitarianism – “The present is the key to the past” James Hutton – Geologic events are not catastrophic
Relative Age Dating • Original Horizontality – sedimentary rocks form horizontal to the surface of the earth. – Sedimentary rocks usually form below sealevel
SEDIMENTARY ROCKS 75% of the Earth’s surface –sed Usually form below sea level form from the compaction and cementation of sediments (lithification) Weathering (breakdown of rock) Sediment (fragments of rock) Erosion (movement/transport of sediment) Deposition (settling of sediment) Burial Compaction (pushing together of sediment Cementation (gluing of sediments) http: //www. westhamptonbeach. k 12. ny. us/Teachers/cohen/sciweb/earthscience/powerpoint_notes. htm
Properties of Sedimentary Rocks • • Layers/Strata Fragments of other rocks Fossils – remains/impression of organism Compacted crystals
Environment of Formation Types of fossils (marine, freshwater) Size and shape of sediment Layers/Strata of sediment, ripple marks
http: //www. classzone. com/books/earth_scien ce/terc/content/visualizations/es 0701 ce/terc/content/visualizations/es 2901 page 01. cfm? chapter_no=visualization (coal forming) Fossil forming http: //www. classzone. com/books/earth_science/terc/content/visualizations/es 0605/es 0 605 page 01. cfm? chapter_no=visualization cementation http: //www. coaleducation. org/miningtv/default. htm Coal mining videos http: //www. wwnorton. com/college/geo/egeo/animations/ch 12. htm Shale becomes oil http: //highered. mcgrawhill. com/sites/0072402466/student_view 0/chapter 10/animations_and_movies. html# Sediment transport http: //www. classzone. com/books/earth_scien ce/terc/content/visualizations/es 0604 page 01. cfm? chapter_no=visualization (sediments being deposited
http: //www. eram. k 12. ny. us/education/sctemp/0 c 525861 b 50 e 177 dace 8 b 634 d 0 e 0 d 5 f 7 /1203603040/sedimentary. swf
Relative Age Dating • Superposition – Oldest at bottom – Youngest at top
Relative Age Dating • Cross-cutting – Younger rocks (igneous intrustions/extrustions) or structures (folds, faults) cross-cut older rock
Complex Bedrock Structures Intrusions Folding (bending) Faulting (break) Tilting
Faults, folding, tilting Folding (bending) Tilting
Relative Age Dating • Include Fragments – Sediment in the rock must be older than the rock itself – Ex: conglomerate
Relative Age Dating • Unconformity – A buried break or gap in rock sequence – Missing rock record – Caused by: • erosion • Lack of deposition
http: //www 2. wwnorton. com/college/geo/egeo/flash/10_2. swf http: //www 2. wwnorton. com/college/geo/egeo/flash/10_1. swf
• • • http: //geography. cst. cmich. edu/Franc 1 M/Animations/animation_list_posted. htm alphabetical list of animations all different topics – animations http: //earthguide. ucsd. edu/earthguide/diagrams. html ! http: //emvc. geol. ucsb. edu/downloads. php 9 ice age, plate tectonics, etc differnt topics – found 4/24/08 Earth History http: //simile. mit. edu/timeline/examples/dinosaurs 2. html you can also make your own interactive timeline (tedious though) http: //simile. mit. edu/timeline/docs/create-timelines. html#getting-started Earth History http: //www. nmnh. si. edu/paleo/geotime/main/index. html geo time line http: //www. indiana. edu/~ensiweb/home. html http: //www. indiana. edu/~ensiweb/evol. fs. html evolution You can get glossaries at http: //www. litstudies. com/bilingual_esl/Bilingual. Glossaries/index. htm The main part of the screen will be white, but you can click on the languages on the left. It is actually from the remains of the http: //www. litstudies. com/bilingual_esl/index. htm and then http: //www. gly. uga. edu/railsback/Geological. Diagrams 1. html geology diagrams
Sedimentary Rocks Texture (3 types) • 1. Clastic – fragments of rocks cemented Land-derived sediments eroded, and deposited(usually in water), buried, compacted and cemented. Ex: sandstone • 2. Crystalline (Chemical) – compacted minerals Dissolved minerals/salts precipitate out of water, settle, buried, compacted and cemented 3. Bioclastic (organic) – have fossils (shells, plant matter) Form from something once living ex: coal, coral http: //www. wiley. com/college/strahler/0471480533/animations/ch 12_animations/animation 2. html
CLASTIC CRYSTALLINE BIOCLASTIC
http: //geography. cst. cmich. edu/Franc 1 M/Animations/animation_list_posted. htm - go to watersheds MISS
- Compare geologic time with the geologic column.
- Graphic organizer about geologic time scale
- In traditional dating patterns dating behavior
- What is the center of the earth made of
- Volcanic belts form along the boundaries of earth's
- Geologic history meaning
- Geologic history of texas
- Principle of original horizontality
- Disconformity
- Mutually exclusive events vs not mutually exclusive events
- The earth dragon awakes
- How is the geologic time scale organized
- Geologic time calendar
- Caprock
- Geologic time scale animals
- Fossils
- The longest subdivision of the geologic time scale is the
- Geologic column definition
- Geologic time
- Largest division of geologic time
- Moth scale
- Geologic time scale
- Geologic time
- Geologic
- Amantz
- Marli miller
- Silurian period
- What is the longest subdivision in geologic time
- 4 zoic eras
- Chapter 12 geologic time
- Cal gem
- Place the following events in chronological order.
- Lava plateau diagram
- Factors affecting volcanic eruption
- Primary volcanic hazards
- Which letter indicates when dinosaurs became extinct?
- Volcanic ash
- Volcanic ash
- Volcanic and plutonic rocks difference
- Volcanic ash
- What is folding faulting and volcanic activity
- Volcanic features
- Thin layers of volcanic ash act as excellent time markers
- Volcanic ash
- Volcanic ash
- Volcanic ash
- Volcanic ash
- Volcanic ash
- Volcanic ash
- Volcanic ash
- What is tephra
- Lava erupts through an opening in earth’s crust called a
- Island arc
- Volcanic island arc
- Volcanic ash