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Fossils
Index Fossils And The Geographic Time Scale
Question | Answer |
---|---|
What is igneous | Forms by the crystallization of magma or lava cooling |
What is sedimentary | Forms by bits of weathered rock and soil are compacted over long periods of time forming layers |
What is metamorphic | Forms from intense heat and pressure deep under the earths surface |
What is the most important difference between Precambrian and the Phanerozoic Eons | The Precambrian era consisted of mainly the earths formation and widespread volcanic activity. The first rock was Igneous. The first life was a single celled bacteria. |
Cont... | Near the end of the Precambrian period there is evidence to prove that there was a large increase of oxygen die to the appearance of photosynthetic organisms. |
Cont2... | Rocks and fossils from the Phanerozoic eon provide evidence that there was an abundant amount of plant and animal life. Early life forms existed mainly in the shallow oceans and seas. |
How do rock layers teach us about the past | They tell us how old or how new they are what organisms lived then what the environment was like and the climate as well as the oxygen rate |
How have fossils and surface features supported theories that the earth has evolved | Because it tells us what kind of chemicals fossils plants major events and animals there were. How landforms came to be. The position of continents. |
What happens when a species becomes better adapted | The population will increase |
How do major climatic events earths impact earths population | Events such as ice ages meteorites increase or decrease of gasses impact earths species to either adapt or become extinct. It often affects other species in the food chain |
How are humans contributing to the extinction of many animals today | Mining agriculture and construction all damage and in many cases destroy the habitats of thousands of species and organisms causing them to be extinct |
What does atmosphere mean | The gaseous part of the planet |
What does era mean | A major division on the geologic time scale that is a subdivision of an eon |
What does eon mean | The largest time unit on the geologic time scale |
What does fossil mean | The remains or traces of an organisms preserved from the geologic time past |
Whats the geologic time scale | The division of the earths history into blocks at a time-eons, eras, periods, and epochs. |
What does glaciation mean | Covered with or effected by a glacier |
What is Pangaea | a super continent winch separated 200 years ago and formed the present day landmasses |
Whats a paleontologist | A scientist who studies fossils and the history of life on earth. |
What does a period mean | A basic unit of the geologic time scale that Isa subdivision of an era |
Whats does Phanerozoic mean | The part of the geologic time scale that represented rocks containing abundant fossil evidence. Also a very volcanic time. |
What are plate tectonics | The theory which proposes the earths outer shell consists of individual plates winch interact in various ways |
What does Precambrian mean | All geologic time prior to the Phanerozoic eon |
What does radiometric dating mean | Dating a complex procedure of calculating the absolute age of rocks |
What is relative dating | A form of dating by placing rocks in their proper sequence |
The geologic history of the earth only describes what kids of rocks existed along time ago | False |
The continental landmasses of the earth have remained in the same location throughout all of earths history | False |
The geologic time scale is a time line dividing the earths history representing millions of years | True |
Over time scientists have observed that life has adapted to varying condition on earth | True |
The force of gravity enables the planet to retain an atmosphere | True |
What information do fossils reveal about earths past | Climate environment geologic events landforms age of rocks and fossils |
Which unit of the time is best represented by rocks containing abundant fossil evidence the Precambrian or Phanerozoic | Phanerozoic |
What happens when glaciers melt | Sea levels rise |
What were the first rocks and first life forms on earth | Igneous rock and single celled bacteria |
Name an environmental condition during the earths history that may have been the cause for a mass extinction of life forms | Meteorite ice age change in oxygen. |
Whats an index fossil | A fossil of an organism that lived a long time ago in a wide range area. |
What caused the dinosaurs extinction | A meteorite |
How does a fossil form | An organism dies and sediments and dirt gather on top until it gets compacted into a rock |
What is limestone | A soft rock often found in caves |