Paleoclimates, ocean depth, and the oxygen isotopic composition of seawater

Kasting, James F.; Howard, M. T.; Wallmann, Klaus; Veizer, Ján; Shields, Graham A.; Jaffrés, Jasmine B.D.

doi:10.1016/j.epsl.2006.09.029

Cited by 211 publications

(94 citation statements)

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“…Perhaps too, interstellar dust accumulating in the atmosphere caused significant cooling as the Earth migrated through giant molecular clouds (Pavlov et al 2005). Thus, contrary to our earlier supposition (Russell and Hall 1997), we now assume that at times the early ocean would have cooled to \ 20°C (Henderson-Sellers and Henderson-Sellers 1988; Caldeira and Kasting 1992;Kasting et al 2006), perhaps a requirement for moderate temperature convection and the onset of life. Being acidulous permitted the Hadean Ocean, as with the lakes in the Cameroon at pH 5 (Kusakabe et al 2000), to maintain in solution the transition metals provided by acidic hydrothermal and volcanic exhalations.…”

Section: The Hadean Oceanmentioning

confidence: 66%

“…Cyanobacterial fossils are first found at 2.52 Ga and evidence of free oxygen is certainly revealed in the isotopic record at $2.32 Ga in extensive ironstone deposits that also speak to an oxygenic atmosphere at this time (Kazmierczak and Altermann 2002;Bekker et al 2004). Nevertheless, Rosing and Frei (2004) have argued cogently for their appearance prior to 3.8 Ga. Morover, high temperatures in the Archaean have been challenged by Kasting et al (2006). If this were the case, what then prevented oxygen from escaping to the atmosphere?…”

Section: Further Evolutionmentioning

confidence: 91%

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The Alkaline Solution to the Emergence of Life: Energy, Entropy and Early Evolution

Russell

2007

Acta Biotheor

113

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The Earth agglomerates and heats. Convection cells within the planetary interior expedite the cooling process. Volcanoes evolve steam, carbon dioxide, sulfur dioxide and pyrophosphate. An acidulous Hadean ocean condenses from the carbon dioxide atmosphere. Dusts and stratospheric sulfurous smogs absorb a proportion of the Sun's rays. The cooled ocean leaks into the stressed crust and also convects. High temperature acid springs, coupled to magmatic plumes and spreading centers, emit iron, manganese, zinc, cobalt and nickel ions to the ocean. Away from the spreading centers cooler alkaline spring waters emanate from the ocean floor. These bear hydrogen, formate, ammonia, hydrosulfide and minor methane thiol. The thermal potential begins to be dissipated but the chemical potential is dammed. The exhaling alkaline solutions are frustrated in their further attempt to mix thoroughly with their oceanic source by the spontaneous precipitation of biomorphic barriers of colloidal iron compounds and other minerals. It is here we surmise that organic molecules are synthesized, filtered, concentrated and adsorbed, while acetate and methane--separate products of the precursor to the reductive acetyl-coenzyme-A pathway-are exhaled as waste. Reactions in mineral compartments produce acetate, amino acids, and the components of nucleosides. Short peptides, condensed from the simple amino acids, sequester 'ready-made' iron sulfide clusters to form protoferredoxins, and also bind phosphates. Nucleotides are assembled from amino acids, simple phosphates carbon dioxide and ribose phosphate upon nanocrystalline mineral surfaces. The side chains of particular amino acids register to fitting nucleotide triplet clefts. Keyed in, the amino acids are polymerized, through acid-base catalysis, to alpha chains. Peptides, the tenuous outer-most filaments of the nanocrysts, continually peel away from bound RNA. The polymers are concentrated at cooler regions of the mineral compartments through thermophoresis. RNA is reproduced through a convective polymerase chain reaction operating between 40 and 100 degrees C. The coded peptides produce true ferredoxins, the ubiquitous proteins with the longest evolutionary pedigree. They take over the role of catalyst and electron transfer agent from the iron sulfides. Other iron-nickel sulfide clusters, sequestered now by cysteine residues as CO-dehydrogenase and acetyl-coenzyme-A synthase, promote further chemosynthesis and support the hatchery--the electrochemical reactor--from which they sprang. Reactions and interactions fall into step as further pathways are negotiated. This hydrothermal circuitry offers a continuous supply of material and chemical energy, as well as electricity and proticity at a potential appropriate for the onset of life in the dark, a rapidly emerging kinetic structure born to persist, evolve and generate entropy while the sun shines.

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Section: The Hadean Oceanmentioning

confidence: 66%

Section: Further Evolutionmentioning

confidence: 91%

The Alkaline Solution to the Emergence of Life: Energy, Entropy and Early Evolution

Russell

2007

Acta Biotheor

113

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“…In the Proterozoic, the biomass in oceans might be smaller than today, but the total organic accumulation produced by microbes could still be significant as no consumption by metazoans [55,65,66] . Owing to the lower oxygen concentration in the early Proterozoic atmosphere (5%-10% PAL) [4,5,61,63,67] , the ocean was perhaps in a permanently stratified state, with a partially oxidized surface ocean but anoxic/euxinic deeper ocean [3][4][5]7,8,63] . These conditions favored the accumulation and burial of organic matter formed in microbial mats.…”

Section: The Origin Of Sand Veins and Significancementioning

confidence: 99%

“…The Proterozoic was a long-lasting ice-free period in earth history (2.4 to 0.78 Ga) [3][4][5] , without significant fluctuations in carbon and oxygen isotopes [8,63,67,70,71] . The surface temperature was inferred as high as 40-55 ℃ [1,2] .…”

Section: The Origin Of Sand Veins and Significancementioning

confidence: 99%

“…2.4 to 0.78 Ga), the Earth was ice-free, with surface temperature probably around 40-55℃ [1,2] , constituting a rare long-lasting warm period in the earth history [3,4] . Given the fact that the solar luminosity was about 15%-25% lower than today [3,5] , an ice-free, warm Proterozoic Earth surface would require an atmospheric methane concentration at least of 100-300 ppmv [6] . Due to the short resident time of methane in atmosphere, maintaining a…”

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confidence: 99%

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Sand veins and MISS from the Mesoproterozoic black shale (ca. 1.7 Ga) in North China: Implication for methane degassing from microbial mats

Shi

Jiang

Chuan-heng

et al. 2008

Sci. China Ser. D-Earth Sci.

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The Mesoproterozoic Chuanlinggou Formation (ca. 1.7 Ga) consists mainly of dark-gray to black shales that are widespread in the North China Platform. Abundant centimeter-scale sand veins are present within the shale layers of this unit, particularly in the middle part. Sand veins display ptygmatic shapes, perpendicular or with a high angle to bedding planes. They penetrate the black shale layers but are often terminated by thin, lenticular sandstone beds, forming small-scale 'tepee-like' structures. On bedding planes, sand veins are expressed as small ridges with 1-3 mm positive relief. Lack of polygonal shapes and their occurrence in thinly laminated, relatively deep-water shales preclude an origin from sand-filled desiccation cracks. Instead, their close association with microbially induced sedimentary structures (MISS) such as micro-wrinkles and gas blisters, putative bacterial fossils (possibly coccoidal cyanobacteria) and framboidal pyrites, suggests that they were formed by degassing of methane from microbial mat decay. Methane gas disrupted overlying sedimentary layers, creating fractures open to seawater. Fine-grained quartz sands, which were transported into the depositional environment by strong winds, filled the fractures. Sand-filled fractures were shortened and folded during burial compaction, forming ptygmatic shapes. The presence of dispersed dolomite and siderite in these sand veins suggests authigenic carbonate precipitation from anaerobic oxidation of methane (AOM). Sand veins are intensely distributed within the Chuanlinggou Formation and are spatially widespread in the North China Platform. If their methane origin is confirmed, they may have important implications for the Mesoproterozoic paleoclimate. With anoxic oceans and low seawater sulfate concentration during the Mesoproterozoic, methane release from microbial mat decay and/or microbial methanogenesis during shallow burial may have been proportionally higher than that of the modern marine environments, with resultant increase in the relative importance of methane in maintaining the Mesoproterozoic greenhouse climate. sand veins, methane degassing, microbial mats, Chuanlinggou Formation, Mesoproterozoic, North China Platform During most of the Proterozoic (from ca. 2.4 to 0.78 Ga), the Earth was ice-free, with surface temperature probably around 40-55℃ [1,2] , constituting a rare long-lasting warm period in the earth history [3,4] . Given the fact that the solar luminosity was about 15%-25% lower than today [3,5] , an ice-free, warm Proterozoic Earth surface would require an atmospheric methane concentration at least of 100-300 ppmv [6] . Due to the short resident time of methane in atmosphere, maintaining a

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Influence of continental growth on mid‐ocean ridge depth

Sim

Stegman

Coltice

2016

Geochem Geophys Geosyst

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The interconnectedness of life, water, and plate tectonics is strikingly apparent along mid‐ocean ridges (MOR) where communities of organisms flourish off the disequilibrium of chemical potentials created by circulation of hydrothermal fluids driven by Earth's heat. Moreover, submarine hydrothermal environments may be critical for the emergence of life on Earth. Oceans were likely present in the Hadean but questions remain about early Earth's global tectonics, including when seafloor spreading began and whether mid‐oceanic ridges were deep enough for maximum hydrothermal activities. For example, plate tectonics influences global sea level by driving secular variations in the volume of ocean basins due to continental growth. Similarly, variations in the distribution of seafloor age and associated subsidence, due to assembly and dispersal of supercontinents, explain the largest sea level variation over the past 140 Myr. Using synthetic plate configurations derived from numerical models of mantle convection appropriate for early Earth, we show that MOR have remained submerged and their depths potentially constant over geologic time. Thus, conditions in the early Earth existed for hydrothermal vents at similar depths as today, providing environments conducive for the development of life and allowing for processes such as hydrothermal alteration of oceanic crust to influence the mantle's geochemical evolution.

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Paleoclimates, ocean depth, and the oxygen isotopic composition of seawater

Cited by 211 publications

References 50 publications

The Alkaline Solution to the Emergence of Life: Energy, Entropy and Early Evolution

The Alkaline Solution to the Emergence of Life: Energy, Entropy and Early Evolution

Sand veins and MISS from the Mesoproterozoic black shale (ca. 1.7 Ga) in North China: Implication for methane degassing from microbial mats

Influence of continental growth on mid‐ocean ridge depth

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