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techniques in paleontology.pptx
- 1. CHAPTER 7…. Techniques inPaleontology Lecturer @ SNU: AbdirizakGeyre
- 2. Contents • Introduction • Fossilization •Excavation Techniques • Tools which used for finding fossils • Find a Marine fossil • Preparing, Preserving and Restorations • Determine the Species of a Fossil • Fossils Age • Important applications with the fossil • Making of fossil • Conclusion • References
- 3. Introduction • Palaeontology orPaleontology is the study of prehistoric life during Past. • It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments (their paleoecology). • Paleontological observations have been documented as far back as the 5th century. • The science became established in the 18th century as a result of Georges Cuvier’s work on comparative anatomy, and developed rapidly in the 19th century • Body fossils and trace fossils are the principal types of evidence about ancient life, and geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave fossils. • As knowledge has increased, Palaeontology has developed specialised subdivisions, such as Vertebrate palaeontology, Invertebrate palaeontology, Paleobotany, Palynology, Micropaleontology and Paleoecology.
- 4. Fossilization • Fossilization ismost likely to occur when an organism dies in a body of water or falls into a body of water shortly after death. The water insulates the organism from total deterioration, and over time what remains becomes trapped beneath large mounds of sediment. • Fossil Preservation; Fossils are preserved in two main ways: with and without alteration. Preservation with alteration includes carbonization, petrifaction, recrystallization replacement,casting and trace fossil. • Preservation without alteration includes the use of molds and the collection of indirect evidence. • Preservation of original form as mold, cast and imprints.
- 5. Excavation Techniques • FossilMatrix Considerations: Paleontologists look for fossils in rock called sedimentary rock. This comes from a matrix of sand and mud that has accumulated over time. It is softer than rocks formed through volcanic eruptions and thus less hard to chip through. • Fossil Location: because the fossil layer is often preserved intact by the actual order of fossilization, this gives paleontologists a powerful clue about where to look for specific fossils. Knowing the habitat of a specific organism may also help paleontologists search locations that once contained the corresponding environment. • Excavation: To initially expose the fossil, broad chunks of rock are taken out with picks or drills. Within a few inches, more subtle tools like chisels, trowels, hammers, whisks and dental drills are used. Larger fossils often require bigger tools.
- 6. Tools which usedfor / separation / in finding out of fossils • Rock Hammers, Jackhammers, Full-Sized Pick Hammer, Sledge Hammer and Pry Bar, Probes , Gloves and Goggles, Brushes, Steel Points and Magnifying Glasses , Rock Chisel, Picks and Shovels, Hand Lenses, Pneumatic Air Scribe, Palaeo Bond, Diamond Saw, Tile Nippers.
- 8. To F in d a M a r i n e fossil • Marine fossils make up the vast majority of fossils from the geological time periods when much of the Earth was under warm, shallow oceans. • Fish appeared in the Ordovician Period (438 to 505 million years ago) as one of the first chordate life forms -- the first organism with a face made up of eyes, a nose and a mouth. Methods Aware about the different species to be found on the ancient 50- million year old Eocene Epoch lake bed covering 25,000 square miles. Familiarize with the stratigraphy and locate one of the several "U- dig" fish fossil quarries in the area. Examine the edges of the slabs/stone for signs of fish fossils. Look for thin, very dark brown lines that contrast with the lighter colored stone.
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- 10. Preparing, Preserving and Restorationof Fossils Palaeontologists’ use finer tools such as dental tools, trowels, small chisels and hammers to carefully remove the fossil. If the sedimentary rock is soft, they will sometimes use a light acid solution to eat away the surrounding rock. Pneumatic air scribes, diamond saws and rock splitters trim, away extraneous rock or sediment surrounding the fossil. Clear acrylic sprays are used in the field to preserve fragile organic remains from drying out and disappearing from the rock. PaleoBond is used as a specialized glue for reassembling broken or damaged fossil pieces during the excavation process. Palaeontologists use either quick-setting glue or a special jacket of plaster of paris applied directly to the fossil before trying to remove the fossil. The cast or glue helps keep the fossil stationary and protects it like a cast a doctor uses to set people's broken bones.
- 12. • Seal afossil with a sealant you can stabilize it, preventing the fossil from flaking or chipping after you remove it from the spot where you found it. • Consolidating the fossil with a sealant hardener will allow to preserve the fossil's imprint so that you can use the fossil for continued research or simply keep it as a collector's item. • Polishing the sample will ensuring the integrity of the fossil study. • Maceration Technique is the separation of microfossil from the matrix by gravity separation or oil floatation method. • Microphotography will help to analyze micro or nano fossil by imaging its structure using microscopic cameras. Cont…
- 13. • Fossil kitis used to correlate fossils specimens according to their occurrence, stratigraphic depth wise etc.,
- 14. Determine the Speciesof a Fossil • There are many resources that a fossil collector can arm himself with to name a species, but it takes a diligent researcher with a keen eye for detail. • Linnean Taxonomy is commonly used for classifying living organisms, but runs into difficulties when dealing with newly-discovered organisms that are significantly different from known ones. • Linnean rules for naming groups are tied to their levels, and hence if a group is moved to a different level it must be renamed, i.e. binomial nomenclature. Levels in the Linnean Taxonomy
- 15. Assessment of FossilsAge • Fossils do leave certain clues in the environment that can help determine their age. • The age of the very ground or rock it was unearthed from may indicate how long a fossil was laid to rest before taking up residence in a museum. Methods of Dating Fossils • Relative dating is based on the laws of stratigraphy. Relative dating does not give you a specific age of the fossil but can tell you a general time period based on the geologic beds above and below the place the fossil was found • Absolute dating or chronometric dating is based primarily on the physical process of radioactive decay. Many minerals contain pure, radioactive, chemical elements.eg; Carbon dating, Potassium- argon dating, Argon-argon dating, etc., • Scientists measure the relative proportions of different elements in rocks, to deduce when the mineral formed.
- 16. • Palaeomagnetism isas rocks formed, the Earth's magnetic field affected the small iron-rich particles within the rock, causing the particles to line up. The Earth's magnetic field varies through time, both in strength and orientation. Certain rocks, usually volcanic in origin, preserve these magnetic changes. Palaeontologists’ have dated these sequence changes; therefore, the age of fossils found is directly related to the age of the volcanic layers above or below the specimen. • Compass- Clinometer is the device that palaeontologists’ used to measure the incline, or dip, of the boundary separating one layer of rock from the layers above and below at various magnetic compass orientations. Paleontologists assess the nature, formation and movement of each rock layer with the exposed fossil, enabling them to approximate the fossil's age. • Index Fossils Some organisms are extremely widespread as fossils with recognizable characteristic changes, making these sequences useful for dating. These well-known fossils are known as index or dating fossils, and help to pinpoint the time of more obscure fossils found with them
- 17. Important Applications with theFossil • Natural Gas Products acts as a desiccant in the manufacturing of consumer products from fossil fuels removing any moisture from the material and ensuring the integrity of the product. Because the presence of moisture during the processing of plastic can cause blemishes and other breakdowns in the makeup of the manufactured substance. • Petroleum has been used for making products for over 150 years. One of the first uses of petroleum in the manufacture of consumer products was invented by Robert Chesebrough, a chemist whose use of balm from an oil well in 1872 gave birth to Vaseline. Vehicle tires are colored black from a process that involves the combustion of oil. This introduction of "carbon black" by the B.F. Goodrich Company in 1910 changed the standards for tire production, which previously were colored white.
- 18. • Coal hasbeen in use as a heating fuel for centuries, and is probably one of the first fossil fuels to be adapted to the manufacture of products for consumer use. Early coal processing produced the by- products coal tar and coke. Coal tar is used for making insecticides, paint thinner, disinfectants, batteries and insulation. Coke is used in the manufacture of synthetic rubber materials, artificial silk and soda water. • Oil is one of the most-often used fossil fuels for the manufacture of consumer products. Toys, telephones, floor coverings, contact lenses, dyes, dishes, diapers, analog recording tape, shower curtains and a variety of chemical products such as paints, varnishes, and adhesives are just a few of the products made from oil. • Recognized Products, the earliest of all consumer products made from fossil fuels is vehicle fuel. Gasoline products were developed hand-in-hand with the automobile as the main fuel for the internal combustion engine. Later innovations in engine technology have forced the gasoline-producing industry to keep up with changes in engine performance and fuel economy guidelines and mandates demanded by both vehicle manufacturers and consumers.
- 19. Making of fossil •The fossils they find are rare and as such can be valuable tools for research into life on Earth in the time of the dinosaurs. For much of the research, scientists prefer to use casts of the fossil rather than the actual fossil to prevent damaging the rare find. Making a mold and cast of a fossil can be a great lesson for the students. Methods • Simply shape some heavy-duty aluminium foil so that it forms a bowl, with the centre area being flat and smooth and the surrounding walls secure from leakage. • Pour a small amount of prepared plaster of paris or 2 to 3 pinches of sand with a ball of clay in the centre of the aluminium bowl. The sand will give the clay a rock like appearance when it hardens. • Insert a shell or other small object into the plaster or mix and let the mixture harden. • Remove the aluminium foil to reveal your fossil.
- 20. Conclusion •Paleontological Techniques areimportant stage in Palaeontology. If any mistake in the field, that mistake enters into laboratory, from laboratory to report. •Utmost care should taken in paleontological techniques to get appropriate results. • Fossils reconstruction helps in understanding its habit, its paleoenvironmental studies. •Techniques will change time to time in exploration of fossils. •Paleontological techniques play a vital role in reconstruction of Earth’s history.
- 21. References • Dr. P.C.Jain and Dr. M.S. Anantharaman 2010 -Paleontology, Evolution and Animal Distribution; (7th edition) Pp.13-35. • Henry Woods 1961 -Paleontology Invertebrate, Cambridge Publication. websites • eHow.com http://www.ehow.com/about_6494983_do- paleontologists-date-fossils_.html#ixzz29ATejY00 • www.intellicus.com • www.buriedtreasurefossils.com • www.tecwriter.com • siemens.co.in/Fossil-Power