Upsetting discovery - Just started sanding back for new finishing

Hi all, Its been a while. Just started getting around to refinishing/ crafting a bit better - the timber slab coffee table I did originally in 2010. Originally I used plastic wood to fill in cracks and gaps in the wood. I thought Id take out the plastic wood as, over time, it had cracked and needed redoing. Parts of the table started coming away in my hand and looked rotted (which im saddened to say). Ive taken some pictures. Can you guys tell me if it was termites or dry rot as Im not sure. I got the chisel out and did some random chiselling and the wood came away easily in places until I got to something more solid. Hoping I dont have to burn it or take it to the dump.

Thanks

Have a look at this and see if any of the descriptions match your problem
https://www.lifestyle.com.au/propert...er-borers.aspx

What I'm seeing is a cross grain slab cut from the butt area of the tree which has a mix of dirt and resin inclusions.
What I think has happened is the resin has dried out leaving extensive areas of poorly supported / unsupported wood.

I'm not sure if flooding the slab with a very runny epoxy will work to stabilise what you have left. But if you don't mind the expense -- 1-1/2 litres of SystemThree cost me about $110 -- you could try raking out the loose surface stuff and a flood coat on both faces and the edges.