Earth's History Flashcards
what is a fossil and what do they tell us?
the trace or remains of an organism that lived long ago, most commonly preserved in sedimentary rock. Fossils can provide information about ancient life, how living things evolved on Earth, and extinction. Fossils are also important scientifically, because they can be used to unravel Earth history.
What type of rock are fossils found in?
Fossils are mostly found embedded in sedimentary rocks, of which shale, limestone and sandstone are the most common..
What is the difference between relative and absolute dating?
relative age
the age of an object in relation to the ages of other objects Absolute dating establishes the age of an object, i.e.,
the numeric age of an object or event, often stated in years before the present, as established by an absolute-dating process, such as radiometric dating
know what tilting, extrusions, intrusions and erosion looks like on a sequencing diagram
See diagram.
How did earth’s atmosphere change once plants developed?
After photosynthesizing organisms multiplied on Earth’s surface and in the oceans, much of the carbon dioxide in the atmosphere was replaced with oxygen.
Vocab: photosynthesis
Food-making process by which plants and many other producers use light energy to produce glucose and oxygen from carbon dioxide and water.
Vocab: index fossil
fossils that are widely distributed geographically and lived during a brief period
vocab: half life
the amount of time required for half of a radioactive isotope to decay to daughter isotope
vocab: radioactive isotope,
chemical element with different masses whose nuclei are unstable that emit radiation.
vocab: crosscutting
Cross-cutting relationships is a principle of geology that states that the geologic feature which cuts another is the younger of the two features.
