Concrete floor

Hi Folks!!

Does anyone know what the "flloor" in my basement is made of. The house was built around 1915. Some parts are hard concrete and are never wet but one section is a crumbling mixture of ...... ? It stays wet and develops mold!
Ugh!

Now... Is it possible to put a plastic sheathing over that and an inch or two of sand topping mix. Is that enough? Will that work.

So (1) What is the crumbly stuff thats a "floor"?
(2) Can I top it with cement mix (I cant use regular cemet because I don't have the head room for a thick enough pour)




Its a lime morter mixture that they used to hold to old fieldstone together to build thier " foundation"

Thanks!!

Might be best to dig out the soft crumbling stuff, install a sump pit and ejector pump and pour a new concrete floor...
It also might be a good idea to get a pro to come in and look at it...
Mark