con(nents, oceans, atmosphere and life evolu(on Ricardo Trindad

University of São Paulo Ins4tute of Astronomy, Geophysics and Atmospheric Sciences

The Precambrian Earth: con1nents, oceans, atmosphere and life evolu1on Ricardo Trindade

www.iag.usp.br/interna4onal

Atmospheric Sciences Head of Department: Fabio Gonçalves ([email protected])

v Climatology v Large and Mesoscale Dynamics v Ocean-‐Atmosphere and Biosphere-‐Atmosphere interac:ons v Micrometeorology v Atmospheric Pollu:on v Hydrometeorology

Par:cipa:on in: Go-‐Amazon, LBA

Astronomy Head of Department: Roberto Costa ([email protected])

Brazilian coordina:on of: GMT, LLAMA, mini-‐CTA, J-‐PAS

v Astrophysics (stellar, galac:c and extragalac:c) v Cosmology v Celes:al Mechanics v Astrometry v Astronomical Instrumenta:on

Astrobiology & Exoplanets Group (AstrobEx) Coordinator: Eduardo Janot Pacheco ([email protected])

AstroCam (Hypobaric Chamber)

v Biomolecules in protoplatenary disks (ALMA) v Exoplanets and habitability (CoRoT, KEPLER, PLATO) v Biomolecules on plametary atmospheres

Geophysics Head of Department: Ricardo Trindade ([email protected]) v South American Plate structure and dynamics v Applied Geophysics (Environment, Mineral Resources)

Magne:c anomaly map (WDMAM)

Electrical proper:es in depth (resis:vity)

Li et al. (2013) Paleo-‐3

Age (Ga)

Och and Shields (2011) Earth Sci. Rev., Sahoo et al. (2012) Science, Lyons et al. (2014) Nature

Oxida4on aKer glacia4on: Fe and Mn deposits Mamatwan (Mn), South Africa

Pilbara (Fe), Australia Qudrilátero Ferrífero (Fe), Brazil

Huronian glacial rocks, Canada

Workshop in NoVnghan, April 2014 Accelera:ng Neoproterozoic Research through Scien:fic Drilling Three key areas for drilling: v  South China (Yangtze region)

v West Brazil (MS State)

v White Sea (Russia)

The actual extension of glacial caps: Did they cover the en1re Earth?

What did cause these glacial events?

Neoproterozoic Snowball Earth

How did we scape the Snowball Earth events?

albedo ~ 0.3 pCO2 ~ 1.0 PAL

Hoffman & Schrag (2000). Scientific American, 282 , 68-75

albedo ~ 0.6 pCO2 ~ 0.1 PAL

The Snowball Earth hypothesis: Freezing

Results suggest that having continents in tropical latitudes is not

sufficient to bring the Earth in total freeze: Snowball

Earth

Donnadieu et al. (2004) Nature

Freezing the Earth: Climate and Geochemical model

Supercontinent configuration (800 Ma): -  pCO2 equilibrates at 1800 ppm -  It corresponds to na average surface temperature of 10.2 °C

Donnadieu et al. (2004) Nature

Freezing the Earth: Climate and Geochemical model

Dispersed continents (Rodinia Break-Up at 750 Ma): -  pCO2 equilibrates at 500 ppm -  It corresponds to na average surface temperature of 2 °C (-8.2 °C)

A paleogeography with dispersed continents is more favorable to CO2

drawdawn.

It may trigger a large glaciation but not a Snowball Earth

Redox evolu1on aKer glacial events?

Mul1ple-‐layered stra1fied oceans (local vs. global signals)?

Neoproterozoic Oxygena1on Event

Ocecan and atmospheric oxygena1on and biological evolu1on

δ13CDIC (‰)

DIC<2 mM

DIC>10 mM

depth (m

)

0

20

40

60

80

0 2 4 -‐2 -‐4 -‐6 Volcanic Lake Pavin (France)

Meromitic, Stratified

(Assayag et al., 2006, Appl. Geochem.)

Ocean redox stratification and metabolic paths

Ccarb from OM

Ccarb from CH4

Ccarb from atm CO2

Ader et al. (2009) EPSL


Doushantuo Forma:on, South China


… But do animals require a lot of oxygen?

Sperling et al. (2013) EPSL

Experiments with the AstroCam: Can we iden:fy plesiomorphic adapta:ons of early metazoans to Neopropterozoic ocean chemistry on extant animal phyla?

In fact, oxygen rise may have been driven by biological innova:on…

Lenton et al. (2014) Nat. Geosciences

low O2 flux

high O2 flux

Did life evolution had impact on oxygenation? (Logan et al., 1995, Cohen et al., 2009)

To be tested through Sulphur isotopes…

Och and Shields-‐Zhou, 2011

Fike and Grotzinger, 2008

Mul:ple sulphur isotopes = insight into the non steady state model

30%

60%

Coupling between carbon and sulphur cycles

CO2 + H2O <=> CH2O + O2 2CH2O + SO42-‐ <=> 2HCO3-‐ + H2S

Forg Fpyr

Photosynthesis Bacterial sulphate-‐reduc:on (BSR)

O2 produc:on, NOE

= Increase of 30 to 70 % PAL pO2

Thanks

2CO2 + 2H2O <=> 2CH2O + 2O2

2CH2O + SO42-‐ <=> 2HCO3

-‐ + H2S

[SO42-‐] = 3 -‐ 6 mM 8*1018 mol of sulphate,

60% (from dis:lla:on) = 5.6*1018 mol

1.2*1019 mol of O2 liberated into the Oc-‐At system

= Increase of 30 to 70 % PAL pO2

« Back-‐of-‐the-‐envelope » O2 quan:fica:on

Es:ma:on of Kah et al. 2004

*Vocean I

II

III

IV

Catling 2011 Sansjofre et al., submised

con(nents, oceans, atmosphere and life evolu(on Ricardo Trindad

Documents

Transcript of con(nents, oceans, atmosphere and life evolu(on Ricardo Trindad