 Atop this basement Paniri developed together with other volcanoes such as Cerro Chao in a linear volcanic chain, the San Pedro-Linzor complex which is formed by lava flows and pyroclastic flows and whose existence may be due to a tectonic lineament.Paniri has erupted rocks ranging from basaltic andesite to rhyolite, which mainly define a potassium-rich calc-alkaline volcanic suite.Phenocrysts include biotite, clinopyroxene, hornblende, olivine, opaque minerals, orthopyroxene, plagioclase, quartz and rutile; the exact composition varies between various units.