OREGON STATE UNIVERSITY

Stop 10: Divisaco Ignimbrite

 

THE DIVISACO IGNIMBRITE

22°15'12.29"S, 68°28'26.91"W



This location is noteworthy due to the exposure of the Divisoco Ignimbrite, 10.6 Ma that underlies the Sifon Ignimbrite, 8.1 Ma. The Divisoco is the lowermost unit in the area north of the Rio Salado, and it lies directly above the basement rocks. The deposit has been described as a massive, crystal-rich (~ 60%) dacite containing quartz, plagioclase, biotite and hornblende. The Divisoco has a fine-grained matrix, abundant lithics and a pink color.