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Geologists have subdivided geologic time into periods that are based on?
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∙ 12y ago
Eons, eras, epochs and ages in geological time are primarily based on large-scale events noted in the fossil record (usually mass-extinctions). For divisions of time earlier than those for which reliable fossil records are know (the Hadean and Archaen eons), absolute time is used as an arbitrary delimiter.
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∙ 14y ago
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∙ 11y agoA second is 'The duration 9,192,631,770 periods of radiation corresponding to the transiti6n between two hyperfine levels of the ground level of Cesium 133 atom'
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∙ 14y agoTypes of dominant organisms, and extinction events.
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∙ 12y agofossil evidence
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∙ 10y agoSonia
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Why are the time periods of the paleozoic and mesozoic subdivided into early middle and late instead of named epochs as they are in Cenozoic?
The time periods of the Paleozoic and Mesozoic are subdivided into early middle and late instead of named epochs as they are in Cenozoic periods is due to the basis of the occurrence of particular fossils. It is also based upon the absence or appearance of geological horizons.
Who is the best geologist?
Your question is kind of broad since geology is comprised of such a wide spectrum of careers, but here are a few of the most renowned geologists in history: James Hutton - http://en.wikipedia.org/wiki/James_Hutton Charles Lyell - http://en.wikipedia.org/wiki/Charles_Lyell Alfred Wegener - http://en.wikipedia.org/wiki/Alfred_Wegener Here's a list of other famous geologists: http://en.wikipedia.org/wiki/List_of_geologists The majority of work that geologists perform today is based on the discoveries of these people. There are many different jobs that geologists perform today, but I'd say that the "best" geologists of today are those who dedicate their lives to the study of environmental sustainability and the prediction/prevention of geologic hazards. Geologists involved with the oil industry are generally the highest paid in the field, but some may not consider these to be the "best" geologists because of their affiliation with oil companies and how detrimental they are to the environment. Many of the best geologists today work for the U.S. Geological Survey (USGS). http://www.usgs.gov/
What was the geologic time scale based upon?
The decay of radiactive isotopes of many different elements whose rate of decay is known, including Uranium-235 and Uranium-238, and Potassium-40. They compare the amount of the parent isotope to the amount of it's stable daughter product.add. The geological time scale is based upon important interruptions to the fossil cohort. Major interruptions are thought to indicate catastrophic and world wide events. In recent times, these events have been able to be dated accurately, using among other things, radioactive dating.
Define geologic time?
The geological time scale organizes a long period of time.
What is the essential difference between Uniformitarianism and Catastrophism?
Uniformitarianism is a principle that geologic processes that occurred in the past can be explained by current geologic processes. So, it is the idea that the same geologic processes that same Earth today have been at work during all of Earth's history. Catastrophism is a principle that states that geologic change occurs suddenly. Catastrophies include floods, asteroids, earthquakes, etc. Today, modern geology is based on the idea that gradual geologic change is interrupted by catastrophies.
What is an era or period?
They are divisions of geologic time, based largely on the fossil record of organisms. Eras are longer subdivisions of time which are further subdivided into periods and epochs. For instance, we are currently in the Holocene epoch of the Quaternary Period, and the larger Cenozoic Era.
Why are the time periods of the paleozoic and mesozoic subdivided into early middle and late instead of named epochs as they are in Cenozoic?
The time periods of the Paleozoic and Mesozoic are subdivided into early middle and late instead of named epochs as they are in Cenozoic periods is due to the basis of the occurrence of particular fossils. It is also based upon the absence or appearance of geological horizons.
What information does the geologic time scale have?
Information on time periods in earth's history and the events that happened in those time periods, all based on the study of fossils and rock layers.
How did geologists determine the division of the geologic time scale?
fossils contained within the rock. got answers from Earth Science book while doing my HW
What are index fossils useful for?
Because organisms that became index fossils lived only during specific intervals of geologic time, geologists can estimate the ages of rock layers based on the particular index fossils they contain.
How are chunks of time in the geologic timeline organized?
The Geologic Time Scale is broken up into several periods of time, during which there were great changes in the biodiversity on Earth. We can see distinct changes in the flora (plants) and fauna (animals of each time period. The age range of each period is determined by radiometric dating.
Diffrenciate geologic time with geologic column?
Geologic column is an ordered arrangement of rock layers that is based on the relative age of the rocks. Geologic time is the time IN the geologic column.
Why did geologists develop the geologic time scale?
The geological time scale is the geologic history of the planet from formation to the present. It starts with large divisions of time called eons and is subdivided into successively smaller units of time based on dominant lifeforms, extinction events, even climate. The development of the geologic time scale was initially based on the observation and reasoning that deeper layers of rock are generally older than less deep layers in what is called the "Law of Superposition".Paleontologists look for index fossils in fossil bearing sedimentary rock. Index fossils are organisms that were widespread, rapidly evolving, and only existed for a short period of time as evidenced by their appearance in the fossil record of specific rock strata. The appearance of a fossil alongside an index fossil gives a rough approximation of the age of the fossil in relative terms as it would appear on the geologic time scale. The appearance of the same fossil alongside index fossils of different geologic ages means that the fossil organism spanned multiple geologic time periods. Associations of specific strata alongside radiographically datable igneous and metamorphic rock determines the absolute age of a fossil.A period of around 4,600,000,000 years, the largest groupings of geologic time are eons, followed in descending order by era, period, epoch, and age.The geologic time scale is very important, especially in fields involving the exploration and retrieval of fossil fuels, which are geologically date range specific.
Is Hazard Class 1 subdivided based upon compatibility and intended use?
False
Who is the best geologist?
Your question is kind of broad since geology is comprised of such a wide spectrum of careers, but here are a few of the most renowned geologists in history: James Hutton - http://en.wikipedia.org/wiki/James_Hutton Charles Lyell - http://en.wikipedia.org/wiki/Charles_Lyell Alfred Wegener - http://en.wikipedia.org/wiki/Alfred_Wegener Here's a list of other famous geologists: http://en.wikipedia.org/wiki/List_of_geologists The majority of work that geologists perform today is based on the discoveries of these people. There are many different jobs that geologists perform today, but I'd say that the "best" geologists of today are those who dedicate their lives to the study of environmental sustainability and the prediction/prevention of geologic hazards. Geologists involved with the oil industry are generally the highest paid in the field, but some may not consider these to be the "best" geologists because of their affiliation with oil companies and how detrimental they are to the environment. Many of the best geologists today work for the U.S. Geological Survey (USGS). http://www.usgs.gov/
What is the geological time scale?
The geologic time scale is the system of chronology that organizes the Earth's history based on stratigraphy, or the study of Earth's rock layers and their ages. The geologic time scale is divided into several spans of time. From longest to shortest they are: Eons, eras, periods, epochs, and ages.
What was the geologic time scale based upon?
The decay of radiactive isotopes of many different elements whose rate of decay is known, including Uranium-235 and Uranium-238, and Potassium-40. They compare the amount of the parent isotope to the amount of it's stable daughter product.add. The geological time scale is based upon important interruptions to the fossil cohort. Major interruptions are thought to indicate catastrophic and world wide events. In recent times, these events have been able to be dated accurately, using among other things, radioactive dating.
