Organic Petrography - gfz-potsdam.de · Organic Petrography Determination of organofacies and...
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Konferenz Klima im System Erde Berlin 2. - 3. November 2009
Organic Petrography Determination of organofacies and thermal maturity
Hans-Martin Schulz
3.2 Organic Geochemistry
Microscope LEICA DM 4 P-Mikroskop,
equipped with the programmes Hilgers FOSSIL and FOSSIL MOT
Konferenz Klima im System Erde Berlin 2. - 3. November 2009
Macerals are organic particles in sediments.
They are composed of three classes:
Huminite/Vitrinite: woody tissue
Inertinte: aromatized particles
Liptinite: pollen, spores, cuticules, algae
Their analysis enables:
Facies analysis
Background
Liptinite (Cuticule)
Inertinite
(Fusinite)
Vitrinite
Vitrinite
Inertinite
(Semifusinite)
(Reflected white light)
Source: coalandcarbonatlas.siu.edu
Konferenz Klima im System Erde Berlin 2. - 3. November 2009
Liptinite appears black under reflected white light.
It can be made visible by UV light illumination.
At the end of the oil window liptinite becomes vitrinite.
Why to use reflected white light and UV light?
Alginite
(UV light illumination) (Reflected white light)
Konferenz Klima im System Erde Berlin 2. - 3. November 2009
The physicochemical properties of
vitrinite and liptinite change during
burial:
Huminite/Vitrinite get aromatized and thus
can better reflect the light. This is used as
a maturity parameter, and is measured as
„vitrinite reflectance (%), calibrated against
known reflectance standards.
Vitrinite reflectance data enable to
reconstruct:
Thermal history of a sediment
Maturation of organic matter
Source: coalandcarbonatlas.siu.edu
Konferenz Klima im System Erde Berlin 2. - 3. November 2009
Macroalga species
Chara in Tibetian lakes
Aichner, B., Herzschuh, U., Wilkes, H., Schulz, H.-M., Wang, Y., Plessen, B., Mischke, S., Diekmann, B.,
and Zhang, C. (2012): Ecological development of Lake Donggi Cona, north-eastern Tibetan Plateau, since
the late glacial on basis of organic geochemical proxies and non-pollen palynomorphs. - Palaeogeography
Palaeoclimatology Palaeoecology, 313-314, p. 140-149.
Case study: Palaeoclimate
Fluorescing algae (UV light illumination)
Fluorescing algae (UV light illumination)
Konferenz Klima im System Erde Berlin 2. - 3. November 2009
100 µm
Graptolites in Ordovician Dictyoname Shale: Reconstruction of palaeo upwelling zones
Case study: Palaeofacies
(UV light illumination) (Reflected white light)
Graptolite Graptolite
Konferenz Klima im System Erde Berlin 2. - 3. November 2009
Hartwig, A., Schulz, H.-M. (2010): Applying classical shale gas evaluation concepts to Germany—Part I: The
basin and slope deposits of the Stassfurt Carbonate (Ca2, Zechstein, Upper Permian) in Brandenburg. - Chemie
der Erde - Geochemistry, 70, Suppl. 3, p. 77-91.
Thermal maturity and organofacies
of Ca2 black shales in the Brandenburg
Case study: Oil and gas potential
Onset of oil generation at 2300 m
Gas generation below 3500 m
Well Schadewalde 2/75 was
tectonically uplifted by 1500 m
Semifusinite
Botryococcus-shaped alginite
Basin and lower slope facies
Lower slope facies
Konferenz Klima im System Erde Berlin 2. - 3. November 2009
20 µm
Schulz et al. (2015): From shale oil to biogenic shale gas: Retracing organic–inorganic interactions in the
Alum Shale (Furongian–Lower Ordovician) in southern Sweden. - AAPG Bulletin, 99, 5, p. 927-956.
Biogenic shale gas in the Alum Shale (c/o)
Fluorescing microbal mats (UV light illumination)
Case study: Unconventionals