A 21 000 cal years paleoclimatic record from Caçó Lake, northern Brazil: evidence from sedimentary and pollen analyses

Sifeddine, Abdelfettah; Albuquerque, Ana Luíza Spadano; Ledru, Marie‐Pierre; Turcq, Bruno; Knoppers, Bastiaan A.; Martin, Louis; Mello, William Zamboni de; Passenau, Horst; Domínguez, José Maria Landim; Cordeiro, Renato Campello; Abrão, Jorge João; Bittencourt, Achiléa Candida Lisboa

doi:10.1016/s0031-0182(02)00591-6

Cited by 106 publications

(68 citation statements)

References 19 publications

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“…This episode is also characterized by higher quartz fluxes, probably of eolian origin, that point to a longer dry season (Sifeddine et al, 2003). During the period dated between 11.8 to 10 ka (Preboreal), δD TA , δD watPA and α TA/wat values reach similar figures as during the late glacial, indicating similar hydrological conditions and accompanied by a discrete increase in arboreal pollen percentages.…”

Section: The Younger Dryas and The Holocenementioning

confidence: 70%

“…This is also depicted by low δ 13 C values for triacontanic acid that attest to a strong contribution of C4 plants and/or lower stomatal conductance of C3 plants (Figure 3). Increased quartz fluxes into the sediment at these times result from the intensification of eolian dune transport, a phenomenon that only occurs when the dry season lasts more than four months (Sifeddine et al, 2003). The presence of sandy sub-horizontal to oblique parallel laminations confirms the occurrences of flash floods during events of heavy rainfalls.…”

Section: The End Of Last Glacial Maximummentioning

confidence: 75%

“…Climatic conditions appear slightly drier during the 13.5-11. a marginal core is noted and corresponds to the lowering of the lake level (Sifeddine et al, 2003). This episode is also characterized by higher quartz fluxes, probably of eolian origin, that point to a longer dry season (Sifeddine et al, 2003).…”

Section: The Younger Dryas and The Holocenementioning

confidence: 88%

“…Interpolated ages were calculated using the intercept of the mean conventional age interval with the calibration curve of 14 C (CALIB version 4.3, Stuiver and Reimer, 1993;Stuiver et al, 1998). In combination with radiocarbon dates obtained on other cores drilled in the lake centre (Sifeddine et al, 2003;Ledru et al, 2005) we assume the sedimentation continuous over the record with mean sedimentation rates from 0.15 to 0.24 cm/yr in the lower half of the core and from 0.01 to 0.05 cm/yr in the upper half of the core.…”

Section: Age Modelmentioning

confidence: 99%

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Paleohydrological changes during the last deglaciation in Northern Brazil

Jacob

Huang

Disnar

et al. 2007

Quaternary Science Reviews

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We here report a reconstruction of hydrological balance variations in Northern Brazil for the last 20 ka deduced from the δD values of aquatic and land plant molecules extracted from the sediment infill of Lake Caçó. Our reconstructed precipitation, lake water isotope ratio and evaporation-evapotranspiration isotope effect allow us to obtain an estimate of moisture balance, and, to a lesser extent, precipitation amount and seasonality changes.

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Section: The Younger Dryas and The Holocenementioning

confidence: 70%

Section: The End Of Last Glacial Maximummentioning

confidence: 75%

Section: The Younger Dryas and The Holocenementioning

confidence: 88%

Section: Age Modelmentioning

confidence: 99%

See 2 more Smart Citations

Paleohydrological changes during the last deglaciation in Northern Brazil

Jacob

Huang

Disnar

et al. 2007

Quaternary Science Reviews

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“…1). The sedimentary filling has been studied using various approaches to better document palaeoclimatic development since the Last Glacial Maximum (LGM) in the Tropics (Ledru et al, 2001;2002;Sifeddine et al, 2003;Jacob, 2003;Jacob et al, 2004a and b). Here we report on the GC-MS characteristics of several series of pentacyclic triterpene methyl ethers (PTMEs) that are present in the lipid extracts of Quaternary sediments from this tropical setting and their significance as plant source indicators or diagenetic indicators.…”

Section: Introduction and Settingmentioning

confidence: 99%

Pentacyclic triterpene methyl ethers in recent lacustrine sediments (Lagoa do Caçó, Brazil)

Jacob

Disnar

Boussafir

et al. 2005

Organic Geochemistry

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The lipid extracts of sediments collected from the Quaternary filling of a tropical lacustrine series (Lagoa do Caçó, Brazil) were investigated by gas chromatography-mass spectrometry (GC-MS). Various pentacyclic triterpene 3-methyl ethers (PTMEs) were present in the neutral fraction. Comparison of retention times and mass spectra with available standards allowed us to certify the presence of olean-12-en-3β-ol ME (β-amyrin ME), olean-18-en-3β-ol ME (miliacin), taraxer-14-en-3β-ol ME (crusgallin), fern-9(11)-en-3β-ol ME (arundoin) and arbor-9(11)-en-3β-ol ME (cylindrin). The following other compounds coud also be tentatively identified from their GC-MS characteristics: urs-12-en-3β-ol ME, bauer-7-en-3β-ol ME and fern-8-en-3β-ol ME. Other compounds such as possible 3α isomers of the PTMEs as well as di-or tri-unsaturated counterparts might be PTME diagenetic derivatives. According to previous chemotaxonomic studies, all these compounds most probably originate from Gramineae that used to colonize the savannas of Northern Brazil at the time of deposition.

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Hydrology and climatology at Laguna La Gaiba, lowland Bolivia: complex responses to climatic forcings over the last 25 000 years

Metcalfe

Whitney

Fitzpatrick

et al. 2014

J Quaternary Science

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Diatom, geochemical and isotopic data provide a record of environmental change in Laguna La Gaiba, lowland Bolivia, over the last ca. 25,000 years. High-resolution diatom analysis around the last glacial -interglacial transition provides new insights into this period of change. The full and late glacial lake was generally quite shallow, but with evidence of periodic flooding. At about 13,100 cal a BP, just prior to the start of the Younger Dryas chronozone, the diatoms indicate shallower water conditions, but there is a marked change at about 12,200 cal a BP indicating the onset of a period of high variability, with rising water levels punctuated by periodic drying. From ca. 11,800 to 10,000 cal a BP stable, deeper water conditions persisted. There is clear evidence for drying in the early to mid Holocene, but not as pronounced as that reported from elsewhere in the southern hemisphere tropics of South America. This was followed by the onset of wetter conditions in the late Holocene consistent with insolation forcing. Conditions very similar to present were 2 established about 2,100 cal a BP. A complex response to both insolation forcing and millennial scale events originating in the North Atlantic is noted.

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A 21 000 cal years paleoclimatic record from Caçó Lake, northern Brazil: evidence from sedimentary and pollen analyses

Cited by 106 publications

References 19 publications

Paleohydrological changes during the last deglaciation in Northern Brazil

Paleohydrological changes during the last deglaciation in Northern Brazil

Pentacyclic triterpene methyl ethers in recent lacustrine sediments (Lagoa do Caçó, Brazil)

Hydrology and climatology at Laguna La Gaiba, lowland Bolivia: complex responses to climatic forcings over the last 25 000 years

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