Valleys Mapgen 1.3

Big improvements : different types of dirts. The dirt can be clayey, silty or sandy. There is also pure red clay, pure silt and desert sand.
There are also beaches. Beaches are generated on… maybe 30% of the coastline. They are usually very thin, but, sometimes, in very flat and sandy places, they may have more than 30 blocks width !

Average generation time : 450 ms on my computer.