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Latest revision as of 06:00, 1 October 2024
Palynology is the science of the study of contemporary and fossil palynomorphs as well as associated particulate organic matter (POM) in sedimentary strata. Palynomorphs are microscopic (from about 5 µm to about 500 µm), decay-resistant remains of certain plants and animals.[1] Micro-fossils classed as palynomorphs include acritarchs,[2] chitinozoans,[3] dinoflagellate cysts (dinoflagellates are marine organisms, comprising the red algae which make up the "red tides" in modern oceans), pollen, spores and scolecodonts.[4] Palynomorphs posses an organic outer wall which then render distinctive fossils. Palynology can be an important tool for a variety of uses, including forensics, water, oil, or gas drilling, or even the identification of floral sources of honey.
Characteristics
Not all microspores are palynomorphs. Polynomorphs can be successfully extracted from sedimentary deposits using routine pollen-extraction procedures including strong acids, bases, acetolysis, and density separation techniques that would destroy other types of microfossils. Non-polynomorph microfossils have siliceous, calcareous, phosphatic, or cellulose walls, that are not decay resistant and do not withstand routine pollen extraction methods. Most microfossils are marine or freshwater organisms, or parts thereof. One type of microfossil, Opaline phytolith, is neither palynomorphic nor aquatic microfossil in that it is the siliceous remains of cells of specific plants. Another type of microfossil, foraminifera, is both polynomorph and non-polynomorph microfossil because it has a non-resistant calcareous tests (segments of the skeleton of the dead plant) and resistant chitinous linings.[5]
Pollen and spores can be dispersed by wind and water and may be deposited over a very wide range. Since pollen and spores are transported over extensive distances before deposition, they are not consistently good sources of information for the environment in which they were deposited having originated elsewhere. They can however be used for the study of ancient climates (e.g. they may be used to study glacial and interglacial periods) and biostratigraphy. Organic chemicals become darker in hotter environments. This characteristic can be used to assess the temperature of the strata during the deposition of the palynomorphs. The color of fossils is useful in determining the possible presence of petroleum or gas since heat from burial in the Earth is a critical component of the process of forming oil and gas from organic deposits.[6][7][8]
Palynology is an interdisciplinary field overlapping with geological and biological sciences.
Disciplinary Subdivisions
Actuopalynology
Actuopalynology is a branch of palynology concerned with the study of microfossils that are either living, retain their cell contents, or whose cell contents have been removed by maceration. This field included further subdivisions of mellisopalynology, pollination ecology, aeroallergy, and criminology. Actuopalynology is distinct from paleopalynology.
Aeroallergy (also a branch of medicine) is concerned with the seasonal variations, abundance, and allerogenic effects of spores and pollen.
Mellisopalynology is the study of pollen in honey and other materials derived from bees.
Pollination ecology studies the distribution of pollen (wind-born or transported by animals) and the efficiency of pollen fertilisation.
Forensic palynology, the science of legal evidence derived from the study of pollen and spores.
Palypaleonology
Palypaleonology includes the fields of stratigraphic palynology, archaeological palynology, and environmental palynology. Palynomorphs studied are specifically fossil remains of non-extant life forms.
Archaeological palynology studies polymorphs at archaeological sites to determine aspects of a life and ecology such as diet, ritual practice, climate, agriculture, and the impact that humans may have had on the environment. Palynomorphs studied may be fossil remains of non-extant life (paleopalynology) or remains of extant life forms (actuopalynology)
Stratigraphic palynology is the study of palynomorphs (identification, distribution, and abundance) so as to establish sedimentary sequences or to provide chronological references for sedimentary sequences.
Environmental palynology is the study of palynomorphs (identification, distribution, and abundance) concerned with determining past changes in the biota, climate, or geology (specifically surface geology). Subdivisions include quaternary palynology and archaeological palynology.
Although environmental and stratigraphic palynology are distinct divisions of palynology, they often overlap in the study of sedimentary sequences.
References
- ↑ resistance due to their composition of material such as sporopollenin, chitin, or related compounds
- ↑ Palynology Definitions Acritarchs Owen Davis, Geosciences, University of Arizona. Acritarch is an “informal utilitarian” category that has no status as a class, order or other suprageneric unit. It includes small microfossils that are of unknown origin and have highly varied biological affinities. Acritarchs have a central cavity which is enclosed by a single or multiple layered wall composed chiefly of organic material. They range in size from 5 to 240 micrometers and have various forms and shapes. They are used in stratigraphic studies of marine sediments of the Paleozoic (about 540 to 120 million years ago) Retrieved 15 June, 2008
- ↑ Chitozoans Owen Davis, Geoscience, University of Arizona. Chitonozoans are extinct marine micro-fossils, usually assumed to be animal remains (e.g. eggs) that are generally shaped like flasks ranging from 50 to 2000 micrometers (micrometer, also called micron, symbol: µm. Equal to one millionth of a meter). Of indeterminate affinity, they occur individually or in chains, and have varied sculptural and basal appendages. Stratigraphically they range from the uppermost Cambrian to Devonian (ca. 510 - 300 Ma).Retrieved 15 June, 2008
- ↑ Tiny Hidden Treasures—The microfossils of Ohio Ohio Department of Natural Resources Scolecodonts Owen Davis, Geoscience, University of Arizona Scolecodonts -- Fossil Polychaete Worm Jaws University of California Museum of Paleotology. Scolecodonts, the jaws of polychaete annelids Retrieved 15 June, 2008. Scolecodonts are the teeth, jaws and associated anatomical parts of class Polychaeta of phylum Annelid (earthworms, leeches etc.), from the Oridivician (ca. 480 million years ago) to the present time. They were composed of scelroprotein, are sometimes mineralised with iron oxide, and range in size from 100 microns to 10 mm in length (usually 0.1 to 2 mm long). Since the bodies of the worms were composed of soft tissue which is rarely fossilised they constitute the chief fossil remains of these creatures.
- ↑ [1] University of Arizona
- ↑ Palynology at the University of Arizona
- ↑ Using Microfossils in petroleum exploration Brian J. O’Neill. University of California Museum of Paleontology
- ↑ Biostratigraphy Els Gervais and Hubert Jansen, J & G Consultants