How do geologists do correlation using rocks and fossils? What ...

[c0205847]

How do geologists do correlation using rocks and fossils? What will be an ideal response?

Question 2

Why is correlation needed to construct a complete geologic history of a region? How does correlation
  work, e.g., in the Colorado Plateau region? What will be an ideal response?

[rachel]

Answer to Question 1

Rock types can be matched up on the basis of similar rock type and superposition, but correlation of
this type can be done only in a limited area where beds can be traced from site to site. To correlate
over larger areas or rocks of different composition, fossils must be used. Fossils are useful because
many organisms lived for a certain length of time. The overlapping geologic ranges of fossil species
allow definition of time intervals because each species is unique and had a definite duration.

Answer to Question 2

No single location in a region has a geologic record of all events that occurred in its history;
correlation allows geologists to determine the complete geologic history of the region. The entire 2-
billion-year record of the Colorado Plateau is not preserved in a single location due to erosion. By
correlating the uppermost rocks at one location with the lowermost equivalent rocks of another area,
the entire geologic sequence can be put together

[c0205847]

Thank you

[rachel]

Happy to help you