More About Ice Cores & Index Fossils

Ice Cores Watch the video for a helpful review of Ice Cores. (2:41) Ice cores and climate change Read the article if you need further clarification on the analysis of Ice Cores. Additional Reading: Ice Cores and Climate Change If we find a fern fossil in a desert, what can we infer about the climate when the organism was living? It has always been a desert It used to be an ocean It used to be a hot, humid climate like a swamp What is the relationship between the concentration of CO2trapped in bubbles in ice cores and atmospheric temperatures? As CO2 increases, atmospheric temperature increases As CO2 increases, atmospheric temperature decreases There is no recorded correlation between CO2 concentration and temperature Where is the youngest layer of an ice core located? top middle bottom Sort the descriptions into the correct headings. Rock Layers Composed of rock (mostly sedimentary) It takes thousands- millions of years to form a layer Can show volcanic activity, erosion, deformation activity in layers Fossils common- can show how the environment changed and how organisms evolved over time Ice Cores Composed of ice from Greenland Antarctica Each season forms a different layer; summer and winter layers will be different as well because of dust particles Pollution, volcanic activity, radioactivity can be recorded CO2 methane in bubbles can tell us the temperature of that year -- supports theory of climate change Both Rock Ice Layers The Principle of Superposition can be used to find the relative age of the layers Can tell us what the environment was like at the time the layers formed Which fossil would be most useful in determining the relative age of the rocks in these geologic columns in the image above? Ammonite Brachiopod Trilobite Turritella Select the TWO pieces of evidence that describe why these fossils (from the question above) are most useful in determining the relative ages of the rock layers. The fossils appear in a single layer. The fossils appear in all but one layer. The fossils appear in different types of rock. The fossils appear in each geologic column. The fossils do not appear with any other fossils in a layer. A geologist is investigating the history of an area that has experienced various geologic events, including sedimentation, erosion, tectonic deformation, and volcanic eruptions. The diagram shows the cross section produced from her study. Using the cross section above, determine the age of the intrusion compared to the gravel (top layer) and the flow. The intrusion is older than the gravel and the flow The intrusion is younger than the gravel and the flow The intrusion is older than the gravel, but younger than the flow The intrusion is younger than the gravel, but older than the flow A scientist finds a snail fossil in a layer of rock in a desert. Which action would help the scientist determine what the environmental conditions may have been when the snail existed? Looking for more fossils in different layers of rock Counting the number of similar snail fossils found in other parts of the world Recording information about plants and animals living in the desert today, near where the fossil was found Analyzing the characteristics of other plant and animal fossils found in the same layer of rock