Example
<Blackspots>
<Blackspot X="-10437.89" Y="-1302.152" Z="43.88797" Radius="17.14727" />
</Blackspots>
There should be that in any profile you are using to mine if not then you can just put
<Blackspots>
</Blackspots>
and put the coord's in the format i said above^
Not sure if there is a built in thing to blacklist.