The two glacier-covered peaks of Iliniza volcano are prominent landmarks west of the Interandean Valley. The smaller Iliniza Norte is a remnant of the main volcanic edifice located 1.8 km NNW of the younger Iliniza Sur, an andesitic-dacitic stratovolcano surrounded by thick pyroclastic-flow deposits. The edifice is mainly Pleistocene, though the Tishigcuchi (Rasuyacu) lava dome on the S flank was active during the Holocene. Iliniza itself, which is substantially eroded, may also have had relatively young eruptions (Hall, 1987, pers. comm.). A lava dome forms the summit of Iliniza Sur, and two more lava domes are found on the southern and NE flanks of the complex.