This topic contains a solution. Click here to go to the answer

Author Question: Briefly explain how magnetic reversals in oceanic crust and fossils in ocean sediments are used to ... (Read 81 times)

jhjkgdfhk

  • Hero Member
  • *****
  • Posts: 569

Briefly explain how magnetic reversals in oceanic crust and fossils in ocean sediments are used to
  construct a magnetic time scale. What will be an ideal response?



Question 2

How does seafloor spreading explain the movement of the continents? What will be an ideal response?



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

yahahah24021

  • Sr. Member
  • ****
  • Posts: 323
Answer to Question 1

A terrestrial sequence of magnetic reversal in volcanic deposits was dated radiometrically. These dates
were extrapolated to regions which were not dated, but showed the same pattern of normal and
reversed magnetic polarities. Ages of ocean-floor basalts lying within a zone of normal or reversed
polarity are dated by the ages of the fossils found in the sediments that directly overlie the basaltic
crust. These fossils have already been incorporated within a biostratigraphic zone.



Answer to Question 2

With seafloor spreading, the continents and oceanic crust move together as part of large plates. The
plate is pushed by the formation of new ocean crust and pulled by the subduction of old ocean crust.
New crust forms due to seafloor spreading.






 

Did you know?

According to animal studies, the typical American diet is damaging to the liver and may result in allergies, low energy, digestive problems, and a lack of ability to detoxify harmful substances.

Did you know?

Certain topical medications such as clotrimazole and betamethasone are not approved for use in children younger than 12 years of age. They must be used very cautiously, as directed by a doctor, to treat any child. Children have a much greater response to topical steroid medications.

Did you know?

People who have myopia, or nearsightedness, are not able to see objects at a distance but only up close. It occurs when the cornea is either curved too steeply, the eye is too long, or both. This condition is progressive and worsens with time. More than 100 million people in the United States are nearsighted, but only 20% of those are born with the condition. Diet, eye exercise, drug therapy, and corrective lenses can all help manage nearsightedness.

Did you know?

Only 12 hours after an egg cell is fertilized by a sperm cell, the egg cell starts to divide. As it continues to divide, it moves along the fallopian tube toward the uterus at about 1 inch per day.

Did you know?

In women, pharmacodynamic differences include increased sensitivity to (and increased effectiveness of) beta-blockers, opioids, selective serotonin reuptake inhibitors, and typical antipsychotics.

For a complete list of videos, visit our video library