Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina)
Lake sediments are excellent sources of palaeoenvironmental and palaeoclimatic information because they provide continuous and high-resolution records. South America is of particular interest because it is the only landmass that stretches southward into the Pacific and Atlantic Oceans towards Antarc...
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2014
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0956540X_v198_n2_p710_Irurzun http://hdl.handle.net/20.500.12110/paper_0956540X_v198_n2_p710_Irurzun |
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paper:paper_0956540X_v198_n2_p710_Irurzun2023-06-08T15:56:12Z Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina) Orgeira, María Julia Sinito, Ana María Compagnucci, Rosa Hilda Magnetic anomalies: modelling and interpretation Rock and mineral magnetism South america Grain size and shape Lakes Lithology Minerals Sediments Climatic fluctuations Magnetic anomalies: modelling and interpretations Magnetic concentration Magnetic mineralogy Magnetic parameters Remanent coercivity Rock and mineral magnetisms South America Magnetism lacustrine deposit lake level magnetic anomaly magnetite meltwater paleobiology paleoclimate paleoenvironment paleomagnetism Quaternary Antarctica Argentina Atlantic Ocean Atlantic Ocean (North) Laguna Potrok Aike Pacific Ocean Santa Cruz [Argentina] Lake sediments are excellent sources of palaeoenvironmental and palaeoclimatic information because they provide continuous and high-resolution records. South America is of particular interest because it is the only landmass that stretches southward into the Pacific and Atlantic Oceans towards Antarctica. The aim of this study is to explore the relationship of magnetic parameters with elemental and palaeobiological data of Laguna Potrok Aike to develop a model of lake-level changes and related hydrological and climatic fluctuations. Magnetic measurements were performed on subsamples from 15 500 cal. BP to the present, and associated rock magnetic parameters were calculated to infer magnetic mineralogy, concentration and grain size. According to the model, parameters dependent on magnetic concentration and grain size are directly related to lake-level changes. During dry periods, the remanent coercivity displays high values, whereas the proportion of magnetite is relatively low. Low percentages of greigite are observed, indicating that the water of the lake was stratified at least four times during the studied period, at approximately 10 300, 8900, 8500 and 8300 cal. BP. The preservation of greigite by inhibiting its complete transformation into pyrite is associated with a rapid burial that occurs with high sedimentation rates. Thermal stratification could be caused by a slight cooling in the area triggered by a weakening of the Westerlies and/or low activity of the sun, sum to the effect of a flood of melt water in the North Atlantic. © The Authors 2014. Published by Oxford University Press on behalf of The Royal Astronomical Society. Fil:Orgeira, M.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Sinito, A.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Compagnucci, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2014 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0956540X_v198_n2_p710_Irurzun http://hdl.handle.net/20.500.12110/paper_0956540X_v198_n2_p710_Irurzun |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Magnetic anomalies: modelling and interpretation Rock and mineral magnetism South america Grain size and shape Lakes Lithology Minerals Sediments Climatic fluctuations Magnetic anomalies: modelling and interpretations Magnetic concentration Magnetic mineralogy Magnetic parameters Remanent coercivity Rock and mineral magnetisms South America Magnetism lacustrine deposit lake level magnetic anomaly magnetite meltwater paleobiology paleoclimate paleoenvironment paleomagnetism Quaternary Antarctica Argentina Atlantic Ocean Atlantic Ocean (North) Laguna Potrok Aike Pacific Ocean Santa Cruz [Argentina] |
| spellingShingle |
Magnetic anomalies: modelling and interpretation Rock and mineral magnetism South america Grain size and shape Lakes Lithology Minerals Sediments Climatic fluctuations Magnetic anomalies: modelling and interpretations Magnetic concentration Magnetic mineralogy Magnetic parameters Remanent coercivity Rock and mineral magnetisms South America Magnetism lacustrine deposit lake level magnetic anomaly magnetite meltwater paleobiology paleoclimate paleoenvironment paleomagnetism Quaternary Antarctica Argentina Atlantic Ocean Atlantic Ocean (North) Laguna Potrok Aike Pacific Ocean Santa Cruz [Argentina] Orgeira, María Julia Sinito, Ana María Compagnucci, Rosa Hilda Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina) |
| topic_facet |
Magnetic anomalies: modelling and interpretation Rock and mineral magnetism South america Grain size and shape Lakes Lithology Minerals Sediments Climatic fluctuations Magnetic anomalies: modelling and interpretations Magnetic concentration Magnetic mineralogy Magnetic parameters Remanent coercivity Rock and mineral magnetisms South America Magnetism lacustrine deposit lake level magnetic anomaly magnetite meltwater paleobiology paleoclimate paleoenvironment paleomagnetism Quaternary Antarctica Argentina Atlantic Ocean Atlantic Ocean (North) Laguna Potrok Aike Pacific Ocean Santa Cruz [Argentina] |
| description |
Lake sediments are excellent sources of palaeoenvironmental and palaeoclimatic information because they provide continuous and high-resolution records. South America is of particular interest because it is the only landmass that stretches southward into the Pacific and Atlantic Oceans towards Antarctica. The aim of this study is to explore the relationship of magnetic parameters with elemental and palaeobiological data of Laguna Potrok Aike to develop a model of lake-level changes and related hydrological and climatic fluctuations. Magnetic measurements were performed on subsamples from 15 500 cal. BP to the present, and associated rock magnetic parameters were calculated to infer magnetic mineralogy, concentration and grain size. According to the model, parameters dependent on magnetic concentration and grain size are directly related to lake-level changes. During dry periods, the remanent coercivity displays high values, whereas the proportion of magnetite is relatively low. Low percentages of greigite are observed, indicating that the water of the lake was stratified at least four times during the studied period, at approximately 10 300, 8900, 8500 and 8300 cal. BP. The preservation of greigite by inhibiting its complete transformation into pyrite is associated with a rapid burial that occurs with high sedimentation rates. Thermal stratification could be caused by a slight cooling in the area triggered by a weakening of the Westerlies and/or low activity of the sun, sum to the effect of a flood of melt water in the North Atlantic. © The Authors 2014. Published by Oxford University Press on behalf of The Royal Astronomical Society. |
| author |
Orgeira, María Julia Sinito, Ana María Compagnucci, Rosa Hilda |
| author_facet |
Orgeira, María Julia Sinito, Ana María Compagnucci, Rosa Hilda |
| author_sort |
Orgeira, María Julia |
| title |
Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina) |
| title_short |
Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina) |
| title_full |
Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina) |
| title_fullStr |
Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina) |
| title_full_unstemmed |
Magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. BP from Laguna Potrok Aike (Argentina) |
| title_sort |
magnetic parameters and their palaeoclimatic implications-the sediment record of the last 15 500 cal. bp from laguna potrok aike (argentina) |
| publishDate |
2014 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_0956540X_v198_n2_p710_Irurzun http://hdl.handle.net/20.500.12110/paper_0956540X_v198_n2_p710_Irurzun |
| work_keys_str_mv |
AT orgeiramariajulia magneticparametersandtheirpalaeoclimaticimplicationsthesedimentrecordofthelast15500calbpfromlagunapotrokaikeargentina AT sinitoanamaria magneticparametersandtheirpalaeoclimaticimplicationsthesedimentrecordofthelast15500calbpfromlagunapotrokaikeargentina AT compagnuccirosahilda magneticparametersandtheirpalaeoclimaticimplicationsthesedimentrecordofthelast15500calbpfromlagunapotrokaikeargentina |
| _version_ |
1768542324723286016 |