Earth SCience

• Relative Dating- Also called as chronostatic time
• Inclusion- is any foreign material found in another material
• Superposition - the oldest layer is at the bottom while the youngest sits at the top
• Original Horizontality- also known as principle of lateral continuity
• Uniformitarianism- states that all geological process known today also occurred in the past, operating slowly throughout the ages
• Intrusion- Older
• Rock- Younger
• Cross-cutting relationship- Evident through igneous dikes forming in sedimentary beds
• Unconformities - Gap beetwen two sedimentary rock
• Uncomformities- A missing stratum
• Physical Correlation- Establishment of correlarion beetwen strata using the physical characteristics beetwen these strata
• Absolute Age Dating- Provides accurate information by stating an objects actual age
• Igneous and Sedimentary Rocks- what rocks is used in noncomformities
• Paracomformity- The strata are parallel with each other
• Angular Uncomformities- originally deposited horizontal layer that has been folded or tilted
• Isotope- is an atom of a given element with varying neutron count
• Radioactive Isotopes- unstable atoms that spontaneously decay into more stable forms
• Beta-plus- Also known as positron emission
• Tree Rings- In locations where summers are warm and winter are cool, trees have distinctive pattern.
• Carbon-14 - Method of determining the age of once-living material
• Varves- are alternating sedimentary bed formations found at the bottom of lakes
• Types of Radioactive Decay:

  • Alpha
  • Beta-plus
  • Beta-minus
  • Gamma (Y)
• Electron Capture- occurs when an unstable atom uses its electron to stabilize itself, creating an electron neutrino in the process
• Ice cores- Each layer of ice tells us what the weather and the climate was like that year
• Summer months- glaciers melt rapidly, delivering thick deposits of sediment.
• Winter- thick sediments layers are by thin clay-rich deposits
• TRUE OR FALSE

  TRUE - Half life of uranium is 4.5 billion years old
• FALSE- Half life of a rubidium-strontium dating method is 50 billion years
• Earth's estimated age is what?

  4.6 billion years
• Radioactive Dating Methods:

  • Potassium-Argon dating method
  • Uranium-lead dating method
  • Rubidium-strontium dating method
  • Carbon-14 dating method
• Disconformities -missing rock layers, formed when sediment layers are uplifted without folding but are exposed to weathering and erosion