Field Trip 5

Leader: M. Mulas (ESPOL)

Dates: September 20th to 23th, 2019 (*)
(*) Due to flight’s reservations, we need people to sign up for this fieldtrip before June 3rd

Approx. cost: $ 600.

Minimum number of participants: 15

Maximum number of participants: 35

The southern sector of Ecuador (between 2°S and 6°S) has been characterized by intense magmatic activity in the period comprised between Oligocene and Miocene (Hungerbuhler et al. 2002). The volcanic sequence in the Pucará-Santa Isabel sector is composed by the Saraguro Fm. (26-21 Ma) followed by the St. Isabel Fm. (18 – 7.6 Ma) and closed by the Tarqui Fm. (6.3 Ma). These volcanic formations, made principally of welded ignimbrites, show large lithofacies variability (boulder size to lapilli size lithics, crystal rich to fiamme-rich ignimbrites) that reflects different PDC run-out and principally different sources. Stratigraphic and geomorphologic constraints allow to locate calderas structures (mean diameter 13 x 7-km) related with the Jubones and Santa Isabel ignimbritic eruptions.


8th ISAG

Fm. Jubones and Fm. Santa Isabel. Observation of fiammae and vithophyre. Photo by M. Mulas.