δ13C and 14C activity of groundwater DOC and DIC in the volcanically active and arid Loa Basin of northern Chile

Godfrey, Linda; Herrera, Christian; Burr, George S.; Houston, John; Aguirre, Igor; Jordan, Teresa E.

doi:10.1016/j.jhydrol.2021.125987

Cited by 15 publications

(9 citation statements)

References 53 publications

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“…Hyperaridity from the Miocene to the present was punctuated by pluvial periods of increased humidity that have been recognised in the region, with multiple such periods documented in Jordan et al (2014), Evenstar et al (2017), Ritter et al (2018) and Godfrey et al (2021). Diederich et al (2020) note that in the northern Atacama, orbital‐scale and millennial‐scale precipitation changes occurred over the past 68 kyr, with wetter periods between 61 ka and 68 ka, several short, wet periods from 33.6 to 58 ka and from 16.4 to 28.5 ka, with the driest period from 8 ka to the present.…”

Section: Introductionmentioning

confidence: 93%

“…Non‐marine limestones in the Calama Basin, a 12,900 km 2 basin located between the High Andes to the east and the Precordillera highlands to the west, provide a record of the past ca 10 Myr of climate change (de Wet et al, 2015, 2020; Godfrey et al, 2021; Rech et al, 2002, 2010) (Figure 1A). This paper documents a suite of previously undescribed Quaternary freshwater tufas from this arid environment and discusses their significance within the context of the region's recent past and potentially changing future climate.…”

Section: Introductionmentioning

confidence: 99%

“…This study draws on stratigraphic relationships, tufa morphologies, biological and geochemical characteristics and depositional environmental interpretations to provide new insight into palaeoclimate and palaeoenvironmental conditions in the western Calama Basin over the past 550,000 years. The Calama Basin was chosen as a study area because it has experienced rapid climate evolution, including intense aridification, over the past hundreds of thousands of years, and has well‐preserved freshwater carbonate deposits across a broad time span, thus providing a record of humidity changes throughout the late Neogene–Quaternary (de Wet et al, 2015, 2020; Godfrey et al, 2021; Jordan et al, 2022). This hyperarid region is thus optimal for studying climate‐responsive freshwater carbonates since small shifts in humidity have significant implications for limestone deposition (de Wet et al, 2015, 2020).…”

Section: Introductionmentioning

confidence: 99%

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Exceptional preservation in Quaternary Atacama Desert Tufas: Evidence for increased groundwater and surface water in the Calama Basin, Atacama, Chile

Wet

Driscoll

Wet

et al. 2023

The Depositional Record

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Exceptionally well‐preserved tufas located west of Calama, Atacama Desert, Chile, designated Santa Juana tufas, record episodic wetter conditions, relative to today, over the past 500,000 years. Globally, tufa architecture and depositional details are poorly understood as most described tufas have been degraded by weathering and erosion. In the hyperarid Atacama, post‐depositional alteration is negligible, therefore, the exceptional preservation of Santa Juana tufas documented in this study provides new information about tufa facies and their complex interactions. Santa Juana facies include microbial stromatolites, phytoherms, cascadestone, flowstone and porous limestone. Phytoherms, consisting of former plant stems coated with calcite, developed in channels, within pools, and along spring discharge aprons. Cascadestone, representing former waterfalls, preserves microbial filaments and delicate V‐shaped calcite crystals. Flowstone lines shallow subvertical to subhorizontal channels, representing sites of rapidly sluicing water flow. Porous limestone, containing sparse calcite and/or gypsum and anhydrite cement crystals, represents detrital accumulations. Stable isotope results, coupled with U/Th ages, show that by the Quaternary, relative to the Neogene, groundwater was less supercharged with volcanogenic CO2 so degassing was moderated. The δ18O ratios from Miocene–Pliocene palustrine and lacustrine freshwater carbonates that underlie Santa Juana tufas indicate significant evaporation, but the tufa δ18O signal indicates a less evaporative trend due to shorter atmosphere exposure time. Biological fractionation in δ13C is largely masked by the region's volcanogenic carbon footprint, although tufa petrography shows well‐preserved microbial filaments and laminations. The range of tufa ages in this study shows that there were wetter time periods within the drainage basin headwater area in the Quaternary, but that by the late Pleistocene to early Holocene, aridity to hyperaridity became established. The lack of diagenesis or alteration within the Santa Juana tufas indicates that there has been minimal rainfall since their deposition.

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Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Exceptional preservation in Quaternary Atacama Desert Tufas: Evidence for increased groundwater and surface water in the Calama Basin, Atacama, Chile

Wet

Driscoll

Wet

et al. 2023

The Depositional Record

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“…Considering the scenario of different hydrothermal systems on the south and west lake coasts, a higher contribution of magmatic CO2 in the southern hydrothermal reservoir compared to those on the west would explain the oldest age of 26,500 ± 1,300 BP recorded in the basin. For example, 14 C ages of the DIC exceeding 20,000 years due to dilution by geogenic DIC sources have been reported also from the Loa and Calama basins located north of the Salar de Atacama (~450 km NNW of the El Peinado basin; Godfrey et al, 2021).…”

Section: C-free Volcanic Co2mentioning

confidence: 98%

“…Another common source of 14 C-depleted carbon in lakes can be the contribution of ancient groundwater (Macdonald et al, 1991;Riggs, 1984;Godfrey et al, 2021). In the Altiplano-Puna Plateau, the contribution of old groundwater to lacustrine systems might be substantial given the present-day negative water balance regime (Grosjean et al, 1995).…”

Section: Groundwater Effectsmentioning

confidence: 99%

Spatial variability of the modern radiocarbon reservoir effect in the high-altitude lake Laguna del Peinado (Southern Puna Plateau, Argentina)

Vignoni

Córdoba

Tjallingii

et al. 2023

Preprint

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Abstract. The high-altitude lakes of the Altiplano-Puna Plateau in the Central Andes often have large radiocarbon reservoir effects. This combined with the general scarcity of terrestrial organic matter makes obtaining a reliable and accurate chronological model based on radiocarbon ages a challenge. As a result, age-depth models based on radiocarbon dating are often constructed by correcting for the modern reservoir effect, however, commonly without consideration of spatial variations of reservoir ages within the lake and across the basin. In order to get a better constrain on the spatial variability of the radiocarbon reservoir effects, we analyse 14C ages of modern terrestrial and aquatic plants from the El Peinado basin in the Southern Puna Plateau, which hosts the Laguna del Peinado lake fed by hydrothermal springs. The oldest 14C ages of modern samples (> 18,000 and > 26,000 BP) were found in hot springs discharging into the lake likely resulting from the input of 14C-depleted carbon from old groundwater and 14C-free magmatic CO2. In the littoral and central part of Laguna del Peinado, modern samples 14C ages were several thousand years lower (> 13,000 and > 12,000 BP) compared to the inflowing waters as a result of CO2 exchange with the atmosphere. Altogether, our findings reveal a spatial variability of up to 14,000 14C years of the modern reservoir effect between the hot springs and the lake in the El Peinado basin. This study has implications for high-precision dating and accurate 14C-based chronologies in paleoclimate studies in the Altiplano-Puna Plateau and similar settings. Our results highlight the need to consider spatial and likely also temporal variations in the reservoir effects when constructing age-depth models.

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Combining hydrochemistry and 13C analysis to reveal the sources and contributions of dissolved inorganic carbon in the groundwater of coal mining areas, in East China

Jiang

et al. 2023

Environ Geochem Health

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δ13C and 14C activity of groundwater DOC and DIC in the volcanically active and arid Loa Basin of northern Chile

Cited by 15 publications

References 53 publications

Exceptional preservation in Quaternary Atacama Desert Tufas: Evidence for increased groundwater and surface water in the Calama Basin, Atacama, Chile

Exceptional preservation in Quaternary Atacama Desert Tufas: Evidence for increased groundwater and surface water in the Calama Basin, Atacama, Chile

Spatial variability of the modern radiocarbon reservoir effect in the high-altitude lake Laguna del Peinado (Southern Puna Plateau, Argentina)

Combining hydrochemistry and 13C analysis to reveal the sources and contributions of dissolved inorganic carbon in the groundwater of coal mining areas, in East China

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