How do scientists use lake sediments to study past climates?
A) Lake sediments contain organic materials that can be identified to species and radiocarbon dated, thereby giving insight into past plant communities and related climatic conditions.
B) Isotopic analysis of the relative proportions of 18O to 16O enable determination of evaporation rates from ancient lakes.
C) During warmer conditions, lake sediments form wider rings, whereas in cooler conditions, these rings are narrower.
D) The amount and type of pollen in lake sediments is an indication of the macrovertebrate assemblages that dominated an area.
E) Lake sediment analysis is used to determine which fish species have persisted in a particular lake over long periods of time.
A
You might also like to view...
The threat of global warming can be addressed by
a. using energy more efficiently b. reducing deforestation c. slowing population growth d. all of these answers e. shifting to renewable resources
Technology is frequently considered to be an “independent agent of social change.” Do you agree? Explain why or why not. Critique this claim.
What will be an ideal response?
The ________ drives the endogenic processes of the rock cycle
A) atmospheric circulation B) rock cycle C) hydrologic cycle D) tectonic cycle
NGOs exert some influence over U.S. environmental policy. Which one of the following is an NGO?
A) Canadian government B) Greenpeace C) U.S. Fish and Wildlife Service D) Democratic Party E) Democratic Republic of the Congo