I searched the index at ancestry.com using his name and approximate birth year. I don't think it was a common practice for the woman to be that much older, but strange things happen. More often I find men who are much older, the wife died and they marry a younger girl to take care of all the children. Those age gaps can span 10 to 20 years or more. I think times were hard back then and people did what they needed to in order to survive.

Here's the 1880:

Source Citation: Year: 1880; Census Place: Hannan, Mason, West Virginia; Roll: 1408; Family History Film: 1255408; Page: 303A; Enumeration District: 095

Harden Black 24
Joanna Black 36
Alexander Black 9
Abraham Black 5
James R. Black 3
Kye K. Black 2m