Groundwater isotopic data as potential proxy for Holocene paleohydroclimatic and paleoecological models in NE Brazil

Abstract

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Global Isotope Hydrogeology―Review

“…Fossil groundwater recharged during the late‐Pleistocene has been identified in over 100 aquifer systems around the globe (e.g., Münnich & Vogel, ; Edmunds & Wright, ; Fontes, ; Edmunds et al, , ; Darling, ; Haldorsen et al, ; Figure ; Table ). Measurements of fossil groundwater δ 18 O values can provide information about Pleistocene climate conditions (Andrews et al, ; Bertrand et al, ; Haggaz & Kheirallah, ; Joussaume & Jouzel, ) or the fate of paleo‐meltwaters derived from large Pleistocene ice sheets (e.g., the Laurentide ice sheet—Desaulniers et al, ; Siegel & Mandle, ; Bottomley et al, ; Siegel, ; Remenda et al, ; Grasby & Betcher, , ; Clark et al, ; Grasby & Chen, ; Ferguson et al, ; Person et al, ; Jasechko et al, ; McIntosh et al, ; Stotler et al, ; Ferguson & Jasechko, ; Vetter et al, ; Ellis & Jasechko, ; Birks et al, —and the Fennoscandian ice sheet—Boulton et al, ; Vaikmäe, Vallner, et al, ; Vaikmäe, Edmunds, et al, ; Raidla et al, ; Pärn et al, , ; Gerber et al, ). Global climate warmed ~4 °C over the past ~20,000 years (Annan & Hargreaves, ).…”

Isotopic evidence for widespread cold‐season‐biased groundwater recharge and young streamflow across central Canada

“…However, few studies have explicitly quantified seasonal groundwater recharge ratio biases, and fewer still have quantified large‐scale spatial distributions of recharge‐seasonality biases (e.g., Sánchez‐Murillo & Birkel, ). Understanding the spatial patterns and variability of recharge ratios is important in order to help predict how groundwater recharge may respond to climatic shifts or to decadal‐scale changes to seasonal water balances, and to interpret the many isotope‐based records of quaternary climate such as speleothems and fossil groundwater (e.g., Bertrand et al, ; Chen et al, ; Clark, Stute, Schlosser, Drenkard, & Bonani, ; Darling, Edmunds, & Smedley, ; Edmunds & Wright, ; Jasechko et al, ; Phillips, Peeters, Tansey, & Davis, ; Plummer, ; Wagner et al, ; Wang et al, ; Wang et al, ).…”

Aplicação do isótopo radioativo de carbono (14c) na determinação de tempos de residência em aquíferos

“…Segundo os autores, os tempos de residência estimados variam de 2.000 a 16.500 anos para esses aquíferos. Posteriormente, BERTRAND et al (2017) combinaram as datações de 14 C das paleoáguas da região com dados de oxigênio-18 e deutério a fim de colaborar com estudos paleoclimáticos do Holoceno na região. Segundo os autores o estudo isotópico de paleoáguas em aquíferos costeiros profundos pode ser uma ferramenta útil na construção de modelos paleoclimáticos e paleoecológicos.…”

“…Em estudos mais recentes, GASTMANS et al (2017) aplicaram a metodologia de datação por carbono-14 para obter os tempos de residência das águas do sistema aquífero Serra Geral. A partir da análise dos tempos de residência e suas associações com isótopos estáveis e a evolução química, foram traçadas as condições de fluxo e origem das águas no referido aquífero de caráter fraturado e heterogêneo.…”