There are five oil-producing districts in Argentina, namely, Comodoro Rivadavia, Neuquen, Cerro Alquitran, Cacheuta, and the Jujuy-Salta district. All but the first-mentioned of these are situated in the eastern foothills belt of the Andes Cordillera.

In western Mendoza, strata of Jurassic, Cretaceous, and Tertiary age are widely exposed. They have been folded, faulted, and tilted, folding being most conspicuous in the older series outcropping to the west, and faulting and tilting being most conspicuous in the younger series more widely represented to the east.

Volcanic activity during early Tertiary time resulted in the intrusion of the older sediments by andesitic plugs, the outpouring of lavas of similar composition, and the deposition of thick beds of agglomerate.

Within the Jurassic is a thick petroliferous shale from which available evidence indicates that oil was formed by pressure and heat attendant on the intrusion of the andesitic plugs and perhaps by pressure and heat due to faulting.

Geologic structures which may possibly be oil-bearing include anticlines, domes above concealed intrusive masses, some types of faults, and porous beds uptilted against igneous plugs.