Strange cave geration and random blocks of air

While I was checking the last snapshot I realized that in the generated world, in this snapshot, there were zones of 1/2 air blocks, caverns one block high and what appear to be caverns generated in bits .

Hope i helped, i'm loving this update! 

Seed: 3161967436989007032

Coordinates: -506 44 74

I attach some screnshot.