| Summary: | Tesis para optar al grado de Doctor en Ciencias, Mención Geología This dissertation presents preliminary and final results of four paleoglacier reconstructions in the regions of Patagonia and Tierra del Fuego (46°-55°S), with the objective of identifying trends in Holocene climate in southernmost South America. Two complete chronologies and one partial chronology of Holocene glacier fluctuations are determined by geomorphologic mapping, cosmogenic surface exposure dating of glacial landforms, dendroglaciology, and radiocarbon dating. Former glacier surfaces from four sites across the region are reconstructed to evaluate spatial variability of equilibrium-line altitude depression associated with age-constrained glacier advances. Glaciar Torre (Chapter 3; 49.3°S / 73.0°W) advanced to pre-Holocene maxima at c. 17 ka and c. 13 ka, coincident with the onset of the Last Glacial Termination and the end of the Antarctic Cold Reversal, respectively. While the record at the Dalla Vedova glacier (Chapter 4; 54.6°S / 69.1°W) is less well-constrained, the few dates available suggest potentially synchronous advances occurred at these times. Glaciar Torre subsequently readvanced several times in the Holocene, registering progressively less-extensive advances at 9.4 ka, 6.8 ka, 6.1 ka, 4.5 ka, and 0.5 ka. Preliminary ages of glacier advances from Cerro Castillo (Chapter 5; 46.1°S / 72.2°W) show advances from c. 10-8 ka and at c. 2.3 ka; an additional six glacier advances occurred between these dates, although no numerical age constraint yet exists for these advances. Paleoglacier reconstructions at Glaciar Torre, Cerro Castillo (Chapter 5), and an already dated glacier advance at Río Tranquilo (47.5°S / 72.4°W), show that Holocene advances in Patagonia corresponded to snowline depressions of 160-200 m. On the other hand, the earliest dated Holocene advance of the Dalla Vedova glacier in Tierra del Fuego occurred at 0.9 ka, which coincided with a much smaller snowline depression of 65 m. The directly dated early Holocene ...
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