Late Holocene wet/dry intervals from Fuegian steppe at Laguna Carmen, southern Argentina, based on a multiproxy record

BORROMEI, ANA MARÍA; CANDEL, MARÍA SOLEDAD; MUSOTTO, LORENA LAURA; CUSMINSKY, GABRIELA; MARTÍNEZ, MARCELO ADRIÁN ; COVIAGA, CORINA ANABEL; PONCE, JUAN FEDERICO; CORONATO, ANDREA

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2018 vol. 499 p. 56 - 71

0031-0182

Late Holocene environmental conditions are reconstructed from a sedimentary core (LCTF2) retrieved fromLaguna Carmen (53° 40′ 60″S, 68° 18′ 0″W, 29 m a.s.l.) in the Fuegian steppe, northern Tierra del Fuego,southern Argentina. The multiproxy study utilizes pollen/spores, algae, ostracods, palynofacies, Total OrganicCarbon (TOC), carbonate content, and lithology. Findings show that grass communities developed over thelandscape from 4200 to 1400 cal yr BP. After that, the plant communities fluctuated between grasses to scrublandvegetation. Changes in the lake level as indicated by the halophytes, algal content and ostracod associations,revealed alternation of wet and dry intervals. The palynofacies indicate environments close to the terrestrialsource with a great input of terrigenous organic matter into the lake in agreement with the sedimentaryenvironment. By comparison with other sites from Tierra del Fuego and southwestern Patagonia, the record ofwind-carried Nothofagus pollen is consistent with variations in the Andean forest communities as a consequenceof shifts in the latitudinal position and/or strength of the westerlies. The short-term wet/dry intervals seem to beassociated with climate events of local occurrence. On the other hand, some wet intervals have been reported inlacustrine records from southern Patagonia. The last millennium showed high environmental variability. Humidconditions characterized the Medieval Climate Anomaly (MCA) event, while dryness conditions were related tothe Little Ice Age (LIA) event. In particular this latter interval has been related to a northward migration of thewesterlies from their present day focus.