I suspect that these "noblets" (great word) are worm casts. As soon as dry, brush them off and they should just crumble up. The worms that cause them are important (partly for drainage) so don't think about ways to kill them. :-)

I too like the 'noblets' bit and like Fractal I also think these are worm casts. The soil is very fine and brushed in helps the soil. or collect it for very fine seed compost.