:Unfortunatly it is a mostly manual process.  There is a general intrest on wikipedia of keeping "historical" record of discussions in a place where they are easy to find.  This is especially true in contentious arguments as they frequently come up at requests for arbatration (WP:RfA) or requests for comment (WP:RFC) and people may want to refer to them.  I can totally see your point about wanting to clear the air though and I have seen archiving used to do so, though in my expirence if a argument is firce enough removing parts of the page (espically if done selectivly) makes things worse.  If it has not caused anyone to object though I suspect you did the correct thing.  I will go ahead and make an archive for you, the basic way is: 
 :# You create a subpage (in this case Talk:Orania/archive1)  
 :# Copy and paste the older inactive conversations into it and save it. 
 :# Add a link to the top of the talk page. 
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