Major shifts in hydroclimate have been documented during the last deglacial period and the Holocene in south‐central Alaska. Rare freshwater calcium carbonate (marl) deposits in lakes on the Kenai Peninsula can be used to reconstruct past changes in hydroclimate, including the influence of groundwater inflow to lakes. Here, the postglacial sediment sequence from groundwater‐fed Kelly Lake (60.514°N, 150.374°W) was analyzed for...

Aim To determine the timing of megafaunal extinction in the high plains of Peru and also to determine if the timing was delayed in grasslands compared with previously published forested settings to dissociate the effects of succession from human or climatic impacts. Location The Junín Plateau, Peru. Taxon Flowering plants and Ascomycetes. Methods The sediments used in this analysis were collected from the edge of Lake Junín, P...

Surface exposure dating of boulders on an exceptionally well‐preserved sequence of moraines in the Peruvian Andes reveals the most detailed record of glaciation heretofore recognised in the region. The high degree of moraine preservation resulted from dramatic changes in the flow path of piedmont palaeoglaciers at the southern end of the Cordillera Blanca (10° 00′ S, 77° 16′ W), which, in turn, generated a series of cross‐cutt...

The Andes of Ecuador, Peru and Bolivia host the majority of the world's tropical glaciers. In the tropical Andes, glaciers accumulate during the wet season (austral summer) and ablate year‐round. Precipitation is delivered mainly by easterlies, and decreases both N–S and E–W. Chronological control for the timing of glacial advances in the tropical Andes varies. In Ecuador, six to seven advances have been identified; dating is...

Based on new 10 Be data for moraines in the Cordillera Blanca of central Peru, we have calculated model ages of three sets of Pleistocene glacial moraines. In order of decreasing age, these are the Cojup, Rurec and Laguna Baja moraines. The oldest moraines occur at the lowest elevations and yield dates of >400 ka pre‐dating the last interglacial and demonstrating that maximum ice volumes occurred during previous glacial period...

Cosmogenic dating provides a long‐awaited means of directly dating glacial deposits that pre‐date the last glacial cycle. Although the potential benefits of longer chronologies are obvious, the greater uncertainty associated with older cosmogenic ages may be less readily apparent. We illustrate the challenges of developing and interpreting a long chronology using our data from the Peruvian Andes. We used surface exposure datin...

The manifestation of major climatic events such as the timing of deglaciation and whether, or not, the Younger Dryas affected Andean systems has garnered considerable recent attention. Even the Holocene is rapidly emerging as a time of considerable interest in Neotropical palaeoclimatology and palaeoecology. The Holocene of the Neotropics is now revealed as a time of some temperature change with precipitation:evaporation ratio...

Glacier equilibrium‐line altitude (ELA), and the difference between modern and palaeo‐ELA can be interpreted as a proxy for climate change. One issue in ELA reconstruction is that different methods of ΔELA reconstruction may produce a range of results for the same palaeoglacier. When a range of methods is used to reconstruct ELAs across a region, resulting variations may be related to the method rather than the past climate. P...

The history of Holocene glaciation serves as an important record of glacier mass balance and, therefore, of climatic change. The moraine record of Holocene glaciation in the tropical Andes, however, is fragmentary and poorly dated. In contrast, increases in the rate of accumulation of inorganic sediment in glacier‐fed lakes have been linked to periods of Neoglaciation in many mountain regions. The interpretation of such a reco...