Testing commonly used X‐ray fluorescence core scanning‐based proxies for organic‐rich lake sediments and peat

Chawchai, Sakonvan; Kylander, Malin E.; Chabangborn, Akkaneewut; Löwemark, Ludvig; Wohlfarth, Barbara

doi:10.1111/bor.12145

Cited by 76 publications

(67 citation statements)

References 45 publications

(45 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…were used in the analyses. Titanium has been used to normalize other elements because of its relatively immobile characteristics after deposition in the lake (Demory et al, 2005;Kylander et al, 2011;Chawchai et al, 2016). Thus, four ratios have been calculated here to describe changes in carbonate productivity (Ca/Ti), redox conditions (Fe/Mn), diatom productivity (Si/Ti) and organic productivity (Br/Ti) (Tipping et al, 1981;Moreno et al, 2007;Barreiro-Lostres et al, 2014;Carrevedo et al, 2015).…”

Section: Methodsmentioning

confidence: 99%

A 7000‐year high‐resolution lake sediment record from coastal central Chile (Lago Vichuquén, 34°S): implications for past sea level and environmental variability

Frugone-Álvarez

Latorre

Giralt

et al. 2017

J Quaternary Science

View full text Add to dashboard Cite

We present a 7‐ka environmental reconstruction based on sedimentological and geochemical data from Lago Vichuquén, a coastal eutrophic lake in central Chile (34°48′S, 72°03′ W, 4 m a.s.l.). A relatively shallow and restricted marine environment with low productivity, high detrital input and dominant anoxic conditions in the Vichuquén Basin occurred from 7.0 to 6.5 cal ka BP. Rapid onset of a Holocene marine transgression at 6.5 cal ka BP favoured deeper and more biologically productive environments that existed until 2.8 cal ka BP. Bioproductivity changes during the mid‐Holocene (6.5–4.2 cal ka BP) were related to upwelling dynamics controlled by the intensity of the South‐east Pacific Anticyclone (SPA). Periods with lower organic productivity and dominant anoxic conditions reflect an increased intensity of SPA (increased upwelling) and decreased precipitation. A shift at ∼4.0 cal ka BP reflects the onset of modern Southern Westerly Winds and El Niño‐Southern Oscillation patterns. Tectonic uplifting and geormorphological activity (dune advancement) are possible reasons behind the Vichuquén Basin closure at ∼1.2 cal ka BP, leading to a low bioproductivity lacustrine environment which has developed until the present. Copyright © 2017 John Wiley & Sons, Ltd.

show abstract

Section: Methodsmentioning

confidence: 99%

A 7000‐year high‐resolution lake sediment record from coastal central Chile (Lago Vichuquén, 34°S): implications for past sea level and environmental variability

Frugone-Álvarez

Latorre

Giralt

et al. 2017

J Quaternary Science

View full text Add to dashboard Cite

show abstract

“…Hence, the ratio of incoherent to coherent (inc/coh) scattering can be used as an indicator of the organic carbon content (Guyard et al 2007;Burnett et al 2011;Chawchai et al 2016). Here, the inc/coh ratio correlates well with measurements of TOC (r = 0.42, p \ 0.001), and therefore provides a high-resolution proxy for organic carbon content in comparison to the TOC measurements performed at coarser resolution (Fig.…”

Section: Inc/coh Ratio and Total Organic Carbon (Toc)mentioning

confidence: 76%

Regional environmental change versus local signal preservation in Holocene thermokarst lake sediments: A case study from Herschel Island, Yukon (Canada)

et al. 2018

View full text Add to dashboard Cite

Thermokarst lakes cover nearly one fourth of ice-rich permafrost lowlands in the Arctic. Sediments from an athalassic subsaline thermokarst lake on Herschel Island (69°36 0 N; 139°04 0 W, Canadian Arctic) were used to understand regional changes in climate and in sediment transport, hydrology, nutrient availability and permafrost disturbance. The sediment record spans the last * 11,700 years and the basal date is in good agreement with the Holocene onset of thermokarst initiation in the region. Electrical conductivity in pore water continuously decreases, thus indicating desalinization and continuous increase of lake size and water level. The inc/coh ratio of XRF scans provides a high-resolution organic-carbon proxy which correlates with TOC measurements. XRFderived Mn/Fe ratios indicate aerobic versus anaerobic conditions which moderate the preservation potential of organic matter in lake sediments. The coexistence of marine, brackish and freshwater ostracods and foraminifera is explained by (1) oligohaline to mesohaline water chemistry of the past lake and (2) redeposition of Pleistocene specimens found within upthrusted marine sediments around the lake. Episodes of catchment disturbance are identified when calcareous fossils and allochthonous material were transported into the lake by thermokarst processes such as active-layer detachments, slumping and erosion of ice-rich shores. The pollen record does not show major variations and the pollen-based climate record does not match well with other summer air temperature reconstructions from this region. Local vegetation patterns in small catchments are strongly linked to morphology and sub-surface permafrost conditions rather than to climate. Multidisciplinary studies can identify the onset and life cycle of thermokarst lakes as they play a crucial role in Arctic freshwater ecosystems and in the global carbon cycle of the past, present and future.

show abstract

“…Whereas Ti and Zr generally associate with coarser silt and sand size sediment fractions, K often associates with clays (Rothwell & Croudace 2015). Thus, given the dissociation of K from the other terrigenic indicators, its concentrations in the sediments of San Lorenzo are probably linked to sediment grain size, with higher values of the K/Ti ratio indicating finer grains (Chawchai et al 2016). On the other hand, the weak correlations of Rb with both K and the group formed by Fe, Zr and Ti are probably a result of the association of this element with a wide range of sediment grain sizes (Kylander et al 2011;Rothwell & Croudace 2015).…”

Section: Discussionmentioning

confidence: 99%

Millennial‐to‐centennial scale lake system development in the mountains of tropical Mexico

Franco-Gaviria

Correa‐Metrio

Núñez‐Useche

et al. 2020

Boreas

View full text Add to dashboard Cite

Rapid degradation of freshwater ecosystems threatens water supply for human populations and natural landscapes. At diverse time scales, this process has been clearly associated with climatic and anthropogenic forcings. The question remains, however, how tropical lakes have responded to these two sources of variability. We present a multiproxy record from Lake San Lorenzo, Lagunas de Montebello National Park, tropical Mexico, spanning the last ~3400 years. We used multi‐elemental concentrations, and Cladocera and pollen assemblages along the record to reconstruct regional and local environmental variability, aiming to infer the factors and processes involved in the evolution of the lacustrine system. A principal component analysis on the pooled biological and geochemical evidence allowed the inference of the main changes in lake level and productivity. At millennial scales, the development of the lake system has been closely associated with regional moisture availability, with wetter (drier) time intervals associated with high (low) lake stands. According to Ti concentrations, from ~3400 to 1000 cal. a BP, regional conditions followed a trend towards drier conditions, with littoral cladoceran assemblages suggesting high lake productivity. The extreme regional droughts reportedly associated with the cultural collapse of the Maya civilization manifested in our study area through both high lake productivity and the lowest lake levels of the record. Through the last ~800 years, the regional moisture availability has increased, with the water body becoming deeper and larger. Overall, our record offers evidence of a highly variable system strongly coupled with regional climates, but also very sensitive to local disturbances associated with human occupation. Lake San Lorenzo has been highly resilient to external pressures and has previously recovered from conditions probably alike those associated with the ongoing modern deterioration process. Nevertheless, such recovery involves a complex network of interactions amongst natural and human factors.

show abstract

Testing commonly used X‐ray fluorescence core scanning‐based proxies for organic‐rich lake sediments and peat

Cited by 76 publications

References 45 publications

A 7000‐year high‐resolution lake sediment record from coastal central Chile (Lago Vichuquén, 34°S): implications for past sea level and environmental variability

A 7000‐year high‐resolution lake sediment record from coastal central Chile (Lago Vichuquén, 34°S): implications for past sea level and environmental variability

Regional environmental change versus local signal preservation in Holocene thermokarst lake sediments: A case study from Herschel Island, Yukon (Canada)

Millennial‐to‐centennial scale lake system development in the mountains of tropical Mexico

Contact Info

Product

Resources

About