I have picked up hundreds and hundreds of pieces of Onondaga Chert debitage from local fields, but never seen this type of red mineralization on a surface before. Under 10x, it appears to be a three dimensional mineral deposit, for sure. Any chance it is an intentional (NA) deposit of red ochre?
If you take a mineral like red ochre, powder it, then mix it with egg whites, you can paint it on a rock and it will adhere because of chemical action of the eggs. Once it adheres it will stay there indefinitely. Gary