Presentation on theme: "Geologic Time sedimentary Man and Dinosaur never lived at the same time."— Presentation transcript:
Man and Dinosaur never lived at the same time
Which is older: F or S How do you know?
contact metamorphism on all sides
Contact metamorphism: occurs at the border where magma touches solid rock- at this boundary, the rock is turned into metamorphic rock through contact with the heat of the magma. Use the ESRT to determine the type of sedimentary rock, then the metamorphic rock table to determine what the sedimentary rock turns in to at this contact boundary
no contact metamorphism on top
Is H an intrusion or extrusion? How can you tell?
H is an intrusion. Contact metamorphism on top
What is an unconformity? a buried erosional surface a part of the rock record is missing a part of the rock record is missing How does it complicate the relative dating of rock layers?
What processes could lead to an unconformity? weathering and erosion
Using the diagram to the left, identify where the unconformity is located by drawing an arrow and writing the word unconformity next to it.
Evolution Explain the theory of evolution. organisms adapt to their environment in order to survive organisms adapt to their environment in order to survive
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
1Approximately how many million years ago did the earliest amphibians appear? Approximately how many million years ago was the initial opening of the Atlantic Ocean? During which era did the earliest fish appear?Paleozoic 4During which epoch did large carnivores appear?Pliocene 5Of the following rocks which would be most likely to contain fossils? a. rhyoliteb. basaltc. metaconglomerated. limestone limestone (its sedimentary) 6At Binghamton, NY what is age of the bedrock?Devonian ( 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 eurypterids development. Silurian age bedrock: Niagara Falls, Syracuse 9Why would fossils be unlikely to be found in quartzite?its 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
Half-Life A half-life is the amount of time necessary for one-half of a radioactive, unstable substance to become not radioactive, stable. Half life depends on the element that is unstable- some radioactive isotopes stabilize quickly, some take much longer
Radioactive IsotopeCircumstance to Use Carbon-14Anything organic or of relatively recent origin- Use if a fossil of any kind is mentioned in a question! PotassiumFor rocks more than 70,000 years in age Uranium-238Relatively middle-aged rocks Rubidium-87A rock of ancient origin
Dating with Carbon-14 When an organism dies, the amount of carbon-14 it contains decreases at a predictable rate By comparing the ratio of carbon-14 to Nitrogen-14 in a sample, absolute age can be determined.
What can be done to change the half-life of a radioactive isotope? Why is this important? NOTHING! it is reliable to calculate age
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 3 half-lives x (5.7 x 10 3 ) =1.71 x 10 4 = 17,100 years