Dating of sedimentary rocks

dating of sedimentary rocks

Is it possible to date sedimentary rocks?

As the sedimentary rock had to have existed to be intruded, this can give us a minimum age for the rock. Similarly, it may be possible to date crystals formed in cleavage caused by deformation, or to date the surrounding rock layers (e.g. volcanic ash layers, as suggested by other answers above).

What is the difference between absolute dating and sedimentary dating?

Absolute dating is necessary for knowing specific time e.g. by isotope K/Ar in mica, especially in the crystalline rock: igneous and metamorphic rock. On the other hand, the sedimentary rock (as I know) usually provide the time of formation by age range of fossil e.g. Upper Miocene - Piocene.

How do you determine the age of sedimentary rocks?

Currently, the age of sedimentary rocks is usually constrained using a number of indirect dating techniques, including the dating of contemporaneous volcanic rocks, bracketing relationships of igneous and metamorphic rocks, and the dating of detrital and diagenetic minerals.

What is dating in geology?

... (Show more) dating, in geology, determining a chronology or calendar of events in the history of Earth, using to a large degree the evidence of organic evolution in the sedimentary rocks accumulated through geologic time in marine and continental environments.

Why is it difficult to date sedimentary rocks using radiometric dating?

Why is it difficult to date sedimentary rocks using radiometric dating techniques? Because the elements used for dating need to be re-set by volcanism. Radioactive elements decay at a certain constant rate and this is the basis of radiometric dating.

How do scientists date rocks and fossils?

Scientists use two approaches to date rocks and fossils. Relative age dating is used to determine whether one rock layer (or the fossils in it) are older or younger than another base on their relative position: younger rocks are positioned on top of older rocks.

How can you determine the age of sedimentary rocks?

Explanation: However, sedimentary rocks can be age dated if a volcanic ash horizon or a diabase sill or dyke can be found within the sequence. For example, if you find a dinosaur bone in a sedimentary sequence and you find an ash layer 10 meter above the bone and another ash layer 20 meters below it, you can determine the age of the two ash layers.

Why is isotopic dating of fossils difficult?

One difficulty in employing this dating technique is that radioactive isotopes occur more commonly in igneous and metamorphic rocks and most fossils occur in sedimentary exposures. Today direct isotopic dating for sedimentary rocks is possible.

What does geological dating mean?

dating, geological dating noun. use of chemical analysis to estimate the age of geological specimens

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