Are dikes always younger than the rocks layers they protrude through?

Question

If there's a dike that protrudes through all the rock lays, is it assumed that it's younger than all the layers?

Answer 1

Yes, in order for anything to protrude into anything else, that anything else must already be there. This generalization includes Geology, since it is science and isn't magic.

Answer 2

No, that is not necessarily true--it depends on how the statement or question is worded. If you say the dike is intruded through the rock, then, yes, the dike is younger. For it to go through a layer of rock, the layer of rock has to already be there. So the layer of rock has to be older than the dike.

However, if you saying "protruding" or "sticking out of" or some similar wording, then there is another possibility.

If the dike has been exposed by erosion or earthquakes, etc. it is possible for other layers to be deposited around it in which case THAT layer would be younger than the dike. However, in that case it should be obvious by observing the rocks in contact with the dike. If they are not heated, or showing signs of an igneous intrusion, then it might be possible that the dike is older.

Answer 3

Almost always.
The rock the dike cuts through has to be in place before it can cut through it.
However, it is possible that after the dike in in place, erosion can occur exposing the dike. If the dike is more resistant to weathering and erosion than the material surrounding it, the dike could stay in place and later, material can be deposited around the dike, thus resulting in the dike being younger than the material around it.
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Answer 4

yes, because the dikes has to have existing rock to go through. it wont just solidify in the air (unless it was very, very, very, very, very, very, impossibly cold)

Answer 5

Yes it is always younger. No exceptions.