Chronological and geomorphological approach to the Holocene tephras from Tafí and Santa María valleys, NW Argentina

SAMPIETRO-VATTUONE, MARÍA M.; BÁEZ, WALTER A.; PEÑA-MONNÉ, JOSÉ L.; SOLA, ALFONSO

QUATERNARY RESEARCH

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2020 vol. 94 p. 14 - 30

0033-5894

A comprehensive morphostratigraphic and chronological study of the complete set of Holocene tephras from Tafí and SantaMaría valleys (northwestern Argentina), including analyses of compositional characteristics, is presented. Five ash tephras arerecognized: V0 (El Rincón), V1a (Carreras 1a ash), V1b (Carreras 1b ash), V2a (Carreras 2 ash), and V2b (El Paso 3 ash).Two of them (V1b and V2b) are described for the first time in the study area. The new 14C and accelerator mass spectrometryages presented, along with the previously published information, allows for the establishment of a chronological framework.The V0 tephra was deposited in the Early Holocene (about 10,000 yr BP), V1a and V1b were deposited in the MiddleHolocene (about 4200 and 3500 yr BP, respectively), and V2a and V2b were deposited in the Late Holocene (after about800 yr BP). The mineralogical, textural, and geochemical characterizations of the five tephras suggest that their tephra provenancewas mainly from the back-arc region. However, the determination of the exact source of each tephra requires moreaccurate high-resolution tephrochronological studies. At least five major eruptions affected the Tafí and Santa María valleysin the last 10,000 yr.