| A | B |
|---|
| What are the 4 methods of determining the absolute age of a rock layer? | Carbon Dating, Half-Life, Varve Count, and Rates of Erosion |
| The most accurate method of determining absolute age of a rock layer? | Carbon dating |
| List 4 methods by which organisms can be preserved | Mummification, Amber, Tar Beds, Freezing |
| gastroliths | stomach stones |
| cast | Fossil formed when mud fills a mold |
| mold | The cavity left when organic remains decay |
| trilobite | A common index fossil |
| eurypterus | The New York State fossil |
| index fossil | Fossils used to determine the age of a rock |
| trace | Examples include footprints and borings |
| coprolites | Fossil animal waste |
| petrification | minerals replace organic materials |
| Why is the geologic column useful to earth scientists | to help them determine which rock layer is older than another |
| What information have fossils provided scientists with | the age of rock layers, which animals developed first |
| Why are fossils rare in Precambrian rocks? | the only life during this time were soft-bodied organisms |
| How did the ice ages affect animal life during the Cenozic Era | Some species became extinct and others appeared |
| Name 4 geologic eras | Cenozoic, Mesozoic, Paleozoic, Precambrian |
| Describe life during Cenozoic | many modern groups of mammals, large running mammals, large carnivores, humans, mammoths |
| Describe Mesozoic | Earliest dinosaurs & mammals, earliest birds, earliest flowering plants |
| Describe Paleozoic | Earliest fish, insects, amphibians, sharks, reptiles |
| Describe Precambrian | stromatolites, soft-bodied organisms |
| Define Principle of Uniformitarianism | Current geologic processes, such as volcanism and erosion, are the same processes that were at work in the past. |
| Law of Superposition | an undeformed sedimentary rock layer is older than the layers above it and younger than the layers below it |
| Law of Cross-Cutting Relationships | states that a fault or an intrusion is always younger than the rock layers it cuts through |
| Unconformity | a break in the geologic record. For a period of time deposition stopped, rock was removed by erosion, and then deposition resumed |
| Cenozoic Era | Era known as the "Age of Mammals" |
| Mesozoic Era | Era known as the "Age of Reptiles" |
| Cenozioc Era | What time era do we live in? |
| Precambrian Era | Which era covers the longest time? |
| Cenozoic Era | Which era covers the shortest time? |
