Question

Scientists found rock deep in the earth and determined it was 3 billion years old. This rock is most likely which type of rock

igneous
sedimentary
metamorphic
limestone

Answer 1

@arek

Answer 2

@is3535

Answer 3

@MrNood

Answer 4

im stuck between c or d

Answer 5

@CallMeKiki

Answer 6

I wouldn't be. Let's look at two things, how age is determined and how each type of rock is made.

Age is determined by isotopic analysis of some chemicals like argon. The thing is though, if the material undergoes great changes, like melting, being crushed, or extremely high temps it can change things with the isotopes. Example, the dating of a bone with carbon isotope analyses vs. the dating of a part of the same bone that has been severely burned would be different. The burned bit would appear younger, the age difference would be relative to the time between the bone and then the burning. So, if part of the bone is burned 300 years later it would appear to be 300 years younger.

Rocks:

igneous, solidified magma/lava that has not been modified via temp or pressure since its original formation

metamorphic rock is igneous rocks that have been under tremendous pressure and/or temp to alter the igneous rock into something different. Example, compress and heat limestone and you have marble.

sedimentary rocks are igneous or metamorphic rocks that have been deposited and incorporated into a new rock, but you can still see parts of the original rocks.

@geny55

Answer 7

@mrdoldum

Answer 8

c?

Answer 9

It is very old. Earth is only 4.7 billion. That means it has been unchanged for 3 billion years. Which of the types of rocks is the most likely to be the oldest with the least changes.

Answer 10

Hint: it is found deep inside the earth.

Answer 11

@arek