Basically they were made from rough cut logs of easily available timber then rendered with clay mud to give smooth weather resistant walls. A practical building technique using available materials. These would be the early settler's dwellings in the back story of Billabong Ghost from the Dreaming Billabong series of crime, mystery, historical romance novels.
Check out more information about Wattle and Daub huts here.
Below are some photos showing some early settler's wattle and daub building structures.