GEOLOGíA DEL MIEMBRO CHAGARTON DE LA FORMACIóN COCONUCOS

about 230 m of volcanic deposits occur around coconucos (cauca department). the lowermost part of these deposits is ignimbritic in character and can be correlated with the popayan formation, whose origin is related to the volcanic activity of the paletará caldera. overlying these ignimbrites about 200 m of potassium-rich, calco-alkaline lavas occur. these include trachyandesites, trachybasalts, basaltic andesites, and andesites. these volcanic deposits evidence both, explosive and effusive activity, associated with at least three emission centers: the paletara caldera, the chagarton caldera, and the purace volcano.