Geography and Environmental ScienceEarthworm secreted calcitegranules as apalaeoenvironmental proxyEmma Versteegh, Stuart ...
A new terrestrialpalaeoenvironment thermometer• Many organisms  biomineralise• Stable isotopes in  CaCO3 can record  envir...
Earthworm secretedcalcite (CaCO3) granulesEarthworm secreted calcite granules as a palaeoenvironmental proxy   3
AimTo construct a new terrestrial isotope – temperature curve  for application to earthworm secreted calcium  carbonate gr...
Oxygen isotopes (δ18O values)               1000 ln αc-w = 18.03 (103T-1) - 32.42              δ18Owater & temperature → δ...
Earthworm secreted calcite granules as a palaeoenvironmental proxy   6
Earthworm secreted calcite granules as a palaeoenvironmental proxy   7
Earthworm secreted calcite granules as a palaeoenvironmental proxy   8
Earthworm secreted calcite granules as a palaeoenvironmental proxy   9
AimTo construct a new terrestrial isotope – temperature curve  for application to earthworm secreted calcium  carbonate gr...
Carbon isotopes (δ13C values)  • “You are what you    eat”  • Calcifying gland is a C    fixing organBriones et al. (2008)...
Experiment 1• 3 soils (C3 and C4  vegetation)• 3 types of water (England,  Fiji, Norway)• Constant temperature  (17 °C)• 4...
Isotope analysesDelta V advantage IRMS• Flash EA 1112 HT     – δ2H and δ18O in water, soils,       manure, earthworms• Gas...
Granule δ18O vs. δ13C                                evaporation                                                        ad...
δ13C in soils                                                 adaptation to food                                          ...
δ13C in soils and granulesEarthworm secreted calcite granules as a palaeoenvironmental proxy   16
Reconstructed δ18OwaterEarthworm secreted calcite granules as a palaeoenvironmental proxy   17
Earthworm secreted calcite granules as a palaeoenvironmental proxy   18
Conclusions• δ18O values of granules appear to  reflect ambient water• δ13C values of granules adapt to  δ13C values of fo...
Experiment 2• 2 soils• 3 types of water (England,  Fiji, Norway)• 3 temperatures (10, 16,  21 °C)• 3 weeks acclimatisation...
Future workMore analyses:• Water δ13C, δ18O• δ2H, δ15N• More granulesApplication on archaeological and geological samples•...
Thank you!                                                                       Questions?  Earthworm secreted calcite gr...
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Aberystwyth June 2011

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Aberystwyth June 2011

  1. 1. Geography and Environmental ScienceEarthworm secreted calcitegranules as apalaeoenvironmental proxyEmma Versteegh, Stuart Black, Mark Hodson15 September 2011 Frontiers in Environmental Geoscience www.reading.ac.uk
  2. 2. A new terrestrialpalaeoenvironment thermometer• Many organisms biomineralise• Stable isotopes in CaCO3 can record environmental variabilityEarthworm secreted calcite granules as a palaeoenvironmental proxy 2
  3. 3. Earthworm secretedcalcite (CaCO3) granulesEarthworm secreted calcite granules as a palaeoenvironmental proxy 3
  4. 4. AimTo construct a new terrestrial isotope – temperature curve for application to earthworm secreted calcium carbonate granules → Potential for granules in dating and palaeo- environmental interpretationEarthworm secreted calcite granules as a palaeoenvironmental proxy 4
  5. 5. Oxygen isotopes (δ18O values) 1000 ln αc-w = 18.03 (103T-1) - 32.42 δ18Owater & temperature → δ18Ocalcite Kim & O’Neil (1997)Earthworm secreted calcite granules as a palaeoenvironmental proxy 5
  6. 6. Earthworm secreted calcite granules as a palaeoenvironmental proxy 6
  7. 7. Earthworm secreted calcite granules as a palaeoenvironmental proxy 7
  8. 8. Earthworm secreted calcite granules as a palaeoenvironmental proxy 8
  9. 9. Earthworm secreted calcite granules as a palaeoenvironmental proxy 9
  10. 10. AimTo construct a new terrestrial isotope – temperature curve for application to earthworm secreted calcium carbonate granules• Potential for granules in dating and palaeo- environmental interpretation• How important are granules in locking up atmospheric CO2?Earthworm secreted calcite granules as a palaeoenvironmental proxy 10
  11. 11. Carbon isotopes (δ13C values) • “You are what you eat” • Calcifying gland is a C fixing organBriones et al. (2008) Earthworm secreted calcite granules as a palaeoenvironmental proxy 11
  12. 12. Experiment 1• 3 soils (C3 and C4 vegetation)• 3 types of water (England, Fiji, Norway)• Constant temperature (17 °C)• 4 months• 4 replicatesEarthworm secreted calcite granules as a palaeoenvironmental proxy 12
  13. 13. Isotope analysesDelta V advantage IRMS• Flash EA 1112 HT – δ2H and δ18O in water, soils, manure, earthworms• GasBench II – δ13C and δ18O in granules, water, DIC, CO2SerCon – δ13C and δ15N in soils, manure, DOC, DONEarthworm secreted calcite granules as a palaeoenvironmental proxy 13
  14. 14. Granule δ18O vs. δ13C evaporation adaptation to food ~3 ‰Earthworm secreted calcite granules as a palaeoenvironmental proxy 14
  15. 15. δ13C in soils adaptation to food ~3 ‰ Earthworm secreted calcite granules as a palaeoenvironmental proxy 15
  16. 16. δ13C in soils and granulesEarthworm secreted calcite granules as a palaeoenvironmental proxy 16
  17. 17. Reconstructed δ18OwaterEarthworm secreted calcite granules as a palaeoenvironmental proxy 17
  18. 18. Earthworm secreted calcite granules as a palaeoenvironmental proxy 18
  19. 19. Conclusions• δ18O values of granules appear to reflect ambient water• δ13C values of granules adapt to δ13C values of food (manure) over < 1 month• So far no evident link between soil and granule δ13C values → more data neededEarthworm secreted calcite granules as a palaeoenvironmental proxy 19
  20. 20. Experiment 2• 2 soils• 3 types of water (England, Fiji, Norway)• 3 temperatures (10, 16, 21 °C)• 3 weeks acclimatisation• 1 month• 6 replicatesEarthworm secreted calcite granules as a palaeoenvironmental proxy 20
  21. 21. Future workMore analyses:• Water δ13C, δ18O• δ2H, δ15N• More granulesApplication on archaeological and geological samples• Reconstruction of past temperatures• Dating of samples by U/ThEarthworm secreted calcite granules as a palaeoenvironmental proxy 21
  22. 22. Thank you! Questions? Earthworm secreted calcite granules as a palaeoenvironmental proxy 22

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