A TEMPERATURE REGULATED ORGANIC CARBON CAPACITOR

ON EARTH’S SURFACE

Gerald R. DickensRice University

(and Nemanja Komar, Benjamin Slotnick, Christopher Hollis, Richard Zeebe )

Glomar Challenger

Lower PaleogeneDSDP Site 577

[Dickens & Backman, News. Strat., 2013]

[ Hollis et al., 2004 ]

~100m

Mead Stream, New Zealand

Late Paleocene-Early Eocene

Carbon Isotope Records

[Slotnick et al., Journal of Geology, 2012]

PETM at Mead Stream, New Zealand

[Nicolo et al., Paleoceanography, 2010]

Ocean

Atmosphere BiosphereVolcanoes

dVol = -5.0FVol = 0.072

Weathering

dWeat = -22FWeat = 0.12

Rivers

dRiv = 0.0FRiv = 0.408

Inputs

dIn = -5.0FIn = 0.60

Organics

dOrg = -28.5 = 0.13

Carbonate

= 1.5 = 0.47

Outputs

dOut = -5.0FOut = 0.60

FOrg

dCarb

FCarb

dEx = -1.45MEx = 56000

dBio = -28.5MBio = 3400

dAtm = -7MAtm = 1400

dOc = 0.5

MOc = 51200

Anthropogenic

dAnt = -30.0FAnt = 8.00

A Carbon Input to the Phanerozoic Carbon Cycle

[adapted from Kump & Arthur, Chem. Geol., 1999 ]

Exo

geni

c C

ompo

sitio

n, d

Ex

(‰)

0

-1

-2

-3

-4 100

1,000

10,000

100,000

0 100 200 300

Time (kyr)

0 100 200 300

Time (kyr)

Car

bon

Inje

ctio

n, M

Ex

(Gt)

Theoretical Carbon Inputs forRapid, Global Negative d13C Excursions

dAdd = -60 ‰

dAdd = -5 ‰

dAdd = -22 ‰

dAdd = -5 ‰

dAdd = -60 ‰

dAdd = -22 ‰

[ Dickens, Geol. Soc. London, 2001 ]

IPCC

Ken Caldeira

Dickens, Bull. Soc. Geol. France, 2000

Zachos et al., Proc ODP Inti. Repts., 208, 2004

PETM at Walvis Ridge

[ Hollis et al., 2004 ]

Predicted Change in Pacific Dissolved Oxygen by AD 2680

[ Matear & Hirst, Global Biogeochemical Cycles, 2003 ]

(mmol/km3)

[Nicolo et al., Paleoceanography, 2010]

PETM at Mead Stream

[ IPCC, 2007 ]

[Slotnick et al., Journal of Geology, 2012]

Figure 7.3: Global Carbon Cycle

[ IPCC, 2007 ]

A Simple Capacitor for Global Carbon Isotope Excursions

Seafloor Methane (Peat/Permafrost)

[ adapted from Dickens, EPSL, 2003 ]

[Dickens and Backman, News. Strat., 2013 ]

Carbon Storage (long-term)

Carbon Release(long-term & short-term)

Carbon Isotope Records at DSDP Site 577

Sulfur Isotopes (Correct Age)

[original sulfur data from Paytan et al., 1996]

Gas Hydrate, AOM and Sulfur Cycling

[ Snyder et al., Deep-Sea Res., 2007 ]

12CH4 + SO42- --->

H12CO3- + HS- + H2O

2CH2O ---> 12CH4 + 13CO2

Alkalinity (HCO3-)

SO42-

Solid S

[ Snyder et al., Deep-Sea Res., 2007 ]

Welcome to the Dark Side: Lee’s Paleogene Machine

[Dickens, Climate of Past, 2011]

[Komar et al., Paleoceanography, in press ]

Long-termModel Results

[Hancock et al., 2007 ]

DSDP Site 259(Indian Ocean)

[Expedition 346 Scientists, 2014]

Back to the Future?

Absolutely. The Eocene is forcingfuture science forward.