EVENTS

OA

E1a

114.44 Ma

“Wei

sser

t Eve

nt”

(coo

l epi

sode

)H

ALI

P vo

lcan

ism

on

Sval

bard

Global Sval

bard

137 Ma

132.29 Ma

129.32 Ma

125.08 Ma

122.16 Ma

117.83 Ma

431 m

459 m

535 m

570.7 m

678 m

741.5 m

18.73 m/Ma

24.78 m/Ma

12.22 m/Ma

17.92 m/Ma

9.65 m/Ma

Sedimentation rate

First glendonites(6.32 myr after onset OAE1a)

655m

Late

Apt

ian

- Ear

ly A

lbia

n c

old

epis

ode

cl si f m c vc gr

800

780

760

740

720

700

680

660

640

620

600

580

560

540

520

500

480

460

440

420

400

380

360

340

320

300

280

260

240

220

200

180

160

140

120

100

80

60

40

20

0

FF

F DEF

ORM

ED

F

X

XX

SAN

DY

MU

DD

Y

F

RU

RIK

FJEL

LET

FO

RM

ATI

ON

HEL

VETI

A- F

JELL

ET

Festningen Mbr

Kiku- todden

Mbr

CA

ROLI

NEF

JELL

ET F

ORM

ATI

ON

Innkjegla Member

DalkjeglaMember

Wim

an�e

llet M

embe

r

Glitre- �ellet

Mbr

Berriasian-Valanginian

Vala

ngin

ian

Barremian

EarlyAptian

Barremian

Age model (this study)

Previous age modelLithostratigraphy

Late Aptian

Vala

ngin

ian

- Hau

teriv

ian

Hauterivian - Barremian

Barremian

Aptian

Mycklegard�ellet bed Berriasian-Valanginian

Hauterivian

Aptian - early Albian

ginko and horsetail leaves

Tu� date123.3Ma(Corfu et al. 2013)

Hei

ght

(m)

Lithology

Jurassic Jurassic

met

res

(m)

Albian?

Fieldwork was carried out in August 2014 and July 2015 at the the Festningen locality, Spitsbergen, Svalbard (78°09.98’N, 13°94.32’E). Macro-plant material was sampled wherever it occurred in the 780 m succession. Bulk rock samples were collected at a resolution of 1 sample every 0.5 m for the entire 780 m succession. Conventional sedimentary logging was carried out at scale of 1 m = 2cm.Woody material was characterised by light microscopy and SEM surface studies using a Jeol JSM 6610LV SEM at Plymouth University. A representative number of bulk rock samples were analysed for TOC at Plymouth University using a Skalar Primacs SLC Analyzer.500 bulk rock samples were selected for δ13C analysis, and 139 samples of woody material selected for δ13C analysis. Samples were ground to a �ne powder using an agate mortar and pestle. Powdered samples were decarbonated by placing the sample in a 50 ml polypropylene centrifuge tube and treating with 10 % HCl for 1 hour until all the carbonate had reacted. Samples were then rinsed with deionized water, centrifuged and rinsed again until neutrality was reached (following the method of Gröcke et al., 1999).

(Analysis performed on a Jeol JSM 6610LV SEM at Plymouth University)

0 2 4 6

TOC (wt %)

0 2 4 6

0

100

200

300

400

500

600

700

800

900

0 50 100 150 200 250

Hydr

ogen

Inde

x (m

gH C

/g o

rg. C

)

Oxygen Index (mg CO2/g org. C)

Bulk organic matter: derived from high plant material(type III kerogen)

Woody material: discrete fragments of coal, charcoal and wood

500μm100μm

500μm

100μm

500μm

100μm

Rock Eval hydrogen and oxygen indices displayed on a Van Krevelen diagram. The pilot samples all clearly fall within type III kerogen. Analysis courtesy of L. Percival, University of Oxford.

Charcoal

Wood

Coal

δ13C of woody material showing the di�erent preservational states of the wood samples.

The isotope data show an overlapping range of values and no appreciable di�erence between each preservation state. Hence the range of preservation observed is unlikely to have an impact on the overall long-term trends of the δ13Cwood curve. This has been previously shown by Gröcke et al. (2002) and Hesselbo et al. (2000).

490.00

540.00

590.00

640.00

690.00

-27.00 -26.00 -25.00 -24.00 -23.00 -22.00 -21.00

all

coal/wood

charcoal-coal

charcoal

homogeneous

-28 -27 -26 -25 -24 -23 -22 -21 -20

wood and bulkwoodbulk

δ13Cterrestrial(‰)(This study)

δ13Cwood (‰)

-29 -28 -27 -26 -25 -24 -23 -22 -21 -20

115

120

125

130

135

140

145

139.4

145.0Jurassic

Apt

ian

Barr

emia

nH

aute

r-iv

ian

Vala

ngin

ian

113.0

126.3

130.8

133.9

Berr

iasi

an

1 2 3 4 5

Composite age-calibrated δ13Ccarb.(‰) (Herrle et al., 2015)

Composite δ13Ccarbonate curve and timescale of Herrle et al. (2015) and Gradstein et al. (2012). Timing of HALIP volcanism on Svalbard from Nejbert et al. (2011).

STRATIGRAPHY AND PALAEOCLIMATE OF SPITSBERGEN, SVALBARD, DURING THE EARLY CRETACEOUS Madeleine L. Vickers1,*, Gregory D. Price1, Meriel E. FitzPatrick1, Matthew Watkinson1, Rhodri M. Jerrett2

1School of Geography, Earth & Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, U.K.2 School of Atmospheric, Earth and Environmental Sciences, University of Manchester, M13 9PL, U.K.

* Corresponding author email: madeleine.vickers@plymouth.ac.uk

60°N

30°N

0°

30°S

60°S

Cathodo-luminescence image: dark areas are iron-rich.

SEM element mapping: P and Fe in di�erent zones.

-13.00

-18.00

-17.00

-16.00

-15.00

-14.00

1 2 3 4 5 6position in sample

FST411b

FST411.2

FST411.5b

FST411.6

FST708.5

δ13C

glen

doni

te (

‰)

1

23

4 56

Anti-correlation of phosphorus and iron in glendonites is consistent with a high phosphate requirement for ikaite growth. Carbon isotope values are consistent with carbon derivation from an organic matter source, with some mixing of carbon from a carbonate source. Carbon isotopic values for transects accross zoned glendonite crystals (e.g. seephotograph of thin section, above), from position one (centre) to 5 or 6 (outer edge).

Thin section of glendonite from 441 m. Pink box outlines section further analysed under CLand SEM. Yellow circles indicate how transects are taken accross zoned crystals.

1. INTRODUCTION 2. METHODS

4. THE FESTNINGEN SECTION: RECORDS OF GLOBAL CARBON CYCLE AND CLIMATE CHANGE

6. CONCLUSIONS

5. GLENDONITES: organic-rich zoned calcite nodules; pseudomorphs after ikaite (CaCO3.6H2O). Ikaite can only grow at temperatures between 0-8°C under high alkalinity, high phosphate conditions.

3. CHARACTERISATION OF ORGANIC MATERIAL

REFERENCES ACKNOWLEDGEMENTS

Palaeogeographic reconstruction of the Early Cretaceous globe (Blakey, 2011). Spitsbergen shown in red.

I would like to thank Lawrence Percival for running Rock Eval analysis of the wood samples, and Marc Davies for his help with the carbon isotope analysis. I would like to thank Ivar Midtkandal for his help and advice with interpreting the data.

Dramatic changes in global climate occurred during the Early Cretaceous, a period traditionally believed to be invariantly “greenhouse”. Here, we examine evidence from palaeo-high latitude Svalbard, and show that large global changes in the carbon cycle are preserved in the terrestrial carbon isotopic record from Early Cretaceous sediments. These carbon isotope excursions are linked to global climatic events, and we examine other climate/temperature proxies from the Early Cretaceous succession at the Festningen locality. Furthermore, we improve age constraints on the succession using carbon isotope stratigraphy.

The Valanginian “Weissert” Event and Early Aptian carbon isotope excursion (CIE) are recorded in the terrestrial carbon isotope record at Festningen. Glendonites,thought be indicators of cold water, are found just above the positive excursionwhich characterises the Weissert Event, and 120 m above the Early Aptian CIE.

Our carbon isotope curve allows us to constrain the Valanginian - Hauterivian, Barremian - Aptian and Early Aptian - Late Aptian boundaries more precisley. However, the only known U-Pb date from a tu� in the Helvetia�ellet Formation (Corfu et al., 2013) is inconsistent with the Gradstein et al. (2012) timescale for the Early Aptian OAE CIE.

The Valanginian “Weissert” Event is thought to be associated with a global cooling episode; the Early Aptian CIE with an ocean anoxic event (OAE1a) and extreme global warmth; and the Late Aptian - Early Albian with a global cooling event. Glendonites appear in the succession at the end of the “Weissert event” and at the beginning of the Late Aptian cooling episode. This suggests that Spitsbergen experienced cooling slightly out of phase with the “whole Earth”, consistent with observations today that the high latitudes are experiencing more rapid climate change than the equatorial regions.

Outline of Spitsbergen, with Festningen denoted by a star. The Mesozoic Adventdalen Group is marked on, the dark grey representing the Janus�ellet Formation (Upper Jurassic - Lower Cretaceous) and the light grey representing the overlying Helvetia�ellet and Caroline�ellet formations (Lower Cretaceous) (after Dallmann et al., 2002).

Dallmann, W.K., Ohta, Y., Elvevold, S. and Blomeier, D., 2002. Bedrock map of Svalbard and Jan Mayen 1:750,000, with insert maps 1:250,000. . Norwegian Polar Institute.Blakey, R., 2011. Early Cretaceous Mollewide Plate Tectonic Map. Colerado Plateau Geosystems, inc., pp.

Gröcke, D.R., Hesselbo, S.P. and Jenkyns, H.C., 1999. Carbon-isotope composition of Lower Cretaceous fossil wood: Ocean-atmosphere chemistry and relation to sea-level change. Geology, 27: 155-158.

Gradstein, F.M., Ogg, J.G., Schmitz, M., and Ogg,G., 2012, A Geologic Time Scale 2012: Amsterdam, Elsevier, 1144 p.

Herrle, J.O., Schröder-Adams, C.J., Davis, W., Pugh, A.T., Galloway, J.M. and Fath, J., 2015. Mid-Cretaceous High Arctic stratigraphy, climate, and oceanic anoxic events. Geology, 43: 403-406.

Gröcke, D.R., 2002. The carbon isotope composition of ancient CO2 based on higher-plant organic matter. Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 360: 633-658.

Hesselbo, S.P., Gröcke, D.R., Jenkyns, H.C., Bjerrum, C.J., Farrimond, P.L., Morgans-Bell, H.S., Green, O.R., 2000. Massive dissociation of gas hydrate during a Jurassic oceanic anoxic event, Nature, 406: 392-395.Nejbert, K., Krajewski, K.P., Dubińska, E. and Pécskay, Z., 2011. Dolerites of Svalbard, north-west Barents Sea Shelf: age, tectonic setting and signi�cance for geotectonic interpretation of the High-Arctic Large Igneous Province. Polar Research, 30: 1-24.

KEY

carbonate concretion

outsized clastglendonite horizon plant material

woodbelemnite

bivalve

asymmetrical ripples

dinosaur footprinthummocky cross-stratification (HCS)

rootshorizontal stratification

trough cross-stratification

bioturbation