At least its block. That's surprising if it really is a 100+ year old house. Everything that old here has minerock foundations.
The house was put on a block wall foundation in the 50ís. House uses all actual lumber and the deed states pre 1900, so I donít actually have a clue how old the house is. My last house was built in 1932 and the only reason I know that is because when I gutted it I found the original recipe in the plaster when they put the walls up.