Limnological controls on stable isotope records of late-Holocene palaeoenvironment change in SW Greenland: a paired lake study

TY - JOUR

T1 - Limnological controls on stable isotope records of late-Holocene palaeoenvironment change in SW Greenland

T2 - a paired lake study

AU - Olsen, Jesper

AU - John Anderson, N.

AU - Leng, M.J.

PY - 2013

Y1 - 2013

N2 - Stable isotope records are increasingly being used in palaeoenvironmental studies of Arctic lakes. Here we compare stable isotope and elemental records (delta C-13, delta N-15 C/N) with high resolution XRF-derived geochemical and colour data from low Arctic lakes (SS1220 and SS85) in southwest Greenland. Lake SS1220 sediments are laminated gyttja whereas SS85 consist of homogeneous gyttja, both records cover the last c. 5000 years. delta C-13 and carbon content suggest that organic matter in both lakes is predominantly autochthonous. The C/N variability, ranging between 11 and 15, is interpreted to be a function of nitrogen deficiency which is further supported by delta N-15 values (at SS1220) falling close to atmospheric delta N-15(atmosphere). Although some changes in the geochemical stratigraphies presented here can be related to regional environmental change (i.e. hydrology, effective precipitation, aeolian activity), these effects are filtered through the lake catchments. These changes alter the nutrient supply and hence lake productivity which appear to be the primary controls on the stable isotope data. We suggest that information of past environmental change can only be gained from the stable isotope composition of lake sediments when there is a reasonable understanding of limnological processes, and records may be lake specific. (C) 2012 Elsevier Ltd. All rights reserved.

AB - Stable isotope records are increasingly being used in palaeoenvironmental studies of Arctic lakes. Here we compare stable isotope and elemental records (delta C-13, delta N-15 C/N) with high resolution XRF-derived geochemical and colour data from low Arctic lakes (SS1220 and SS85) in southwest Greenland. Lake SS1220 sediments are laminated gyttja whereas SS85 consist of homogeneous gyttja, both records cover the last c. 5000 years. delta C-13 and carbon content suggest that organic matter in both lakes is predominantly autochthonous. The C/N variability, ranging between 11 and 15, is interpreted to be a function of nitrogen deficiency which is further supported by delta N-15 values (at SS1220) falling close to atmospheric delta N-15(atmosphere). Although some changes in the geochemical stratigraphies presented here can be related to regional environmental change (i.e. hydrology, effective precipitation, aeolian activity), these effects are filtered through the lake catchments. These changes alter the nutrient supply and hence lake productivity which appear to be the primary controls on the stable isotope data. We suggest that information of past environmental change can only be gained from the stable isotope composition of lake sediments when there is a reasonable understanding of limnological processes, and records may be lake specific. (C) 2012 Elsevier Ltd. All rights reserved.

KW - Southwest Greenland

KW - Holocene

KW - Lakes

KW - Climate

KW - Environment

KW - Stable isotopes

KW - XRF

KW - KANGERLUSSUAQ SONDRE STROMFJORD

KW - SEDIMENTARY ORGANIC-MATTER

KW - WEST GREENLAND

KW - CLIMATE EVOLUTION

KW - LACUSTRINE RECORD

KW - BAFFIN-ISLAND

KW - DISKO-BUGT

KW - ICE MARGIN

KW - CARBON

KW - GEOCHEMISTRY

UR - https://www.scopus.com/pages/publications/84881550714

U2 - 10.1016/j.quascirev.2012.10.043

DO - 10.1016/j.quascirev.2012.10.043

M3 - Journal article

AN - SCOPUS:84881550714

SN - 0277-3791

VL - 66

SP - 85

EP - 95

JO - Quaternary Science Reviews

JF - Quaternary Science Reviews

ER -