Geology final part 5

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Across
  1. 3. • process where nuclei of atoms spontaneously break apart (decay) • parent material decays into daughter product • occurs at a specific rate
  2. 4. Archbishop, added up generations from the Old Testament, came up with the idea of a 6000 year old earth, determined that Earth formed on October 23, 4004 BCE (creation beginning at nightfall on Oct. 22) “Ussher chronology"
  3. 5. this person studied rock formations dug out of canals in SW England • noticed rock similarities and changes in different locations • discovered that fossils could be used to correlate rocks of the same age
  4. 7. *Discovers lead as final decay product of uranium (1907) *Discovers that older rocks have greater Lead-Uranium ratios
  5. 10. – younger material is roughly parallel to older material
  6. 11. greatest expanses of time • Phanerozoic, Precambrian (Hadean, Archean, Proterozoic)
  7. 12. – type of inclusion, piece of rock contained within another
  8. 14. • understanding the time component of geological processes and age of rocks and formations • Earth is really old and quite big! Lots of stuff happens to and on a planet in 4.6 billion years
  9. 20. • correlation with fossil assemblages • fossils are arranged in rock layers according to their age (time during which they lived) • younger fossils are above older fossils
  10. 21. this person studied rock formations in British Isles • theorized that Earth’s internal heat created igneous rocks like basalt and granite • recognized that slow processes like erosion and deposition will cause great change in Earth’s landscape over long periods of time, Uniformitarianism.
  11. 24. • erosional surface • represent a break in the stratigraphic record (“pause” in deposition) • 3 types (disconformity, angular unconformity, nonconformity)
  12. 26. • older layer at bottom, younger at top • applies to any rock that is deposited horizontally • primarily sedimentary, but also lava flows and ash falls • e.g., Grand Canyon
  13. 28. = thousand years ago (1,000)
  14. 32. (4.6 Ba), Uniformitarianism, used the same scientific laws that operate today, also happened in the past… Gradualism also prominent
  15. 33. Form of numerical age dating, uses Ice cores and the configuration of snow, granular ice, firm, and glacial to draw conclusions about the past.
  16. 36. – putting things in relative (comparative) age order • Joey is older than Robbie • judged from height, facial features, etc. • The brown sandstone is older than the white limestone • judged by stratigraphic position, fossils, etc.
  17. 39. • the way Earth’s history is organized • calendar of events for Earth’s history • time units are divided based on rock units and changes on Earth • each unit is given a meaningful name
  18. 40. _______ also called an Unstable Isotope decays to a stable product
  19. 42. # of nucleons (protons + neutrons) in nucleus
  20. 44. index fossil existed in Jurassic and Cretaceous (201-66 Ma)
  21. 47. same scientific laws that operate today, also happened in the past…therefore: • Earth’s features shaped by processes that we can still see today (e.g., erosion, wind, water) • “the present is the key to the past” – use the modern to interpret the ancient
  22. 49. – determining a numerical age of something • Joey is 10, Robbie is 4 • determine from dental records, birth certificates, etc. • The brown sandstone is 5 Ma, the white limestone is 1 Ma • determined by radioactive isotopes, paleomagnetism, dendrochronology, etc.
Down
  1. 1. smaller divisions based on major changes in life • Paleozoic, Mesozoic, Cenozoic
  2. 2. • determining “equivalence” of rock layers that may be spread over great distances • sedimentary layers of the same origin can be found spread across great distances • e.g., Navajo sandstone in both Bryce canyon and Zion National parks
  3. 6. Form of numerical age dating using trees to draw multiple conclusions about the past
  4. 8. • sedimentary layers are initially deposited in horizontal layers • may later be deformed (but layered deposition happened first)
  5. 9. # of protons in nucleus
  6. 13. most processes occur slowly over long periods of time • e.g., transport, deposition, and lithification of clay to form shale
  7. 15. • the time it takes for half of the parent isotope to decay to a daughter product • constant rate of decay, specific to each isotope • examples • 40 Potassium → 40 Argon (1.25 billion years) • 14 Carbon → 14 Nitrogen (5730 years)
  8. 16. • an inclusion is older than the rock containing it
  9. 17. or Ga = billion years ago (1,000,000,000)
  10. 18. type of Unconformity – underlying sedimentary strata are at an angle to overlying strata
  11. 19. Form of numerical age dating that uses the magnetic time scale mapped using the magnetic polarity of the crust usually on the seafloor to make conclusions about the past
  12. 22. Earth’s features shaped by great catastrophes (e.g., worldwide floods, enormous eruption periods, earthquakes) and processes that no longer occur
  13. 23. (6 Ka): • early Europeans retrofitted observations to fit religious beliefs • the past before humans is “unknowable” (Dark Ages) • everything on Earth was created just as we see it today • inaccurate
  14. 25. smallest divisions within periods
  15. 27. • a rock is older than anything that cuts through it • e.g., dike (igneous intrusion) or fault (break) • you can’t break or intrude a rock that hasn’t formed yet!
  16. 29. index fossil existed in Paleozoic (521-252 Ma)
  17. 30. • calculating the ages of rocks and minerals that contain specific unstable isotopes • parent/daughter ratio is measured to determine how many half lives passed
  18. 31. Discovers radioactivity (1896)
  19. 34. Marie and Pierre,Discover heat energy is released from radioactive decay (1903)
  20. 35. – fossil that is especially useful for determining age of rock • must be: easily recognizable, abundant, wide geographic distribution, short range of time
  21. 37. smaller divisions within eras based on smaller changes in life
  22. 38. – sedimentary rocks overlie crystalline rock (igneous or metamorphic)
  23. 41. index fossil existed Miocene-Pleistocene (23 Ma-11 Ka)
  24. 43. • varieties of an element with different number of neutrons
  25. 45. index fossil existed in Mesozoic (252-65 Ma)
  26. 46. = million years ago (1,000,000)
  27. 48. this type of Isotope lasts forever