Geology 101 HW 8

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  1. Fossil
    preserved remains or traces of animals (also known as zoolites), plants, and other organisms from the remote past.
  2. Paleontology
    the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments.
  3. Fossilization
    The process in which an animal dies in environments such as [mud, swamp, and etc] and overtime become burred by sediments. As the body decays water seeps through the remains with minerals that help preserve to bone structure of the body.
  4. Body Fossil
    preservation of the entire bodies bone strucure.
  5. Trace Fossil
    Preservation of traces of footprint of a species.
  6. Chemical Fossil
    • chemicals found in rocks that provide an organic signature for ancient life.
    • Molecular fossils and isotope ratios represent two types of chemical fossils.
  7. Evolution
    any change across successive generations in the heritable characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.
  8. Natural Selection
    • the gradual, non-random, process by which biological traits become either more or less common in a populationas a function of differential reproduction of their bearers.
    • It is a key mechanism of evolution.
  9. Gradualism
    a theory which holds that profound change is the cumulative product of slow but continuous processes, often contrasted with catastrophism.
  10. Punctuated Equilibrium
    • When significant evolutionary change occurs, the theory proposes that it is generally restricted to rare andgeologically rapid events of branching speciation called cladogenesis.
    • Cladogenesis is the process by which a species splits into two distinct species, rather than one species gradually transforming into another
  11. Extinction
    • a sharp decrease in the diversity and abundance of macroscopic life.
    • They occur when the rate of extinction increases with respect to the rate of speciation.
  12. Uniformitarianism
    the assumption that the same natural laws and processes that operate in the universe now, have always operated in the universe in the past and apply everywhere in the universe
  13. Correlation
    • methods by which the age relationship between various strata of Earth's crust is established.
    • by comparing the type of fossils found in various strata (fossil correlation).
  14. Unconformity
    a boundry between rock units created by erosion.
  15. Angular Unconformity
    where an older package of sediments has been tilted, truncated by erosion, and than a younger package of sediments was deposited on this erosion surface.
  16. Disconformity
    an erosion surface between two packages of sediment, but the lower package of sediments was not tilted prior to deposition of the upper sediment package.
  17. Nonconformity
    unconformities that separate igneous or metamorphic rocks from overlying sedimentary rocks. They usually indicate that a long period of erosion occurred prior to deposition of the sediments
  18. Hiatus
    break in the depositional sequence
  19. Cambrian explosion
    the relatively rapid appearance (over a period of many millions of years), around530 million years ago, of most major animal phyla, as demonstrated in the fossil record, accompanied by major diversification of organisms including animals, phytoplankton, and calcimicrobes.
  20. Radiometric dating
    a technique used to date materials such as rocks, usually based on a comparison between the observed abundance of a naturally occurring radioactive isotope and its decay products, using known decay rates.
  21. Radioactive decay
    the process by which an atomic nucleus of an unstable atom loses energy by emitting ionizing particles (ionizing radiation).
  22. Parent Isotope
    the temperature of a system, such as a mineral, at the time given by its radiometric date.
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Geology 101 HW 8
2012-05-09 16:53:30
Geology Paleontology

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