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Palaeo‐geoecological significance of Pleistocene trees in the Lluta Valley, Atacama Desert
Author(s) -
Veit Heinz,
May JanHendrik,
Madella Andrea,
Delunel Romain,
Schlunegger Fritz,
Szidat Sönke,
Capriles José M.
Publication year - 2016
Publication title -
journal of quaternary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.142
H-Index - 94
eISSN - 1099-1417
pISSN - 0267-8179
DOI - 10.1002/jqs.2857
Subject(s) - pluvial , geology , radiocarbon dating , pleistocene , stream power , vegetation (pathology) , paleontology , geomorphology , quaternary , physical geography , sediment , geography , medicine , pathology
In the Lluta Valley, northern Chile, climate is hyperarid and vegetation is restricted to the valley floors and lowermost footslopes. Fossil tree trunks and leaves of predominantly Escallonia angustifolia , however, are abundant up to ∼15 m above the present valley floor, where they are intercalated with slope deposits, reflecting higher water levels in the past. A total of 17 samples have been radiocarbon dated, yielding ages between 38 and 15k cal a BP. The youngest ages of 15.4k cal a BP are interpreted as reflecting the beginning of river incision and lowering of the valley floor, impeding the further growth of trees at higher parts of the slopes. The most plausible scenario for this observation is intensified river incision after 15.4k cal a BP due to increased stream power and runoff from the Río Lluta headwaters in the Western Cordillera and Altiplano corresponding to the highstand of the Tauca and Central Andean Pluvial Event (CAPE) wet phase.