Like other volcanic front volcanoes in Guatemala, Fuego is located along a WNW-trending line at the Southern edge of a belt of Tertiary volcanic rocks which make up the Guatemalan highlands. The topography of this Tertiary belt is highly irregular and Fuego is built on the same irregular topography. The Tertiary rocks include lava flows and laharic units, and probably represent erosional remnants of volcanoes which range from Miocene to Quaternary age (Reynolds, 1980). The older volcanic remnants buttress the modern Fuego cone and are topographic barriers to all gravity-driven deposits.
Fuego is located just South of another young volcano, Acatenango; the two make up a paired volcano, like others in Northern Central America (Halsor and Rose, 1987). The two volcanoes have erupted lavas which differ notable in composition - most of Acatenango's lavas are andesites, while Fuego has recently erupted only basalt. Acatenango also has a much lower level recent activity. The N trending line between Acatenango and Fuego also encompasses the positions of two minor vents, Yepocapa and Meseta. Meseta represents an older, partly eroded or collapsed vent just North of Fuego. It is broadly andesitic in composition (Chesner and Rose, 1984).
(Rose et al., ???)
(Rose et al., 1978)