Submillennial palynology and palaeoecology of the last glaciation at Taiquemó (∼50,000 cal yr, MIS 2–4) in southern Chile

• Published in: Quaternary science reviews Vol. 25; no. 5; pp. 446 - 454
• Main Authors: Heusser, C.J., Heusser, L.E.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2006
• Subjects: Astelia; Myrtaceae; Nothofagus; Podocarpus; Chile
• ISSN: 0277-3791; 1873-457X
• DOI: 10.1016/j.quascirev.2005.04.008

Stratigraphic palynology of core HE94-2B from a mire at Taiquemó (42.17°S, 73.60°W) on Isla Grande de Chiloé is one of the most closely sampled, continuous Pleistocene records in southern South America. Chronology of the 655-cm core that extends from Marine Isotope Stage (MIS) 4 through the Lateglacial is controlled by 27 finite radiocarbon dates. Sampled at 1-cm intervals, the high temporal resolution (mean ∼85 yr cm −1) captures short-term palaeoecological changes and successional restabilization of plant communities. Preponderance of Gramineae (grass) with Nothofagus dombeyi type (southern beech) characterizing Subantarctic Parkland under a cold climate in MIS 4 was followed by a conspicuously milder interval that lasted for some ten millennia in MIS 3. Of greater frequency and diversity at this time were more thermophilic taxa associated with North Patagonian Evergreen Forest ( Podocarpus, Pilgerodendron type , Pseudopanax, Myrtaceae). Subsequently with increasing cold and hyperhumidity, N. dombeyi type–Gramineae assemblages that included Subantarctic Parkland indicator taxa ( Lepidothamnus, Astelia, Gaimardia) increased stepwise in MIS 2–3. Parkland maxima in MIS 2 during the Last Glacial Maximum (LGM) date to glacial advances between ∼17,800 and 33,400 cal yr BP. On deglaciation, Lateglacial North Patagonian Evergreen Forest was subject to short-term stadial and interstadial climatic fluctuations. The high-resolution Taiquemó pollen record details and supports previous conclusions of interhemispheric synchrony of climatic and glacial events.