Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record

A.Moreno (1,2), H. Stoll (3), I. Cacho (4), Montserrat Jiménez-Sánchez (3), Carlos Sancho (5), Ánchel Belmonte (5), R. L.

Edwards (1), E. Ito (1), B. L. Valero-Garcés (2)

(1) Limnological Research Center, University of Minnesota, 310 Pillsbury Drive SE, Minneapolis, MN 55455 (USA)

(2) Pyrenean Institute of Ecology - CSIC, Apdo. 202, 50080 Zaragoza, (Spain), (3) Departamento de Geologia, Universidad de Oviedo, C/ Arias de Velasco, s/n 33005 Oviedo (Spain), (4) University of Barcelona, C/ Marti i Franquès s/nº, 28080 Barcelona (Spain), (5) Departamento de Ciencias de la Tierra, Facultad de Ciencias. Universidad de Zaragoza (Spain),

Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record

http://www.unizar.es/

Outline

Speleothems as exceptional paleoclimate archives

Orbital scale

Last deglaciation main trends

Early Holocene abrupt changes

Study sites in the north of the Iberian Peninsula

Main questions

Conclusions

A. Moreno (IPE-CSIC) Speleothem records from the northern Iberian Peninsula

Some preliminary results…



Advantages

- Absolute dating by using the U-Th desintegration series (0-500 kyrs)- High precipitation rate (banding) –abrupt/rapid climate changes- Good records of temperature and precipitation (stable isotopes, trace metals, growth rates…)

Disadvantages

- Only in karstic systems- System monitoring is required (lot of time and money….) - Presence of hiatus in dry or cold climates

Fairchild et al., 2006





2 initial assumptions:- Closed system to U and Th- Initial 230Th = 0 (“pure” samples, with low detrital)

Some sources of errors:- Low U content (depends on the type of limestone)- High 232Th (high 230Th initial)- Post-precipitation effects

18O

Diagenetic processes (evaluated by petrography to discard re-crystallization)

Non-equilibrium fractionation (evaluated by 13C vs 18O correlation, replication or Hendy test)

18O of rainfall

Cave Tª (seasonally stable, long-term variations can modulate the signal)

Other fractionation (eg. evaporation of water in the soil or vadose zone)

Air temperature variations

Variability in the precipitation sources

Amount of precipitation

0.34‰/ºC

NAO; glacial vs interglacial

13C13C values of the carbonate bedrock (fixed values)

13C values of the soil CO2

Soil processes and residence time

Type of vegetation overlying the cave (C3 vs C4)


Mg/Ca, Sr/Ca, Ba/Ca

Vegetation cover overlying the cave

Marine aerosols – distance to the coast

Prior calcite precipitation (link to dry/wet climates)



Study sites in the north of the Iberian Peninsula

Cueva de las Güixas

Cueva 5 de Agosto

Sima de Estebán Felipe

Cueva de Molinos

Zonas calcáreas

CAVECAL-CICYT: Cambios climáticos rápidos en la Península Ibérica basados en calibración de indicadores, series instrumentales largas y análisis de alta resolución de registros en espeleotemas.DGA-LaCaixa: Formaciones de espeleotemas en Aragón: una innovadora aproximación a la reconstrucción del clima de los últimos milenios.

El Pindal and Calabrez caves

PathwayOld fluvial channel

EL PINDAL

Old alluvial deposits

Block accumulations

Mud depositsFlowstone

Complex

SpeleothemsFluviokarstic and gravity features

Gours

Dripstone

Jiménez-Sánchez et al., 2002

non-dolomitic limestones of the Carboniferous Barcaliente Formation


R2 = 0.85

- +

5 de Agosto


First stalagmites dated from the Spanish Pyrenees.

High altitude cave (1664 m) Monitoring in progress

(temperature, rainfall, dripwaters)


Main questions

1) Temporal and spatial reconstruction of main abrupt changes in the Northern Iberian Peninsula during the Pleistocene and Holocene

2) Interpretation of main mechanisms of abrupt climate change in the past, including phenomena affecting the most recent millennia (NAO, solar variability…)

3) Response of terrestrial ecosystems (hydrology, vegetation) to abrupt climate changes at different timescales (orbital, millennial, decadal)


At an orbital-scale

Espeleothems from 5 de Agosto Cave (Central Pyrenees) only growth during short periods associated to interglacials: OIS 1, OIS 7, OIS 9, OIS 11. Surprisingly, there is no sample (after dating 16 stalagmites) growing during OIS 5


18O 13C MAX MIN MAX MIN 5Agosto -1 Estadio 11 -5,62 -6,79 1,70 -1,3 5 Agosto-10 Holoceno -5,74 -6,92 -1,41 -4,5 5 Agosto-14 Estadio 7 -5,9 -6,93 4,13 1,55

Isotopes18O values very similar in the three interglacials; 13C has higher variability (particularly, OIS 7)

Identify the growth periods as the warmer and wetter intervals Compare duration and characteristics of the last interglacials Look for an “analogous” for the Holocene (OIS 5??, OIS 11?)

At an orbital-scale

During last deglaciation

CANDELA

CAN sample covers from 25 to 8 kyrs ago with an interruption during the Mystery Interval (Denton, 2005), a particular time period characterized by an increase in sea level but colder temperatures in Greenland and North Atlantic than during the LGM.

We would expect a very cold, and probably dry, scenario for southern Europe.


H1YD IAC

P

ODPB LGM HE2

10.39.28.27.4

7000 9000 11000 13000 15000 17000 19000 21000 23000 25000

-48

-44

-40

-36

7000 9000 11000 13000 15000 17000 19000 21000 23000 25000

0

-2

-4

-6

-8

-10

-12

-2

-3

-4

-5

-613C

(‰

)

18O

(‰

)18

O (

‰)

NG

RIP

(G

CC

05)

(Ra

ssm

uss

en

et

al.

QS

R 2

00

8)Age (years BP)

CANDELAMARIA

HIATUS

HIATUS

Mystery interval

GI-1 HOLOCENE GS-1 GS-2bGS-2aGi-2 GS-2C

DrierNAO +

WetterNAO -




H1YD IAC

P

ODPB LGM HE2

18O

(‰

) N

GR

IP (

GC

C05

)(R

ass

mu

sse

n e

t a

l. Q

SR

20

08

)

MARIA

GI-1 HOLOCENE GS-1 GS-2bGS-2aGi-2 GS-2C

13C

(‰

)

7000 9000 11000 13000 15000 17000 19000 21000 23000 25000

-48

-44

-40

-36

7000 9000 11000 13000 15000 17000 19000 21000 23000 25000

0.006

0.005

0.004

0.003

0.002

0.001

0

-2

-4

-6

-8

-10

-12

10.39.28.27.4

Ba/

Ca

CANDELA

Wetter

Drier


7.4 8.3 9.4 10.2 11.2

7000 7500 8000 8500 9000 9500 10000 10500 11000 11500 12000

-4

-6

-8

-10

-12

-3

-3.5

-4

-4.5

-5

-5.5

-8

-4

0

4

8

7000 7500 8000 8500 9000 9500 10000 10500 11000 11500 12000

13C

(‰

)

18O

(‰

)H

SG

(de

tren

ded)

Bond et al., 2001


During the Early Holocene

COLD

WARM

WET

DRY


109.99.2

10.3

9.4 9.6

18O

(‰

)

18O

(‰

)

MARÍA(this study)

18O

(‰

)

18O

(‰

)Dongge Cave(Dykoski et al., 2005)

NGRIP

Dongshiya Cave(Cai et al., 2008)

PB10.910.4109.39.1

8800 9200 9600 10000 10400 10800 11200 11600 12000

-3

-3.5

-4

-4.5

-5

-5.5

-7

-7.5

-8

-8.5

-9

-9.5

-9

-10

-11

-12

-40

-38

-36

-34

During the Early Holocene


Conclusions

Speleothem records from Northern Spain are excellent paleoclimate records of past hydrological variability that need to be studied with further detail

Growing periods in the Central Pyrenees are related to some interglacials pointing to the most humid and the warmest intervals for the last 400 kyrs.

The driest period for the last 25 kyrs is the “mystery interval” as indicated by the hiatus

Paleohydrological and vegetational response to the abrupt changes during deglaciation (HE1, B/A, oldest and older Dryas, IACP) and Early Holocene abrupt changes

NAO-type mechanism behind abrupt climate changes recorded in the Iberian Peninsula?

Documents

Paleoclimate reconstruction from northern Iberian Peninsula: the speleothem record