Review for Earth Science Chapter 9 A Trip through Geologic Time

Earth Science Chapter 9 A Trip through Geologic Time What are the 5 major types of fossil remains? (25 points) Petrified fossils---when fossils are actually turned into stone molds and casts---most common way fossils are made carbon films---made when a layer of carbon coats the item and makes an image of the item. trace fossils---footprints and other imprints made by organisms preserved remains---when tar or other stuff preserves the remains

Earth Science Chapter 9 A Trip through Geologic Time What is the point of the fossil record? (5 points) It can tell you what organisms were alive during a particular time.

Earth Science Chapter 9 A Trip through Geologic Time What is the difference between relative age and absolute age? (10 points) Relative age is based on what is found around an item. Absolute age is based on the known age of the rock which is determined by the amount of radioactive isotope in the fossil. The older the fossil the less radioactive it is.

Earth Science Chapter 9 A Trip through Geologic Time What is the law of superposition? (5 points) It means that the lowest layer forms first, so the youngest layer will always be on top. Assuming that the layers don’t get moved around

Earth Science Chapter 9 A Trip through Geologic Time What is the point of an index fossil? (5 points) An index fossil is a fossil that is known to have been present in a certain time frame. This allows the other fossils to be dated.

Earth Science Chapter 9 A Trip through Geologic Time Explain the concept of a half-life. (5 points) How long it takes for half of the radioactive material to become non- radioactive.

Earth Science Chapter 9 A Trip through Geologic Time What are the 4 major eras of geological time and their major feature? (40 points) Precambrian---first cells appear Paleozoic---invertebrates Mesozoic—dinosaurs Cenozoic—mammals

Earth Science Chapter 9 A Trip through Geologic Time What are periods and epochs? (10 points) Periods are divisions of eras epochs are divisions of periods

Earth Science Chapter 9 A Trip through Geologic Time What is Pangaea? (5 points) Pangaea is the original land mass formed on Earth.