1. 1University of Nottingham 2Natural History Museum 3GeoArktis As
Origin of Abundant Palaeocene Oil Prone Type III Kerogen Deposits, Spitsbergen
C Marshall, D J. Large, C E. Snape, W Meredith, C Uguna, J Babatunde1 B F Spiro2 A Orheim3
Acknowledging
I Mokogwu1 and Y. Wang1
NERC, UNIS, SNSK AS
1University of Nottingham 2Natural History Museum 3GeoArktis As

2. Palaeocene Stratigraphy
Longyear
5 Seams found within the Palaeocene Todalen Member
The Svea seam is inertinite rich and has a relatively low HI ( )
4 seams have HI values exceeding 300 which are named (oldest-youngest)
Todalen
Longyear
Svarteper
Askeladd
Of these the Longyear seam is the only oil-prone coal mined commercially
Todalen
Mid-Late palaeocene – Poorly constrained, 5 coal seams part of todalen member earliest palaeogene rocks on svalbard, Focus on two currently mined Period of arctic warmth -
Svea
Svea

3. Maturity of the Longyear Seam
Mean Ro % 0.63
Maturity Predicted
by maturity parameters
Correlation with bitumen yield.
Actual Ro % 0.78
20% Suppression between mean and actual Ro %

4. Oil Potential of the Longyear seam
Values >300 indicate significant oil potential

5. Degree of in-situ generation (S1)
Lower seam has not generated significant amounts of hydrocarbons
Upper seam has greater yields of generated hydrocarbons due to greater oil potential and also some evidence of limited migration to the top of the seam
Show transition
Key
Red = Soxhlet Solvent Extraction
Blue = Accelerated Solvent Extraction

6. Residual Oil Potential (S2)
Hydrous pyrolysis used to simulate geological yields of hydrocarbons after furthur burial
Indicates that around 60-85% of hydrocarbons yet to be generated
PI is low also indicating that yields thus far represent immature oil generation due to organo-sulfur bond breakage during early diagenesis

7. Retorting oil yields (Nitrogen Pyrolysis)

8. Comparison with Global Crude Oils
Svalbard
Coals
Source needed, coal derived oil
Lundegard & Knott, 2001

9. Why are these Coals Oil-Prone?
Coal composition a function of the peatland environment in which it formed
Palaeoclimate
Depositional Setting
Organic Source material
Hydrological stability and geochemical conditions within the peat
Amount and type of bacterial activity
Source needed, coal derived oil

10. Palaeoclimatology Arctic ~ 60Ma
Svalbard in the Palaeocene was situated ~68N (Lüthje , 2008) and winter temperatures are thought to have rarely fallen below zero (Greenwood et al, 2010)

11. Depositional Setting
Meso-tidal
Estuary
Sand Flat
Peatland
Mouth Bar
Proximity to the coast controls the type of peatland environment and its vulnerability to inundation.
Also the pH regulating effect of seaspray has a direct control on the amount of microbial degradation in the peatland
Major environmental and chemical change in mid longyear. N
5km

12. Peatland Conditions during the formation of the Longyear Seam
Fen
What is the red line?
Raised Bog
Drier/Increased Fire

13. Total Bacterial input to Palaeocene Arctic Peatland
n-alkane
hopanes Pr
Total Ion Chromatogram Longyear Seam
Large amounts of bacteria leading to more decomposed peat

14. Total Bacterial input to Palaeocene Arctic Peatland
Hopane content of the Svalbard Coals
Longyear – µg/g TOC hopanes
Svea – 12-34µg/g TOC hopanes
Palaeocene New Zealand Cool Temperate coals – 50-60µg/g TOC (Source Vu et al. 2009)
Hopanes thought to reflect primary microbial activity
Biodegradation indicators such as norhopanes and methyl-steranes absent
High absolute concentrations of hopanes

15. Sulfur and Oil Potential
Hydrogen Index and Total Sulfur follow similar trends, increasing upwards
Sulfur related to increased preservation of oil-prone source material liberated by biodegradation
Allows formation of organo-sulfur molecules
Also indicative of coastal influence and degree of pH regulation by sea spray
Major environmental and chemical change in mid longyear.
Key
Red = HI
Blue = Total Sulfur

16. Conclusions
Longyear coals are significantly oil-prone with nitrogen pyrolysis indicating significant economic potential using retortion.
Oil prone coal formation on Spitsbergen is favoured by
Intense aerobic decay processes both bacterial and fungal
High Productivity compared to modern high latitudes
Formation in a coastal environment providing alkalinity and S
Stable hydrological conditions
These conditions help to liberate and preserve hydrogen rich oil-prone plant material during subsequent burial and diagenesis

17. Any Questions?