Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31
DOI 10.1186/s40645-017-0145-6

Progress in Earth andPlanetary Science

RESEARCH ARTICLE

Open Access

Weak hydrothermal carbonation of the
Ongeluk volcanics: evidence for low CO2
concentrations in seawater andatmosphere during the Paleoproterozoic
global glaciation
Takazo Shibuya1,2,3*, Tsuyoshi Komiya4, Ken Takai1,2,3, Shigenori Maruyama5,7 and Michael J. Russell6

Abstract
It was previously revealed that the total CO2 concentration in seawater decreased during the Late Archean. In thispaper, to assess the secular change of total CO2 concentration in seawater, we focused on the Paleoproterozoic era
when the Earth experienced its first recorded global glaciation. The 2.4 Ga Ongeluk Formation outcrops in the
Kaapvaal Craton, South Africa. The formation consists mainly of submarine volcanic rocks that have erupted during
the global glaciation. The undeformed lavas are mostly carbonate-free but contain rare disseminated calcites. The
carbon isotope ratio of the disseminated calcite (δ13Ccc vs. VPDB) ranges from − 31.9 to − 13.2 ‰. The relatively low
δ13Ccc values clearly indicate that the carbonation was partially contributed by 13C-depleted CO2 derived fromdecomposition of organic matter beneath the seafloor. The absence of δ13Ccc higher than − 13.2‰ is consistent
with the exceptionally 13C-depleted CO2 in the Ongeluk seawater during glaciation. The results suggest thatcarbonation occurred during subseafloor hydrothermal circulation just after the eruption of the lavas. Previously, it
was reported that the carbonate content in the uppermost subseafloor crust decreased from 3.2 to 2.6 Ga,
indicating a decrease in total CO2 concentration in seawater during that time. However, the average CO2 (ascarbonate) content in the Ongeluk lavas (< 0.001 wt%) is much lower than those of 2.6 Ga representatives and evenof modern equivalents. This finding suggests that the total CO2 concentration in seawater further decreased during
the period between 2.6 and 2.4 Ga. Thus, the very low content of carbonate in the Ongeluk lavas is probableevidence for the extremely low CO2 concentration in seawater during the global glaciation. Considering that the
carbonate content of the subseafloor crusts also shows a good correlation with independently estimatedatmospheric pCO2 levels through the Earth history, it seem highly likely that the low carbonate content in the
Ongeluk lavas reflects the low atmospheric pCO2 at that time. We conclude that the continuous decrease in CO2
concentration of seawater/atm. from 3.2 Ga was one of the contributing factors to the Paleoproterozoic global glaciation.
Keywords: Paleoproterozoic global glaciation, Ongeluk volcanics, Carbonation, Carbon and oxygen isotopes, Seawater/
atmosphere CO2 level* Correspondence: takazos@jamstec.go.jp
1
Department of Subsurface Geobiological Analysis and Research (D-SUGAR),
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15
Natsushima-cho, Yokosuka 237-0061, Japan
2
Research and Development Center for Submarine Resources, Japan Agency
for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho,
Yokosuka 237-0061, Japan
Full list of author information is available at the end of the article© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, andreproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.

Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31

Introduction
Because the Sun was approximately 30% less luminousat 4.6 Ga (Gough 1981), the mean temperature of the
Earth’s surface would have been below the freezing pointof seawater if the albedo and atmospheric compositionof the early Earth had been the same as at the present(Sagan and Mullen 1972). However, the occurrence of
pillow lavas and sedimentary rocks clearly indicate thepresence of liquid water on the early Earth (Sagan andMullen 1972). This “faint young Sun paradox” has been
explained by positing a greenhouse effect to counteract
the lower solar luminosity (e.g., Kasting 1987, 1993;
Sleep and Zahnle 2001). Yet, at present, this paradox has
not yet been entirely resolved because the geologic record suggests that CO2 levels in the Archean atmospherepotentially exerted enough of a greenhouse effect toavoid Earth freezing for contemporary albedos, whereas
the presence of other greenhouse gases such as CH4 and
OCS was also reported (e.g., Pavlov et al. 2003; Ueno etal. 2009). Furthermore, the changes in albedos of theearly Earth also had the potential to compensate thefaint young Sun (Rosing et al. 2010). However, comprehensive geological studies provide evidence suggestingthat atmospheric CO2 levels in the early Earth were substantially higher than at present: e.g., > 100 PAL at 3.8–
1.8 Ga (Ohmoto et al. 2004), > 100 PAL at 3.5–3.2 Ga(Lowe and Tice 2004), at > 7 PAL bar (25 °C) at 3.2 Ga(Hessler et al. 2004), 23×/÷3 PAL at 2.2 Ga (Sheldon
2006), 30–190 PAL at 2.15 Ga, and various other estimates for 2.77–1.85 Ga (Kanzaki and Murakami 2015).
The putative CO2-rich atmosphere in the early Earthwould also have kept oceans acidic and CO2- and metalrich (Konhauser et al. 2007). Such CO2-rich seawaterprovided seafloor hydrothermal vent environments thatwould sustain the emergence and early evolution of life
(Takai et al. 2006; Russell et al. 2010, 2014; Shibuya et al.
2015, 2016). Furthermore, chemical exchange reactions
would have had particular characteristics as the thenCO2-rich seawater interfaced oceanic lithosphere (e.g.,
intense CO2 fixation into the crust) (Nakamura and Kato
2004; Rouchon and Orberger 2008) resulting in the generation of novel high-temperature hydrothermal fluids(e.g.., alkaline, silica-rich, metal-poor fluid, and Mg-richfluid) (Shibuya et al. 2010; Ueda et al. 2016). These processes would have played a significant role in controllingthe chemistry of early oceans. Therefore, the secularchange of CO2 levels in the atmosphere and seawater isimportant for understanding the evolution of surface environments and life on Earth.
In this context, the degree of carbonation of greenstones has been considered to qualitatively reflect CO2
concentrations in ancient seawater (Kitajima et al. 2001;
Nakamura and Kato 2004; Hofmann and Harris 2008).
The 3.5 and 3.2 Ga greenstones in extensional geologicalPage 2 of 13

settings (mid-ocean ridge or rift basin) underwent strong
carbonation caused by intense interaction with ambient
CO2-rich seawater (Nakamura and Kato 2004; Shibuya
et al. 2007a, 2012). Furthermore, the lower carbonate
content in the 2.6 Ga greenstones compared to those in
the 3.5 and 3.2 Ga greenstones indicated that the CO2
concentration in seawater decreased during Late
Archean period—possibly caused by the formation andbreakdown of the supercontinent at around 2.7 Ga (Shibuya et al. 2013a). However, there are no data for the
carbonation of subseafloor crust after 2.6 Ga, although
the data from the DSDP/ODP drill cores have been obtained from the Phanerozoic crusts (Alt and Teagle
1999; Gillis and Coogan 2011).
In this paper, we focus on the Paleoproterozoic era
when global climate drastically cooled to produce an ice
age, though it reverted thereafter (Evans et al. 1997;
Kirschvink et al. 2000; Harada et al. 2015). In this era,
the atmospheric CO2 level was temporarily insufficient
to keep the Earth’s surface above the freezing point ofwater. Previously, a number of triggers for the Paleoproterozoic global glaciation have been proposed: (1) thecollapse of a methane greenhouse caused by the global
rise of oxygen over the period ~2.5–2.2 Ga (Kopp et al.
2005), (2) the removal of atmospheric CO2 via increased
silicate weathering of the amalgamated supercontinent
at ~2.5 Ga (Young 2013) and/or of the newly created voluminous continental flood basalts at 2.45 Ga (Melezhik2006), and (3) the shutdown of volcanic CO2 emissions
resulting from a global magmatic lull that lasted from
2.45 to 2.2 Ga (Condie et al. 2009). All these models are
premised upon low atmospheric CO2 levels. To test this
supposed prerequisite and to reveal the secular change
of CO2 concentration in seawater after 2.6 Ga, we investigated the carbonation of the Paleoproterozoic submarine volcanics in the Ongeluk Formation, Transvaal
Supergroup, South Africa. Based on the lines of geological evidence, the Ongeluk volcanics are considered
to have erupted during the global glaciation (Kirschvink
et al. 2000; Kopp et al. 2005). Therefore, it is expectedthat the degree of carbonation of the Ongeluk volcanics
qualitatively reflects the CO2 concentration in seawaterand atmosphere during that glaciation.

Methods
The Ongeluk formation

The Griqualand West Sequence in South Africa mainlycomprises Late Archean to Paleoproterozoic sedimentary rocks and intercalating volcanic rocks deposited on
the Kaapvaal Craton (Beukes and Smit 1987; Cornell etal. 1996). In the Griqualand West Sequence, the Transvaal Supergroup is subdivided into three groups bymajor unconformities; Ghaap Group, Postmasburg
Group and Olifantshoek Group in stratigraphicacllyShibuya et al. Progress in Earth and Planetary Science (2017) 4:31

ascending order. The Paleoproterozoic Ongeluk Formation belongs to the Postmasburg Group that mainly
consists of diamictite, volcanic rocks, terrigenous clastic
rocks, banded iron formations, manganese formations,and shallow marine dolostones (Beukes and Smit 1987).
The Postmasburg Group unconformably overlies theGhaap Group, including Koegas and Asbestos Hill
Subgroups composed of iron formation, shale, andquartzite (Fig. 1).
The Ongeluk Formation consists ~ 500–1000 m ofbasaltic-andesitic lavas comprising pillow lavas, massive
sheet flows, and hyaloclastites, intercalated with jaspilite
beds (Grobler and Botha 1976) (Fig. 2), indicating the
subaqueous eruption of the Ongeluk lavas. The formation conformably overlies the glaciogenic deposits (Makganyene diamictite). The diamictite/lava contacts appear
conformable without paleosols in borehole cores (de Villiers and Visser 1977; Evans et al. 1997). Additionally,
volcanic shards and fragments are abundant in the upper
part of the Makganyene Formation (de Villiers and Visser 1977; Evans et al. 1997), and the diamictite and thelava are interdigitated (Kirschvink et al. 2000; Polteau etal. 2006). These lines of geological evidence indicate that
the Ongeluk volcanism and Makganyene glaciation overlapped in time. Therefore, the depositional paleolatitudeof the Ongeluk Formation (11 ± 6°) provides strong evidence for low-latitude glaciation in a maritime setting

Page 3 of 13(Evans et al. 1997; Kirschvink et al. 2000; Hoffman 2013;
Gumsley et al. 2017). Furthermore, the Hotazel Formation, consisting predominantly of manganese formation/
banded iron formation which includes dropstones at its
base (Kirschvink et al. 2000; Polteau et al. 2006), conformably overlies the Ongeluk Formation. The contact
between these two formations is characterized by parallel bedding planes in both, ferruginous alteration at the
top of the Ongeluk Formation, and the absence of abasal conglomerate. These relationships indicate that the
Ongeluk lavas erupted during the global glacial period(Kirschvink et al. 2000; Kopp et al. 2005) (Fig. 2). Metamorphism of the Ongeluk Formation does not exceed
prehnite-pumpellyite facies, so that the effects of ancientpassive subseafloor hydrothermal alteration are still plain
to see (Gutzmer et al. 2001). The age of the Ongeluk
Formation had long been under debate because two possible depositional ages (2.2 and 2.4 Ga) were constrainedby other formations stratigraphically close to the Ongeluk Formation (Bau et al. 1999; Cornell et al. 1996; Dorland 2004). However, a recent geochronogical work on
the Ongeluk Formation itself strongly suggested that theexact age of the volcanism of the Ongeluk lavas was
2426 ± 3 Ma (Gumsley et al. 2017). Thus, 2.4 Ga is tentatively used here as the age of the Ongeluk Formation.
The Ongeluk lavas are considered to have erupted in ashallow marine environment during the development ofMozambique

Namibia

BotswanaSouth Africa
Swaziland

Northern Cape
Province

LesothoGRIQUATOWN

Younger cover
Postmasburg GroupN

Asbestos Hills
Subgroup
Fault
Thrust fault

20 km

Syncline axis

Fig. 1 Simplified geological map of the Transvaal Supergroup, Northern Cape Province, South Africa (modified after Gutzmer et al. 2003)

Ghaap Gp

Koegas SubgroupShibuya et al. Progress in Earth and Planetary Science (2017) 4:31

Mooidraai Dolomite

Postmasburg Gp

Hotazel Iron-formation(& Kalahari Manganese)
Dropstone Layer

Jaspilite

Ongeluk Volcanics

Ghaap Gp

Makganyene Diamictite

Unconformity
Koegas Formation

Fig. 2 Stratigraphy of the Transvaal Supergroup in the GriqualandWest region, South Africa. The relationship among the Ongeluk
Formation, the Makganyene diamictite, and the overlying Hotazel
Formation are shown (after Kirschvink et al. 2000). The Ongeluk
Formation (~ 500–1000 m thick) conformably overlies the
Makganyene Diamictite (~ 3–70 m thick) and underlies a dropstonelayer at the bottom of the Hotazel Formation (~ 100–250 m thick)(Hoffman 2013)

Page 4 of 13

chlorite, albite, quartz, and minor pumpellyite and calcite, but igneous clinopyroxene survives. Although lowtemperature clay minerals, often observed for modern
altered seafloor rocks, are minor in the Ongeluk lavas,such textures are similar to those of modern hydrothermally altered seafloor volcanic rocks (e.g., Alt et al.
2010). The degree of carbonation of the Ongeluk basaltic
andesites is weak; 17 of the 115 samples were identified
to contain calcite under a microscope. These samples
mainly contain disseminated calcites replacing igneous
phases, but a few samples have vein-filling calcites(Fig. 3b, c).
The Ongeluk pillow lavas still retain open drainage
cavities and interpillow voids. These are filled with quartz
and/or jaspilite, which was likely precipitatedpenecontemporaneously with the interbedded jaspilite(Grobler and Botha 1976; Gutzmer et al. 2001, 2003). The
precipitates in the drainage cavities have smooth, oval
tubular shapes and are oriented parallel to the pillow tubes
themselves or to the direction of lava flow. The cavities
are isolated from one another and never cross-cut pillow
rims nor do the precipitates in the voids ever cut thechilled margins of these rims. In the absence of such precipitates, the open spaces in volcanic rocks are obliterated
by compaction during burial—strong evidence that thesequartz precipitates formed relatively soon after eruption of
the host volcanic rocks (Gutzmer et al. 2003). The jaspilite
precipitates are composed mainly of microquartz andhematite and frequently form banded textures of red andwhite layers. The red layer consists of hematite and minor
amounts of microquartz, magnetite, and pyrite, whereas
the white layer comprises microquartz and larger
subhedral andradite with subordinate hematite and disseminated calcite (Fig. 3d, e), as previously reported(Gutzmer et al. 2001). As observed for the lavas, minor
jaspilite samples exhibit deformation textures such as
brecciation and/or calcite veining (Fig. 3f). The formation
temperature of these hydrothermal precipitates wasestimated to be 64–160 °C from the homogenization
temperature of fluid inclusions in the quartz(Gutzmer et al. 2001, 2003; Saito et al. 2016).
Analytical methods

an extensional rifting basin on the Kaapvaal Craton(Cornell et al. 1996).
Lavas and hydrothermal jaspilites in the Ongeluk
formation

The Ongeluk basaltic andesites are mostly undeformed,
and igneous textures, such as intergranular, intersertal,and subophitic textures, are well preserved (Cornell etal. 1996; Gutzmer et al. 2001, 2003) (see also Fig. 3a). Igneous plagioclase and glass are mainly replaced byPowdered samples were prepared with a tungsten millfrom slab samples from which the weathered surface
had been removed. In sealed vessels, CO2 was extracted
from the powder samples by using anhydrous phosphoric acid. The stable carbon and oxygen isotope ratios
were analyzed using an isotope ratio mass spectrometerequipped with an automatic sampler (DELTA V plus and
GasBench II at SI Science Co., Ltd., Japan) (Révész and
Landwehr 2002). The isotopic ratios are presented inconventional δ notation. The carbon and oxygen isotope
ratios were calibrated relative to the Vienna Pee DeeShibuya et al. Progress in Earth and Planetary Science (2017) 4:31

Page 5 of 13

a

b
Cpx
Cpx
Cc
Ab+Chl+Qz

Chl+Qz

Pl-ps
250µm

c

500µm

d

Cc vein

Hem
Adr
Pl-ps

Py

Cc vein
Hem+Qz

Cc
500µm

e

250µm

f
Hem+Qz+Cc
Cc veinCc

Hem+Qz

Adr

Qz

Hem

250µm

250µm

Fig. 3 Photomicrographs of basaltic andesites and hydrothermal jaspilites in the Ongeluk Formation. a A typical basaltic andesite in which theigneous minerals and glass have been replaced by secondary minerals but the igneous texture is well preserved. b Disseminated calcite-bearing
basaltic andesite in which igneous plagioclase has been replaced by secondary albite, chlorite, quartz, and calcite. c A calcite vein cutting allalteration minerals and igneous texture. d A hematite-rich layer of interpillow hydrothermal jaspilite. e A microquartz-rich layer of the interpillow
hydrothermal jaspilite that includes calcite and andradite. f A calcite vein cutting jaspilite

Belemnite (VPDB). Based on replicate analyses oflaboratory standard, the analytical reproducibility is
estimated to be better than ± 0.2‰ for carbon and better
than ± 0.5‰ for oxygen isotope ratios. In the analysis of
the CO2 content in the samples, the relative error is 5–10%of the reported values, depending on the amount of
extracted CO2.

Results and discussion
Based on the occurrence and mineral texture of the
Ongeluk lavas and jaspilites, the disseminated calcites are considered to have formed during subseafloor hydrothermal circulation at that time, aspreviously reported (Gutzmer et al. 2001). In contrast, the calcite veins must have formed at least

after the formation of the disseminated calcites,
which might have occurred during a later stage ofsubseafloor hydrothermal circulation, though they
could also relate to a later metamorphic or deformation event. The oxygen isotope ratios (δ18O) of thedisseminated calcites in the lavas and hydrothermal
jaspilites range from − 17.9 to − 10.2 ‰ while theircarbon isotope ratio (δ13C) shows relatively low
values ranging from − 31.9 to − 13.2 ‰ (Table 1 andFig 4). Most of the calcites in hydrothermal jaspilites
have lower δ18O values than those in the Ongeluk
lavas, but there is no obvious correlation to be madebetween the δ18O and δ13C values for all samples,indicating that the isotopic values have not been
greatly modified since their formation. The CO 2

Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31

Page 6 of 13

Table 1 Isotopic compositions of calcites and CO2 content in the Ongeluk basaltic andesites and hydrothermal jaspilites
Sample no. Rock typeClassification of calcite CO2 (wt%) δ13C (VPDB, ‰) δ18O (VPDB, ‰) Temperature (°C)aGU033

Basaltic andesite

Disseminated0− 14.2− 15.2

123

GU034

Basaltic andesite

Disseminated0− 15.6− 13.8109

GU035

Basaltic andesite

Disseminated0− 13.2− 14.6

117

GU036

Basaltic andesite

Disseminated

0.01− 15.8− 15.8130

GU037

Basaltic andesite

Disseminated

0.01− 16.1− 14.3114

GU038

Basaltic andesite

Disseminated0− 15.9− 12.9100

GU041

Basaltic andesite

Disseminated0− 18.9− 14.1

112

GU045

Basaltic andesite

Disseminated0− 18.3− 13.3

104

GU048

Basaltic andesite

Disseminated0− 15.7− 13.2103

GU049

Basaltic andesite

Disseminated0− 14.9− 14.6

117

GU054

Basaltic andesite

Disseminated0− 23.5− 14.3

114

GU055

Basaltic andesite

Disseminated0.01− 24.9

− 15

121

GU063

Basaltic andesite

Disseminated0− 22.3− 12.394

GU110

Pillowed basaltic andesite (core)

Disseminated0− 15.6− 10.2

77

GU172

Basaltic andesite

Disseminated0− 18.0− 10.882

GU174

Basaltic andesite with calcite veins

Disseminated/vein

0.060− 16.1− 17.1147

GU144Interpillow jaspilite–0− 17.0− 17.6153

GU149

Interpillow jaspilite–0− 21.3− 13.4105

GU151

Interpillow jaspilite

–

0.01

− 31.9− 17.9158

GU150Interpillow jaspilite with calcite/quartz veins –0.1− 15.4− 17.7155

GU158

Brecciated interpillow jaspilite

–

0.05

− 12.5− 17.8156aFormation temperature was estimated from the reported oxygen fractionation factor (O’Neil et al. 1969; Friedman and O’Neil 1977; Chacko et al. 2001) assuming
a fluid with δ18O = 0‰ (SMOW)

contents of the undeformed samples (with disseminated calcites only) are lower than 0.007 wt%(almost equivalent to 0.016 wt% as CaCO3) whereas
those of the deformed samples (with calcite vein)have clearly higher CO2 contents reaching 0.099 wt%(0.23 wt% as CaCO3) (Table 1 and Fig 5). Based onthese data, we discuss the carbonation of lavas andthe formation temperature of jaspilites in the following sections.

−5
Basaltic andesite
Interpillow jaspilite

With disseminated calcite−10

Oxygen isotopes of the calcites in the Ongeluk lavas andjaspilites−15
Brecciatedjaspilite

With calcite vein

−20
−35

−30

−25

−20

−15

−10

Fig. 4 Relationship between δ18O and δ13C values of thehydrothermal calcites from the Ongeluk Formation−5

The formation temperatures of calcites in the Ongeluk
lavas and hydrothermal jaspilite should—if the calcites
were formed due to the seafloor hydrothermal
circulation—ideally be consistent with the temperaturesof seafloor hydrothermal alteration independently estimated from fluid inclusions in the Ongeluk hydrothermal quartz (Gutzmer et al. 2003; Saito et al. 2016). To
estimate the formation temperatures of calcites fromtheir δ18O values, a δ18O value of seawater must be assumed. However, there have long been two different
models on the evolution of the δ18O value of seawater
through the Earth’s history; the one is a constant δ18O
value (e.g., Muehlenbachs and Clayton 1976; Blake et al.

Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31

170aTemperature (°C)

150

Brecciatedjaspilite

With calcite vein

100With disseminated calcite

Basaltic andesite
Interpillow jaspilite

50
0

0.05

0.1

0.12

−10

b
−15

Brecciatedjaspilite−20

With calcite vein

−25

−30
With disseminated calcite

Page 7 of 13

within the range of homogenization temperatures of thefluid inclusions (64–160 °C) in the Ongeluk hydrothermal quartz precipitates (Gutzmer et al. 2001, 2003; Saito
et al. 2016). The consistency of the formation temperatures suggests that the generation of disseminated calcites in the lavas and jaspilites coincided with theprecipitation of the hydrothermal quartz during subseafloor hydrothermal circulation. On the other hand, thecalcites in the deformed samples show only high formation temperatures (147–156 °C), which are consistent
with a metamorphic temperature not exceeding
prehnite-pumpellyite facies (Gutzmer et al. 2001).
In the latter case that δ18O value of seawater has increased from − 9‰ (vs. SMOW) at 4.6 Ga to the present
value (e.g., Kasting et al. 2006), and the δ18O value of
seawater is approximately − 8‰ at 2.4 Ga. Using thisvalue, the formation temperature of hydrothermal calcites and jaspilite was estimated to be 28–75 °C, which
is clearly much lower than the formation temperature(64–160 °C) of hydrothermal quartz estimated from fluidinclusions therein (Gutzmer et al. 2003; Saito et al.
2016) and the alteration temperature estimated from theassemblage of secondary minerals in the lavas (Gutzmer
et al. 2001). This discrepancy also forces the conclusionthat the δ18O value of seawater has remained almost
constant through the Earth history (e.g., Holmden andMuehlenbachs 1993).

−35
0

0.05

0.1

0.12

CO2 content (wt%)
Fig. 5 Content of CO2 fixed as carbonate vs. a temperature
obtained from δ18O values and b δ13C values (‰, VPDB) of calcites
from the Ongeluk basaltic andesites and hydrothermal jaspilites. The
deformed samples (brecciated or with calcite vein) have higher CO2
content than the undeformed samples

2010; Tartèse et al. 2017) and the other is a gradually
increasing δ18O value (e.g., Kasting et al. 2006).
In the former case, using the oxygen isotope fractionation factors (O’Neil et al. 1969; Friedman and O'Neil
1977; Chacko et al. 2001), the formation temperatures ofdisseminated calcites in the lavas are calculated to be
77–130 °C (Table 1 and Fig. 5a). The δ18O values of thecalcites in the undeformed jaspilites provide a slightly
higher formation temperature range (105–158 °C). The
difference in the formation temperatures indicates thatthe disseminated calcites in the lavas were formed
mainly as a result of interaction with relatively lowtemperature downwelling seawater from the seafloor,
whereas the precipitation of jaspilites took place with alarger contribution of high-temperature iron-rich hydrothermal fluids derived from the lower part of the hydrothermal circulation cell. Be that as it may, thetemperatures obtained for both calcites in the undeformed lavas and the hydrothermal jaspilites fall

Carbon isotopes of the calcites in the Ongeluk lavas andjaspilites

Variation of calcite δ13C values (δ13Ccc) in seafloor volcanic rocks tends to reflect the geological setting ofhydrothermal alteration and the carbon sources (Fig. 6).
In general, modern and Archean unsedimented ridgederived oceanic crusts have δ13Ccc values close to thoseof seawater (mostly − 4 to 4‰), because subseafloor volcanic sequences are generally dominated by seawaterderived fluid due to their high permeability (Nakamura
and Kato 2004; Gillis and Coogan 2011; Shibuya et al.
2012). On the other hand, the δ13Ccc values of some riftlake volcanics in the Afar Rift (− 7 to − 1‰) are explained as a mixture of meteoric water (~− 15‰) andseawater, with a possible contribution of magmatic CO2(~− 5‰) (Fouillac et al. 1989), whereas hydrothermal
calcite chimneys in Lake Abhé in the Afar Rift have
δ13Ccc values (~ 2 to 4‰) consistent with that of the alkaline lake water (0.6‰) equilibrated with atmospheric
CO2 (~− 7‰) (Dekov et al. 2014). In contrast, allsediment-related settings, such as modern sedimented
ridge-derived oceanic crusts and modern/Archean
oceanic rift basin basalts, bare relatively low δ13Ccc
values (<− 15‰) as well as the values near the δ13C of
CO2 (δ13CCO2) in seawater which would represent a significant input of CO2 derived from the decomposition ofShibuya et al. Progress in Earth and Planetary Science (2017) 4:31

Page 8 of 13

20

3.5 Ga MOR basalt (Marble Bar)
Interpillow deposit

N 10

Archean

020

3.2 Ga MOR basalt (Cleaverville)

N 10
0
10

2.6 Ga oceanic rift basalt (Fortescue)

N
0
20

N 10

Rift lake volcanics and chimney (Afar Rift)
Chimney010

Oceanic rift basalt (Guaymas)N
0Modern10

Sedimented ridge-drived
MOR crust (Juan de Fuca)

N
0

100

Unsedimented ridge-derived
MOR crustN
50This study

0

Fig. 6 (See legend on next page.)

10

Ongeluk basaltic andesite

NInterpillow Jaspilitewith cc vein
Basaltic andesite with cc vein

Interpillow jaspilite

Brecciated interpillow jaspilite

0
−40

−30

−20

−10

0

10

Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31

Page 9 of 13(See figure on previous page.)
Fig. 6 δ13C values (‰, VPDB) of hydrothermal calcites from the Ongeluk Formation. For comparison, data from modern unsedimented ridgederived mid-ocean ridge (MOR) crusts (Gillis and Coogan 2011), sedimented ridge-derived MOR crusts (Coggon et al. 2004), rift-zone seafloor
basalts (Gieskes et al. 1982), rift lake basement volcanics (Fouillac et al. 1989), and hydrothermal chimney (Dekov et al. 2014) from Afar Rift,
Archean MOR basalts (Nakamura and Kato 2004; Shibuya et al. 2012), and rift-zone seafloor basalts (Shibuya et al. 2013a) are also shownorganic matter (Gieskes et al. 1982; Coggon et al. 2004;
Shibuya et al. 2013a).
In this regard, the relatively low δ13Ccc values down
to −31.9‰ in the Ongeluk Formation is consistent
with its geological setting (a sedimented rifting basin)
where decomposition of organic matter in sedimentary rocks (e.g., underlying Makganyene Formation)
could occur during the hydrothermal circulation. Another characteristic point is that δ13Ccc values higher
than − 13.2‰ were not identified in the undeformed
lavas. This is consistent with the exceptionally 13C–
depleted CO2 in the Ongeluk seawater at that time;
the Paleoproterozoic long-term seawater δ13CCO2 generally decreased and reached its lowest value (− 14 to− 8‰) at the time of the glaciation and thenrecovered thereafter (Polteau et al. 2006). Therefore,
the wide variation of δ13Ccc values of the Ongeluk
lavas can be well explained by varying the mixing ratios between the CO2 derived from the decompositionof subseafloor sedimentary organic matter and the13
C-depleted CO2 in seawater. For this reason, themeasured CO2 (as carbonate) content in the lavas
likely corresponds to the upper limit of seawaterderived CO2.

Secular change of carbonate content in the alteredsubseafloor crust

Because permeability decreases while temperature increases with increasing depth below the seafloor, carbonate minerals tend to become unstable, thereby leading to
a decrease in fixed CO2 in the basaltic crust and ophiolite (Gillis and Robinson 1988; Gillis and Coogan 2011;
Alt and Teagle 1999; Shibuya et al. 2007a, 2007b, 2012).
However, the carbonation of highly permeable, low- tomoderate-temperature (<c. 200 °C) uppermost basaltic
sequences presumably tends to reflect seawater CO2
concentration. Furthermore, carbonation of seafloor basalts would be less significantly influenced by the seawater pH governing the speciation of CO2aq, HCO3−,
and CO2−
3 . Under constant pressure-temperature conditions, calcite precipitation from a solution is governed2+by activities of CO2−
ions. In other words, the3 and Casaturation state of calcite mainly depends on the total
CO2 concentration (CO2aq + HCO3− + CO2−3 ) and pH
value in seawater, at least when the activity of Ca2+ isconstant. In seafloor hydrothermal systems, however, pHvariations at low-moderate temperatures are muchsmaller than in solution because alteration minerals substantially buffer the pH of a coexisting fluid. For example, thermodynamic calculations indicated that fluid
pH at 150 °C is potentially buffered to be 7.7 and 7.6even after reactions with the Hadean weakly acidic,
CO2-rich seawater (total CO2 = 200 mmol/kg) and withthe present-day seawater (total CO2 = 2 mmol/kg),
respectively (Macleod et al. 1994). Such behavior of pH
at low-moderate temperatures is also distinct from hightemperature fluids (> 300 °C) where pH values are
influenced by an input of magmatic volatiles (e.g.,
Butterfield et al. 2003) and the presence or absence ofcarbonate minerals (Shibuya et al. 2010, 2013b).
Accordingly, it is suggested that the content of fixed
CO2 as carbonate in the uppermost subseafloor crust
qualitatively reflects total CO2 concentration in seawater
under a constant pressure-temperature condition. On
the other hand, it was pointed out that high-temperaturebottom seawater elevates temperature of subseafloor
fluids and kinetically facilitates the formation reactionsof carbonate minerals in the uppermost crust (Gillis andCoogan 2011), although carbonate minerals in alteredmafic rocks become unstable with increasing
temperature under equilibrium condition (e.g., Shibuya
et al. 2013b). In this section, therefore, we discuss thesecular change of total CO2 concentration, pH,temperature, and partial pressure of CO2 (pCO2) in seawater based on the CO2 content in the subseafloor
uppermost crust (< 1 km deep from the seafloor)
through geologic time.
In the Phanerozoic, the content of CO2 as carbonate
in the Jurassic/Cretaceous crusts is generally higher thanthat of younger crusts (Fig. 7a). This trend is moreclearly evidenced in crusts with greater penetration
depth. The CO2 contents in the young crusts (<13.6 Ma) with penetration depth of > 200 m (Holes
369B, 896A, and 504B) are lower than 1 wt% (Gillis andCoogan 2011; Alt and Teagle 1999) (Fig. 7a). These
values probably reflect the total CO2 concentration inseawater because the temperature of bottom seawater ispresumably almost constant (e.g., 2 °C) and not highenough to effect carbonate formation in the uppermost
crust during this period. In contrast, Jurassic and Cretaceous crusts with penetration depths of > 200 m (Holes
801C, 417A, 417D, and 418A) have higher CO2 contents, up to 4.2 wt.%, than the younger crusts. It waspreviously suggested that the enhanced CO2 uptake by
the crust in the Cretaceous period can be explained only

Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31

Page 10 of 13

5

a

417D

CO2 content (wt.%)

Penetration depth

4> 200 m

418A
417A

< 200 m

3
801C
843B

595B

2

543A

556

Jurassic/Cretaceous
high pCO2 and temperature

1

562

369B
896A
1224F

0
200

150

100

597C 504B

500

Age (Ma)
10bRegal Fm. (Cleaverville)
Apex Basalt (Marble Bar)
DSDP/ODP (Fig. 7a)
Mount Ada Basalt (North Pole)

5
ean
rch
eA
se
Lat
rea
dec
CO 2

CO2 content (wt.%)

Early to Late Archeanhigh pCO2

Jerrinah and Bunjinah Fm.
(Beasley River)

0
4.0

3.0

Ongeluk Fm (this study)
Global glaciation
low pCO2 and temperature

Further
CO2 decrease

2.0

1.0

0

Age (Ga)
Fig. 7 Secular change of CO2 (as carbonate) content in the alteredsubseafloor crust. a DSDP/ODP drill cores that penetrated basaltic
basement (Alt and Teagle 1999; Gillis and Coogan 2011). The CO2
content in the Jurassic/Cretaceous crusts is generally higher thanthat of younger crusts. Because the crusts with shallower
penetration depth have large variation of CO2 content, the crusts
with penetration depth > 200 m is mainly discussed in the text. b
The CO2 content in Precambrian greenstones with geologicallyreconstructed depth > 1000 m from the ancient seafloor. Data from
3.5 Ga Apex Basalt in the Marble Bar area (Nakamura and Kato 2004),
3.5 Ga Mount Ada Basalt in the North Pole area (Kitajima et al. 2001;
Terabayashi et al. 2003), 3.2 Ga Regal Formation in the Cleavervillearea (Shibuya et al. 2012), 2.6 Ga Jeerinah and Bunjinah Formationsin Beasley River area (Shibuya et al. 2013a) in the Pilbara Craton(Western Australia), and this study. Note that the CO2 contents inthe 3.5 Ga Mount Ada Basalt and the 3.2 Ga Regal Formation were
calculated from the modal abundance of carbonate minerals
in greenstones

by higher seawater temperatures (Brady and Gíslason
1997; Gillis and Coogan 2011). In this case, the hightemperature of seawater was likely maintained by thestrong greenhouse effect induced by high atmospheric
pCO2 in this era (Berner and Kothavala 2001), assuggested by other geologic records (e.g., paleosols;
Ekart et al. 1999). High atmospheric pCO2 might also
elevate the total CO2 concentration in seawater, in whichcase, the high total CO2 concentration along with hightemperature of seawater potentially accounts for thehigh carbonate content in the Jurassic/Cretaceous
uppermost crust.
In the Archean, the carbonate contents in the 3.5–
3.2 Ga subseafloor crusts (5.7–7.9 wt% as CO2) are obviously much higher than modern equivalents (Kitajima etal. 2001; Terabayashi et al. 2003; Nakamura and Kato
2004; Shibuya et al. 2012, 2013a) (Fig. 7b). Although theArchean seawater temperature has not been quantitatively constrained (Knauth and Lowe 2003; Robert andChaussidon 2006; Blake et al. 2010), it is highly possiblethat the strong carbonation of Archean greenstones reflects high total CO2 concentration in seawater. Furthermore, many geological and theoretical investigations
indicate that the Early to Middle Archean atmosphere
was extremely enriched in CO2 to compensate the faintyoung Sun (Sagan and Mullen 1972; Kasting 1987;
Ohmoto et al. 2004; Lowe and Tice 2004). Therefore,
the high pCO2 in the Early to Middle Archean seawater/
atm. would be the primary factor elevating the total CO2
concentration in seawater and the carbonate content in
the subseafloor crust. In contrast, the 2.6 Ga subseafloor
crust has relatively low CO2 content (0.6 wt.%) that iscomparable to modern equivalents, which suggests that
total CO2 concentration in seawater decreased during
the period between 3.2 and 2.6 Ga (Shibuya et al.
2013a). The trigger for this decrease in seawater CO2 ispossibly the formation and breakdown of the supercontinent in the late Archean, the removal of precipitatedsedimentary carbonate onto land during the amalgamation of continents, and the precipitation of platform
carbonate on newly created passive margins during/after
the continental breakdown (Shibuya et al. 2013a).
Compared with the contents of fixed CO2 as carbonateof the Archean and Phanerozoic subseafloor uppermost
crusts, the average CO2 content in the Ongeluk lavas (<0.001 wt% including calcite veins) is clearly lower thanthose of Late Archean and even the modern equivalents(e.g., 0.21 wt% in 504B), even though the CO2 in the
Ongeluk lavas includes organic matter-derived CO2 in
addition to the original seawater CO2. These results
carry the implication that total CO2 concentration inseawater further decreased from Late Archean to the
Paleoproterozoic because the temperature of the Ongeluk bottom seawater would not have been much lower
than the modern temperature (e.g., 2 °C). Thus, the total
CO2 concentration in 2.4 Ga seawater may have been
lower than the present level. Such decrease in the total
CO2 concentration in seawater from 3.2 to 2.4 Ga is also
consistent with the decrease in atmospheric pCO2 fromthe late Archean to Paleoproterozoic estimated from thepaleosols (Kanzaki and Murakami 2015).
In principle, carbonate formation in the uppermost
subseafloor crust should be influenced by not only
temperature and total CO2 concentration of seawater,

Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31

but also other factors such as pressure dependence ofcarbonate stability. Nevertheless, as discussed above, thedegree of hydrothermal carbonation of the uppermost
subseafloor crust shows a good correlation with independently estimated atmospheric pCO2 levels throughout Earth history. This overall trend implies that thesecular change of atmospheric pCO2 relates more closely
to that of total CO2 concentration in seawater rather
than pH change. Thus, the exceptionally low CO2 contents in the Ongeluk lavas would also reflect extremely
low CO2 levels in the seawater/atm. during the Paleoproterozoic global glaciation. Our conclusion supports
the low atmospheric CO2 levels at that time—a premiseof the previously proposed hypotheses for the trigger of the
Paleoproterozoic global glaciation (Kopp et al. 2005; Melezhik 2006; Condie et al. 2009; Young 2013).

Conclusions
The carbonate content in the Ongeluk lavas and its
comparison with other equivalents of various ages revealed that the total CO2 concentration in 2.4 Ga seawater was extremely low, which potentially accounts forthe assumed low atmospheric CO2 levels during the
Paleoproterozoic global glaciation. More importantly,
the present study indicates the possibility that the degreeof carbonation of subseafloor crusts reflects the qualitative secular change of CO2 concentration in seawaterand atmosphere. Therefore, the carbonate content inpost-2.4 Ga subseafloor crusts should be investigated to
decode secular changes of CO2 concentrations in seawater/atm., especially during the Proterozoic. Moreover,
it is suggested that more quantitative compositions ofancient seawater can be estimated by analysis of subseafloor crust materials such as hydrothermally precipitatedminerals and their fluid inclusions.
Abbreviations
Adr: Andradite; Cc: Calcite; Chl: Chlorite; Cpx: Clinopyroxene; Hem: Hematite;
MOR: Mid-ocean ridge; PAL: Present atmospheric level; Pl-ps: Plagioclase
pseudomorph; Py: Pyrite; Qz: Quartz; VPDB: Vienna Pee Dee Belemnite
Acknowledgements
We thank for M. Cloete (Council for Geoscience, South Africa), K. Kitajima, S.
Yamamoto, N. Enomoto, and A. Nakajima for assistance during the fieldwork.
We are grateful to two anonymous reviewers for constructive comments and
H. Kawahata for editorial handling and suggestions.
Funding
This research was partially supported by MEXT/JSPS KAKENHI Grant Numbers
JP25707038, JP17H04580, and JP17H06455, and the Ministry of Educationand Science of the Russian Federation, Project no. 14.Y26.31.0018.
Authors’ contributions
TS and SM proposed the topic and conceived and designed the study. TK
and TS carried out the geological investigation. TS conducted thepetrological description and obtained the geochemical data. TK, KT, and MJR
helped in their interpretation and collaborated with the corresponding
author in the construction of the manuscript. All authors read and approved
the final manuscript.

Page 11 of 13

Authors’ information
MJR’s research was carried out at the Jet Propulsion Laboratory, California
Institute of Technology, under a contract with the National Aeronautics andSpace Administration, through the NASA Astrobiology Institute undercooperative agreement issued through the Science Mission directorate, No.
NNH13ZDA017C (Icy Worlds), at the Jet Propulsion Laboratory. US
Government sponsorship acknowledged.
Competing interests
The authors declare that they have no competing interests.

Publisher’s NoteSpringer Nature remains neutral with regard to jurisdictional claims inpublished maps and institutional affiliations.
Author details
1
Department of Subsurface Geobiological Analysis and Research (D-SUGAR),
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15
Natsushima-cho, Yokosuka 237-0061, Japan. 2Research and Development
Center for Submarine Resources, Japan Agency for Marine-Earth Science andTechnology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
3
Project Team for Development of New-Generation Research Protocol for
Submarine Resources, Japan Agency for Marine-Earth Science andTechnology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
4
Department of Earth Science and Astronomy, The University of Tokyo, 3-8-1
Komaba, Meguro-ku, Tokyo 153-8902, Japan. 5Earth-Life Science Institute,Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo
152-8551, Japan. 6Jet Propulsion Laboratory, California Institute ofTechnology, 4800 Oak Grove Drive, Pasadena, CA 91108, USA. 7Novosibirsk
State University, Pirogova 1 630090, Russia.
Received: 8 May 2017 Accepted: 27 September 2017

References
Alt JC, Laverne C, Coggon RM, Teagle DAH, Banerjee NR, Morgan S, Smith-DuqueCE, Harris M, Galli L (2010) Subsurface structure of a submarine hydrothermal
system in ocean crust formed at the East Pacific Rise, ODP/IODP Site 1256.
Geochem Geophy Geosy 11:Q10010. https://doi.org/10.1029/2010gc003144
Alt JC, Teagle DAH (1999) The uptake of carbon during alteration of ocean crust.
Geochim Cosmochim Acta 63:1527–1535
Bau M, Romer RL, Lüders V, Beukes NJ (1999) Pb, O, and C isotopes in silici¢ed
Mooidraai dolomite (Transvaal Supergroup, South Africa): implications for thecomposition of Paleoproterozoic seawater and ‘dating’ the increase ofoxygen in the Precambrian atmosphere. Earth Planet Sci Lett 174:43–57
Berner RA, Kothavala Z (2001) GEOCARB III: a revised model of atmospheric CO2
over Phanerozoic time. Am J Sci 301:182–204
Beukes NJ, Smit CA (1987) New evidence for thrust faulting in Griqualand West,South Africa: implications for stratigraphy and the age of red beds. S Afr J
Geol 90:378–394
Blake RE, Chang SJ, Lepland A (2010) Phosphate oxygen isotopic evidence for atemperate and biologically active Archaean ocean. Nature 464:1029–1032
Brady PV, Gíslason SR (1997) Seafloor weathering controls on atmospheric CO2
and global climate. Geochim Cosmochim Acta 61:965–973
Butterfield DA, Seyfried WE Jr, Lilley MD (2003) Composition and evolution ofhydrothermal fluids. In: Halbach PE, Tunnicliffe V, Hein JR (eds) Energy andmass transfer in marine hydrothermal systems. Dahlem University Press,
Berlin, pp 123–161
Chacko T, Cole DR, Horita J (2001) Equilibrium oxygen, hydrogen and carbon
isotope fractionation factors applicable to geologic systems. In: Valley JW,
Cole DR (eds) Stable isotope geochemistry. Reviews in Mineralogy andGeochemistry. Mineralogical Society of America, Washington, D. C, pp 1–81
Coggon RM, Teagle DAH, Cooper MJ, Vanko DA (2004) Linking basement
carbonate vein compositions to porewater geochemistry across theeastern flank of the Juan de Fuca Ridge, ODP Leg 168. Earth Planet Sci
Lett 219:111–128
Condie KC, O'Neill C, Aster RC (2009) Evidence and implications for a widespreadmagmatic shutdown for 250 My on Earth. Earth Planet Sci Lett 282:294–298
Cornell DH, Schütte SS, Eglington BL (1996) The Ongeluk basaltic andesite
formation in Griqualnd West, South Africa: submarine alteration in a 2222 Ma
Proterozoic sea. Precambr Res 79:101–123

Shibuya et al. Progress in Earth and Planetary Science (2017) 4:31

de Villiers PR, Visser JNJ (1977) The glacial beds of the Griqualand West
Supergroup as revealed by four deep boreholes between Postmasburg andSishen. Trans Geol Soc S Afr 80:1–8
Dekov VM, Egueh NM, Kamenov GD, Bayon G, Lalonde SV, Schmidt M,
Liebetrau V, Munnik F, Fouquet Y, Tanimizu M, Awaleh MO, Guirreh I,
Le Gall B (2014) Hydrothermal carbonate chimneys from a continental
rift (Afar Rift): mineralogy, geochemistry, and mode of formation.
Chem Geol 387:87–100
Dorland HC (2004) Provenance ages and timing of sedimentation of selected
Neoarchean and Paleoproterozoic successions on the Kaapvaal Craton. Rand
Afrikaans University, Johannesburg
Ekart DD, Cerling TE, Montanez IP, Tabor NJ (1999) A 400 million year carbon
isotope record of pedogenic carbonate: Implications for paleoatmosphericcarbon dioxide. Am J Sci 299:805–827
Evans DA, Beukes NJ, Kirschvink JL (1997) Low-latitude glaciation in the
Palaeoproterooic era. Nature 386:262–266
Fouillac AM, Fouillac C, Cesbron F, Pillard F, Legendre O (1989) Water-rockinteraction between basalt and high-salinity fluilds in the Asal Rift, Republicof Djibouti. Chem Geol 76:271–289
Friedman I, O'Neil JR (1977) Compilation of stable isotope fractionation
factors of geochemical interest. U.S. Geological Survey, Professional
Paper:440–KK
Gieskes J, Elderfield H, Lawrence JR, Johnson J, Meyers B, Campbell A (1982)
Geochemistry of interstitial waters and sediments, Leg-64, Gulf of California.
Initial Rep Deep Sea 64:675–694
Gillis KM, Coogan LA (2011) Secular variation in carbon uptake into the ocean
crust. Earth Planet Sci Lett 302:385–392
Gillis KM, Robinson PT (1988) Distribution of alteration zones in the upper
oceanic crust. Geology 16:262–266
Gough DO (1981) Solar interior structure and luminosity variations. Sol Phys 74:
21–34
Grobler NJ, Botha BJV (1976) Pillow lavas and hyaloclastites in the Ongeluk
andesite formation in a road-cut west of Griquatown, South Africa. Trans
Geol Soc S Afr 79:53–57
Gumsley AP, Chamberlain KR, Bleeker W, Söderlund U, de Kock MO, Larsson ER,
Bekker A (2017) Timing and tempo of the Great Oxidation Event. Proc Natl
Acad Sci U S A 114:1811–1816
Gutzmer J, Banks DA, Luders V, Hoefs J, Beukes NJ, von Bezing KL (2003) Ancient
sub-seafloor alteration of basaltic andesites of the Ongeluk Formation, South
Africa: implications for the chemistry of Paleoproterozoic seawater. Chem
Geol 201:37–53
Gutzmer J, Pack A, Lüders V, Wilkinson JJ, Beukes NJ, van Niekerk HS (2001)
Formation of jasper and andradite during low-temperature hydrothermal
seafloor metamorphism, Ongeluk Formation, South Africa. Contrib Mineral
Petrol 142:27–42
Harada M, Tajika E, Sekine Y (2015) Transition to an oxygen-rich atmosphere withan extensive overshoot triggered by the Paleoproterozoic snowball Earth.
Earth Planet Sci Lett 419:178–186
Hessler AM, Lowe DR, Jones RL, Bird DK (2004) A lower limit for atmosphericcarbon dioxide levels 3.2 billion years ago. Nature 428:736–738
Hoffman PF (2013) The Great Oxidation and a Siderian snowball Earth: MIF-S
based correlation of Paleoproterozoic glacial epochs. Chem Geol 362:
143–156
Hofmann A, Harris C (2008) Silica alteration zones in the Barberton greenstone
belt: a window into subseafloor processes 3.5-3.3 Ga ago. Chem Geol 257:
221–239
Holmden C, Muehlenbachs K (1993) The 18O/16O ratio of 2-billion-year-old
seawater inferred from ancient oceanic crust. Science 259:1733–1736
Kanzaki Y, Murakami T (2015) Estimates of atmospheric CO2 in the
Neoarchean–Paleoproterozoic from paleosols. Geochim Cosmochim
Acta 159:190–219
Kasting JF (1987) Theoretical constraints on oxygen and carbon dioxide
concentrations in the Precambrian atmosphere. Precambr Res 34:205–229
Kasting JF (1993) Earth’s early atmosphere. Science 259:920–926
Kasting JF, Howard MT, Wallmann K, Veizer J, Shields G, Jaffrés J (2006)
Paleoclimates, ocean depth, and the oxygen isotopic composition ofseawater. Earth Planet Sci Lett 252:82–93
Kirschvink JL, Gaidos EJ, Bertani LE, Beukes NJ, Gutzmer J, Maepa LN,
Steinberger RE (2000) Paleoproterozoic snowball Earth: extreme
climatic and geochemical global change and its biologicalconsequences. Proc Natl Acad Sci U S A 97:1400–1405

Page 12 of 13

Kitajima K, Maruyama S, Utsunomiya S, Liou JG (2001) Seafloor hydrothermal
alteration at an Archaean mid-ocean ridge. J Metamorph Geol 19:583–599
Knauth LP, Lowe DR (2003) High Archean climatic temperature inferred fromoxygen isotope geochemistry of cherts in the 3.5 Ga Swaziland Supergroup,
South Africa. Geol Soc Am Bull 115:566–580
Konhauser KO, Amskold L, Lalonde SV, Posth NR, Kappler A, Anbar A (2007)
Decoupling photochemical Fe(II) oxidation from shallow-water BIF
deposition. Earth Planet Sci Lett 258:87–100
Kopp RE, Kirschvink JL, Hilburn IA, Nash CZ (2005) The Paleoproterozoic snowball
Earth: a climate disaster triggered by the evolution of oxygenic
photosynthesis. Proc Natl Acad Sci U S A 102:11131–11136
Lowe DR, Tice MM (2004) Geologic evidence for Archean atmospheric andclimatic evolution: fluctuating levels of CO2, CH4, and O2 with an overriding
tectonic control. Geology 32:493–496
Macleod G, McKeown C, Hall AJ, Russell MJ (1994) Hydrothermal and oceanic pH
conditions of possible relevance to the origin of life. Orig Life Evol Biosph 24:
19–41
Melezhik VA (2006) Multiple causes of Earth's earliest global glaciation. Terra
Nova 18:130–137
Muehlenbachs K, Clayton RN (1976) Oxygen isotope composition of the oceanic
crust and its bearing on seawater. J Geophys Res 81:4365–4369
Nakamura K, Kato Y (2004) Carbonatization of oceanic crust by the seafloorhydrothermal activity and its significance as a CO2 sink in the Early Archean.
Geochim Cosmochim Acta 68:4595–4618
Ohmoto H, Watanabe Y, Kumazawa K (2004) Evidence from massive siderite beds
for a CO2-rich atmosphere before ~1.8 billion years ago. Nature 429:395–399
O'Neil JR, Clayton RN, Mayeda TK (1969) Oxygen isotope fractionation in divalent
metal carbonates. J Chem Phys 51:5547–5558
Pavlov AA, Hurtgen MT, Kasting JF, Arthur MA (2003) Methane-rich Proterozoic
atmosphere? Geology 31:87–90
Polteau P, Moore JM, Tsikos H (2006) The geology and geochemistry of the
Palaeoproterozoic Makganyene diamictite. Precambr Res 148:257–274
Révész KM, Landwehr JM (2002) δ13C and δ18O isotopic composition of CaCO3
measured by continuous flow isotope ratio mass spectrometry: statisticalevaluation and verification by application to Devils Hole core DH-11 calcite.
Rapid Commun Mass Sp 16:2102–2114
Robert F, Chaussidon M (2006) A palaeotemperature curve for the Precambrianoceans based on silicon isotopes in cherts. Nature 443:969–972
Rosing MT, Bird DK, Sleep NH, Bjerrum CJ (2010) No climate paradox under the
faint early Sun. Nature 464:744–747
Rouchon V, Orberger B (2008) Origin and mechanisms of K-Si-metasomatism of
ca. 3.4-3.3 Ga volcaniclastic deposits and implications for Archean seawaterevolution: examples from cherts of Kittys Gap (Pilbara craton, Australia) and
Msauli (Barberton Greenstone Belt, South Africa). Precambr Res 165:169–189
Russell MJ, Barge L, Bhartia R, Bocanegra D, Bracher P, Branscomb E, Hand K, Kidd
R, McGlynn S, Meier DH, Nitschke W, Shibuya T, Vance S, White L, Kanik I(2014) The drive to life on wet and icy worlds. Astrobiology 14:308–343
Russell MJ, Hall AJ, Martin W (2010) Serpentinization as a source of energy at theorigin of life. Geobiology 8:355–371. https://doi.org/10.1111/j.1472-4669.2010.
00249.x
Sagan C, Mullen G (1972) Earth and Mars: evolution of atmospheres and surface
temperatures. Science 177:52–56
Saito T, Shibuya T, Komiya T, Kitajima K, Yamamoto S, Nishizawa M, Ueno Y,
Kurosawa M, Maruyama S (2016) PIXE and microthermometric analyses of
fluid inclusions in hydrothermal quartz from the 2.2 Ga Ongeluk Formation,
South Africa: implications for ancient seawater salinity. Precambr Res 286:
337–351
Sheldon ND (2006) Precambrian paleosols and atmospheric CO2 levels. Precambr
Res 147:148–155
Shibuya T, Kitajima K, Komiya T, Terabayashi M, Maruyama S (2007a) Middle
Archaean ocean ridge hydrothermal metamorphism and alteration recordedin the Cleaverville area, Pilbara Craton, Western Australia. J Metamorph Geol
25:751–767
Shibuya T, Komiya T, Anma R, Ota T, Omori S, Kon Y, Yamamoto S, Maruyama S(2007b) Progressive metamorphism of the Taitao ophiolite; evidence for axial
and off-axis hydrothermal alterations. Lithos 98:233–260
Shibuya T, Komiya T, Nakamura K, Takai K, Maruyama S (2010) Highly alkaline,
high-temperature hydrothermal fluids in the early Archean ocean. Precambr
Res 182:230–238
Shibuya T, Russell MJ, Takai K (2016) Free energy distribution and hydrothermal
mineral precipitation in Hadean submarine alkaline vent systems: ImportanceShibuya et al. Progress in Earth and Planetary Science (2017) 4:31

of iron redox reactions under anoxic conditions. Geochim Cosmochim Acta
175:1–19
Shibuya T, Tahata M, Kitajima K, Ueno Y, Komiya T, Yamamoto S, Igisu M,
Terabayashi M, Sawaki Y, Takai K, Yoshida N, Maruyama S (2012) Depth
variation of carbon and oxygen isotopes of calcites in Archean altered upper
oceanic crust: implications for the CO2 flux from ocean to oceanic crust in
the Archean. Earth Planet Sci Lett 321–322:64–73. https://doi.org/10.1016/j.
epsl.2011.12.034
Shibuya T, Tahata M, Ueno Y, Komiya T, Takai K, Yoshida N, Maruyama S, Russell
MJ (2013a) Decrease of seawater CO2 concentration in the Late Archean: an
implication from 2.6 Ga seafloor hydrothermal alteration. Precambr Res 236:
59–64
Shibuya T, Yoshizaki M, Masaki Y, Suzuki K, Takai K (2013b) Reactions between
basalt and CO2-rich seawater at 250 and 350 °C, 500 bars: implications for
the CO2 sequestration into the modern oceanic crust and the compositionof hydrothermal vent fluid in the CO2-rich early ocean. Chem Geol 359:1–9
Shibuya T, Yoshizaki M, Satoh M, Shimizu K, Nakamura K, Omori S, Suzuki K, Takai
K, Hideo T, Maruyama S (2015) Hydrogen-rich hydrothermal environments in
the Hadean ocean inferred from serpentinization of komatiites at 300 °C and
500 bar. Prog Earth Planet Sci 2:46. https://doi.org/10.1186/s40645-015-0076-z
Sleep NH, Zahnle K (2001) Carbon dioxide cycling and implications for climate
on acient Earth. J Geophys Res 106:1373–1399
Takai K, Nakamura K, Suzuki K, Inagaki F, Nealson KH, Kumagai H (2006)
Ultramafics-Hydrothermalism-Hydrogenesis-HyperSLiME (UltraH3) linkage: a
key insight into early microbial ecosystem in the Archean deep-sea
hydrothermal systems. Paleontol Res 10:269–282
Tartèse R, Chaussidon M, Gurenko A, Delarue F, Robert F (2017) Warm Archean
oceans reconstructed from oxygen isotope composition of early-life
remnants. Geochemical Perspectives Letters 3:55–65. https://doi.org/10.7185/
geochemlet.1706
Terabayashi M, Masuda Y, Ozawa H (2003) Archean ocean-floor
metamorphism in the North Pole area, Pilbara Craton, Western
Australia. Precambr Res 123:167–180
Ueda H, Shibuya T, Sawaki Y, Saitoh M, Takai K, Maruyama S (2016) Reactions
between komatiite and CO2-rich seawater at 250 °C and 350 °C, 500 bars:
implications for hydrogen generation in the Hadean seafloor hydrothermal
system. Prog Earth Planet Sci 3:35. DOI: https://doi.org/10.1186/s40645-0160111-8
Ueno Y, Johnson MS, Danielache SO, Eskebjerg C, Pandey A, Yoshida N (2009)
Geological sulfur isotopes indicate elevated OCS in the Archean atmosphere,
solving faint young sun paradox. Proc Natl Acad Sci U S A 106:14784–14789
Young GM (2013) Precambrian supercontinents, glaciations, atmospheric
oxygenation, metazoan evolution and an impact that may have changed thesecond half of Earth history. Geosci Front 4:247–261

Page 13 of 13