Mold ? (or oil ?)

[TONYFRANCE]

Hi everyone,

Since years, most of time, what I see is white mold (in powder form). Nothing incredible, pretty easy to remove.

Today I received a tape with that thing on it (see attached). Looks like petrol, I don't know how describe it.
I'm not ready to put it in my vcr for now.

I just want to know if this is dirt or this is worse ? I tried to clean twice, same result. I don't know if the tape itself is damaged or this is just mold/dirt that will dissapear after XX rewind cleaning attempt.

What do you think about it ? Ever seen this ?

mold01.jpg : same result after every cleaning
mold02.jpg : what I see when I play the tape, marks...