Simplify the following text for a Grade 8 native English-speaking person.
Original: Much of the region is an ancient highland , but there is basaltic bedrock near Cooma and Nimmitabel that produce the only true chernozems in the whole continent , which are some of the best soils in Australia .
Simplified: Much of the region is an ancient highland , but there is basaltic bedrock near Cooma and Nimmitabel . This produces the only true chernozems in Australia .