What year was Argentina's GI system created? I'm having trouble finding the answer on guildsomm or in any of my books
A system for the "recognition, protection, and register of" IG's, IP's, and DOC's in Argentina was created in 1999 with the passing of Law 25.163 by the National Institute of Viticulture (INV). It defined among other things what qualities a potential IG would have to meet. 1999 was an instrumental year as regards Argentine wine law with a number of other resolutions going forward as well.
A quick summary of the law (Spanish): https://www.argentina.gob.ar/sites/default/files/origenvinosbebidasespirituosas.pdf
The Wines of Argentina website is a great resource... http://www.winesofargentina.org/en