I need help identifying old dark red or brown floor tiles

I have recently bought a house in North West England and found some kind of dark brown or dark red tile throughout the ground floor. They seem to be laid onto concrete with some kind of black bonding.

The tiles are 9 inches square (about 23 cm). Where they are chipped they form fragments or layers. Any parts that are loose seem very light, as if they would be plastic. If there is a grain structure it is very fine.

As far as I know the house is part of an estate built around 1950. The deeds I have say it was sold by the council in 1970 but I am confident it was built prior to that.

Would these be oil, clay, brick or coal dust, or just mostly asbestos and dooooom?

Just in case it helps, here is a photo of the underside of a bit which has flacked off.

I have included a curtain hook for a sense of scale.

Probably Marley floor tiles. A sort of plastic/thermoplastic/Lino that had asbestos in them? They were stuck down with bitumen.
Precautions are needed But you won't die

I left ours down, they act as damp proofing as well on concrete slab floor.

I've put laminate down in the living room and tiled over them in the kitchen.

They do contain asbestos, people say they are low risk though?.

Ours is an ex concil house 1950's build as well..

They are low risk, not zero risk, true (Google "chrysotile" or "white asbestos"). Probably better to contain them and limit the risk than lift them and sweep the remaining floor regularly or vacuum them (both of which will redistribute any loose fibres all over the house)

All depends how far you want to go.
But best way is to take them up then Apply a coat of ardex NA , then some Ardex DPM1c to whole area.