2. Geologic Time Notes Page 3 Geologic Time

3. Fossils can only be found in rocks. sedimentary

5. Why is this statement false: “The caveman had dinosaur for breakfast.”? Why is this statement false: “The caveman had dinosaur for breakfast.”? man and dinosaurs never lived at the same time man and dinosaurs never lived at the same time

6. Man vs. Dinos

7. Mammoth vs. Mastodont

11. Absolute Age The “actual time” of an event – determined by using radioactive isotopes.

12. Relative Age Placing events in the order of their occurrence – “sequence of events.”

14. 1Approximately how many million years ago did the earliest amphibians appear?359-416 2Approximately how many million years ago was the initial opening of the Atlantic Ocean?146-200 3During which era did the earliest fish appear?Paleozoic 4During which epoch did large carnivores appear?Pliocene/Miocene 5Of the following rocks which would be most likely to contain fossils? a. rhyoliteb. basaltc. metaconglomerated. limestone limestone (it’s sedimentary) 6At Binghamton, NY what is age of the bedrock?Devonian (359-416 million years) 7How does the age of the bedrock at Old Forge compare with that at Jamestown?Jamestown is younger 8Name a location in NY State where you may be able to find bedrock which was formed at the peak of the eurypterid’s development. Silurian age bedrock: Niagara Falls, Syracuse 9Why would fossils be unlikely to be found in quartzite?it’s metamorphic 10For each of the following locations in NY State below, identify whether fossils would be likely or unlikely: Old Forge; Binghamton; Albany Old Forge: unlikely Binghamton: likely Albany: likely

15. Relative Age If a sedimentary rock outcrop has not been overturned, which layer would be the oldest? What is this principle known as?

16. Principle of Superposition oldest rock layers are on bottom, youngest on the top

17. Using this principle, label the strata below from oldest to youngest.

18. Grand Canyon

21. FaultsFaults are always (older, younger) than the rocks they cut through. FaultsFaults are always (older, younger) than the rocks they cut through.

23. Which is older: F or S How do you know? Any fault, fold, metamorphism, or igneous intrusion is YOUNGER than the rocks they cut across. Principle of cross- cutting relationships

25. If a geologist finds an igneous sill, how can they determine if the sill is an intrusion or an extrusion?igneous sill If a geologist finds an igneous sill, how can they determine if the sill is an intrusion or an extrusion?igneous sill

27. Is “H” an intrusion or extrusion? How can you tell?

28. H is an intrusion. Contact metamorphism on top

31. What is an unconformity? How does it complicate the relative dating of rock layers? Box 1 = a buried erosional surface Box 2 = a part of the rock record is missing – a gap Box 3 = process of uplift and erosion Box 2 = a part of the rock record is missing – a gap Box 3 = process of uplift and erosion

32. Hutton’s Unconformity – 1788 Scotland

33. Using the diagram to the left, identify where the unconformity is located by drawing an arrow and writing the word “unconformity” next to it. Unconformity

34. E - fault I D H B - fault F A C G

35. E B I F G - fault C A H D

37. What characteristics must fossils have in order to be good index fossils? lived over a large geographic area (large horizontal distribution) - widespread lived for a short period of time (small vertical distribution) – short-lived lived over a large geographic area (large horizontal distribution) - widespread lived for a short period of time (small vertical distribution) – short-lived

38. In the diagram below, a geologist has matched up rock layers based on index fossils. In geology, this is referred to as CORRELATION

42. Evolution Explain the theory of evolution. organisms adapt to their environment in order to survive organisms adapt to their environment in order to survive

43. Evolution Explain how the fossil record supports this theory can see that different organisms have changed over time can see that different organisms have changed over time

45. http://people.ucsc.edu/~kplacet/whales.html http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html http://www.pbs.org/wgbh/evolution/library/03/4/l_034_05.html video

48. Why are radioactive isotopes useful in determining the absolute age of a rock? their half-lives are constant

49. What can be done to change the half-life of a radioactive isotope? Why is this important? NOTHING! it is reliable to calculate age

52. What radioactive isotope could be used to determine the absolute age of material that was recently living ? carbon-14 What radioactive isotope could be used to determine the absolute age of material that was recently living ? carbon-14

53. What is the half life of uranium-238? 4.5 x 10 9 4,500,000,000 4.5 billion years choice (c)

54. If there is a 100g sample of C 14, how many grams of C 14 would remain after three half-lives? How long would this take? Show all work. 100g50g25g12.5g  5700  5700  5700 3 half-lives x (5.7 x 10 3 ) =1.71 x 10 4 = 17,100 years

55. Carbon-14 5700 years = 50% 11,400 yrs. = 25% 17,100 yrs. = 12.5% 22,800 yrs. = 6.25% 28,500 yrs. = 3.125% 34,200 yrs. = 1.6% 39,900 yrs. = 0.8% 45,600 yrs. = 0.4% 51,300 yrs. = 0.2% 57,000 yrs. = 0.1% 5700 years = 50% 11,400 yrs. = 25% 17,100 yrs. = 12.5% 22,800 yrs. = 6.25% 28,500 yrs. = 3.125% 34,200 yrs. = 1.6% 39,900 yrs. = 0.8% 45,600 yrs. = 0.4% 51,300 yrs. = 0.2% 57,000 yrs. = 0.1% 62,700 yrs = 0.05% 68,400 yrs. = 0.025% 74,100 yrs. = 0.0125% 79,800 yrs. = 0.0625% 85,500 yrs. = 0.03125%