Estimating Duration and Intensity of Neoproterozoic Snowball Glaciations from Ir Anomalies

Bodiselitsch, Bernd; Koeberl, Christian; Master, Sharad; Reimold, W. U.

doi:10.1126/science.1104657

Cited by 115 publications

(48 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The increase in initial 187 Os/ 188 Os in the sandstone-siltstone interval is matched by an increase in Os abundance, strongly indicative of a marked increase in the input of radiogenic Os at the cessation of glaciation. Elevated Os levels in sedimentary rocks might also arise from extraterrestrial 21,22 or hydrothermal inputs 23 ; however, these processes typically provide non-radiogenic Os 21,23 . The occurrence of much younger alteration would have added Re and radiogenic Os via interaction between oxygenated fluids and organic material in the sediments.…”

Section: Geochemical Trend Of the Bruce-espanola Boundarymentioning

confidence: 99%

Osmium evidence for synchronicity between a rise in atmospheric oxygen and Palaeoproterozoic deglaciation

et al. 2011

View full text Add to dashboard Cite

Early Palaeoproterozoic (2.5-2.0 billion years ago) was a critical phase in Earth's history, characterized by multiple severe glaciations and a rise in atmospheric o 2 (the Great oxidation Event). Although glaciations occurred at the time of o 2 increase, the relationship between climatic and atmospheric transitions remains poorly understood. Here we report high concentrations of the redox-sensitive element os with high initial 187 os/ 188 os values in a sandstone-siltstone interval that spans the transition from glacial diamictite to overlying carbonate in the Huronian supergroup, Canada. Together with the results of Re, mo and s analyses of the sediments, we suggest that immediately after the second Palaeoproterozoic glaciation, atmospheric o 2 levels became sufficiently high to deliver radiogenic continental os to shallow-marine environments, indicating the synchronicity of an episode of increasing o 2 and deglaciation. This result supports the hypothesis that climatic recovery from the glaciations acted to accelerate the Great oxidation Event.

show abstract

Section: Geochemical Trend Of the Bruce-espanola Boundarymentioning

confidence: 99%

Osmium evidence for synchronicity between a rise in atmospheric oxygen and Palaeoproterozoic deglaciation

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Estimations of glacial epoch durations have been derived from palaeomagnetic reversal studies (Sohl et al, 1999), thermal subsidence modeling (Hoffman et al, 1998a) and accumulation rates of inter-planetary dust particles (Bodiselitsch et al, 2005), all of which indicate long-lived glacial activity. While many successions lie within the predicted range of Snowball Earth timescales, none are unusual in their longevity.…”

Section: Fig 12mentioning

confidence: 99%

Neoproterozoic Glaciated Basins: A Critical Review of the Snowball Earth Hypothesis by Comparison with Phanerozoic Glaciations

Etienne¹,

Allen

Rieu

et al. 2007

Glacial Sedimentary Processes and Products

View full text Add to dashboard Cite

The Neoproterozoic is widely considered to have experienced some of the most severe climatic perturbations recorded in Earth history, with extensive glaciations often referred to as 'Snowball Earth' events. The Snowball Earth and competing hypotheses seek to explain a wide range of geological data on Neoproterozoic pre-, syn-and post-glacial successions including glacial sedimentology, chemostratigraphy, palaeoceanography, geochronology, palaeomagnetism and palaeogeography, geodynamics, tectonics, palaeontology and palaeobiogeochemistry. However, our understanding of the Phanerozoic and particularly the Cenozoic and contemporary glacial geological record is often relatively neglected when evaluating the evidence for apparent severe and prolonged periods of globally synchronous glaciation. This paper presents a review of the available geological data for Neoproterozoic glacial successions in the light of what we know about the Cenozoic and recent glacial record. Most Neoproterozoic successions are shown to exhibit spatial and temporal variability, with sediment stacking patterns and facies associations indicative of dynamic ice masses. These characteristics are typical of sedimentary sequences deposited along glaciated continental margins throughout Earth history, without the need for global synchroneity or necessarily severe climatic excursions. Although recurrent very widespread glaciation is envisaged in the Neoproterozoic, the presence of analogous glacigenic and interglacial successions in the Neoproterozoic and Cenozoic suggest the operation of a similar set of processes across a similar range of depositional environments. Consequently, an unambiguous sedimentary record of hydrological shutdown during a prolonged global glaciation appears to be lacking. This indicates either a preservational bias in Neoproterozoic successions of the advance and recessional stages of glacial epochs, or the occurrence of dynamic, non-global glaciations during the Neoproterozoic.

show abstract

“…As ice cover and low temperatures would have greatly hindered silicate weathering, atmospheric accumulation of greenhouse gases, particularly CO 2 , would have eventually allowed temperatures to rise above freezing (30). In Neoproterozoic time, over the likely 12-million-year lifetime of the Snowball event (20), atmospheric CO 2 could have reached a level of 0.2 bar at the present-day outgassing rate of Ϸ10 10 molecules cm Ϫ2 ⅐s Ϫ1 . Although it has recently been noted that greenhouse warming caused directly by CO 2 at a level as high as 0.2 bar may not have been sufficient to initiate the deglaciation of Neoproterozoic Snowballs (30,31), in our model we still follow typical suggestions to estimate the duration of the Paleoproterozoic Snowball event.…”

Section: Atmospheric Chemical Modelsmentioning

confidence: 99%

“…The Paleoproterozoic Makganyene glaciation occurred approximately between 2.3 and 2.2 Ga, and at least two other low-latitude glaciations occurred during the Cryogenian period, between Ϸ740 and 630 Ma (9,10,20). The severity of these ''Snowball Earth'' events is debated, but the low latitude of the glaciations indicates that, at least on the continents, ice extended to the equator, average global temperatures were likely well below freezing, and the hydrological cycle was much diminished (21,22).…”

mentioning

confidence: 99%

Production of hydrogen peroxide in the atmosphere of a Snowball Earth and the origin of oxygenic photosynthesis

Liang

Hartman

Kopp

et al. 2006

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

106

View full text Add to dashboard Cite

During Proterozoic time, Earth experienced two intervals with one or more episodes of low-latitude glaciation, which are probable ''Snowball Earth'' events. Although the severity of the historical glaciations is debated, theoretical ''hard Snowball'' conditions are associated with the nearly complete shutdown of the hydrological cycle. We show here that, during such long and severe glacial intervals, a weak hydrological cycle coupled with photochemical reactions involving water vapor would give rise to the sustained production of hydrogen peroxide. The photochemical production of hydrogen peroxide has been proposed previously as the primary mechanism for oxidizing the surface of Mars. During a Snowball, hydrogen peroxide could be stored in the ice; it would then be released directly into the ocean and the atmosphere upon melting and could mediate global oxidation events in the aftermath of the Snowball, such as that recorded in the Fe and Mn oxides of the Kalahari Manganese Field, deposited after the Paleoproterozoic low-latitude Makganyene glaciation. Low levels of peroxides and molecular oxygen generated during Archean and earliest Proterozoic non-Snowball glacial intervals could have driven the evolution of oxygen-mediating and -using enzymes and thereby paved the way for the eventual appearance of oxygenic photosynthesis.atmospheric processes ͉ Paleoproterozoic ͉ photochemistry

show abstract

Estimating Duration and Intensity of Neoproterozoic Snowball Glaciations from Ir Anomalies

Cited by 115 publications

References 22 publications

Osmium evidence for synchronicity between a rise in atmospheric oxygen and Palaeoproterozoic deglaciation

Osmium evidence for synchronicity between a rise in atmospheric oxygen and Palaeoproterozoic deglaciation

Neoproterozoic Glaciated Basins: A Critical Review of the Snowball Earth Hypothesis by Comparison with Phanerozoic Glaciations

Production of hydrogen peroxide in the atmosphere of a Snowball Earth and the origin of oxygenic photosynthesis

Contact Info

Product

Resources

About