Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina
The Pampean Sand Sea, which occurs from the Argentinian Pampas to the eastern Andean piedmont, hosts presently stabilized dune fields spanning the late Quaternary. This study integrates previous results and presents new geomorphic, stratigraphic, sedimentological, and chronologic data for nineteen &...
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todo:paper_02773791_v139_n_p77_Tripaldi2023-10-03T15:16:02Z Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina Tripaldi, A. Forman, S.L. Argentina Dune field Eolian Paleoclimate Pampean Sand Sea Lakes Sand Stratigraphy Argentina Dune fields Eolian Paleoclimates Pampean Sand Sea Deposition climate variation deposition dune field environmental response eolian deposit Heinrich event historical record monsoon Northern Hemisphere paleoclimate Quaternary shrub Southern Hemisphere vegetation type Andes Argentina Pampas San Luis The Pampean Sand Sea, which occurs from the Argentinian Pampas to the eastern Andean piedmont, hosts presently stabilized dune fields spanning the late Quaternary. This study integrates previous results and presents new geomorphic, stratigraphic, sedimentological, and chronologic data for nineteen >2 m-thick eolian successions for the San Luis paleo-dune field, western Pampas, to better constrain the depositional history. Six eolian depositional phases are identified spanning the past 50 ka, interposed with paleosols and/or bounded by erosive surfaces. Age control was from 61 OSL ages of small aliquots of quartz grains from eolian stratigraphic units. The inferred timing of eolian phases are at ca. 70 ± 10 yr, 190 ± 20 yr, 12 to 1 ka, 22 to 17 ka, 29 to 24 ka, and 40 to 32 ka. A maximum span for periods of pedogenesis at ca. 12 to 17 ka, 22 to 24 ka, and 29 to 32 ka was provided by bounding OSL ages, which broadly overlap with high stands of pluvial lakes and glacier advances in the central Andes. We infer that the added precipitation may reflect expansion of the Southern Hemisphere monsoon, associated with Northern Hemisphere Heinrich events, leading to episodes of significantly wetter conditions (>350 mm MAP) to at least 35° S. Most of the Holocene (12 ka to 0.8 ka) was characterized by sand sheet deposit under drier than present conditions (100-450 mm MAP), associated with Monte-type vegetation (shrub steppe). The latest two eolian depositional phases, occurred at ca. 190 and 70 yr ago, during the historic period with European settlement and are related to anthropogenic landscape disturbance, though the youngest phase was concomitant with 1930s drought. Wet conditions dominated since ca. AD 1970 with new lakes and rivers forming across this eolian terrain; an incongruous environmental response in reference to drier conditions for most of the Holocene. © 2016 Elsevier Ltd. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_02773791_v139_n_p77_Tripaldi |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Argentina Dune field Eolian Paleoclimate Pampean Sand Sea Lakes Sand Stratigraphy Argentina Dune fields Eolian Paleoclimates Pampean Sand Sea Deposition climate variation deposition dune field environmental response eolian deposit Heinrich event historical record monsoon Northern Hemisphere paleoclimate Quaternary shrub Southern Hemisphere vegetation type Andes Argentina Pampas San Luis |
| spellingShingle |
Argentina Dune field Eolian Paleoclimate Pampean Sand Sea Lakes Sand Stratigraphy Argentina Dune fields Eolian Paleoclimates Pampean Sand Sea Deposition climate variation deposition dune field environmental response eolian deposit Heinrich event historical record monsoon Northern Hemisphere paleoclimate Quaternary shrub Southern Hemisphere vegetation type Andes Argentina Pampas San Luis Tripaldi, A. Forman, S.L. Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina |
| topic_facet |
Argentina Dune field Eolian Paleoclimate Pampean Sand Sea Lakes Sand Stratigraphy Argentina Dune fields Eolian Paleoclimates Pampean Sand Sea Deposition climate variation deposition dune field environmental response eolian deposit Heinrich event historical record monsoon Northern Hemisphere paleoclimate Quaternary shrub Southern Hemisphere vegetation type Andes Argentina Pampas San Luis |
| description |
The Pampean Sand Sea, which occurs from the Argentinian Pampas to the eastern Andean piedmont, hosts presently stabilized dune fields spanning the late Quaternary. This study integrates previous results and presents new geomorphic, stratigraphic, sedimentological, and chronologic data for nineteen >2 m-thick eolian successions for the San Luis paleo-dune field, western Pampas, to better constrain the depositional history. Six eolian depositional phases are identified spanning the past 50 ka, interposed with paleosols and/or bounded by erosive surfaces. Age control was from 61 OSL ages of small aliquots of quartz grains from eolian stratigraphic units. The inferred timing of eolian phases are at ca. 70 ± 10 yr, 190 ± 20 yr, 12 to 1 ka, 22 to 17 ka, 29 to 24 ka, and 40 to 32 ka. A maximum span for periods of pedogenesis at ca. 12 to 17 ka, 22 to 24 ka, and 29 to 32 ka was provided by bounding OSL ages, which broadly overlap with high stands of pluvial lakes and glacier advances in the central Andes. We infer that the added precipitation may reflect expansion of the Southern Hemisphere monsoon, associated with Northern Hemisphere Heinrich events, leading to episodes of significantly wetter conditions (>350 mm MAP) to at least 35° S. Most of the Holocene (12 ka to 0.8 ka) was characterized by sand sheet deposit under drier than present conditions (100-450 mm MAP), associated with Monte-type vegetation (shrub steppe). The latest two eolian depositional phases, occurred at ca. 190 and 70 yr ago, during the historic period with European settlement and are related to anthropogenic landscape disturbance, though the youngest phase was concomitant with 1930s drought. Wet conditions dominated since ca. AD 1970 with new lakes and rivers forming across this eolian terrain; an incongruous environmental response in reference to drier conditions for most of the Holocene. © 2016 Elsevier Ltd. |
| format |
JOUR |
| author |
Tripaldi, A. Forman, S.L. |
| author_facet |
Tripaldi, A. Forman, S.L. |
| author_sort |
Tripaldi, A. |
| title |
Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina |
| title_short |
Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina |
| title_full |
Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina |
| title_fullStr |
Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina |
| title_full_unstemmed |
Eolian depositional phases during the past 50 ka and inferred climate variability for the Pampean Sand Sea, western Pampas, Argentina |
| title_sort |
eolian depositional phases during the past 50 ka and inferred climate variability for the pampean sand sea, western pampas, argentina |
| url |
http://hdl.handle.net/20.500.12110/paper_02773791_v139_n_p77_Tripaldi |
| work_keys_str_mv |
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