Holocene environmental characteristics of the Barrancas River basin, Abdón Castro Tolay (Cochinoca Department, Jujuy) from diatom analysis New Holocene paleoenvironmental records from the Dry Puna, Northwestern Argentina

BUSTOS, SABRINA

La Serena y Coquimbo

Workshop; PAGES-INQUA joint ECR workshop: Past Socio-Environmental Systems (PASES); 2022

PAGES

Holocene environmental characteristics of the Barrancas River basin, Abdón Castro Tolay (Cochinoca Department, Jujuy) from diatom analysisDra. Sabrina Bustos- Laboratorio de Diatomeas Continentales IBBEA-CONICET (FCEN-UBA)Paleoclimatic reconstructions carried out through the analysis of indirect evidence of changes in climatic parameters have been of vital importance for the understanding of processes in the climate systems that operate on scales of hundreds or thousands of years. For these studies, the assemblages of aquatic organisms have been used, among other indicators, since they are modified in response to changing environmental conditions and when they are recovered from the sedimentological record contained in the bodies of water where they lived, their analysis allows to reconstruct some environmental conditions of the past. In particular, diatoms are considered excellent paleolimnological indicators since their siliceous valves are generally abundant and can be often found well preserved in sedimentary records. In previous studies, I focused on three profiles and one sediment core recovered from the Barrancas River basin (Jujuy, Argentina). Throughout this study, I deepen the existing knowledge about the biodiversity and ecology of diatoms, identifying more than 200 infrageneric taxa, including two new species, Luticola juliae and Luticola punae. Regarding past environmental conditions, the dominant diatom assemblages allowed me to determine that although Barrancas was in an area that gradually aridized throughout the Holocene, this site had a behavior different allowing the generation of small wetlands during the driest regional moments. To continue with this study, I am working in a new profile retrieved from the river bank of Calahoyo in the locality of Santa Catalina (Jujuy, Argentina), which includes the Pleistocene-Holocene transition. The time frame of this sedimentary core is important because there is scarce paleoenvironmental information from this region in this period.