Is this a planchet error or just corrosion?

[Louisa]

I've been going through all my rolls of coins and cans of change since joining this forum trying to educate myself on what errors look like. Is this a planchet error? I saw another lincoln with pock marks here also but this appears different.

 

[enamel7]

Sorry , it is corrosion.

 

[Louisa]

Thank you!

 

[cedarratt]

Yep those zinc pennys dont last long in the ground I have found some of them that the edges were all messed up from corrodeing away.