letter - uni-bremen.de6,000–4,000 years before present (yr bp; ref. 9), implying that non-...

LETTERdoi:10.1038/nature10685

Forcing of wet phases in southeast Africa over thepast 17,000 yearsEnno Schefuß1, Holger Kuhlmann1, Gesine Mollenhauer1,2, Matthias Prange1 & Jurgen Patzold1

Intense debate persists about the climatic mechanisms governinghydrologic changes in tropical and subtropical southeast Africasince the Last Glacial Maximum, about 20,000 years ago. In par-ticular, the relative importance of atmospheric and oceanic pro-cesses is not firmly established1–5. Southward shifts of theintertropical convergence zone (ITCZ) driven by high-latitudeclimate changes have been suggested as a primary forcing2,3,whereas other studies infer a predominant influence of IndianOcean sea surface temperatures on regional rainfall changes4,5.To address this question, a continuous record representing anintegrated signal of regional climate variability is required, buthas until now beenmissing.Here we show that remote atmosphericforcing by cold events in the northern high latitudes appears tohave been themain driver of hydro-climatology in southeast Africaduring rapid climate changes over the past 17,000 years. Ourresults are based on a reconstruction of precipitation and riverdischarge changes, as recorded in a marine sediment core off themouth of the Zambezi River, near the southern boundary of themodern seasonal ITCZ migration. Indian Ocean sea surfacetemperatures did not exert a primary control over southeastAfrican hydrologic variability. Instead, phases of high precipita-tion and terrestrial discharge occurred when the ITCZ was forcedsouthwards during Northern Hemisphere cold events, such asHeinrich stadial 1 (around 16,000 years ago) and the YoungerDryas (around 12,000 years ago), or when local summer insolationwas high in the late Holocene, that is, during the past 4,000 years.Climate changes reconstructed from sediments in Lake Malawi, the

southernmost of the East African great lakes and located within theZambezi catchment, point to arid conditions and strong northerlywind anomalies during Northern Hemisphere cold events, such asthe Younger Dryas2,3. It has been inferred that these periods representsouthward shifts of the ITCZ2,3,6. Dry conditions during the YoungerDryas andHeinrich stadial 1 (HS1) in Lake Tanganyika, located closerto the Equator in East Africa, were interpreted to have been caused bylowered Indian Ocean sea surface temperature4 (SST). Recently, wide-spread drought conditions during HS1 in East Africa have similarlybeen suggested to be driven by cold conditions in the Indian Ocean5.Such interpretations are based on meteorological observations thatmodern rainfall in eastern and southern Africa is strongly related tohigh SST in the western and southwestern IndianOcean, respectively7.In contrast, Lake Chilwa—located southeast of LakeMalawi—recordedhigh-stands, which appear to be solely associated with NorthernHemisphere cold events8. Further westward in the interior of sub-tropical southern Africa, palaeo-environmental information is sparse.Age dating of dunes in western Zambia and western Zimbabwe pointsto dry conditions at 18,000–17,000, 15,000–14,000, 11,000–8,000 and6,000–4,000 years before present (yr BP; ref. 9), implying that non-dune-building periods around 16,000 yr BP and from 13,000 to12,000 yr BP roughly correspond to the wet periods found at LakeChilwa8. Palaeo-shorelines and other geomorphologic evidence fromthe Central Kalahari point to the existence of an extended lake system

around the time of HS1 and around 8,500 yr BP, with evidence for theexistence of smaller lakes around the time of the Younger Dryas10. Itthus appears that the climatic history of subtropical southern Africa iscomplex, and the importance of the various potential climatic forcingmechanisms remains unresolved.To provide more insights into the climatic forcing of hydrology

and land–ocean linkages in southeast Africa, we present a reconstruc-tion of precipitation changes in the Zambezi catchment and its sedi-mentary discharge fluctuations in conjunction with SST estimates ofthe southwest Indian Ocean. The Zambezi catchment is located at thesouthern boundary of the present-day seasonal ITCZmigration, and isthus ideally suited to have recorded past changes in its southwardextension. Under modern conditions, austral summer rainfall asso-ciated with the ITCZ extends to 15–20u S (ref. 6; Fig. 1a, b). A low-pressure cell forms over southern Africa during summer; it attracts

1MARUM – Center for Marine Environmental Sciences and Faculty of Geosciences, University of Bremen, D-28359 Bremen, Germany. 2Alfred Wegener Institute for Polar and Marine Research, D-27568

Bremerhaven, Germany.

Eq

20° S

20° E 40° E

CAB

ITCZ

Eq

20° S

20° E 40° E

Longitude

a

b

12

3

4

5

3

9

15

21

27

Eq

20° S

5

25

45

65

85

Longitude

c

20° E 40° E

35° E 36° E 37° E

17° S

18° S

19° S Delta

d

Latitu

de

Latitu

de

Rainfa

ll (cm

month

–1)

Perc

enta

ge o

f C4 p

lants

Rift

mountains

Figure 1 | Modern atmospheric circulation over southern Africa duringSouthern Hemisphere summer, summer rainfall and vegetation types.a, Schematic representation of the atmospheric circulation over southernAfricaduring austral summer (December, January, February; DJF) with approximateposition of the ITCZ and the Congo Air Boundary (CAB). Indicated are: themain course of the Zambezi River (blue), the Zambezi catchment (grey) and thelocation of GeoB9307-3 (red diamond). Filled red circles indicate locations ofother records discussed in the text: (1) LakeMalawi2, (2) Lake Tanganyika4, (3)Lake Chilwa8, (4) dunes in Zambia and Zimbabwe9, and (5) palaeo-shorelinesin the Kalahari10. b, Austral summer (DJF) rainfall for the period 1950–99(University of Delaware data set; http://www.esrl.noaa.gov/psd/data/gridded/data.UDel_AirT_Precip.html). Outline of the Zambezi catchment in white andmain course of the Zambezi River in blue. c, Modern-day vegetation typedistribution15, shown as percentage of C4 plants. White areas are either.95%C4 or not vegetated. Zambezi catchment and Zambezi River as in b. Colourscale as in d. Black box indicates the area shown in d. d, Map of the relative C4

plant abundance15 in the lower Zambezi catchment. White areas are notvegetated. White box indicates the location of the lower Zambezi floodplain.

2 2 / 2 9 D E C E M B E R 2 0 1 1 | V O L 4 8 0 | N A T U R E | 5 0 9

Macmillan Publishers Limited. All rights reserved©2011

moisture from the tropical Atlantic by tropical westerly air flow, andfrom the Indian Ocean by easterly air flow6. Atlantic moisture influ-ences are restricted to the highlands south of the Congo basin, sepa-rated by the Congo Air Boundary from the majority of subtropicalsouthern Africa that receives moisture from the Indian Ocean11.During austral winter, a high-pressure system over southern Africaleads to dry conditions, except in a small winter rainfall zone at itssouthwestern tip6. The Zambezi River is the fourth-largest river inAfrica, originating in Zambia and flowing southeastward to theIndian Ocean. The upper Zambezi is separated from its lower partby the Victoria Falls. After flowing through a series of gorges, the riverenters a broad valley and spreads out over a large floodplain in its lowerpart. About 150 km from the coast, the catchment narrows where theriver flows through the easternRiftmountains.Maximumrainfall in thecatchment during the peak of the southward ITCZmigration occurs inthis area12 (Fig. 1b), periodically causing extensive flooding13. The flood-plain is dominated bypapyrus swamps (dominatedbyCyperus papyrus,a C4 plant) with a lower importance of reed swamps (Phragmites andTypha, C3 plants)

14. The C4 plant dominance in the lower Zambezifloodplain is seen in the relative abundance of C4 plants

15 (Fig. 1c, d).Downstream from the Rift mountains, the Zambezi splits up into a flatandwide delta13.Woodlands, savannah and extensivemangrove forests(C3 plants) vegetate the delta and coastal areas14.The 6.51-m-long marine sediment core GeoB9307-3 (18u 33.99 S,

37u 22.89 E, 542m water depth) was retrieved about 100 km off theZambezi delta. The core location is in the zone of high deglacial-Holocene sedimentation of material discharged by the ZambeziRiver16. The chronology of the core is established by 19 14C AMS(acceleratormass spectrometry) dates onmixedplanktonic foraminifera(Supplementary Table 1). On the basis of this chronology, the corecovers the past 17,000 years. The average time resolution between the125 samples is 130 years. For the time periods of HS1 and the YoungerDryas, we detect large increases in sedimentary terrestrial versusmarine elemental ratios (Fig. 2b), in relative soil organic matter con-tributions17 (branched and isoprenoid tetraether (BIT) index, Fig. 2c),and in sedimentary concentrations of terrestrial-plant-derived long-chain n-alkanes (Fig. 2d), indicating enhanced terrestrial discharge bythe Zambezi River. The elevated concentrations of n-alkanes indicatesustained vegetation cover during HS1 and the Younger Dryas, anddecreases of soil pH estimates during these intervals (SupplementaryFig. 4) suggest higher rainfall as primary cause. For all these para-meters, a slight increase is alsodetected for the lateHolocene comparedto the early Holocene. Comparison to records from Lake Malawi2,3

suggests that the rainfall maximum associated with the ITCZ shiftedsouthward of the Malawi basin during HS1 and the Younger Dryas,causing arid conditions at Lake Malawi while increasing rainfall in thelower Zambezi catchment. The stronger increases in these discharge-related parameters during the Younger Dryas and HS1 compared tothe late Holocene points to the influence of sea-level changes. Sea levelwas reducedduring the last deglaciation18, resulting in amore proximallocation of the Zambezi outflow to the core site.In order to investigate the continental hydrologic changes without

the influence of sea-level changes, we analysed the hydrogen isotopecomposition of lipid biomarkers derived from higher plants.Hydrogen isotope compositions of the n-C31 alkane range from2136% to 2164% (relative to the VSMOW standard), showingdepleted values from 16,950 to 14,700 yr BP, corresponding to theperiod of HS1, and from 12,800 to 11,350 yr BP, representing theYounger Dryas period (Fig. 2e). The most enriched values are foundin the early Holocene, followed by a gradual decline towards the lateHolocene that is interrupted by several short-term excursions to moreenriched values. The n-C31 alkane derives from the protective waxcoating of leaves of terrestrial higher plants19. Its hydrogen isotopecomposition reflects changes in the isotopic composition of precipita-tion, with potential enrichment due to evaporation from soils andevapo-transpiration from leaves20, which amplify the recorded signal

under arid conditions21. Inmonsoonal regions, depleted isotopic com-positions of precipitation are indicative of changes in the amount ofrainfall22. These data suggest that changes in rainfall amount causedthe discharge pulses detected for the Younger Dryas and HS1.

–44

–40

–36

–32

25

26

27

28

29

30

0

10

20

30

40

50

0

0.4

0.6

0.8

440

460

480

BIT

index

NGRIP

δ18O

SST G

eoB9307

wetter

(°C)

b

c

e

a

g

f

h

HS1YD

–32

–30

–28

–26

–24

–22

400

800

1,200

1,600

2,000

(ng g

–1)

d

Σn-C

25-3

5 a

lkanes

–130

–140

–150

–160(‰

VSM

OW

)

Fe/C

a ratio

(‰ V

SM

OW

)

drier

δD n

-C31 a

lkane

more

C4

more

C3

(‰ V

PDB)

δ13C n

-C31 a

lkane

DJF insolation a

t 20° S

(W

m–2)

Age (kyr BP)

0 2 4 6 8 10 12 14 16 18

–170

0.2

Figure 2 | Records of environmental variability in southeastern Africa overthe past 17,000 years. a, Oxygen isotope changes in NGRIP ice core28, mainlyreflecting northern high-latitude temperature changes.b, Fe/Ca ratio, indicatingterrestrial versus marine elemental contributions to sediments of GeoB9307-3.c, BIT index of GeoB9307-3, reflecting changes in relative soil organic mattercontribution. d, Concentrations of long-chain, odd-numbered n-alkanes (n-C25

to n-C35) in the sediments of GeoB9307-3. e, Hydrogen isotope compositions ofthe n-C31 alkane in GeoB9307-3, reflecting rainfall changes in the Zambezicatchment. Error bars based on replicate analyses are shown in SupplementaryFig. 1. f, Stable carbon isotope compositions of n-C31 alkanes in GeoB9307-3,indicating relative contribution changes from the lower Zambezi floodplain.Error bars based on replicate analyses are shown in Supplementary Fig. 2.g, Long-term insolation changes over southern Africa (20u S) during SouthernHemisphere summer (DJF)25. h, TEX86-derived SST record from GeoB9307-3,reflecting ocean temperature changes in the southwest Indian Ocean. Verticalgrey bars indicate intervals of Heinrich Stadial 1 (HS1) and the Younger Dryas(YD). Black triangles indicate 14C AMS ages.

RESEARCH LETTER

5 1 0 | N A T U R E | V O L 4 8 0 | 2 2 / 2 9 D E C E M B E R 2 0 1 1


Comparisonof thedDvalues of the long-chainplant-waxeswith theirstable carbon isotope (d13C) compositions reveals that sedimentaryn-alkanes with depleted dD values show a stronger C4 plant signaland vice versa (Fig. 2f). As C4 plants are usually more drought-tolerantthan C3 plants

23, this correlation is unexpected. Although long-termvegetation changes are not ruled out (see Supplementary Informa-tion), the strong coherence of both isotopic signals rather points to ashift in source area associated with the hydrologic changes as theprimary cause for the observed relation.We infer that whenmaximumrainfall and flooding occurs in the floodplain, as under modern-dayconditions, more C4-plant-derived waxes are exported to the ocean, asreflected in the core-top isotopic signature (Figs 1d, 2e). Under morearid conditions, such as during the early Holocene, the export of C4-plant-derived lipids from the floodplain was diminished, and only lowamounts of predominantly C3-plant-derived waxes from near-coastalvegetation were exported. We thus deduce that the terrestrial signal incore GeoB9307-3 is predominantly derived from the lower Zambezicatchment, dominated by changes in relative contributions from thefloodplain. Aeolian transport of terrigenous material from subtropicalsouthern Africa towards the southwest Indian Ocean is negligible,owing to the prevailing easterly winds12.Part of the signal seen in the dD record may thus derive from the

changes in relative contributions from different vegetation types, seen inthe C3/C4 changes (see, for example, ref. 24). Although we cannot com-pletely rule out this possible effect, the evidence provided by the otherparameters (Fe/Ca ratio, BIT index, n-alkane concentrations, soil pHestimates) indicates that the depleted dD values during HS1, theYounger Dryas and the late Holocene indeed reflect increased precipita-tion in the lower Zambezi catchment.The long-term trends in the dD and d13C records correlate with

mean summer insolation (Fig. 2g) over southern Africa25: higherinsolation intensifies atmospheric convection, leading to higherrainfall over that region26. For Heinrich events, modelling results indi-cate an increase of precipitation associated with isotopically depletedrainfall over southern Africa27, consistent in magnitude with the iso-topic changes detected for HS1. A detailed comparison of the plant-wax isotopic changes with the oxygen isotope changes in the NGRIPice core28 (Fig. 3), which reflect northern high-latitude temperaturechanges, reveals a synchronous onset and end of the Younger Dryas

and a synchronous end of HS1. This synchronicity supports our con-clusion that the plant waxes are not transported over long distances. Assuggested by other studies8–10, rainfall during HS1 and the YoungerDryas probably also increased in the western parts of the Zambezicatchment. However, plant waxes derived from these more inlandparts would carry a much more depleted dD signal due to increasedmoisture rainout during long-distance transport29. We thus infer thatlong-distance transport of plant waxes by the Zambezi River is ofminor importance. Furthermore, the detected synchronicity of iso-topic changes suggests a direct forcing of southeast African wet phasesbyNorthernHemisphere cold events, and points to a large-scale atmo-spheric teleconnection (see, for example, ref. 30). It is likely that per-sistent cold conditions in theNorthernHemisphere forced the ITCZ toa more southerly position during these events. The deviations in theamplitudes of isotopic changes of the ice core and the plant waxesduring HS1 (Fig. 3) are probably explained by the modulation ofrainfall intensity by local insolation.Inorder to evaluate the effect of southwest IndianOceanSSTchanges

on continental hydrology, we compare the terrestrial records to aTEX86-based SST record fromGeoB9307-3 (Fig. 2h). The TEX86 indexreflects distributional variations in membrane lipids from marineThaumarchaeota, related to ocean temperature (see SupplementaryInformation). The high BIT values in part of the record did not leadto a substantial bias in SST estimates (see Supplementary Information).The SST record shows warm conditions during the Younger Dryas,but does not indicate similarly warm conditions during HS1.Moreover, the timing of SST changes does not correspond to theobserved hydrologic changes. Therefore, we suggest that sufficientlywarm conditions in the southwest Indian Ocean may have been animportant pre-condition for southward movements of the ITCZ andthe supply of moisture, but that rainfall changes in the Zambezicatchment over these timescales were not primarily driven by theseSSTs. We find no evidence for drought conditions in southeast Africaduring HS1 driven by cold conditions in the Indian Ocean5.In summary, we conclude that rainfall and discharge changes in the

Zambezi catchment result from a combination of local insolation andlatitudinal ITCZ shifts, with the latter being directly forced by high-latitude climate changes in the Northern Hemisphere. SST changes inthe southwest Indian Ocean appear not to be the primary forcing ofpast hydrologic changes, but may be an important prerequisite forsuch changes.

METHODS SUMMARYElement intensities were measured at 1 cm resolution using a XRF-I core scannerat MARUM, University of Bremen. The central sensor unit is equipped with amolybdenum X-ray source (3–50 keV), a Peltier-cooled PSI detector with a125mm beryllium window, and a multichannel analyser with 20 eV spectral reso-lution. XRF (X-ray fluorescence) data for this study were collected over a 1 cm2

area using 30 s count time, and conditions of 20 kV and 0.087mA for the X-raysource.

Sediments were extracted with a Dionex accelerated solvent extractor usingdichloromethane:methanol (9:1; v/v). Saturated hydrocarbon fractions wereobtained using silica column chromatography by elution with hexane and sub-sequent elution over AgNO3-coated silica. Squalane was added before extractionas an internal standard.Hydrogen isotope compositions of lipidswere analysed ona Trace gas chromatograph coupled via a pyrolysis reactor to a MAT 253 massspectrometer. Isotope values were measured against calibrated H2 reference gas.dD values are reported in % versus VSMOW. Further technical information isprovided in Supplementary Information.

Compound-specific stable carbon isotope values were analysed on a Trace gaschromatograph coupled via a combustion reactor to a MAT 252 mass spectro-meter. Isotope values were measured against calibrated CO2 reference gas. d

13Cvalues are reported in% versus VPDB. Further technical information is providedin Supplementary Information.

Polar fractions of the total lipid extracts eluted from silica columnswith dichlor-omethane:methanol (1:1; v/v) were filtered through a 4-mm pore size PTFE filterand dissolved in hexane/isopropanol (99:1; v/v) before analysis by high perform-ance liquid chromatography/atmospheric pressure chemical ionization–mass

–46

–44

–42

–40

–38

–36

–34

–165

–160

–155

–150

–145

–140YD HS1

NGRIP

δ18O (‰

VSM

OW

)

GeoB9307-3

δD (‰

VSM

OW

)

Age (kyr BP)

10 11 12 13 14 15 16 17

Figure 3 | Detailed comparison of Greenland climate changes withhydrologic variations in the Zambezi catchment during the lastdeglaciation. Greenland temperature changes reflected in oxygen isotopecompositions (blue) of the NGRIP ice core28 compared to hydrogen isotopechanges of the n-C31 alkane in sediments of GeoB9307-3 reflecting rainfallchanges in the Zambezi catchment (black, note inverted scale). Deviations inamplitudes are partly due tomodulation of rainfall intensity by local insolation(Fig. 2g). Grey bars and black triangles as in Fig. 2. Error bars based on replicateanalyses are shown in Supplementary Fig. 1.

LETTER RESEARCH

2 2 / 2 9 D E C E M B E R 2 0 1 1 | V O L 4 8 0 | N A T U R E | 5 1 1


spectrometry (HPLC/APCI-MS). AnAgilent 1200 series HPLC/APCI-MS systemequippedwith aGrace Prevail Cyano column (150mm3 2.1mm; 3mm)was used,and separation was achieved in normal phase.

Received 11 May; accepted 27 October 2011.

1. Clement, A. C. & Peterson, L. C. Mechanisms of abrupt climate change of the lastglacial period. Rev. Geophys. 46, RG4002 (2008).

2. Johnson, T. C. et al. A high-resolution paleoclimate record spanning the past25,000 years in southern east Africa. Science 296, 113–132 (2002).

3. Castaneda, I. S., Werne, J. P. & Johnson, T. C. Wet and arid phases in the southeastAfrican tropics since the Last Glacial Maximum. Geology 35, 823–826 (2007).

4. Tierney, J. E. et al. Northern Hemisphere controls on tropical southeast Africanclimate during the past 60,000 years. Science 322, 252–255 (2008).

5. Stager, C. J., Ryves,D.B., Chase,B.M.&Pausata, F. S.R.Catastrophicdrought in theAfro-Asian monsoon region during Heinrich Event 1. Science 331, 1299–1302(2011).

6. Gasse, F. et al. Climatic patterns in equatorial and southern Africa from 30,000 to10,000 years ago reconstructed from terrestrial and near-shore proxy data. Quat.Sci. Rev. 27, 2316–2340 (2008).

7. Jury,M.R., Enfield, D.B.&Melice, J. L. TropicalmonsoonsaroundAfrica: stability ofEl Nino-Southern Oscillation associations and links with continental climate.J. Geophys. Res. 107(C10), 3151, http://dx.doi.org/10.1029/2000JC000507(2002).

8. Thomas, D. S. G. et al. Late Quaternary highstands at Lake Chilwa, Malawi:frequency, timingandpossible forcingmechanisms in the last44ka.Quat. Sci.Rev.28, 526–539 (2009).

9. Thomas, D. S. G. & Shaw, P. A. Late Quaternary environmental change in centralsouthern Africa: new data, synthesis, issues and prospects. Quat. Sci. Rev. 21,783–797 (2002).

10. Burrough, S. L., Thomas, D. S. G. & Singarayer, J. S. Late Quaternary hydrologicaldynamics in the Middle Kalahari: forcing and feedbacks. Earth Sci. Rev. 96,313–326 (2009).

11. Gimeno, L. et al. On the origin of continental precipitation. Geophys. Res. Lett. 37,L13804, http://dx.doi.org/10.1029/2010GL043712 (2010).

12. Nicholson, S. E. The nature of rainfall variability over Africa on time scales ofdecades to millennia. Glob. Planet. Change 26, 137–158 (2000).

13. Beilfuss, R. & dos Santos, D. Patterns of Hydrological Change in the Zambezi Delta,Mozambique (Working Paper No. 2, International Crane Foundation, Sofala,Mozambique, 2001); available at Æhttp://www.savingcranes.org/images/stories/pdf/conservation/Zambezi_hydrology_Working_Paper2.pdfæ.

14. Beilfuss, R., Moore, D., Bento, C. & Dutton, P. Patterns of Vegetation Change in theZambeziDelta,Mozambique (WorkingPaperNo.3, InternationalCraneFoundation,Sofala, Mozambique, 2001); available at Æhttp://www.savingcranes.org/images/stories/pdf/conservation/Zambezi_Vegetation_Working_Paper3.pdfæ.

15. Still, C. J. & Powell, R. L. in Understanding Movement, Pattern, and Process on Earththrough Isotope Mapping (eds West, J. B., Bowen, G. J., Dawson, T. E. & Tu, K. P.)179–194 (Springer, 2010).

16. Schulz, H., Luckge, A., Emeis, K.-C. & Mackensen, A. Variability of Holocene to LatePleistocene Zambezi riverine sedimentation at the upper continental slope offMozambique, 15u–21uS. Mar. Geol. 286, 21–34 (2011).

17. Hopmans, E. C., Schefuß, E., Sinninghe Damste, J. S. & Schouten, S. A novel proxyfor terrestrial carbon input based on branched and isoprenoid tetraethers. EarthPlanet. Sci. Lett. 224, 107–116 (2004).

18. Fairbanks, R. G. Sea level rise during the last deglaciation as recorded in Barbadoscorals. Nature 342, 637–642 (1989).

19. Eglinton, G. & Hamilton, R. J. Leaf epicuticular waxes. Science 156, 1322–1335(1967).

20. Sachse,D., Radke, J.&Gleixner,G. dDvaluesof individualn-alkanes fromterrestrialplants along a climatic gradient — implications for the sedimentary biomarkerrecord. Org. Geochem. 37, 469–483 (2006).

21. Schefuß, E. Schouten, S. & Schneider, R. R. Climatic controls of Central Africanhydrology during the last 20,000 years. Nature 437, 1003–1006 (2005).

22. Risi, C., Bony, S. & Vimeux, F. Influence of convective processes on the isotopiccomposition (d18O and dD) of precipitation and water vapor in the tropics: 2.Physical interpretation of the amount effect. J. Geophys. Res.113,D19306, http://dx.doi.org/10.1029/2008JD009943 (2008).

23. Ehleringer, J. R. & Cerling, T. E. in Encyclopedia of Global Environmental Change Vol.2 (ed. Munn, T.) 186–190 (Wiley & Sons, 2002). pp. 186.

24. Hou, J. Z., D’Andrea, W. J., MacDonald, D. & Huang, Y. S. Hydrogen isotopicvariability in leaf waxes among terrestrial and aquatic plants around Blood Pond,Massachusetts (USA). Org. Geochem. 38, 977–984 (2007).

25. Laskar, J. et al. A long-term numerical solution for the insolation quantities of theEarth. Astron. Astrophys. 428, 261–285 (2004).

26. Partridge, T. C. et al. Orbital forcing of climate over South Africa: a 200,000 yearrainfall record from the Pretoria Saltpan. Quat. Sci. Rev. 16, 1125–1133 (1997).

27. Lewis, S. C., LeGrande, A. N., Kelley, M. & Schmidt, G. A. Water vapour sourceimpacts on oxygen isotope variability in tropical precipitation during Heinrichevents. Clim. Past 6, 325–343 (2010).

28. Andersen, K. K. et al. High-resolution record of Northern Hemisphere climateextending into the last interglacial period. Nature 431, 147–151 (2004).

29. Frankenberg, C. et al.Dynamic processes governing lower-troposphericHDO/H2Oratios as observed from space and ground. Science 325, 1374–1377 (2009).

30. Broccoli, A. J., Dahl, K. A. & Stouffer, R. J. Response of the ITCZ to NorthernHemisphere cooling. Geophys. Res. Lett. 33, L01702, http://dx.doi.org/10.1029/2005GL024546 (2006).

Supplementary Information is linked to the online version of the paper atwww.nature.com/nature.

Acknowledgements This work was supported by the DFG Research Center/Cluster ofExcellence ‘The Ocean in the Earth System’ and DFG grant Sche903/8. Laboratoryassistance was provided by K. Siedenberg, M. Segl, W. Bevern, B. Meyer-Schack andR. Kreutz. We thank R. Schneider for logistical support and S. Weldeab for samplepreparation for radiocarbon analyses. Comments by Y. Huang and J. Russell improvedthe manuscript.

Author Contributions Experimental work was carried out by E.S., H.K., G.M. and J.P.;data analysis and interpretation were carried out by E.S., H.K., G.M., M.P. and J.P.

Author Information Data reported here are stored in the Pangaea database(http://www.pangaea.de/10.1594/PANGAEA.771396). Reprints and permissionsinformation is available at www.nature.com/reprints. The authors declare nocompeting financial interests. Readers are welcome to comment on the online versionof this article at www.nature.com/nature. Correspondence and requests for materialsshould be addressed to E.S. ([email protected]).

RESEARCH LETTER

5 1 2 | N A T U R E | V O L 4 8 0 | 2 2 / 2 9 D E C E M B E R 2 0 1 1


!!

!

Supplementary material

Hydrologic signals in !D compositions of long-chain n-alkanes

"#$%&'()*$!#++&$,-./0/+!n&)12)$/34!/5%54!n&6784!n&6794!n&6:;!)$+!n&6::4!)0/!+/0*</+!

=0#-!>(/!/?*&',>*',1)0!@)A!'#)>*$%!#=!>/00/3>0*)1!(*%(/0!?1)$>3;5!B>,+*/3!#=!@)A!1*?*+!

+*3>0*.,>*#$3!#=!C=0*')$!</%/>)>*#$7!3,%%/3>!>()>!n&)12)$/!+*3>0*.,>*#$3!#=!0)*$=#0/3>!

?1)$>3!D-#3>1E!6:F!-)A*-*G/!)>!>(/!n&679!)12)$/4!@(/0/)3!n&)12)$/!+*3>0*.,>*#$3!#=!6:!

3)<)$$)(!>0//3!)$+!3(0,.3!)$+!6H!%0)33/3!()</!>(/*0!-)A*-,-!)>!>(/!n&6:;!)12)$/75!

6H!%0)33/3!#=>/$!3(#@!(*%(/0!)-#,$>3!#=!n&6::!>()$!#>(/0!3)<)$$)!?1)$>34!(#@/</04!

@*>(!3,.3>)$>*)1!<)0*).*1*>E!./>@//$!*$</3>*%)>/+!>)A)75!I-/0%/$>!)J,)>*'!?1)$>3!

#'',00*$%!*$!>(/!K)-./G*!=1##+?)*$4!+/1>)!)$+!*$!'#)3>)1!)0/)3!D/5%54!Cyperus!3??54!

Phragmites!3??54!Rhizophora!3??5F!()</!n&)12)$/!+*3>0*.,>*#$3!3*-*1)0!>#!>/00/3>0*)1!

</%/>)>*#$4!>E?*')11E!+#-*$)>/+!.E!1#$%/0&'()*$!DLn&679F!(#-#1#%,/3:5!M$!#,0!

3)-?1/34!>(/!n&678!)12)$/!'#,1+!$#>!0/1*).1E!./!*3#>#?*')11E!)$)1E3/+!+,/!>#!*>3!

0/1)>*</1E!1#@!).,$+)$'/5!N(/!O:&=)'>#0!<)0*/+!=0#-!P57!>#!P5H!#</0!>(/!-/)3,0*$%!

?/0*#+5!C$!)12)$/!3>)$+)0+!#=!;P!/A>/0$)11E!')1*.0)>/+!)12)$/3!@)3!-/)3,0/+!/</0E!Q!

0,$35!C</0)%/!).3#1,>/!+/<*)>*#$3!=0#-!2$#@$!!R!<)1,/3!@/0/!'#$3*3>/$>1E!S!P!T5!C11!

3)-?1/3!@/0/!0,$!)>!1/)3>!*$!+,?1*')>/5!U/?0#+,'*.*1*>E!=#0!>(/!n&6794!>(/!n&6:;4!)$+!

>(/!n&6::!)12)$/!@)3!;5P!T4!;5Q!T!)$+!757!T!#$!)</0)%/4!0/3?/'>*</1E5!V0/'*3*#$!

)$+!)'',0)'E!#=!>(/!3J,)1)$/!*$>/0$)1!3>)$+)0+!@/0/!:5W!)$+!;5Q!T4!0/3?/'>*</1E!

D$X:;9F5!6#-?)0*3#$!#=!>(/!!R!3*%$)13!#=!>(/!n&6794!n&6:;!)$+!n&6::!)12)$/!0/</)13!

3>0#$%!'#(/0/$'/!./>@//$!>(/!n&6:;!)$+!n&6::!)12)$/4!@(*1/!>(/!n&679!)12)$/!3(#@3!

1/33!?0#$#,$'/+!'()$%/3!DY*%5!B;F5!N(/!)</0)%/!!R!<)1,/!#=!)11!3)-?1/3!+/'0/)3/3!

=0#-!n&679!>#!>(/!n&6::!Dn&679Z!&;HW![!:!T!\B]^_4!n&6:;Z!&;P;![!P!T!\B]^_4!n&

6::Z!&;PW![!8!T!\B]^_F!@(*1/!>(/!>#>)1!0)$%/!*$'0/)3/3!=0#-!>(/!n&679!>#!>(/!n&6::!

SUPPLEMENTARY INFORMATIONdoi:10.1038/nature

WWW.NATURE.COM/NATURE | 1

!!

Dn&679Z!7;!T4!n&6:;Z!79!T4!n&6::Z!:`!TF5!N(/!#.3/0</+!?)>>/0$!>(,3!3,%%/3>3!>()>!>(/!

n&6:;!)$+!n&6::!)12)$/3!*$!#,0!3)-?1/3!)0/!+/0*</+!=0#-!-#0/!'#$=*$/+!?1)$>!

3#,0'/3!@(/0/)3!>(/!n&679!)12)$/!0/=1/'>3!'#$>0*.,>*#$3!=0#-!)!.0#)+/0!0)$%/!#=!?1)$>!

>E?/34!/5%54!@*>(!+*==/0/$>!%0#@*$%!3/)3#$34!%0#@>(!=#0-34!)$+!3/$3*>*<*>E!>#!3#*1!

/<)?#0)>*#$!)$+a#0!/<)?#&>0)$3?*0)>*#$5!R,/!>#!>(/!1)'2!#=!+/>)*1/+!3>,+*/3!#$!n&

)12)$/!+*3>0*.,>*#$3!#=!?1)$>3!=0#-!>(/!K)-./G*!')>'(-/$>4!@/!*$>/0?0/>!>(/!!R!3*%$)1!

#=!>(/!n&6:;!)12)$/!)3!./*$%!+/0*</+!=0#-!>/00/3>0*)1!(*%(/0!?1)$>3!*$!%/$/0)15!!

IA'/?>!=#0!>(/!*3#>#?*'!/$0*'(-/$>!+,/!>#!/<)?#0)>*#$!*$!3#*13!)$+!/<)?#&>0)$3?*0)>*#$!

=0#-!1/)</34!3/+*-/$>)0E!?1)$>!@)A/3!-)*$1E!0/'#0+!>(/!*3#>#?*'!'#-?#3*>*#$!#=!

?0/'*?*>)>*#$H5!B/</0)1!=)'>#03!-*%(>!)==/'>!'()$%/3!*$!*3#>#?*'!'#-?#3*>*#$3!#=!

?0/'*?*>)>*#$!*$!>(/!1#@/0!K)-./G*!')>'(-/$>P5!B>#0)%/!#=!*3#>#?*')11E!+/?1/>/+!@)>/0!

*$!*'/!3(//>3!)1>/03!>(/!%1#.)1!-/)$!3/)@)>/0!*3#>#?*'!'#-?#3*>*#$!)3!-#*3>,0/!

3#,0'/!#=!?0/'*?*>)>*#$P4Q5!_/!+*+!$#>!'#00/'>!>(/!!R!0/'#0+!=#0!3/)@)>/0!*3#>#?/!

'()$%/3!+,/!>#!<)0E*$%!*'/!<#1,-/5!C3!%1#.)1!-/)$!3/)@)>/0!@)3!*3#>#?*')11E!

(/)<*/0!+,0*$%!>(/!+/%1)'*)>*#$!>()$!)>!?0/3/$>Q4!3,'(!'#00/'>*#$!@#,1+!1/)+!>#!/</$!

1*%(>/0!!R!<)1,/3!#=!?1)$>&@)A/3!+,0*$%!+/%1)'*)>*#$!)$+!>(,3!1/)+!>#!-#0/!

?0#$#,$'/+!'()$%/3!*$!>(/!0/'#0+35!_)>/0!<)?#,0!3#,0'/!)0/)!'()$%/3!)0/!0,1/+!#,>!

)3!)1-#3>!)11!-#*3>,0/!?0/'*?*>)>*$%!#</0!3#,>(&/)3>!C=0*')!+/0*</3!=0#-!>(/!3#,>(@/3>!

M$+*)$!^'/)$85!6#$>*$/$>)1!>/-?/0)>,0/!/3>*-)>/3!D3//!./1#@F!*$+*')>/!@)0-/0!)*0!

>/-?/0)>,0/3!+,0*$%!OB;!)$+!>(/!bR!'#$>0)+*'>*$%!)!>/-?/0)>,0/!/==/'>!+,0*$%!>(/3/!

*$>/0<)135!6()$%/3!*$!>(/!*$>/$3*>E!#=!0)*$=)11W!)$+!3(*=>3!*$!>(/!1#')>*#$!#=!-)*$!0)*$=)11!

0/-)*$!)3!?#>/$>*)1!+0*</03!#=!*3#>#?*'!<)0*).*1*>E5!O*%(/0!?0/'*?*>)>*#$!0)>/3!D)-#,$>!

/==/'>F!)3!@/11!)3!)!3(*=>!#=!-)*$!?0/'*?*>)>*#$!>#!)$!)0/)!=,0>(/0!*$1)$+!)$+a#0!>#@)0+3!

(*%(/0!)1>*>,+/3!'#,1+!1/)+!>#!>(/!#.3/0</+!+/?1/>/+!*3#>#?*'!'#-?#3*>*#$3!+,0*$%!


SUPPLEMENTARY INFORMATIONRESEARCHdoi:10.1038/nature

!!

!

OB;4!>(/!bR!)$+!>(/!1)>/!O#1#'/$/5!N(/!0/1)>*</1E!3-)11!)-?1*>,+/!#=!>(/!#.3/0</+!

!R!'()$%/3!+,0*$%!>(/!bR!)$+!OB;!'#-?)0/+!>#!>(/!1)0%/!%0)+*/$>!*$!!R!

'#-?#3*>*#$3!#=!-#*3>,0/!#</0!3#,>(/0$!C=0*')94!(#@/</04!0,1/3!#,>!)!1)0%/!*$1)$+!3(*=>!

#=!>(/!1#')>*#$!#=!-)A*-,-!0)*$=)115!M$!)++*>*#$4!>(/!#.3/0</+!0/1)>*</!3E$'(0#$*'*>E!

./>@//$!>(/!*3#>#?*'!'()$%/3!*$!>(/!cdUMV!*'/!'#0/!0/'#0+!)$+!>(/!*3#>#?*'!'()$%/3!

#=!>(/!?1)$>!@)A/3!)0%,/!)%)*$3>!)!3,.3>)$>*)1!>0)$3?#0>!+*3>)$'/5!_/!>(/0/=#0/!*$=/0!

>()>!>(/!'()$%/3!*$!!R!'#-?#3*>*#$!#=!>(/!n&6:;!)12)$/!-)*$1E!0/=1/'>!0)*$=)11!*$>/$3*>E!

'()$%/3!*$!>(/!1#@/0!K)-./G*!')>'(-/$>5!!



!!

!

OB;

&;:`

&;H`

&;P`

&;Q`

&;8`

&;W`

&;:`

&;H`

&;P`

&;Q`

&;8`

&;W`

&;:`

&;H`

&;P`

&;Q`

&;8`

&;W`T!\B]^_

T!\B]^_

T!\B]^_

!R!&6 !)12)$/n ::

!R!&6 !)12)$/n :;

!R!&6 !)12)$/n 79

a

b

c

` 7 H Q W ;` ;7 ;H ;Q ;W

C%/!D;4```!E/)03!eVF

bR

!

Supplementary Figure S1: Hydrogen isotope compositions of long-chain plant

waxes.!a4!!R!#=!n&6::!)12)$/5!b4!!R!#=!n&6:;!)12)$/5!c4!!R!#=!n&679!)12)$/5!I00#0!.)03!

.)3/+!#$!0/?1*')>/!)$)1E3/35!d0/E!.)03!*$+*')>/!*$>/0<)13!#=!O/*$0*'(!B>)+*)1!;!DOB;F!

)$+!>(/!b#,$%/0!R0E)3!DbRF5!



!!

!

Vegetation signals in !13C compositions of long-chain n-alkanes

B>).1/!')0.#$!*3#>#?/!'#-?#3*>*#$3!#=!?1)$>!@)A/3!+/?/$+!#$!>(/!>E?/!#=!

?(#>#3E$>(/>*'!')0.#$!=*A)>*#$5!N0//34!3(0,.3!)$+!.,3(/3!,3/!>(/!6:!?)>(@)E4!@(*1/!

%0)33/3!-)E!,>*1*G/!/*>(/0!>(/!6:!#0!>(/!6H!?)>(@)E;`5!C3!>(/3/!')0.#$!=*A)>*#$!

?)>(@)E3!1/)+!>#!+*3>*$'>!')0.#$!*3#>#?*'!3*%$)>,0/34!</%/>)>*#$!3#,0'/3!')$!./!

+*3>*$%,*3(/+5!!;:6!<)1,/3!#=!?1)$>!@)A!n&)12)$/3!=0#-!6:!?1)$>3!)0/!)0#,$+!&:P5`!T!

\VRe4!@(*1/!>(/E!)0/!)0#,$+!&7;5P!T!\VRe!=#0!6H!?1)$>3;;5!R,0*$%!-/)3,0/-/$>!)$!

)12)$/!3>)$+)0+!#=!;7!/A>/0$)11E!')1*.0)>/+!)12)$/3!@)3!-/)3,0/+!/</0E!Q!0,$35!

C</0)%/!).3#1,>/!+/<*)>*#$3!=0#-!2$#@$!!;:6!<)1,/3!@/0/!'#$3*3>/$>1E!S!`5P!T5!C11!

3)-?1/3!@/0/!0,$!)>!1/)3>!*$!+,?1*')>/5!U/?0#+,'*.*1*>E!=#0!>(/!n&679!)$+!>(/!n&6::!

)12)$/!@)3!`5:!T!#$!)</0)%/!)$+!`57!T!#$!)</0)%/!=#0!>(/!n&6:;!)12)$/5!V0/'*3*#$!

)$+!)'',0)'E!#=!>(/!3J,)1)$/!*$>/0$)1!3>)$+)0+!@/0/!`5Q!)$+!`!T4!0/3?/'>*</1E!

D$X::HF5!N(/!)</0)%/!!;:6!<)1,/3!#=!>(/!n&679!D&7W59![!;5:!T!\VReF!)$+!n&6:;!

)12)$/!D&7W5:![!;5P!T!\VReF!)0/!3*-*1)04!@(*1/!>(/!n&6::!)12)$/!*3!-#0/!;:6&/$0*'(/+!

D&7Q5W![!;5W!T!\VReF4!*$+*')>*$%!>()>!*>!'#$>)*$3!)!(*%(/0!0/1)>*</!6H!?1)$>!

'#$>0*.,>*#$!DY*%5!B7F5!C++*>*#$)11E4!<)0*).*1*>E!*$'0/)3/3!=0#-!>(/!n&679!>#!>(/!n&6::!Dn&

679Z!Q5Q!T4!n&6:;Z!85:!T4!n&6::Z!W5;!TF5!C%)*$4!>(*3!*$+*')>/3!>()>!>(/!n&679!)12)$/3!

)0/!+/0*</+!=0#-!-#0/!3>).1/!@##+E!6:!?1)$>!3#,0'/34!@(*1/!>(/!n&6:;!)$+ n&6::!

)12)$/3!'#$>)*$!(*%(/0!'#$>0*.,>*#$3!=0#-!6H!?1)$>3!D>0#?*')1!%0)33/3!)$+!3/+%/3F!)>!

'/0>)*$!>*-/35!M>!()3!.//$!=#,$+!+*==/0/$>!?1)$>!>E?/3!+*==/0!3,.3>)$>*)11E!*$!>(/*0!

(E+0#%/$!*3#>#?/!=0)'>*#$)>*#$;75!!B*$'/!>(/0/!*34!(#@/</04!E/>!1)0%/!,$'/0>)*$>E!).#,>!

)??)0/$>!(E+0#%/$!*3#>#?*'!=0)'>*#$)>*#$!=)'>#03!=#0!>0#?*')1!C=0*')$!?1)$>34!@/!

0/=0)*$/+!=0#-!'#00/'>*$%!>(/!!R!0/'#0+3!=#0!'()$%/3!*$!6:!)$+!6H!?1)$>!'#$>0*.,>*#$35!!



!!

N(/!#.3/0</+!'#00/1)>*#$!#=!+/?1/>/+!!R!<)1,/3!#=!>(/!n&6:;!)$+!n&6::!)12)$/3!@*>(!

-#0/!/$0*'(/+!!;:6!<)1,/34!*$+*')>*$%!(*%(/0!6H!?1)$>!'#$>0*.,>*#$4!*3!,$/A?/'>/+!)3!

6H!%0)33/3!>E?*')11E!#'',0!,$+/0!-#0/!)0*+!'#$+*>*#$3!>()$!6:!?1)$>3;:5!^>(/0!=)'>#03!

=)<#,0*$%!6H!?1)$>3!)0/!1#@/0!)>-#3?(/0*'!6^7!1/</13!)$+!(*%(/0!>/-?/0)>,0/3;:5!

6^7!=#0'*$%!*34!(#@/</04!0,1/+!#,>!)3!)>-#3?(/0*'!6^7!1/</13!+*+!$#>!+/'1*$/!+,0*$%!

>(/!bR;H5!C*0!>/-?/0)>,0/!'()$%/3!-)E!/A/0>!)!'#$>0#1!#$!6:a6H!?1)$>!).,$+)$'/3!*=!

]eN&+/0*</+!)*0!>/-?/0)>,0/!/3>*-)>/3!0/=1/'>!)!'1*-)>*'!3*%$)1!)$+!$#>!3#1/1E!

?0#</$)$'/!'()$%/3!#=!>(/!#0%)$*'!-)>/0*)1!D3//!+*3',33*#$!./1#@F5!61*-)>/&+0*</$!

1#$%&>/0-!</%/>)>*#$!'()$%/3!1*2/1E!#'',00/+!*$!>(/!K)-./G*!')>'(-/$>5!N(/!3>0#$%/0!

'#00/1)>*#$!#=!>(/!!;:6!<)1,/3!#=!>(/!n&)12)$/3!@*>(!>(/*0!!R!<)1,/3!D07!X!`5::!=#0!>(/!

n&6:;!)12)$/F!>()$!@*>(!>(/!)*0!>/-?/0)>,0/!/3>*-)>/3!D07!X!`5;:!=#0!>(/!n&6:;!)12)$/F4!

(#@/</04!?#*$>3!>#!)!'#--#$!(E+0#1#%*'!=#0'*$%5!_/!*$=/0!>()>!6H!?1)$>&+/0*</+!

#0%)$*'!-)>/0*)1!*3!?0/=/0/$>*)11E!+/0*</+!=0#-!>(/!1#@/0!K)-./G*!=1##+?1)*$!,$+/0!@/>!

'#$+*>*#$34!@(*1/!#$1E!6:!?1)$>&+/0*</+!#0%)$*'!-)>/0*)1!*3!/A?#0>/+!=0#-!$/)0&'#)3>)1!

</%/>)>*#$!,$+/0!+0E!'#$+*>*#$35!N(/3/!?0#</$)$'/!'()$%/3!1*2/1E!-)32!)$E!

?#>/$>*)1!1#$%&>/0-!</%/>)>*#$!'()$%/35!!

!



!!

&:7

&:`

&7W

&7Q

&7H

&77

&:7

&:`

&7W

&7Q

&7H

&77

&:7

&:`

&7W

&7Q

&7H

&77

` 7 H Q W ;` ;7 ;H ;Q ;W

C%/!D;4```!E/)03!eVF

T!\VRe

T!\VRe

!;:6!& 6 !)12)$/n ::

!;:6!& 6 !)12)$/n :;

!;:6!& 6 !)12)$/n 79

a

b

c

bR OB;

T!\VRe

Supplementary Figure S2: Stable carbon isotope compositions of long-chain

plant waxes.!a4!!;:6!#=!n&6::!)12)$/5!b4!!;:6!!#=!n&6:;!)12)$/5!c4!!

;:6!!#=!n&679!

)12)$/5!I00#0!.)03!.)3/+!#$!0/?1*')>/!)$)1E3/35!d0/E!.)03!*$+*')>/!*$>/0<)13!#=!

O/*$0*'(!B>)+*)1!;!DOB;F!)$+!>(/!b#,$%/0!R0E)3!DbRF5!



!!

!

Regional significance of ocean temperature reconstructions from GeoB9307-3

C12/$#$/&.)3/+!BBN!/3>*-)>/3!=0#-!d/#e9:`8&:!'#,1+!$#>!./!#.>)*$/+!+,/!>#!1#@!

).,$+)$'/!#=!)12/$#$/3!*$!>(/!3)-?1/35!N(/0/=#0/4!NIfWQ&.)3/+;W!>/-?/0)>,0/!

/3>*-)>/3!@/0/!+/>/0-*$/+5!g$'/0>)*$>E!#=!NIfWQ!-/)3,0/-/$>3!*3!`5`7!.)3/+!#$!

+,?1*')>/!)$)1E3/3!#=!3/1/'>/+!3)-?1/35!N(/!-#3>!0/'/$>!')1*.0)>*#$!#=!NIfWQ!>#!

#'/)$!>/-?/0)>,0/!@)3!,3/+;95!N(/!)$)1E>*')1!,$'/0>)*$>E!)-#,$>3!>#!)$!).3#1,>/!

/00#0!#=!`59h64!3-)11/0!>()$!>(/!')1*.0)>*#$!/00#05!Y#0!'#-?)0*3#$!#=!>(/!NIfWQ&.)3/+!

BBN!0/'#0+!=0#-!d/#e9:`8&:!@/!,3/!>(/!=#0)-*$*=/0)&.)3/+!BBN!/3>*-)>/3!=0#-!

'#0/!]R89&7P8!D7`h7HiB4!:Qh7`iI4!;7Q7!-!@)>/0!+/?>(F!*$!>(/!]#G)-.*J,/!

6()$$/17`4!@(*'(!*3!>(/!#$1E!?,.1*3(/+!3/+*-/$>!'#0/!BBN&0/'#0+!*$!>(/!<*'*$*>E!@*>(!

'#-?)0).1/!>/-?#0)1!0/3#1,>*#$!DY*%5!B:F5!C3!NIfWQ&.)3/+!>/-?/0)>,0/!/3>*-)>/3!

)0/!>(#,%(>!>#!0/=1/'>!-/)$!)$$,)1!3*%$)134!-/)$!)$$,)1!BBN3!=0#-!]R89&7P8!@/0/!

')1',1)>/+!=0#-!@)0-!)$+!'#1+!3/)3#$!/3>*-)>/37`5!e#>(!0/'#0+3!3(#@!3*-*1)0!0)$%/3!

#=!>/-?/0)>,0/!/3>*-)>/3!)$+!?)0)11/1!'()$%/3!#</0!>(/!1)3>!;84```!E/)035!B#-/!

+/<*)>*#$3!/A*3>!#$!3(#0>!>*-/&3')1/34!@(*'(!-*%(>!./!+,/!>#!)%/!-#+/1!,$'/0>)*$>*/35!

C</0)%/!).3#1,>/!>/-?/0)>,0/!+/<*)>*#$!*3!`58h6!./>@//$!0/'#0+34!@*>(*$!')1*.0)>*#$!

/00#03!#=!.#>(!-/>(#+35!N(/!(*%(!BBN!*$!>(/!3#,>(&@/3>!M$+*)$!^'/)$!+,0*$%!>(/!

+/%1)'*)>*#$!+/?*'>/+!.E!>(/3/!0/'#0+3!)0/!=,0>(/0!3,??#0>/+!.E!@)0-!3,0=)'/!#'/)$!

'#$+*>*#$3!*$!>(/!@/3>/0$!>0#?*')1!M$+*)$!^'/)$4!>(/!3#,0'/!)0/)!#=!>(/!]#G)-.*J,/!

6,00/$>7;5!!

N(/!'#(/0/$>!'()$%/3!*$!>(/!>/-?/0)>,0/!0/'#0+3!=0#-!d/#e9:`8&:!)$+!]R89&7P8!

3,%%/3>!>()>!NIfWQ&.)3/+!>/-?/0)>,0/!/3>*-)>/3!)>!3*>/!d/#e9:`8&:!0/=1/'>!BBN5!

N(/!NIfWQ&.)3/+!>/-?/0)>,0/!/3>*-)>/3!3(#@!$#!'#00/1)>*#$!@*>(!'()$%/3!*$!eMN!

*$+/A!D07!X!`5;:F5!N(*3!3,%%/3>3!>()>!NIfWQ&.)3/+!>/-?/0)>,0/!/3>*-)>/3!#=!



!!

d/#e9:`8&:!)0/!$#>!.*)3/+!.E!>(/!(*%(!eMN!<)1,/3!*$!?)0>3!#=!>(/!0/'#0+775!N(*3!

#.3/0<)>*#$!*3!*$!)''#0+)$'/!@*>(!>(/!3,%%/3>*#$!>()>!NIfWQ&.)3/+!>/-?/0)>,0/3!@*11!

./!.*)3/+!.E!1)$+&+/0*</+!%1E'/0#1&+*)12E1&%1E'/0#1&>/>0)/>(/0!'#$>0*.,>*#$3!@(/$!)*0!

>/-?/0)>,0/3!)0/!(*%(!0/1)>*</!>#!#'/)$!>/-?/0)>,0/377!@(*'(!*3!$#>!>(/!')3/!=#0!>(*3!

3/>>*$%5!C++*>*#$)11E4!>(/!#.3/0</+!>/-?/0)>,0/!0)$%/!D7P&79h6F!*$!#,0!0/'#0+!3>0#$%1E!

0/3/-.1/3!>(/!0)$%/!#=!NIfWQ&.)3/+!>/-?/0)>,0/!/3>*-)>/3!#.3/0</+!*$!'#0/!]R9Q&

7`HW!D7Qh;`iB4!:Hh`;iI4!QQ`!-!@)>/0!+/?>(F!#==!>(/!"*-?#?#!3(#@*$%!'#$3*3>/$>1E!

1#@!eMN!*$+*'/37:5!g$1*2/!>(/!)12/$#$/&.)3/+!BBN!/3>*-)>/3!=0#-!]R89&7P87H4!@(*'(!

@/0/!*$=/00/+!>#!./!*$=1,/$'/+!.E!3>0#$%!1)>/0)1!>0)$3?#0>!*$!>(/!]#G)-.*J,/!

6,00/$>7`4!NIfWQ&.)3/+!BBN!/3>*-)>/3!#=!d/#e9:`8&:!)0/!>(#,%(>!>#!0/=1/'>!

'#$+*>*#$3!)>!>(/!'#0/!3*>/!)3!>(*3!1#')>*#$!*3!-#0?(#1#%*')11E!?0#>/'>/+!=0#-!>(/!

]#G)-.*J,/!6,00/$>!+,/!>#!*>3!$/)0!'#)3>)1!3/>>*$%5!!



!!

7P

7Q

78

7W

79

7P

7Q

78

7W

79

` 7 H Q W ;` ;7 ;H ;Q ;W

C%/!D;4```!E/)03!eVF

h6

h6BBN!]R89&7P8

BBN!d/#e9:`8&:b

bR OB;

!

Supplementary Figure S3: Southwest Indian Ocean temperature records. a4!

C$$,)1!BBN!#=!'#0/!]R89&7P8!.)3/+!#$!)</0)%*$%!#=!'#1+&!)$+!@)0-!3/)3#$!

=#0)-*$*=/0)1!BBN!/3>*-)>/37`5!b4!NIfWQ&.)3/+!BBN!/3>*-)>/3!#=!d/#e9:`8&:5!c#>/!

>()>!b&3')1/3!)0/!/J,)1!.,>!#==3/>!=#0!'#-?)0*3#$5!d0/E!.)03!*$+*')>/!*$>/0<)13!#=!

O/*$0*'(!B>)+*)1!;!DOB;F!)$+!>(/!b#,$%/0!R0E)3!DbRF5!

!



!!

!

Air temperature and soil pH reconstructions from GeoB9307-3

c/A>!>#!NIfWQ!)$+!eMN!)$)1E3/3!DeMN!3(#@$!*$!Y*%5!7'4!?0/'*3*#$!#=!eMN!)$)1E3/3!`5`7!

.)3/+!#$!+,?1*')>/!)$)1E3/3!#=!3/1/'>/+!3)-?1/3F!>(/!'E'1*3)>*#$!0)>*#!D6eNF!)$+!>(/!

-/>(E1)>*#$!*$+/A!D]eNF!#=!>(/!.0)$'(/+!>/>0)/>(/03!@/0/!+/>/0-*$/+5!e)3/+!#$!

+,?1*')>/!)$)1E3/3!#=!3/1/'>/+!3)-?1/34!,$'/0>)*$>*/3!#=!6eN!)$+!]eN!)$)1E3/3!)0/!

`5`9!)$+!`5`:4!0/3?/'>*</1E5!\)0*)>*#$3!*$!6eN!)0/!>(#,%(>!>#!0/1)>/!>#!3#*1!?O!

'()$%/3!)$+!<)0*)>*#$3!*$!]eN!>#!-/)$!)$$,)1!)*0!>/-?/0)>,0/!'()$%/3!D]CCNF;P5!

I00#03!#=!)*0!>/-?/0)>,0/!)$+!3#*1!?O!/3>*-)>/3!)-#,$>!>#!`5Wh6!)$+!`57!?O!,$*>34!

.#>(!-,'(!3-)11/0!>()$!')1*.0)>*#$!/00#03;P5!B#*1!?O!/3>*-)>/3!3>0#$%1E!'#&<)0E!@*>(!

'()$%/3!*$!>(/!eMN!*$+/A!DY*%5!BHF5!C3!3#*1!?O!'()$%/3!)0/!-)*$1E!+0*</$!.E!<)0*).1/!

0)*$=)11!)-#,$>3!+,/!>#!3#*1!1/)'(*$%;Q4!>(/!0/'#$3>0,'>/+!3#*1!?O!'()$%/3!?0#<*+/!

3>0#$%!3,??#0>!>#!>(/!*$=/00/+!0)*$=)11!'()$%/3!.)3/+!#$!/1/-/$>)1!+)>)4!eMN!*$+*'/34!

3/+*-/$>)0E!n&)12)$/!'#$'/$>0)>*#$3!)$+!n&)12)$/!*3#>#?*'!'#-?#3*>*#$35!N(/!%1#.)1!

3#*1!')1*.0)>*#$;P4!(#@/</04!0/3,1>3!*$!>##!1#@!)*0!>/-?/0)>,0/!/3>*-)>/3!D;Hh6F!=#0!>(/!

'#0/&>#?!3)-?1/!@(/$!'#-?)0/+!>#!-#+/0$!'1*-)>#1#%*')1!+)>)!Dg$*</03*>E!#=!

R/1)@)0/!+)>)!3/>4!(>>?Zaa'1*-)>/5%/#%5,+/15/+,aj'1*-)>/aF5!N(/!#==3/>!>#!-#+/0$!

]CCN!)-#,$>3!>#!).#,>!;`h65!C!3*-*1)0!#==3/>!*$!]eN&0/'#$3>0,'>/+!]CCN!

/3>*-)>/3!()3!.//$!#.3/0</+!=#0!@)>/0&3)>,0)>/+!3#*13!*$!g%)$+);85!_/!>(/0/=#0/!

3,%%/3>!>()>!>(/!%1#.)1!]eN&]CCN!3#*1!')1*.0)>*#$!-)E!$#>!./!)??1*').1/!>#!>(/!1#@/0!

K)-./G*!')>'(-/$>!1*2/1E!+,/!>#!3?/'*=*'!1#')1!3#*1!'#$+*>*#$3!)$+!'()0)'>/0*3>*'35!M=!

0/1)>*</!'()$%/3!*$!]CCN!/3>*-)>/3!)0/!'#$3*+/0/+4!>(/!0/'#$3>0,'>/+!)*0!

>/-?/0)>,0/3!=#11#@!BBN!/3>*-)>/3!=0#-!d/#e9:`8&:5!_)0-/3>!>/-?/0)>,0/3!)0/!

0/'#$3>0,'>/+!=#0!>(/!bR!@*>(!31*%(>1E!'#1+/0!'#$+*>*#$3!+,0*$%!OB;5!M$!>(/!O#1#'/$/4!

1#@/0!>/-?/0)>,0/3!?/03*3>/+!@*>(!)!3,++/$!+0#?!*$!>/-?/0)>,0/3!./>@//$!94```!)$+!



!!!

!

84```!E/)03!)%#5!N(*3!3,%%/3>3!>()>!)*0!>/-?/0)>,0/3!*$!>(/!1#@/0!K)-./G*!')>'(-/$>!

?0*$'*?)11E!=#11#@!BBN!'()$%/35!B#,0'/!)0/)!'()$%/3!+,/!>#!0/1)>*</!'#$>0*.,>*#$!

'()$%/3!./>@//$!=1##+?1)*$!)$+!'#)3>)1!)0/)34!(#@/</04!-*%(>!*$>/0=/0/5!g$+/0!

@/>>/0!'#$+*>*#$34!@(/$!-#0/!3#*1!#0%)$*'!-)>/0*)1!=0#-!>(/!=1##+?1)*$!*3!/A?#0>/+4!

]CCN!/3>*-)>/3!3(#@!(*%(/0!<)1,/3!>()$!,$+/0!+0*/0!'#$+*>*#$3!@(/$!#$1E!'#)3>)1!

)0/)3!)0/!/A?#0>*$%!3#*1!#0%)$*'!-)>>/0!@*>(!)!'#1+/0!3*%$)>,0/5!V#33*.1E!>(,34!

?0#</$)$'/!'()$%/3!*$!3#*1!#0%)$*'!-)>>/0!#0*%*$!3,?/0*-?#3/!>(/!'1*-)>*'!

>/-?/0)>,0/!/<#1,>*#$!*$!>(/!1#@/0!K)-./G*!')>'(-/$>!0/'#$3>0,'>/+!.E!]eN&]CCN!

/3>*-)>/35!!

!



!!

C%/!D;4```!E/)03!eVF

eMN!*$+/Aa

3#*1!?Ob

]CCNc

bR OB;

` 7 H Q W ;` ;7 ;H ;Q ;W

;`

;7

;H

;Q

;W

7` 85Q

85H

857

8

Q5W

Q5Q

`

`57

`5H

`5Q

`5W

!

Supplementary Figure S4: Tetraether-based proxy records for soil organic

matter contributions, soil pH, and mean annual air temperature (MAAT).!!a4!

0/1)>*</!3#*1!#0%)$*'!-)>>/0!'#$>0*.,>*#$3!.)3/+!#$!eMN!*$+/A7W5!b4!3#*1!?O!/3>*-)>/3!

.)3/+!#$!6eN!0)>*#;P5!c4!]CCN!/3>*-)>/3!.)3/+!#$!>(/!]eN!*$+/A;P5!!B#*1!?O!)$+!

]CCN!/3>*-)>/3!.)3/+!#$!>(/!%1#.)1!3#*1!')1*.0)>*#$;P5!d0/E!.)03!*$+*')>/!*$>/0<)13!#=!

O/*$0*'(!B>)+*)1!;!DOB;F!)$+!>(/!b#,$%/0!R0E)3!DbRF5!!



!!

Table S1: 14C-AMS dates used for the chronology of GeoB9307-3

B)-?1/!6#0/!+/?>(!!

D'-F!

;H6!)%/!

D;H6!E/)03F!

I00#0!

D;H6!E/)03F!

6)1/$+)0!)%/!

0)$%/!D;"F!!

DE/)03F!

kMC!7WHH7! :! 9:`! :`! :9W&HW:!

kMC!7WHH;! 7W!79H P!HP! 7H88&7QQ;!

kMC!7WHH`! PW!HPP P!:P! HP``&HQP;!

kMC!7WH:W! 9W!Q79 `!P`! QP`W&QQP;!

kMC!7WH:8! ;HW! W9;`! PP! 9:9Q&9P`:!

kMC!7WH:Q! ;8W! 98:`! Q`! ;`:WP&;`P:P!

kMC!7WH:P! 7`W! ;``8P! Q`! ;`8Q`&;;`:P!

kMC!7WH:H! 7HW! ;`H8`! Q`! ;;7`Q&;;H`Q!

kMC!7WH:;! 7W:! ;`P8`! Q`! ;;:HW&;;QQ;!

kMC!7WH:`! :::! ;`WH`! Q`! ;;9H;&;7;9H!

kMC!7WH79! :8W! ;`97`! 8`! ;7`8:&;7:P:!

kMC!7WH7W! H;:! ;;77`! 8`! ;7PHP&;7Q8P!

kMC!788PW! HPW! ;;W8`! W`! ;:;:7&;:7W:!

kMC!788P8! H8W! ;7;H`! 9`! ;::77&;:P;:!

kMC!788PP! P`W! ;7QW`! 9`! ;:WPP&;H`97!

kMC!788PH! P::!;:; 7`!;``! ;HPHQ&;P`9;!

kMC!788P:! PPW!;:P :`!;``! ;P;W9&;P9;;!

kMC!788P7! P9:!;H` 7`!;7`! ;QHH:&;QW:`!

kMC!788P;! Q::!;HH P`!;;`! ;QWHQ&;8`9W!

6#$</03*#$!#=!0)+*#')0.#$!)%/3!>#!')1/$+)0!)%/3!@)3!+#$/!,3*$%!>(/!?0#%0)-!6)1*.!Q5`5;7P!

)$+!>(/!])0*$/`9!')1*.0)>*#$!',0</7Q5!C!0/%*#$)1!0/3/0<#*0!)%/!#==3/>!#=!l;H`[7P!E/)03!@)3!

)??1*/+785!C%/3!@/0/!1*$/)01E!*$>/0?#1)>/+!./>@//$!-/)$!?#*$>3!#=!)%/!0)$%/35!!

!



!!

References

;! I%1*$>#$4!d5!)$+!O)-*1>#$4!U5m54!"/)=!/?*',>*',1)0!@)A/35!Science!1564!;:77!D;9Q8F5!7! U#--/032*0'(/$4!Y5!/>!)154!6(/-#>)A#$#-*'!3*%$*=*')$'/!#=!+*3>0*.,>*#$!)$+!3>).1/!

')0.#$!*3#>#?*'!'#-?#3*>*#$!#=!1#$%&'()*$!)12)$/3!)$+!)12)$&;&#13!*$!6&H!%0)33!@)A/35!Organic Geochemistry!37!D;`F4!;:`:!D7``QFn!\#%>34!C54!]##33/$4!O54!U#--/032*0'(/$4!Y54!)$+!U,112o>>/04!m54!R*3>0*.,>*#$!?)>>/0$3!)$+!3>).1/!')0.#$!*3#>#?*'!'#-?#3*>*#$!#=!)12)$/3!)$+!)12)$&;&#13!=0#-!?1)$>!@)A/3!#=!C=0*')$!0)*$!=#0/3>!)$+!3)<)$$)!6&:!3?/'*/35!Organic Geochemistry!40!D;`F4!;`:8!D7``9F5!

:! Y*'2/$4!k5!m54!"*4!e54!B@)*$4!R5!"54!)$+!I%1*$>#$4!d54!C$!$&)12)$/!?0#AE!=#0!>(/!3/+*-/$>)0E!*$?,>!#=!3,.-/0%/+a=1#)>*$%!=0/3(@)>/0!)J,)>*'!-)'0#?(E>/35!OrganicGeochemistry!31!D8&WF4!8HP!D7```Fn!]/)+4!U54!f,4!b5!V54!6(#$%4!m54!)$+!m)==/4!U54!B/+*-/$>!)$+!3#*1!#0%)$*'!-)>>/0!3#,0'/!)33/33-/$>!)3!0/</)1/+!.E!>(/!-#1/',1)0!+*3>0*.,>*#$!)$+!')0.#$!*3#>#?*'!'#-?#3*>*#$!#=!$&)12)$/35!Organic Geochemistry!36!D:F4!:Q:!D7``PFn!\/03>//%(4!d5!m5!]5!/>!)154!N)0)A/0#1!)$+!U(*G#?(#0)!?#11/$!)3!?0#A*/3!=#0!>0)'2*$%!?)3>!-)$%0#</!/'#3E3>/-35!Geochimica et Cosmichimica Acta!68!D:F4!H;;!D7``HF5!

H! U)#4!K5!d5!/>!)154!6#-?#,$+!3?/'*=*'!+/1>)!R!<)1,/3!#=!1#$%!'()*$!$&)12)$/3!+/0*</+!=0#-!>/00/3>0*)1!(*%(/0!?1)$>3!)0/!*$+*')>*</!#=!>(/!+/1>)!R!#=!-/>/#0*'!@)>/03Z!I<*+/$'/!=0#-!3,0=)'/!3#*13!*$!/)3>/0$!6(*$)5!Organic Geochemistry!40!DWF4!977!D7``9Fn!B)'(3/4!R5!4!U)+2/4!m54!)$+!d1/*A$/04!d54!OE+0#%/$!*3#>#?/!0)>*#3!#=!0/'/$>!1)',3>0*$/!3/+*-/$>)0E!n&)12)$/3!0/'#0+!-#+/0$!'1*-)>/!<)0*).*1*>E5!Geochimica et Cosmochimica Acta!684!HW88!D7``HFn!B)'(3/4!R54!U)+2/4!m54!)$+!d1/*A$/04!d54!+R!<)1,/3!#=!*$+*<*+,)1!$&)12)$/3!=0#-!>/00/3>0*)1!?1)$>3!)1#$%!)!'1*-)>*'!%0)+*/$>!&!M-?1*')>*#$3!=#0!>(/!3/+*-/$>)0E!.*#-)02/0!0/'#0+5!Organic Geochemistry!374!HQ9!D7``QFn!N*/0$/E4!m5!I54!U,33/114!m5!]54!)$+!O,)$%4!b5!B54!C!-#1/',1)0!?/03?/'>*</!#$!")>/!p,)>/0$)0E!'1*-)>/!)$+!</%/>)>*#$!'()$%/!*$!>(/!")2/!N)$%)$E*2)!.)3*$4!I)3>!C=0*')5!Quaternary Science Reviews!29!DP&QF4!8W8!D7`;`F5!

P! d)>4!m5!U54!^AE%/$!)$+!(E+0#%/$!*3#>#?/3!*$!>(/!(E+0#1#%*'!'E'1/5!Annual Review of Earth and Planetary Sciences!244!77P!D;99QF5!

Q! B'(0)%4!R5!V5!/>!)154!N(/!#AE%/$!*3#>#?*'!'#-?#3*>*#$!#=!3/)@)>/0!+,0*$%!>(/!")3>!d1)'*)1!])A*-,-5!Quaternary Science Reviews!21!D;&:F4!::;!D7``7F5!

8! d*-/$#4!"5!/>!)154!^$!>(/!#0*%*$!#=!'#$>*$/$>)1!?0/'*?*>)>*#$5!Geophysical Research Letters!374!";:W`H!D7`;`F5!

W! U*3*4!654!e#$E4!B54!)$+!\*-/,A4!Y54!M$=1,/$'/!#=!'#$</'>*</!?0#'/33/3!#$!>(/!*3#>#?*'!'#-?#3*>*#$!D+/1>)D;WF^!)$+!+/1>)!RF!#=!?0/'*?*>)>*#$!)$+!@)>/0!<)?#0!*$!>(/!>0#?*'3Z!75!V(E3*')1!*$>/0?0/>)>*#$!#=!>(/!)-#,$>!/==/'>5!J. Geophys. Res.-Atmos.!113!DR;9F!D7``WFn!U*3*4!65!/>!)154!_()>!'#$>0#13!>(/!*3#>#?*'!'#-?#3*>*#$!#=!>(/!C=0*')$!-#$3##$!?0/'*?*>)>*#$q!M$3*%(>3!=0#-!/</$>&.)3/+!?0/'*?*>)>*#$!'#11/'>/+!+,0*$%!>(/!7``Q!C]]C!=*/1+!')-?)*%$5!Geophys. Res. Lett.!35!D7HF!D7``WF5!

9! Y0)$2/$./0%4!65!/>!)154!RE$)-*'!V0#'/33/3!d#</0$*$%!"#@/0&N0#?#3?(/0*'!OR^aOD7F^!U)>*#3!)3!^.3/0</+!=0#-!B?)'/!)$+!d0#,$+5!Science!325!DP9HQF4!;:8H!D7``9F5!

;`! I(1/0*$%/04!m5U5!)$+!6/01*$%4!N5I54!*$!Encyclopedia of Global Environmental Change4!/+*>/+!.E!N5!],$$!Dm#($!_*1/E!r!B#$34!">+4!6(*'(/3>/04!7``7F4!\#15!74!??5!;WQ5!

;;! 6)3>)$/+)4!M5!B5!/>!)154!_/>!?()3/3!*$!>(/!B)()0)aB)(/1!0/%*#$!)$+!(,-)$!-*%0)>*#$!?)>>/0$3!*$!c#0>(!C=0*')5!Proceedings of the National Academy of Sciences!106!DHWF4!7`;P9!D7``9F5!

;7! O#,4!m5!K54!RsC$+0/)4!_5!m54!])'R#$)1+4!R54!)$+!O,)$%4!b5!B54!OE+0#%/$!*3#>#?*'!<)0*).*1*>E!*$!1/)=!@)A/3!)-#$%!>/00/3>0*)1!)$+!)J,)>*'!?1)$>3!)0#,$+!e1##+!V#$+4!])33)'(,3/>>3!DgBCF5!Organic Geochemistry!38!DQF4!988!D7``8F5!



!!!

!

;:! 6#11)>G4!d5m54!e/00E4!m5C54!)$+!61)024!m5B54!I==/'>3!#=!'1*-)>/!)$+!)>-#3?(/0*'!6^7!?)0>*)1!?0/33,0/!#$!>(/!%1#.)1!+*3>0*.,>*#$!#=!6H!%0)33/3Z!?0/3/$>4!?)3>!)$+!=,>,0/5!Oecologia!1144!HH;!D;99WF5!

;H! e1,$*/04!N5!/>!)154!N*-*$%!#=!>(/!C$>)0'>*'!'#1+!0/</03)1!)$+!>(/!)>-#3?(/0*'!6^7!*$'0/)3/!@*>(!0/3?/'>!>#!>(/!b#,$%/0!R0E)3!/</$>5!Geophysical Research Letters!24!D7;F4!7QW:!D;998F5!

;P! _/*t/034!m5!_5!O5!/>!)154!I$<*0#$-/$>)1!'#$>0#13!#$!.)'>/0*)1!>/>0)/>(/0!-/-.0)$/!1*?*+!+*3>0*.,>*#$!*$!3#*135!Geochimica et Cosmochimica Acta!71!D:F4!8`:!D7``8F5!

;Q! m#($3#$4!R5!_5!/>!)154!V0/'*?*>)>*#$!'()$%/!)$+!3#*1!1/)'(*$%Z!Y*/1+!0/3,1>3!)$+!3*-,1)>*#$3!=0#-!_)12/0!e0)$'(!_)>/03(/+4!N/$$/33//5!Water, Air, & Soil Pollution!105!D;&7F4!7P;!D;99WF5!

;8! "##-*34!B5I54!U,33/114!m5!]54!)$+!B*$$*$%(/!R)-3>u4!m5!B54!R*3>0*.,>*#$3!#=!.0)$'(/+!dRdN3!*$!3#*13!)$+!1)2/!3/+*-/$>3!=0#-!@/3>/0$!g%)$+)Z!M-?1*')>*#$3!=#0!)!1)',3>0*$/!?)1/#>(/0-#-/>/05!Organic Geochemistry!424!8:9!D7`;;F5!

;W! B'(#,>/$4!B54!O#?-)$34!I5654!B'(/=,v4!I54!)$+!B*$$*$%(/!R)-3>u4!m5B54!R*3>0*.,>*#$)1!<)0*)>*#$3!*$!-)0*$/!'0/$)0'(/#>)1!-/-.0)$/!1*?*+3Z!)!$/@!>##1!=#0!0/'#$3>0,'>*$%!)$'*/$>!3/)!@)>/0!>/-?/0)>,0/3q!Earth and Planetary Science Letters!2044!7QP!D7``7F5!

;9! k*-4!m5!O5!/>!)154!c/@!*$+*'/3!)$+!')1*.0)>*#$3!+/0*</+!=0#-!>(/!+*3>0*.,>*#$!#=!'0/$)0'()/)1!*3#?0/$#*+!>/>0)/>(/0!1*?*+3Z!M-?1*')>*#$3!=#0!?)3>!3/)!3,0=)'/!>/-?/0)>,0/!0/'#$3>0,'>*#$35!Geochimica et Cosmichimica Acta!74!D;QF4!HQ:9!D7`;`F5!

7`! "/<*4!65!/>!)154!"#@&1)>*>,+/!(E+0#1#%*')1!'E'1/!)$+!0)?*+!'1*-)>/!'()$%/3!+,0*$%!>(/!1)3>!+/%1)'*)>*#$5!Geochemistry Geophysics Geosystems!84!+#*Z;`5;`79a7``Qd6``;P;H!D7``8F5!

7;! k*/=/04!N54!]'6)</4!M5!c54!)$+!I1+/0=*/1+4!O54!C$>)0'>*'!'#$>0#1!#$!>0#?*')1!M$+*)$!^'/)$!3/)!3,0=)'/!>/-?/0)>,0/!)$+!(E+0#%0)?(E5!Geophysical Research Letters!33!D7HF!D7``QF5!

77! _/*t/034!m5_5O54!B'(#,>/$4!B54!B?))0%)0/$4!^5654!)$+!B*$$*$%(/!R)-3>/4!m5B54!^'',00/$'/!)$+!+*3>0*.,>*#$!#=!>/>0)/>(/0!-/-.0)$/!1*?*+3!*$!3#*13Z!M-?1*')>*#$3!=#0!>(/!,3/!#=!>(/!NIfWQ!?0#AE!)$+!>(/!eMN!*$+/A5!Organic Geochemistry!374!;QW`!D7``QF5!

7:! 6)1/E4!N5!/>!)154!O*%(&1)>*>,+/!#.1*J,*>E!=#0'*$%!+0*</3!>(/!C%,1()3!1/)2)%/5!Climate of the Past Discussions!74!7;9:!D7`;;F5!

7H! e)0+4!I5!4!U#3>/254!Y54!)$+!B#$G#%$*4!654!M$>/0(/-*3?(/0*'!3E$'(0#$E!#=!>(/!1)3>!+/%1)'*)>*#$!*$=/00/+!=0#-!)12/$#$/!?)1/#>(/0-#-/>0E5!Nature!3854!8`8!D;998F5!

7P! B>,*</04!]5!)$+!U/*-/04!V5m54!IA>/$+/+!;H6!+)>)!.)3/!)$+!0/<*3/+!6C"Me!:5`!;H6!)%/!')1*.0)>*#$!?0#%0)-5!Radiocarbon!354!7;P!D;99:F5!

7Q! U/*-/04!V5!m5!/>!)154!M$>6)1`9!)$+!])0*$/`9!U)+*#')0.#$!C%/!6)1*.0)>*#$!6,0</34!`&P`4```!b/)03!')1!eV5!Radiocarbon!51!DHF4!;;;;!D7``9F5!

78! B#,>(#$4!m5!/>!)154!])0*$/!0/3/0<#*0!'#00/'>*#$3!=#0!>(/!M$+*)$!^'/)$!)$+!3#,>(/)3>!C3*)5!Radiocarbon!44!D;F4!;Q8!D7``7F5!

7W! O#?-)$34!I5654!B'(/=,v4!I54!B*$$*$%(/!R)-3>u4!m5B54!)$+!B'(#,>/$4!B54!C!$#</1!?0#AE!=#0!>/00/3>0*)1!')0.#$!*$?,>!.)3/+!#$!.0)$'(/+!)$+!*3#?0/$#*+!>/>0)/>(/035!Earthand Planetary Science Letters!2244!;`8!D7``HF5!

!

!



letter - uni-bremen.de6,000–4,000 years before present (yr bp; ref. 9), implying that non-...

Documents