black mold/spores on grass???

im hoping someone can help me.

ive had a patch on my lawn for about a week now and another small one popped up last night near the original one. it looks like the soil under the grass has turned black and theres like spots or spores of purpley/grey/black on the grass leaves. if you touch the grass it seems to emit a dust or cloud of some sort.

i was thinking this is something to do with cats or foxes weeing in the grass but i really dont know.

any idea????

 

Any chance you can provide us with a picture please shopgirl?

 

It sounds like an algae to me, pics would be very useful.