A chironomid
A chironomid - - based temperature reconstruction for the Younger Dryas based temperature reconstruction for the Younger Dryas - - Holocene transition from a palaeo
Holocene transition from a palaeo - - channel of the Niers channel of the Niers - - Rhine, Germany Rhine, Germany
S. Kuiper 1,2 , E.I. Lammertsma 2 , O. Heiri 1 , W.Z. Hoek 2 , C. Kasse 3
1
Laboratory of Palaeobotany and Palynology, Institute of Environmental Biology, Utrecht University, The Netherlands;
2Department of Physical Geography, Utrecht University, The Netherlands;
3Department of Palaeoclimatology and Geomorphology, Vrije Universiteit Amsterdam, The Netherlands
Contact: [email protected]; [email protected]
Research outline Conclusion
A multi-proxy analysis of a calcareous gyttja from a palaeo-channel resulted in a reconstruction of
temperature and local environmental conditions at the end of the last ice age (~12,000 to 10,500 cal yr BP).
Both aquatic and terrestrial proxies indicate a rapid ecosystem response to warming at the Younger
Dryas–Holocene transition in the Niers-Rhine valley.
Chironomids indicate a ~3˚C increase in mean July air temperature at this boundary.
1. Research area
Weeze Goch
Uedem
Kevelaer
Geldern
Kapellen
Issum Rhine Valley Kendel
Niers
Fleuth
NN
Palaeo
Palaeo channelschannels Floodplain
Floodplain Meander level Meander level
‘‘TransitionTransition’’levellevel Braided
Braidedlevellevel Older
OlderRhineRhineterraceterrace Pushed
Pushedridgeridge/ Sandr/ Sandr
Legend Legend
City City
Village Village Niers Niers
DuneDune
ss Pollen and Pollen and 1414C siteC site This study
This study
27 26 25 24 23
50 m 22
0
Legend Legend
water water topsoil topsoil peat peat
calcareous gyttja calcareous gyttja fine sand
fine sand gravelly gravellysandsand older older terrace terrace detrital gyttja detrital gyttja
Sample core
m + NN
2. Methods 3. Local
developments
4. Regional framework
A sediment core (a) from one of the palaeo-
channels was analysed for chironomids (=non-biting midges) (b), pollen (c), stable isotopes (d) and
lithological parameters (e).
All proxies were measured on the same
sediment core to avoid problems previously encountered with correlating multiple,
independently dated records.
b. c. d. e. a.
60
80
100
120
140
160
180
200
Depth (cm)
0 30
Mite
0 90
Percentage (%) Statoblast Plumatella-type
0 10
Sialis mandible
0 50
Ephemeroptera mand.
0 10
Trichoptera mandible
0 10
Simuliidae hypostoma
60
80
100
120
140
160
180
200
Depth (cm)
0 20
Ablabesmyia
0 10
Dicrotendipes notatus-type
0 20
Cricotopus cylindraceus-type
0 20
Tanytarsus mendax-type
0 10
Paratanytarsus penicillatus-type
0 20
Percentage (%) Parakiefferiella
0 40
Zalutschia type B
0 40
Microtendipes
0 10
Phaenopsectra flavipes-type
0 10
Pagastiella
0 40
Tribelos-type
Invertebrates
Chironomids
Local vegetation
A clear shift in aquatic flora and fauna occurs at 137 cm sediment depth, indicating a sudden change in the local environment.
Early Holocene
Younger Dryas
˚
In comparison with regional pollen, the
transition in local flora and fauna reflects the Younger Dryas–Holocene boundary.
Channel infills of the Niers-Rhine fluvial system (abruptly abandoned in the Early Holocene) provide well-preserved records of Lateglacial/Early Holocene climate and environmental changes.
60
80
100
120
140
160
180
200
Depth (cm)
0 100
Characeae
0 40
Botryococcus
0 90
Percentage (%) Pediastrum
0 30
Potamogeton
0 20
Myriophyllum spic.
0 20
Myriophyllum vert.
0 10
Nuphar
0 80
Nymphaea
0 10
Sparganium -type
0 10
Typha latifolia
