Coupled Stable-Isotope and Trace-Element Measurements of Lacustrine Carbonates as Paleoclimatic Indicators

Chivas, Allan R.; Deckker, Patrick De; Cali, Joseph A.; Chapman, Audrey; Kiss, E.; Shelley, J. M. G.

doi:10.1029/gm078p0113

Cited by 68 publications

(25 citation statements)

References 30 publications

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“…Major and minor element concentrations of carbonate (specifically, Sr and Mg) were measured as an additional assessment of environmental change during lake evolution (cf. Chivas, De Deckker, & Shelley, ; Chivas et al., ). Results of elemental analysis are recorded in Table and displayed in Figure .…”

Section: Resultsmentioning

confidence: 99%

Mineralized microbialites as archives of environmental evolution, Laguna Negra, Catamarca Province, Argentina

et al. 2018

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Environmental fluctuations are recorded in a variety of sedimentary archives of lacustrine depositional systems. Geochemical signals recovered from bottom sediments in closed‐basin lakes are among the most sensitive paleoenvironmental indicators and are commonly used in reconstructing lake evolution. Microbialites (i.e., organosedimentary deposits accreted through microbial trapping and binding of detrital sediment or in situ mineral precipitation on organics [Palaios, 2, 1987, 241]), however, have been largely overlooked as paleoenvironmental repositories. Here, we investigate concentrically laminated mineralized microbialites from Laguna Negra, a high‐altitude (4,100 m above sea level) hypersaline, closed‐basin lake in northwestern Argentina, and explore the potential for recovery of environmental signals from these unique sedimentary archives. Spatial heterogeneity in hydrological regime helps define zones inside Laguna Negra, each with their own morphologically distinct microbialite type. Most notably, platey microbialites (in Zone 3A) are precipitated by evaporative concentration processes, while discoidal oncolites (in Zone 3C) are interpreted result from fluid mixing and biologically mediated nucleation. This spatial heterogeneity is reflected in petrographically distinct carbonate fabrics: micritic, botryoidal, and isopachous. Fabric type is interpreted to reflect a combination of physical and biological influences during mineralization, and paired C‐isotope measurement of carbonate and organic matter supports ecological differences as a dominant control on C‐isotopic evolution between zones. Laminae of Laguna Negra microbialites preserve a range of δ13Ccarb from +5.75‰ to +18.25‰ and δ18Ocarb from −2.04‰ to +9.28‰. Temporal trends of lower carbon and oxygen isotopic compositions suggest that the influence of CO2 degassing associated with evaporation has decreased over time. Combined, these results indicate that microbialite archives can provide data that aid in interpretation of both lake paleohydrology and paleoenvironmental change.

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Section: Resultsmentioning

confidence: 99%

Mineralized microbialites as archives of environmental evolution, Laguna Negra, Catamarca Province, Argentina

et al. 2018

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“…This record compares well with palaeoclimatic interpretations of Lake Keilambete (Bowler ; De Deckker ; Chivas et al . ) and Blue Lake (Stanley & De Deckker ).…”

Section: Discussionmentioning

confidence: 99%

Chronology, stratigraphy and palaeoenvironmental interpretation of a Late Pleistocene to mid‐Holocene cave accumulation on Kangaroo Island, South Australia

McDowell

Bestland

Bertuch

et al. 2013

Boreas

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Chronological, sedimentological and geochemical analyses of a clastic infill from Kelly Hill Cave (5K1), Kangaroo Island, document a palaeoenvironmental record that spans from the Late Pleistocene to the middle Holocene. We AMS radiocarbon‐dated bone collagen and U–Th‐dated speleothem to determine that fossiliferous sediments were deposited between >20 ka and 7 ka ago. Most of the 15 sedimentary layers are dominated by sand‐ and silt‐sized quartz that is physically and geochemically comparable with surface soils in the Kelly Hill area. Late Pleistocene and Last Glacial Maximum strata are represented primarily by homogeneous, poorly sorted quartz‐rich sediments that contain little organic matter, but include a thin layer composed largely of silt‐sized clay pellets that resemble sediments deflated from playa lakes. Microstructures observed in petrographic slides indicate that, with the exception of one layer, all sediments experienced little reworking once deposited in the cave. Some layers display pedogenic microstructures such as redeposited clays and opaline silica infilling that indicate postdepositional modification; that is, cave‐floor soil development. Overlying Holocene‐aged sediments also consist mainly of quartz but have much greater organic matter content. Some of these sediments have been strongly influenced by re‐precipitated organic matter that appears to have been transported into the cave via vadose drip water. The presence of dissolved organic matter in soil/vadose waters suggests a high vegetation density and acidic soils, which are congruent with the more equitable climatic conditions characteristic of the Holocene. The sediments described here provide a valuable palaeoenvironmental record that will facilitate future interpretation of associated vertebrate fossils.

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“…Dentro del amplio grupo de indicadores ambientales, las relaciones entre los isótopos estables de C y O (δ 13 C y δ 18 O) en sedimentos lacustres, son una herramienta fundamental en los estudios paleohidrológicos ya que poseen un gran potencial como amplificadores de la información hidroclimática almacenada (Talbot, 1990;Chivas et al, 1993;Valero-Garcés et al, 2003;Leng et al, 2005;Liu et al, 2009;Steinman y Abbott, 2013;Costa et al, 2014). Las reconstrucciones paleolimnológicas basadas en la geoquímica de los isótopos estables comúnmente utilizan los carbonatos autigénicos ya que precipitan en equilibrio isotópico con el cuerpo de agua (Cohen, 2003).…”

Section: Introductionunclassified

Reconstrucción paleohidrológica de la Salina de Ambargasta(Argentina) durante los últimos 45000 años mediante geoquímica de isótopos estables

Zanor¹,

Piovano²,

Ariztegui³

et al. 2017

BSGM

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Coupled Stable-Isotope and Trace-Element Measurements of Lacustrine Carbonates as Paleoclimatic Indicators

Cited by 68 publications

References 30 publications

Mineralized microbialites as archives of environmental evolution, Laguna Negra, Catamarca Province, Argentina

Mineralized microbialites as archives of environmental evolution, Laguna Negra, Catamarca Province, Argentina

Chronology, stratigraphy and palaeoenvironmental interpretation of a Late Pleistocene to mid‐Holocene cave accumulation on Kangaroo Island, South Australia

Reconstrucción paleohidrológica de la Salina de Ambargasta(Argentina) durante los últimos 45000 años mediante geoquímica de isótopos estables

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