What is this material?

[Stina71]

I have a house from the late 1800s.
Surely renovated in stages over the years.

It has an old glass veranda with an overlying balcony.
I have had the sheet metal roof on the balcony replaced because the metal was bad and water was leaking into the glass veranda.
The sheet metal lay under the wooden decking on the balcony.
I also took the opportunity to replace all the wooden board, which was under the old sheet metal and lay above the underlying glass veranda's ceiling.

The picture is from a corner in the underlying glass veranda's ceiling.
The damaged sheet metal had caused a leak in this corner, which drew water into the ceiling and the actual "corner". The insurance company, when conducting moisture measurements in the corner, sawed out a round hole in the glass veranda's ceiling. To be able to measure and look inside. See the picture!

In the picture, you can see black mold, etc., from the previous water damage.

What I am now wondering is:

Does anyone recognize the material visible in the hole?
It seems like it is underneath the joists, i.e., between the wooden board and the glass veranda's ceiling.
I have no idea how old it is.
It feels like some form of "paper".

And, since I am worried about asbestos, I also wonder:

Does anyone know if this type of "paper" could contain asbestos?
I want to know before I start tearing into and renovating the glass veranda's moisture-damaged ceiling.

Grateful for any response!