The answer in finding the age of a sedimentary rock layer through radiometric dating can be assumed <span>between the absolute ages of the two igneous units.
Sedimentary rocks don't have radioactive elements so the beast way to know the age is through understanding what can elements in between can provide as evidence</span>
Pretty sure its called the 38th Parallel, or the Demilitarized Zone. :)
Believe it's... people working in midday.
Two questions which arises in my mind about aurora borealis are:
- Why does aurora borealis occur?
- Why does aurora borealis occur in a particular time of the year?
Answers:
- As solar wind approaches the Earth, it meets the Earth's magnetic field. In the ionosphere, the ions of the solar wind collide with atoms of oxygen and nitrogen from the Earth's atmosphere. The energy released during these collisions causes aurora borealis.
- Aurora borealis is active the whole year. Since it needs to be dark in order to see aurora borealis in the sky, late August/September through the very beginning of April is the best time to go to a destination located in the aurora zone for a chance to see them.
Note: These are the questions which arises in my mind only. It may differ from person to person.
Hope you could understand.
If you have any query, feel free to ask.