Coal - the Ice Core of the Warm Past: Using the Palaeogene Coal Archive on Svalbard to Reconstruct High Resolution Paleoclimate from a Warm Arctic
Abstract
Palaeocene coal seams from the Firkanten Fm, Svalbard, Arctic Norway provide a globally important record of environmental change and atmospheric conditions in a terrestrial setting in the high Arctic during greenhouse conditions. The Firkanten Formation comprises continental to shallow marine sandstones, shale and coal deposited in an early foreland basin with alternating sea level at c 78 degrees north. For each sea level cycle a thick coal seam developed with maximum thicknesses ranging between 1 to 5 m and lateral distributions in the order of tens of km. Continuous peat growth at this scale relies on a fine balance between precipitation and sea level.
Peat (coal) represents a relatively undisturbed environment from which geochemical signatures of climate change can be extracted. High resolution inorganic geochemical data from coal seams are known to record circulation patterns, dust deposition rates, (atmospheric nutrient supply), wildfires, provenance and its response to changing climate (Marshall et al., 2016). Marshall (2013) interpret the 1,4 m thick Longyear seam as representing continuous deposition for 90 000 - 100 000 years. The up to 5 m thick Svea seam may represent up to 400.000-500.000 years. Such time frames make palaeoclimate records from coal seams comparable to e.g. ice cores and deep marine records, with the added benefit that palaeoclimate data from palaeowetlands, record changes in a terrestrial environment comparable to where people live. We have taken continuous samples of the Longyear seam in two different mines 40 km apart, and this study presents data from the high-resolution sampling of one of these sites (Mine 7 near Longyearbyen). Samples are taken for carbon and ash content, inorganic content of major elements and trace elements, palynology, maceral analysis and isotope analysis providing δ13C values. We present the chemostratigraphy and palaeovegetation of the Longyear seam and discuss dust deposition, forest fire records and implications for a warm Arctic system. Marshall, C (2013). Palaeogeographic and Economic Development of the Coal Bearing Todalen Member, Spitsbergen PhD Thesis, University of Nottingham Marshall, C., Large, D.J. and Heavens, N.G., 2016. Coal-derived rates of atmospheric dust deposition during the Permian. Gondwana Research, 31(Supplement C): 20-29.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMPP13C1482J
- Keywords:
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- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 4901 Abrupt/rapid climate change;
- PALEOCEANOGRAPHY;
- 4912 Biogeochemical cycles;
- processes;
- and modeling;
- PALEOCEANOGRAPHY;
- 4948 Paleocene/Eocene thermal maximum;
- PALEOCEANOGRAPHY