Direct observations of aluminosilicate weathering in the hyporheic zone of an Antarctic Dry Valley stream

Maurice, Patricia A.; McKnight, Diane M.; Leff, Laura Gunn; Fulghum, Julia E.; Gooseff, M. N.

doi:10.1016/s0016-7037(01)00890-0

Cited by 88 publications

(74 citation statements)

References 51 publications

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“…Indeed, 1D modeling with oxygen and sulfate boundary conditions encompassing those hypothesized from the Archean to present indicates that oxygen production and redox zonation within ancient microbial mats should have been independent of the chemistry of their environment (45). It is important to note that the attendant effects of BSCs and FMMs in the Archean would have been multiple, and would also have included enhanced mineral dissolution of underlying sediments (46) and increased flux of dissolved organic carbon to overlying waters, which in turn, facilitates transport of normally insoluble metals (e.g., Fe, Al) downstream (47).…”

Section: Significancementioning

confidence: 99%

Benthic perspective on Earth’s oldest evidence for oxygenic photosynthesis

Lalonde

Konhauser

2015

Proc. Natl. Acad. Sci. U.S.A.

189

147

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The Great Oxidation Event (GOE) is currently viewed as a protracted process during which atmospheric oxygen increased above ∼10−5 times the present atmospheric level (PAL). This threshold represents an estimated upper limit for sulfur isotope mass-independent fractionation (S-MIF), an Archean signature of atmospheric anoxia that begins to disappear from the rock record at 2.45 Ga. However, an increasing number of papers have suggested that the timing for oxidative continental weathering, and by conventional thinking the onset of atmospheric oxygenation, was hundreds of million years earlier than previously thought despite the presence of S-MIF. We suggest that this apparent discrepancy can be resolved by the earliest oxidative-weathering reactions occurring in benthic and soil environments at profound redox disequilibrium with the atmosphere, such as biological soil crusts and freshwater microbial mats covering riverbed, lacustrine, and estuarine sediments. We calculate that oxygenic photosynthesis in these millimeter-thick ecosystems provides sufficient oxidizing equivalents to mobilize sulfate and redox-sensitive trace metals from land to the oceans while the atmosphere itself remained anoxic with its attendant S-MIF signature. As continental freeboard increased significantly between 3.0 and 2.5 Ga, the chemical and isotopic signatures of benthic oxidative weathering would have become more globally significant from a mass-balance perspective. These observations help reconcile evidence for pre-GOE oxidative weathering with the history of atmospheric chemistry, and support the plausible antiquity of a terrestrial biosphere populated by cyanobacteria well before the GOE.

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Section: Significancementioning

confidence: 99%

Benthic perspective on Earth’s oldest evidence for oxygenic photosynthesis

Lalonde

Konhauser

2015

Proc. Natl. Acad. Sci. U.S.A.

189

147

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“…As a result of these upstream processes, closed-basin lakes receive stream waters that are enriched in solutes compared to meltwater originating at the glaciers. Previous studies of chemical weathering in the dry valleys have shown that denudation rates are higher than expected for such a cold, dry climate Nezat et al, 2001;Gooseff et al, 2002;Maurice et al, 2002). Hyporheic exchange in dry valley streams controls the transport of water through storage and evaporation , and controls stream water dissolved solute loads through in-hyporheic chemical weathering and dissolution of marine aerosols and calcium carbonate .…”

Section: Introductionmentioning

confidence: 99%

Reach-Scale Cation Exchange Controls on Major Ion Chemistry of an Antarctic Glacial Meltwater Stream

Gooseff

McKnight

Runkel³

2004

Aquat Geochem

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Abstract. The McMurdo dry valleys of Antarctica represent the largest of the ice-free areas on the Antarctic continent, containing glaciers, meltwater streams, and closed basin lakes. Previous geochemical studies of dry valley streams and lakes have addressed chemical weathering reactions of hyporheic substrate and geochemical evolution of dry valley surface waters. We examine cation transport and exchange reactions during a stream tracer experiment in a dry valley glacial meltwater stream. , Li + and K + were taken up in downstream transport and Na + was released. Simulations of conservative and reactive (firstorder uptake or generation) solute transport were made with the OTIS (one-dimensional solute transport with inflow and storage) model. Among the four experimental reaches of Green Creek, solute transport simulations reveal that Li + was removed from stream water in all four reaches, K + was released in two reaches, taken up in one reach, and Na + was released in all four reaches. Hyporheic sediments appear to be variable with uptake of Li + in two reaches, uptake of K + in one reach, release of K + in two reaches, and uptake of Na + in one reach. Mass balances of the conservative and reactive simulations show that from 1.05 to 2.19 moles of Li + was adsorbed per reach, but less than 0.3 moles of K + and less than 0.9 moles of Na + were released per reach. This suggests that either (1) exchange of another ion which was not analyzed in this experiment or (2) that both ion exchange and sorption control inorganic solute transport. The elevated cation concentrations introduced during the experiment are typical of initial flows in each flow season, which flush accumulated dry salts from the streambed. We propose that the bed sediments (which compose the hyporheic zone) modulate the flushing of these salts during initial flows each season, due to ion exchange and sorption reactions.

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“…; Ballantyne, 2002;Carrivick et al, 2013). Moreover, they substantially control exchange of material, nutrients Maurice et al, 2002;Conovitz et al, 2006) and organic matter (Spaulding et al, 1994;Simmons et al, 2013). Equally important is the function of proglacial hydrology as a habitat supporting the existence and evolution of flora and fauna (e.g.…”

Section: Introductionmentioning

confidence: 99%

Seasonal hydrological and suspended sediment transport dynamics in proglacial streams, James Ross Island, Antarctica

Kavan

Ondruch

Nývlt

et al. 2016

Geografiska Annaler: Series A, Physical Geography

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Rapid warming of the Antarctic Peninsula is producing accelerated glacier mass loss and can be expected to have significant impacts on meltwater runoff regimes and proglacial fluvial activity. This study presents analysis of the hydrology and suspended sediment dynamics of two proglacial streams on James Ross Island, Antarctic Peninsula. Mean water discharge during 8/1/2015 to 18/2/2015 reached 0.19 m 3 s -1 and 0.06 m 3 s -1 for Bohemian Stream and Algal Stream, respectively, equivalent to specific runoff of 76 mm month -1 and 60 mm month -1 . The daily discharge regime strongly correlated with air and ground temperatures. The effect of global radiation on proglacial water discharge was found low to negligible. Suspended sediment concentrations of Bohemian Stream were very high (up to 2927 mg L -1 ) due to aeolian supply and due to the high erodibility of local rocks. Total sediment yield (186 t km -2 yr -1 ) was high for (nearly) deglaciated catchments, but relatively low in comparison with streams draining more glaciated alpine and arctic catchments. The sediment provenance was mostly local Cretaceous marine and aeolian sediments; volcanic rocks are not an important source for suspended load. High Rb/Sr ratios for some samples suggested chemical weathering. Overall, this monitoring of proglacial hydrological and suspended sediment dynamics contributes to the dearth of such data from Antarctic environments and offers an insight to the nature of the proglacial fluvial activity, which is likely to be in a transient state with ongoing climate change.

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Direct observations of aluminosilicate weathering in the hyporheic zone of an Antarctic Dry Valley stream

Cited by 88 publications

References 51 publications

Benthic perspective on Earth’s oldest evidence for oxygenic photosynthesis

Benthic perspective on Earth’s oldest evidence for oxygenic photosynthesis

Reach-Scale Cation Exchange Controls on Major Ion Chemistry of an Antarctic Glacial Meltwater Stream

Seasonal hydrological and suspended sediment transport dynamics in proglacial streams, James Ross Island, Antarctica

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