ROLE OF PALYNOLOGY IN PALEOPALYNOLOGY.pptx

This presentation provide a brief knowledge about the roles of palynology in palaeopalynology and hydrocarbon exploration.

1. ROLE OF PALYNOLOGY IN PALaEOPALYNOLOGY & HYDROCARBON EXPLORATION PRESENTED BY – SUBHAM SAHA GUIDED BY – DR. NILAKSHI DEVI M.SC. 3 RD SEMESTER, PROFESSOR, DEPARTMENT OF BOTANY, DEPARTMENT OF BOTANY, GAUHATI UNIVERSITY. GAUHATI UNIVERSITY, 2021.

2. CONTENTS Introduction - Palynology & Palaeopalynology Methods in Palaeopalynology Applications of Palaeopalynology Applications of Microfossils in fossil fuel exploration Scale of Palynomorphs colour Introduction - Hydrocarbon & its exploration Formation of Petroleum and Natural Gas Methods of commercial “Petroleum Product Life Cycle” Conclusions References

3. What Is Palynology ? Palynology (“ study of dust ” or of “ particles that are strewn ”) is the science of pollen grains and spores. Pollen grains are male gametophytes or reproductive cells of a flowering plant. This term was coined by Hyde and Williams in 1945. Pollen grain of Morning Glory ( Ipomoea sp .) Pollen grain of Acacia sp .

4. Palaeopalynology Palaeopalynology ( palaeo -/paleo-) is one of the disciplines of palynology and concerned with the study of fossil pollen grains and spores. Fig: Nomenclature in Paleopalynology. (A.) Oculopollis sp., fossil, Upper Cretaceous, Hungary, polar view. (B.) Oculopollis sp., fossil, Upper Cretaceous, Hungary, polar view. (C.) Trudopollis sp., fossil, Upper Cretaceous, Hungary, polar view. D. Trudopollis sp., fossil, Upper Cretaceous, Hungary, polar view

5. METHODS IN PALaEOPALYNOLOGY Palynologists have developed a series of standard methods that are applied to collect, extract, identify, and describe organic-walled microfossils. (A) Sample Collection Palynological sampling thus requires a good knowledge of sedimentology in order to identify those lithologies most likely to preserve OM particles of microscopic size. Ideal facies usually correspond to fine-grained mudstone or silty mudstone, indicating deposition in a calm aqueous environment where palynomorphs could settle and get buried. Color of the rock is another very important indicator, as usually rocks of dark gray/black color are rich in OM. Whether collected in the field from outcrop or cores, or from material in museum collections, cross-contamination by surrounding matrix or dirty tools should always be of major concern. Collection of the sample itself is usually straightfor -ward and consists of the extraction of ~10 g of sediment. This is usually done using a rock hammer or a knife in case of soft rocks (Fig. 3A). Samples can conveniently be stored in air-tight ziplock bags with an acid-free paper label inside (Fig. 3B).

6. (B) Extraction Back in the laboratory, Samples are first covered in hydrochloric acid (HCl) to remove carbonates, then thoroughly washed and rinsed three or four times. The second acid treatment removes silicates using 40%–70% HF for ~24 h in plastic beakers. At the end of the reaction, the organic residue should be apparent as a fine black sludge, which is an indication of a positive sample. Samples are then cleaned of acid by a series of decantations and rinses, and a last treatment using boiling HCl is used to remove the insoluble fluorosilicate crystals that formed during the previous step and that would greatly impair observation. Staining of samples (with Safranin Red dye, which gives a pinkish color to palynomorphs) may be used if palynomorphs are clear/translucent to improve contrast. The residue that is obtained can then be stored in vials, either dried or in alcohol (Fig. 3C) for future use.

7. (C) Sample Mounting and Observation For optical microscopy, the material is prepared and mounted for observation on microscope glass slides (Fig. 3D). The simplest way is to make a wet mount slide by trapping a drop of residue between a microscope slide and a coverslip. Canada balsam used to be a traditional mounting medium, but has a tendency to crack and yellow as it ages. Now, modern polymers like epoxy and polyester resin display very good stability, optimum refractive index, and are very easy to use. Several drops of the palynological residue are spread on a coverslip with a drop of polyvinyl alcohol. The polyvinyl alcohol attaches the residue to the coverslip, ensuring that the material lies on the same optical plane. The focus-through process allows the palynologist to observe the surface ornamentation, details of the germination aperture, and thickness and layering of the spore/pollen wall, all important taxonomic characteristics. The coverslip is then flipped onto the slide bearing several drops of the mounting medium, and left to cure. Position of important and photographed slides for archiving and taxonomic description can be noted with the use of a gridded micrometer slide called an England Finder.

8. Electron microscopy can be beneficial in resolving details of the surface and ornamental structure of palynomorphs at much higher magnification than optical microscopy. SEM provides three-dimensional images of the outer surface of imaged objects (Fig. 4A and B), whereas transmitted electron microscopy (TEM) is used to elucidate the internal structure through ultrathin sections roughly 100 nm thick. Because electron microscopy cannot be performed on material already mounted on optical microscopy slides, it is often desirable to keep palynological residue in vials for mounting on metal stubs and gold plated for SEM, or for embedding and ultramicrotomy sectioning for TEM.

9. (D) Palynological Analysis Palynological slides can be characterized though palynofacies analysis in a manner similar to that used for description of sedimentary facies from rock thin sections, in which the proportion, shape, and size of the constitutive minerals are derived. The concept of palynofacies analysis was introduced by Batten (1973, 1996b, 1982) and Batten and Stead (2005) and aims at describing the proportion, shape, color, and size of every piece of organic debris ( palynodebris ) present on a slide. Palynofacies data is highly relevant in the characterization of depositional environments, as the proportion, preservation, and shape of palynodebris is a function of taphonomy. The insoluble macromolecular OM dispersed in sedimentary rocks, called kerogen, is a major source for oil and natural gas (Batten, 1981a). Thus palynofacies analysis is not only critical for characterizing depositional environments and taphonomy, but is also of prime importance for assessing potential source rocks for petroleum ( Vandenbroucke and Largeau , 2007).

10. Application of Palaeopalynology Palaeopalynology is of immense value in a wide range of scientific studies, a few of which are mentioned below: ( i ) To trace the history of vegetation: Palaeopalynology is most effectively exploited in the investigation of vegetation history. It is fruitfully employed with regard to the pollen grains of Quaternary deposits, because most of pollen in these deposits is referable to extant genera and species.  (ii) To correlate deposits and assigning dates: Each stratum of a particular region during a particular geologic time has characteristic pollen assemblage. With the aid of pollen assemblage palynologists determine a relative chronology or a sequence of events that occurred during plant succession. The prominent changes in pollen proportions being correlated with a particular timing form the basis of using pollen analysis as dating tool. (iii) To study climatic change: Climate influences vegetation patterns. Determination of past vegetation types through pollen analysis is a useful tool for the study of past climates. Relative pollen frequencies are used exclusively in the reconstruction of past climate.

11. (iv) To study evolution of plants and establish affinity: It is regarded that monocolpate pollen grains are most primitive. Monocolpate pollen grains are found in extinct Bennettitales and extant Magnoliaceae of angiosperms. So there exists an affinity between Bennettitales and Magnoliaceae so far as pollen morphology is concerned. (v) To determine coal-bearing strata: Coal beds have characteristic abundance of certain pollen and spore genera on the basis of which they are identified. The seams can be traced laterally by comparing the pollen assemblage of the adjacent sections. The pollen assemblage is expressed in the shape of tables and diagrams, and separate horizons that have definite pollen genera. Such horizons are compared with horizons of adjacent sections to correlate and extend the coal seam. This correlation is successfully utilized in the Paleozoic, especially in the Pennsylvanian coal seams. The correlation tool has been proved to be of immense value in coal investigation of North America and Europe. In India Birbal Sahani Institute, Lucknow, has successfully employed such correlation tool in the investigations of coal basins of Assam, West Bengal, Bihar, Madhyapradesh and other states.

12. APPLICATION OF MICROFOSSIL IN FOSSIL FUEL EXPLORATION Microfossils have many application to petroleum Geology Three microfossils which are of particular importance to hydrocarbon exploration are: (1) Foraminifera, (2) Calcareous Nannofossils and (3) Palynomorphs. (1) Foraminifera Foraminifera have many uses in petroleum exploration and are used to interpret the ages and paleo environments of sedimentary strata in oil wells. Agglutinated fossils Foraminifera buried deeply in sedimentary basins can be used to estimate thermal maturity, which is a key factor for petroleum generation. The Foraminiferal Colouration Index (FCI) is used to quantify colour changes and estimate burial temperature. FCI data is particularly useful in the early stages of petroleum generation (~100 c)

13. (2) Calcareous nannofossils These are extremely small objects (less than 25 microns) produced by planktonic unicellular algae Coccolithophores, planktonic golden brown algae that are very abundant in the world’s oceans. The calcareous plates accumulate on the ocean floor, become buried beneath later layers, and are preserved as Nannofossils.

14. (3) Palynomorphs Spores and Pollens are transported by wind and water and can travel long distances before final deposition. Organic chemicals comprising Palynomorphs get darker with increased heat. Helps to assess the temperature to which a rock sequence was heated during burial and thus it is useful in predicting whether oil or gas may have formed in the area under study. This includes chitinozoans (animal remains), fungal spores, dinoflagellates, acritarchs and other organisms (except diatom) that are preserved in sedimentary rocks, composed of sporopollenin and chitin etc.

15. Fig: Photomicrographs of microspores from the studied boreholes Brochotriletes foveolatus Clivosispora verrucata Camarozonotriletes sextantii Dictyotriletes emsiensis Dictyotriletes subgranifer Knoxisporites riondae Knoxisporites riondae Geminospora lemurata Samarisporites eximius Monolete spores Synorisporites papillensis Synorisporites papillensis Retusotriletes maculatus Verrucosisporites polygonalis

16. Fig: Outcrop photographs and fossil pollen micrographs of typical lithologies in Jurassic strata, northern Qaidam Basin. (a) Coal-bearing strata of J 1 x; (b) Neocalamites fossil in J 2 d 1 strata; (c) red strata of J 2 d 3 ; (d) Classopollis contented in J 2 d 3 strata; (e) coal-bearing strata of J 2 d 5 ; (f) ferns and conifers sporopollen fossil contented in J 2 d 5-6 strata; (g) red strata of J 3 h; (h) aeolian deposits overlying successive strata above Hongshuigou Formation.

17. Scale of palynomorphs colour Observed colour of Palynomorphs Significance 1. Colourless , pale yellow, yellowish orange Chemical change negligible; organic matter immature, having no source potential for hydrocarbon. 2. Yellow Some chemical change, but organic matter still immature. 3. Light brownish yellow, yellowish orange Some chemical change, marginally mature but not likely to have potential as a source. 4. Light medium brown Mature, active volatilization, oil generation. 5. Dark brown Mature, production of wet gas and condensate transition to dry gas phase 6. Very dark brown black Overmature; source potential for dry gas 7. Black (opaque) Trace of dry gas only

18. Fig: Palynomorphs exine colouration with geothermal maturation. Thermal Alteration Index Scale (TAI) is based on Palynomorphs colour and on Vitrinite reflectance

19. Hydrocarbon A compound of hydrogen and carbon, such as any of those which are the chief components of petroleum and natural gas. Hydrocarbons are chemical compounds that are utilized as the basis of the vast majority of global energy production. Hydrocarbon exploration Hydrocarbon exploration (or oil and gas exploration) is the search by petroleum geologists and geophysicists for deposits of hydrocarbons, particularly petroleum and natural gas, in the Earth using petroleum geology.

20. Petroleum formation M.V. Lomonosov laid down the fundamentals of the organic theory of origin of oil. He was the first to suggest the hypothesis of formation of coal from peat through its coalification caused by increasing pressures and temp. Through this theory, it is generally accepted that the living material from which petroleum was formed consisted of millions of foraminifera, diatoms and radiolaria etc. Petroleum formation occurs by various hydrocarbons combining with certain minerals such as sulphur under extreme pressure. When small sea plants and animals die they will sink; they will then lie on the sea bed where they will decompose and mix with sand and silt. These sediments prevented the dead bodies from rotting away completely and thus they subject these remnants to the action of anaerobic bacteria. This bacterial action leads to the final transformation of the fatty contents of these organisms into minute droplets of petroleum.

21. FORMATION OF PETROLEUM AND NATURAL GAS

22. Methods of commercial “Petroleum Product Life Cycle” There are seven major conceptual steps involved in the complete commercial “Petroleum Product Life Cycle” (Figure 1). These steps are (1) Prospecting, (2) Leasing or acquiring access, (3) Drilling operations, (4) Developing and producing, (5) Transporting, (6) Processing and refining, (7) Marketing and sales. Of the seven steps listed above, the first three steps are called the “exploration phase” and the forth step is the “production/extraction phase”. The majority of wildcat wells drilled to date have been dry holes that contained no commercial hydrocarbons. Wildcat drilling success rates in the industry have climbed from about a 10% success rate 20 years ago, to approximately 56% of wells discovering hydrocarbons currently. Thus steps 1 through 3 in Figure 1 may need to be repeated many times before a successful venture that moves forward to steps 4 through 7 is achieved.

23. CONCLUSIONS Whether used for biostratigraphy, paleoenvironmental analysis, or characterization of organic content of rocks, palynology has proven to be an essential tool for the study of unoxidized terrestrial sediments and sedimentary rocks. Palynology and palynofossils can play significant role hydrocarbon exploration and exploitation throughout the life of an oil field from exploration to development to production Fossil pollen and spores can be used to reconstruct a picture of past vegetation and can provide information on ancient climates. ONGC is currently exploring Coal Bed Methane in Singrauli , Madhya Pradesh and north of Godavari valley in Andhra Pradesh. Furthermore, palynological processing and analysis is cost effective and provides a fast turnaround, in comparison with other analytical techniques.

24. REFERENCES https://www.sciencedirect.com/science/article/pii/B9780128032435000030 https://study.com/academy/lesson/palynology-definition-branches-applications.html https://app.dimensions.ai/details/publication/pub.1085447831 https://www.researchgate.net/publication/291248921_An_introduction_to_the_applications_of_palaeobotany_and_palynology_to_coal_geology https://www.slideshare.net/danbel2/fossil fuels PowerPoint Martin F Glaessner , 1972, Principles of micropalaeontology, Hafner publishing company, Pp226-234. Brassier MD, 1980, Microfossils, George Allen & Unwin, London, 193p . Stanley SM, 1998, Earth system history, WH Freeman & company, New York, 615P. A textbook of Palynology – Bhattacharya, Majumdar & Bhattacharya.

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