Geobiology 2007 Lecture 10The Biogeochemical Carbon Cycle
Readings: Assigned Reading:Stanley Chapter 10, pp 221-244Kump et al., Chap. 7Hayes, J. M., Strauss, H. & Kaufman, A. J.., 1999. The abundance of 13C in marine
organic matter and isotopic fractionation in the global biogeochemical cycle of carbon during the past 800 Ma Chem. Geol. 161, 103–125.
Kerr R.A. 2005. The story of O2. News focus article from Science 308, 1730 (MIT Server)
Catling et al., 2005. Astrobiology 5, 415
Other readings: Logan G.A., Hayes J.M., Hieshima G.B. and Summons R.E., 1995, Terminal
Proterozoic reorganisation of biogeochemical cycles. Nature 376, 53-56.Rothman D. H., Hayes J. M., and Summons R. E., 2003, Dynamics of the
Neoproterozoic carbon cycle. Proceedings of the National Academy of Science (USA) 100, 8124-8129.
Acknowledgements: John Hayes and Dan Rothman who provided figures used in this lecture
Geobiology 2006 Lecture 9The Biogeochemical Carbon Cycle
Need to know: • Elements of the geological C-cycle and exogenic or
biological (ocean/atm/biology) C-cycle that affect carbon burial
• ‘Idealized’ redox structure of the surface environment• Concept of mass balance and use of isotopic data to
model C-cycle over different timescales• What this tells us about progressive oxygenation of the
crust/atm/ocean• Excursions in the δ13C record of inorganic carbon,
concept of ‘oxidation’ events and significance for biology
Geobiology 2006 Lecture 9The Biogeochemical Carbon Cycle
• Isotopes are fractionated during chemical and physical equilibrations and during enzyme mediated reactions
• Patterns in the distributions of C, H, N, S &O isotopic tracers can be related to uptake mechanisms (assimilation), energy-yielding redox reactions (dissimilation) and biosynthetic processes
• Patterns in the distributions of C, H, N, S &O isotopic tracers in rocks can be understood by analogies to modern processes
Courtesy Sam Gon III. Image from Wikimedia Commons, http://commons.wikimedia.org.
LifeLife’’s History on Earths History on EarthProkaryote
World
1
Multi-cell Life
0.1 Humans
0.01First
EukaryotesFirst
Invertebrates
P O2(
atm
)
GOE0.001
0.0001
0.000014.5 4 3.5 3 2.5 2
Time before Pre1.5 1 0.5
sent (Ga)0
© JM Hayes Courtesy John Hayes. Used with permission.
© JM Hayes Courtesy John Hayes. Used with permission.
100-10-20-30
Carbon Input
CO HCO2 3=
Microorganisms
0.80.2
Kinetic Isotope Effect
Crustal Average
Isotopic Mass Balance of Crustal Carbon Reservoirs
C13δ
Reduced Carbon
Carbonate
(Des Marais, 2002)Courtesy of Dave Des Marais, NASA Ames. Used with permission.
© Rothman et al., 2005 Courtesy of Dan Rothman. Used with permission.
Image removed due to copyright restrictions.
Please see Fig. 2 in Shields, Graham, and Veizer, Ján. “Precambrian marine carbonate isotope database: Version 1.1.”Geochemistry Geophysics Geosystems 3 (June 6, 2002): 12 pages.
© Rothman et al., 2005 Courtesy of Dan Rothman. Used with permission.
© JM HayesMarine Isotopic Signals
800Ma-presentCourtesy of Elsevier, Inc., http://www.sciencedirect.com. Used with permission.
Courtesy John Hayes. Used with permission.
Courtesy of Dan Rothman. Used with permission.
© JM Hayes
δi
ε
f
Courtesy John Hayes. Used with permission.
© JM Hayes Courtesy John Hayes. Used with permission.
Marine Isotopic Signals 150Ma-present
Courtesy Elsevier, Inc., http://www.sciencedirect.com. Used with permission.
Courtesy John Hayes. Used with permission.© JM Hayes
Courtesy of Dan Rothman. Used with permission.
Massive Mesozoic-Cenozoic Seven Sisters Fossils (East Sussex) Plankton Deposits
Chl a+c PhytoplanktonDiatoms
DinoflagellatesCoccolithophorids
Courtesy Dan Taylor. Image from Wikimedia Commons, http://commons.wikimedia.org.
White Cliffs of Dover
Courtesy NASA
Diatomaceous Earth Mine,Kenya
SeaWiFS views a phytoplankton bloom near the Grand Banks of Newfoundland.
Courtesy Adrian Barnes© J Waldbauer
© JM Hayes
So, how did it all start?
Courtesy John Hayes. Used with permission.
Biogeochemical C Cycles before O2 PhotosynthesisFluxes, x 1012 Moles per Year
0 - 10
10 - 10
10 - 10
10 - 10
3
3 8
6 9
7 9
Cycle Timescales, years
?>20
20Metamorphic and Igneous
Reduced Carbon
Mantle Carbon
4
Marine HCO3-
Carbo-nates
>15
Marble
16
CO : Sea,Atm.
2
Fresh Organic Matter
Sedimentary Organic Matter
~40
~40-?
Courtesy of Dave Des Marais, NASA Ames. Used with permission.
Biogeochemical Carbon CycleFluxes, x 10 Moles per Year12
0 - 10
10 - 10
10 - 10
10 - 10
3
3 8
6 9
7 9
Cycle Timescales, years
10
C13-40 -30 -20 -10 0 +10
10 960
6
2
45
Metamorphic and Igneous Reduced Carbon
Mantle Carbon
0.4
2
Marine HCO3-
Carbo- nates
50
Marble
1.6
CO : Sea,Atm.
2
Fresh Organic Matter
Sedimentary Organic Matter
9000
8990
(Des Marais, 2001)Courtesy of Dave Des Marais, NASA Ames. Used with permission.
© JM Hayes Courtesy John Hayes. Used with permission.
© JM Hayes Courtesy John Hayes. Used with permission.
LifeLife’’s History on Earths History on EarthProkaryote
World
1
Multi-cell Life
0.1 Humans
P O2(
atm
) 0.01 First EukaryotesDinosaursFirst
Invertebrates
0.001
0.0001
0.000014.5 4 3.5 3 2.5
Time befo2
re Pre1.5 1 0.5 0
sent (Ga)
*
(Des Marais, 2001)
-1.0-2.0-3.0-4.0-4.0-70-60-50-40-30-20-10
01020
C13δ
Carbon Isotopic Recordin Sedimentary Carbonates and Organic Matter
Age, Ga
Organics
Oxidized Paleosols
BIF Disappear
Carbonates
Courtesy of Dave Des Marais, NASA Ames. Used with permission.
C-Cycle Models; Des Marais et al., 1992, Carbon Isotopic Evidence for Stepwise Oxidation of the Proterozoic Environment. Nature 359, 605
εp for well-preserved organic matter
and modeled using a moving 30Ma window
In steady state, and assuming δ ~ δa
δi = f * δo – (1-f) δo
δa = δi + f * ε
Image removed due to copyright restrictions.
Please see Fig. 2 in Des Marais, David J., et al. “Carbon Isotope Evidence for the Stepwise Oxidation of the Proterozoic Environment.”Nature 359 (October 15, 1992): 605-609.
C-Cycle Models; Des Marais et al., 1992, Carbon Isotopic Evidence for Stepwise Oxidation of the Proterozoic Environment. Nature 359, 605
and modeled using a 200 or 100 Ma running average
evidence for changes in f over time
Image removed due to copyright restrictions.
Please see Fig. 3 in Des Marais, David J., et al. “Carbon Isotope Evidence for the Stepwise Oxidation of the Proterozoic Environment.”Nature 359 (October 15, 1992): 605-609.
C-Cycle Models; Des Marais et al., 1992, Carbon Isotopic Evidence for Stepwise Oxidation of the Proterozoic Environment. Nature 359, 605
Evidence for an increasing crustal inventory of Corg
Image removed due to copyright restrictions.
Please see Fig. 4 in Des Marais, David J., et al. “Carbon Isotope Evidence for the Stepwise Oxidation of the Proterozoic Environment.”Nature 359 (October 15, 1992): 605-609.
Ocean RedoxStates through
Time
The first order approximation
Image removed due to copyright restrictions.
Please see Fig. 2 in Shields, Graham, and Veizer, Ján. “Precambrian Marine Carbonate Isotope Database: Version 1.1.”Geochemistry Geophysics Geosystems 3 (June 6, 2002): 12 pages.
Figure by MIT OCW.
Major Divisions of Earth History
I II III
Sola
r Sys
tem
For
mat
ion
Late
Hea
vy B
omba
rdm
ent
Earli
er S
now
ball
Epis
odes
Late
r Sno
wba
ll Ep
isod
es
Archean Proterozoic Phanerozoic
pO2 < 0.002 pO2 > 0.03 pO2 > 0.2bar bar bar
ferrousoceans
sulfidicoceans
oxicoceans
cyano-bacteria
algae,protists
complexanimals& plants
5.0 4.0 3.0 2.0 1.0 0.0
© JM HayesMarine Isotopic Signals
800Ma-presentCourtesy John Hayes. Used with permission.
Courtesy of Dan Rothman. Used with permission.
δa (inorganic carbon) for the past 800Ma (Hayes et al., 1999)
Courtesy of Dan Rothman. Used with permission.
Courtesy of Dan Rothman. Used with permission.
Steady State Carbon Burial Model
Sedimentδa δo
δi Oceanδ
In steady state, and assuming δ ~ δaδi = f * δo – (1-f) δoδa = δi + f * ε Where ε = δa – δo
weathering volcanism
Courtesy of Dan Rothman. Used with permission.
A Carbon Cycle with Two Timescales
Sedimentδa δo
δi Oceanδ1, τ1 δ2, τ2δ2− ε
δ2weathering volcanism
inorganic-C organic-C
Courtesy of Dan Rothman. Used with permission.
A Carbon Cycle with Two Timescales
Sedimentδa δo
δi Oceanδ1, τ1 δ2, τ2δ2− ε
δ2weathering volcanism
inorganic-C organic-C
Courtesy of Dan Rothman. Used with permission.
A Carbon Cycle with Two Timescales
δa
δo
δi δ1, τ1 δ2, τ2
δ2−ε
δ2weathering, volcanism
carbonate carbon
organic carbon
Courtesy of Dan Rothman. Used with permission.
Courtesy of Dan Rothman. Used with permission.
A Biogeochemical Model of the Proterozoic Ocean
Image removed due to copyright restrictions.
Please see Fig. 3a in Logan, Graham A., et al. “Terminal Proterozoic Reorganization of Biogeochemical Cycles.” Nature 376 (July 6, 1995): 53-56.
After Ventilation
Image removed due to copyright restrictions.
Please see Fig. 3b in Logan, Graham A., et al. “Terminal Proterozoic Reorganization of Biogeochemical Cycles.” Nature 376 (July 6, 1995): 53-56.
Text removed due to copyright restrictions.
Please see Julian Cribb, “Faeces rain spawned humans,” The Australian, July 7, 1995.
and
Deborah Smith, “Scientists May Have Found the Origin of the Faeces,” The Sydney Morning Herald, July 7, 1995.
© JM Hayes Courtesy John Hayes. Used with permission.
f organic-C buried
13C fractionationεTOC
Carbon Isotopic Excursions 800-500Ma
δ13C limestones
δ13C marine organic matter
More complete sediment record
+
Improved chronology
=
More detailed picture showing abrupt and extreme C-isotopic shifts
750 Ma 720 Ma 580 Ma
Marinoan/Varangerglacial(s)
Sturtianglacial(s)
Image courtesy of Elsevier, Inc., http://www.sciencedirect.com. Used with permission.
Courtesy of Dan Rothman. Used with permission.
http://www.sciencedirect.com
Composite carbon isotopic curve for the Neoproterozoic compared to glacial intervals and absolute geochronology
Varanger Glaciation
1000
0
δ13C (VPDB)-10 -5 0 5 10
Arth
ropo
dsCambrian
Vendian
Edia
cara
531
U-Pbages(Ma)
543.3 1+_
545.1 1+_
548.1 1+_
580?
Spin
y pl
ankt
on
650
+_746 2+_758 4
+_827 6
Stra
tigra
phic
thic
knes
s(c
omm
on sc
ale
exce
pt a
rbitr
ary
for g
laci
atio
n)
-10 -5 0 5 10
Seawater proxy δ13Ccarb850-530 Ma
MoroccoAdoudounian FormationMagaritz et al. (1991)A.C. Maloof (unpubl.) SiberiaTurkut FormationBartley et al. (1998) NamibiaNama GroupSaylor et al. (1998) AustraliaWonoka FormationCalver (2000) OmanHuqf Group - Shuram FmBurns and Matter (1993) NamibiaOtavi GroupHalverson and Hoffman (2003)
SvaibardAkademikerbreen GroupHalverson (2003) AustraliaBitter Springs FormationHill and Walter (2000)
Compilation modified fromHalverson (2003: in prep.)
Marinion Glaciation
Sturtian Glaciation NamibiaGariep GroupFolling and Frimmel (2002)"
Figure by MIT OCW.
Paradigm• The C-cycle has evolved radically through
time• Prior to 2.2 Ga anaerobic prokaryotes
dominated; wide spread of δorg (δo) values; oxygenic photosynthesis extant but oxygen remained low as sinks >> sources
• Mantle may have been an important sink for oxidising power (Cloud/Holland)
• Extreme δcarb(δa) values around 2.2 Gaprobably signify the ‘GOE’ and rise to prominence of aerobes; Decreased spread of δorg (δa) values may reflect dominance of aerobic autotrophs and reductive pentose (Benson-Calvin; C3) cycle
Paradigm• Although ample evidence for aerobes, the
abundance of O2 in atm and ocean remained low (sulfidic ocean) until another major oxidation event caused a second ‘reorganization’ In the Neoproterozoic. This was also signified by extreme δafluctuations.
• The Neoproterozoic ‘reorganization’ led to pO2 rising to near PAL allowing animals to flourish and stabilizing the new regime (Hayes, Rothman, Summons et al.)
• Environmental evolution reflected changes in the balance between thermal, crustal, atmospheric & biological processes
Fig. 1 in Fike, D. A., et al. "Oxidation of the Ediacaran Ocean." Nature 444 (December 7, 2006): 744-747. Courtesy of Nature. Used with permission.
© JM Hayes Phanerozoic coupling of C- and S-cyclesCourtesy John Hayes. Used with permission.
© JM Hayes Phanerozoic coupling of C- and S-cyclesCourtesy John Hayes. Used with permission.
Fractionation of C-Isotopes during AutotrophyPathway, enzyme React & substr Product ε ‰ OrganismsC3 10-22Rubisco1 Rubisco2 PEP carboxylasePEP carboxykinase
CO2 +RUBPCO2 +RUBP
-HCO3 +PEPCO2 +PEP
3-PGA x 23-PGA x 2oxaloacetateoxaloacetate
30222
plants & algaecyanobacteriaplants & algaeplants & algae
C4 and CAM 2-15PEP carboxylaseRubisco1
-HCO3 +PEP CO2+RUBP
oxaloacetate3-PGA x 2
230
plants & algae (C4)
Acetyl-CoACO dehydrogPyruvate synthasePEP carboxylasePEP carboxykinase
CO2 + 2H+ CoASHCO2 + Ac-CoA
-HCO3 +PEPCO2 +PEP
AcSCoApyruvateoxaloacetateOxaloacetate
15-3652
2
bacteria
Reductive or reverse TCA
CO2 + succinyl-CoA (+ others)
α-ketoglutarate
4-13 Bacteria espgreen sulfur
3-hydroxypropionate HCO3- + acetylCoA
Malonyl-CoA Green non-S
0
10
0 10 20 30 40 50
0
10
0
10
0
10
Reduct ive TCA Cycle
Reduct ive Acetyl CoA Pathway
Reduct ive Pentose Phosphate Cycle
3 -Hydroxypropionate Cycle
Numberof Taxa
Δδ C Compiled by C. House13Courtesy of Dave Des Marais, NASA Ames. Used with permission.
© JM HayesCourtesy John Hayes. Used with permission.
© JM Hayes Isotopic RelativitiesCourtesy of Elsevier, Inc., http://www.sciencedirect.com. Used with permission.Courtesy John Hayes. Used with permission.
© JM Hayes Courtesy John Hayes. Used with permission.
© JM HayesCourtesy John Hayes. Used with permission.
Total Global Bacteria: 4 - 6 x 1030 Cells
Elemental Inventories, 10 g
TerrestrialBacteria Bacteria/Plantsplants
C
N
P
350 - 550 560 0.6 - 1
85 - 130 10 8.5 - 13
9 - 14 1 9 - 14
Number Division PercentageLocation
Soil
TerrestrialSubsurface
1030 Cells Time, yrs of Total
0.26 2.5 5
1.4 1500 27
Open Ocean
OceanicSubsurface
0.12 0.02 - 0.8 2
3.5 1500 67
15
Figure by MIT OCW.
© JM Hayes Courtesy John Hayes. Used with permission.
© JM Hayes Courtesy John Hayes. Used with permission.
Geobiology 2007 Lecture 10�The Biogeochemical Carbon CycleGeobiology 2006 Lecture 9�The Biogeochemical Carbon CycleGeobiology 2006 Lecture 9�The Biogeochemical Carbon CycleCarbon Isotopic Excursions �800-500MaParadigmParadigmFractionation of C-Isotopes during Autotrophy