Agua Poca has erupted basalt lava. Bisceglia (1977) assumed that Agua Poca, together with the neighbouring volcanoes Del Nido and Escorial/Amarillo, is the origin of the El Puente basalt formation. Later, Linares et al (1980) assumed that these basalts originated in volcanoes of the Mendoza province with little input from these three volcanoes.: The volcano itself has an easily recognizable crater, but part of the volcano's flanks has been subject to gully erosion. The crater is deep below the crater rim, and the cone itself has dimensions of -. The cone is constructed from alternating layers of cinder and spatter and contains ultramafic xenoliths.: There are two subsidiary structures, Cherro Chico and Loma Sur of small dimensions.: Chemically, the lavas of Agua Poca are intra-plate alkali basalts, with some lavas transitioning in tholeite.: