Green slime on stone chippings

[billm]

Can anyone identify this green slime that appears to be living on the stone chippings on my drive ? The chippings have been there 20+ years and this is the first time the slime has appeared.

It appears to be growing and slowly taking over all the area. I have put weedkiller on but it didn't make any difference.

Other than digging up all the chippings, any suggestions what it is and how to get rid of it ?

thanks

 

[JohnD]

you could water it (on a dry day) with Wet and Forget (other brands may exist)

the smallest order I could make was 2 litres which will last you a long time.

If you want, I have a discount code I can email you. It's recommended in a club I'm in.

 

[lostinthelight]

It looks like nostoc algae, we had lots at our last property which was brought home from treading on an infected garden we were maintaining so watch where your treading or it will be everywhere where conditions are suitable for it to flurish..
litl

 

[r896neo]

A good dose of bleach will sort it in quick order.

 

[billm]

Thanks for the suggestions folks, I've also been told that Washing Soda (Sodium Carbonate) will kill it too.