Drainage basin response to climate change in the Pisco valley, Peru

The Quaternary development of the Pisco valley in central Peru has been characterized by multiple phases of sediment accumulation and erosion that formed distinct levels of cut-and-fill terraces and alluvial fans. Luminescence dating shows that they formed in response to at least two different stages of sediment accumulation and erosion during the past 60 ka, the main phase of sediment aggradation occurring between ca. 54 and 38 ka ago. The ages show that sediment accumulation was contemporaneous with the time intervals of the Minchin (47.8–36 ka ago, with enhanced precipitation beginning ca. 54.8 ka ago) and Tauca (26–14.9 ka ago) paleolakes on the Altiplano, where the headwaters of the Pisco River are located. We conclude that sediment accumulation was triggered by shifts toward a more humid climate, whereas erosion is the response of the fluvial system to the depletion of the hillslope sediment reservoirs.

[1]  Paul F. Green,et al.  Estimating the component ages in a finite mixture , 1990 .

[2]  Geoffrey O. Seltzer,et al.  Hydrologic variation during the last 170,000 years in the southern hemisphere tropics of South America , 2004, Quaternary Research.

[3]  C. Rigsby,et al.  Climatic Influence on Sedimentology and Geomorphology of the Rio Ramis Valley, Peru , 2005 .

[4]  M. Strecker,et al.  Luminescence dating of alluvial fans in intramontane basins of NW Argentina , 2005, Geological Society, London, Special Publications.

[5]  R. Ferguson,et al.  Field evidence for rapid downstream fining of river gravels through selective transport , 1996 .

[6]  Geoffrey O. Seltzer,et al.  The history of South American tropical precipitation for the past 25,000 years. , 2001, Science.

[7]  K. Whipple,et al.  Uplift of the western margin of the Andean plateau revealed from canyon incision history, southern Peru , 2007 .

[8]  J. Wallinga.  Optically stimulated luminescence dating of fluvial deposits: a review , 2002 .

[9]  G. Tucker,et al.  Drainage basin responses to climate change , 1997 .

[10]  M. Aldenderfer,et al.  Fluvial history of the Rio Ilave valley, Peru, and its relationship to climate and human history , 2003 .

[11]  D. Keefer,et al.  A 38 000-year record of floods and debris flows in the Ilo region of southern Peru and its relation to El Niño events and great earthquakes , 2003 .

[12]  R. Robinson,et al.  Dating intramontane alluvial deposits from NW Argentina using luminescence techniques: Problems and potential , 2008 .

[13]  A. Murray,et al.  Luminescence dating of quartz using an improved single aliquot regenerative-dose protocol , 2000 .

[14]  A. Miall.  Lithofacies Types and Vertical Profile Models in Braided River Deposits: A Summary , 1977 .

[15]  Norbert Marwan,et al.  Multiple landslide clusters record Quaternary climate changes in the northwestern Argentine Andes , 2003 .

[16]  B. Eitel,et al.  GEOARCHAEOLOGICAL EVIDENCE FROM DESERT LOESS IN THE NAZCA–PALPA REGION, SOUTHERN PERU: PALAEOENVIRONMENTAL CHANGES AND THEIR IMPACT ON PRE‐COLUMBIAN CULTURES* , 2005 .

[17]  F. Schlunegger,et al.  Scale of relief growth in the forearc of the Andes of Northern Chile (Arica latitude, 18°S) , 2006 .

[18]  B. Rust.  STRUCTURE AND PROCESS IN A BRAIDED RIVER , 1972 .

[19]  J. Quade,et al.  Geochronology and stratigraphy of late Pleistocene lake cycles on the southern Bolivian Altiplano: Implications for causes of tropical climate change , 2006 .

[20]  Geoffrey O. Seltzer,et al.  Tropical climate changes at millennial and orbital timescales on the Bolivian Altiplano , 2001, Nature.

[21]  D. Sandweiss.  Terminal Pleistocene through Mid-Holocene archaeological sites as paleoclimatic archives for the Peruvian coast , 2003 .

[22]  Amy C. Clement,et al.  The climate of the Altiplano: observed current conditions and mechanisms of past changes , 2003 .

[23]  V. Mejdahl.  Thermoluminescence dating of partially bleached sediments , 1985 .

[24]  A. Wintle,et al.  Assessing the reproducibility and accuracy of optical dating of fluvial deposits , 2006 .

[25]  P. A. Baker,et al.  Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 yr ago , 2005, Quaternary Research.

[26]  G. Tucker,et al.  Statistical treatment of fluvial dose distributions from southern Colorado arroyo deposits , 2007 .

[27]  T. Törnqvist,et al.  Fluvial responses to climate and sea‐level change: a review and look forward , 2000 .