Definition of PalynologySome palynologists suggest that Palynology, and hence also paleopalynology, applies

only to pollen and spores or, more specifically even, only to pollen and the spores of embryo-producing (embryophytic) plants.

It should seem true as Hyde and Williams (l944) had that in mind when they coined the term palynology, a word from the Greek v (“I sprinkle”), suggestive of “fine meal,” which is cognate/related with the Latin word pollen (“fine flour,” “dust”).

However most paleopalynologists instead, use the word pragmatically, saying in effect that

paleopalynology consists of the study of the organic microfossils that are found in our maceration preparations of sedimentary rocks, i.e. “What my net catches is a fish”

This means palynomorphs, the microfossils which are the subject matter of this study, consist at least partly of very resistant organic molecules, usually sporopollenin, chitin or “pseudochitin”.

Palynomorphs are also by common consent in the approximately 5–500 micrometer = micron = size range.

What is not palynology Nannofossils are not palynomorphs on two scores.

1. First, they are calcium carbonate CaCO3 and hence are destroyed by the dilute hydrochloric acid (HCl).

2. Secondly, they are also too small, prevailingly less than 5 micron.

Diatoms are not palynomorphs, although they are in the right size range, because they are usually siliceous and destroyed by the hydrofluoric acid (HF) that is the major weapon in the paleopalynological maceration.

Phytoliths, usually consisting of silica or calcium oxalate, produced typically by grasses.

They are very useful in various forms of environmental reconstruction. These are also in the correct size range but are dissolved by the acids in conventional palynological maceration.

Palynofacies Associations of palynological matter (PM) in sediments, considered primarily in

terms of the reasons for the association, usually geological, but may related to the biological origin of particles.

Spores, pollen, dinocysts, acritarchs and all other palynomorphs are of course included in the palynofacies, but so are other visible organic particles in the palynological size range (roughly 2–250 µm) that occur in palynological maceration residues.

In an older sense, “palynofacies” may imply the palynomorph load of a sedimentary rock, seldom including any of the palynodebris, in which palynomorphs of a particular species are enriched in concentration.

Traverse (2007) called it palynobiofacies, to contrast it with the more recently emphasized and now dominant usage for palynofacies, which is for particular assortments of PM, including both palynomorphs and palynodebris that are associated with an environment of deposition for prevailingly non-biologic reasons.

Traverse (1999; 2007) suggested calling this sort of palynofacies a palynolithofacies to emphasize that the concept is primarily geological not biological, although all constituents of the palynofacies are of biological origin.

Palynology sample preparation techniques Field methodology:

North-face of the exposure

Digging for a minimum of 5cm into the rock

Sample weight up to 200 grams

Plastic bags with seal or zip

Label each sample and mark the sample location on log

Laboratory Methodology:

1. Wash sample with water or clean with brush

2. Keep the sample in sunlight or in oven to dry the sample

3. Crush the sample up to 4mm

4. Weight 50-100 grams sample for processing

5. Pour 50 – 100g of sample in labelled plastic bottle.

6. Add 10% HCl and few drops of ethanol if the reaction is vigorous

7. After an hour check the reaction, Wait for settling and Remove the water

8. Add fresh distilled water and Repeat this procedure for 3 times

9. Add HF (40%) to sample and keep it in HF for six days

10. When broken down, decant 3 times with water leaving to settle each time

11. Treat with HCl to dissolve flouro-silicate

12. Sieve through a 250 micron brass sieve and 10 micron nylon sieve

13. Prepare 10% weight-weight solution of ZnBr or Zncl

14. *Label the tubes and Centrifuge for 30 minutes at 4000 rpm

15. Layer will appear on the top, Remove the layer carefully and drop the layer on the glass slide

16. Keep for 24 hours in safe place now Mount it with mounting magic and leave it for a while

17. Ready for microscopic studies

PurposesThe primary reasons for doing paleopalynology are as follows.

1. GeochronologyPalynomorphs represent parts of the life-cycles of various plants and animals that

have at times evolved quite rapidly, with the result that such palynomorphs are characteristic of a fairly narrow time-range and hence are useful for age dating (geochronology).Before palynological study was available, geologists often did not know, even within a period or two, what the age of the rock was (in Pakistan e.g. we don’t know the exact dates of many formation that are otherwise unfossiliferous).

2. BiostratigraphyPaleopalynology has become economically important mostly because palynofloras

can be used, beginning with about one-billion year old rocks (acritarch palynofloras), to show correlation of a section of rocks from one place with another section of rocks, from a different locality and of perhaps quite different thickness and quite different lithology.

This work of biostratigraphic (in this case, palynostratigraphic) correlation is common among oil company palynologists. The sections correlated may be hundreds of kilometers apart.

More often they are not widely separated, and may be in the same oil field, where it is very important to know at what level one is drilling, not in meters of depth, but with reference to known gas or oil production levels.

3. PaleoecologyIt may be important to know as much as possible about various sorts of environments

represented by a sedimentary rock.

Palynology can help here in several ways;

Palynomorphs can be sensitive indicators of the processes of sedimentation and the source of sediments.

The source organisms of some palynomorphs, e.g. dinoflagellates and other marine algae, are primarily marine organisms, and their fossils (dinocysts, various other algal remains attributable to specific groups, and acritarchs) may be indicators of the biological environment of the organisms.

Spores/pollen occurring as sporomorphs originate almost exclusively on the continents. They indicate therefore the presence of source vegetation.

Because plants are sensitive indicators of continental environments (mostly climates), spores/pollen have much to tell us about climatic paleoenvironments. This is, of course, the reason for the original successes of palynology/pollen analysis in Holocene vegetational analysis.

4. Sequence StratigraphySequence stratigraphy is based on recognition of correlatable

transgressive (flooding) and regressive surfaces in sedimentary sequences. In general (Haq et al., 1987), such surfaces are related to worldwide eustatic change in sea level, but some similar phenomena have been attributed in some places as to local tectonic activity.

5. Applicability to Petroleum Source-rock ExplorationPalynofacies data along with TOC (total organic carbon) and

HI (hydrogen index) information is a good approach for evaluating the total effect of processes that result in hydrocarbon accumulation in sediments.

TOC is especially important for source rock formation–most are in the 2–10% range. Sediments with less than 2% TOC are usually found to be barren or contain only gaseous hydrocarbons.

On the other hand, TOC of more than 10% is a rare phenomenon in extensive sequences (Batten, 1996a). Mehrota, et al. (2002) point out that high total carbon does not necessarily mean high petroleum source potential, as the carbon could consist of dark woody material, which is very poor indicator for oil. A small percent of TOC consisting of AOM of marine algal origin is a much better indicator.

Al-Ameri and Batten (1997) found that platform environments with a palynofacies containing more than 50% AOM are indicative of high petroleum potential.

Vigran et al. (1998) found that their transgressive levels were mostly high in AOM and in TOC and are potential source rocks.

Batten (1996) says that high amounts of structural matter (STOM) such as phytoclasts and sporomorphs are poor indicators for source rocks, and brown-black woody matter and evidence of reworking in the palynofacies of non-marine sediments are very negative indicators.

Why Paleopalynology Works

1. Ubiquity (omnipresence) of PalynomorphsBeginning with Precambrian acritarchs, up to 1.4 billion years old, sporopolleninous

and chitinous palynomorphs occur in sedimentary rocks of all ages and from many different sedimentary and biological environments.

They originate both on land (spores/pollen = sporomorphs) and in fresh water (Botryococcus and other algae, some dinoflagellates and a few sporomorphs) and salt water

(most dinoflagellates, acritarchs, and other algal microscopic remains, the extinct chitinozoans, scolecodonts, foraminiferal test linings, a few sporomorphs).

2. Abundance and Durability of PalynomorphsMost palynomorphs, especially spores/pollen and dinoflagellates tend to be much

more abundant than most other fossils. A silt e.g. can contain five million dinoflagellates per gram.

This provides possibilities for statistics and population studies nearly unique in paleontology.

A large part of the explanation for this abundance in sediments is the tiny size of palynomorphs.

3. Fast EvolutionPalynomorphs of various sorts represent preserved parts of the life cycles of various

organisms that, during one or more segments of Earth history, were comparatively fast evolving, as well as abundant and easy to collect.

This is a “must” for biostratigraphy and is true of acritarchs for the latest Precambrian, Cambrian, and Ordovician, scolecodonts and chitinozoans in marine sediments of the Ordovician and Silurian, spores in the Devonian, spores/pollen in all periods since the Devonian, and dinoflagellates in marine rocks since the Triassic.

Disadvantages and LimitationsPalynomorphs are silt-sized and are therefore sparse or absent in well-sorted, coarse-

grained sandstones and fine-grained claystones. Palynomorphs are sensitive to oxidation and to high alkalinity and therefore are not usually recoverable from red bed deposits, “clean” limestones generally, evaporitic deposits generally, or weathered rocks, although there are exceptions.

Palynomorphs are sensitive to high temperatures and pressures and apparently to crystallization processes in rocks, and are therefore not usually studied with profit from metamorphosed rock. With methods in routine laboratory use i.e. light micrscopy , pollen and plant spores are not routinely determinable below the generic level. Dinoflagellate cysts are usually not subject to the generic level limitation characteristic for pollen and spores, and they are therefore intrinsically better suited to biostratigraphic use in general.

Unfortunately, dinoflagellate cysts are not regularly found in non-marine sediments, and sporomorphs remain the best microfossils for non-marine sediments and for connection of non-marine and marine levels in the same set of sediments. All palynomorphs are subject to reworking, just because they are so sturdy. They can be weathered and eroded out of the original sediments, sometimes in multiple cycles of redeposition. A paper by Utting et al. (2004) reports an especially distressing example of massive reworking of Devonian, Carboniferous and Permian palynomorphs into Lower Triassic rocks over very large parts of the world.

When To Use Palynofacie. Palynofacie are most use full when we have unfossilferrous formation like sandstone,

silt stone etc. To know the migration of hydrocarbon in oil field. As palynofacie move with the oil

migration, therefore they give that information which biostratigraphy can't. Through Palynostaratigraphy one can know about the terrestrial condition as

terrestrial environment can't bear any fossil...

General Occurrence of Palynomorphs in TimeThe palynomorphs commonly studied include representatives of four “kingdoms” of

organisms, all belonging to the eukaryotic domain.

One of the strong selling points for paleopalynology is that from about one billion years ago (late Precambrian) to present, sporopolleninous or chitinous palynomorphs of one group or another are always present in sedimentary rocks of suitable lithology and they are often biostratigraphically useful (that is, rapidly evolving, ubiquitous, abundant).

The oldest sporopollenin-containing palynomorphs are sphaeromorph acritarchs over one billion years old from the former Soviet Union and from other parts of the world.

The oldest chitinous palynomorphs are Cambrian scolecodonts and chitinozoans. (Chitinous fungal spores appear much later. With a few exceptions in the Permian and Triassic, they do not occur regularly until the Late Jurassic and are not abundant until mid-Cretaceous.)

Precambrian sphaeromorph, sporopolleninous acritarchs were joined by acritarchs with processes and other modifications in the Cambrian and Ordovician. Even non-marine sediments began to contain sporopolleninous fossils in late Ordovician.

Some of these are cryptospores, spore-like bodies lacking the haptotypic marks typical of true spores. The earliest unquestioned embryophyte spores are Ashgill (Late Ordovician) trilete spores.In referring palynomorphs to their appropriate stratigraphic level we use the

general geological time scale.

The “Archeophytic” extends from about 3.5 billion years (and the earliest known fossils) to the level of the first robust-walled acritarchs and the eukaryotes, at about 1.2 bi years ago.

With the first sporopolleninous acritarchs begins the “Proterophytic,” extending up to the level of the first spores or spore-like tetrads of the Late Ordovician-early Silurian

This marks the commencement of the “Paleophytic” which is typified by ancient sorts of vascular plants and persists until the Upper Permian, when conifers, cycadophytes, and other advanced gymnosperms came to dominate the land flora, and the “Mesophytic” began. The “Mesophytic” gave way to the present “Cenophytic” in the very early Cretaceous, with the first significant appearance of angiosperms.