Fossil preservation

Canfield D. E. and Raiswell R. (1991) Pyrite formation and fossil preservation. In Taphonomy Releasing the Data Locked in the Fossil Record. Topics in Geobiology 9 (eds. P. A. Allison and D. E. G. Briggs). Plenum, New York, pp. 411-453. 

Bottjer D. J., Etter W., Hagadorn J. W., and Tang C. M. (2002) Exceptional Fossil Preservation A Unique View on the Evolution of Marine Life. Columbia University Press, 403pp. 

Allison, P.A. Pye, K. (1994) Early diagenetic mineralization and fossil preservation in modern carbonate concretions. Palaios 9, 561-75. 

Schlanger S. O., Douglas R. G., Lancelot Y., Moore T. C. and Roth P. H. (1973) Fossil preservation and diagenesis of pelagic carbonates from the Magellan Rise, central North Pacific Ocean. Initial Reports of the Deep Sea Drilling Project 17, 407-427. 

Schopf JM (1973) The contrasting plant assemblages from Permian and Triassic deposits in southern continents. In Logan A, tfills LV (eds) The Permian and Triassic system and the mutual boundary. Canadian Society of Petroleum Geologists, Memoir 2., Calgary, Alberta, Canada, pp 379-397 Schopf JM (1975) Modes of fossil preservation. Rev Palaeobot Palynol 20 27-53... 

Because of their well-developed exoskeletal armour , fossils preserving whole articulated heterostracans considerably outnumber those of conodonts. These articulated specimens have also been known and studied for a longer period of time, but this seems simply to have increased the range and variability of interpretations of how they fed (see Figure 12.7). The evidence from conodonts, myxinoids and... 

From the beginnings of ecology as a discipline, the mining industry has been at the center of the battle over preservation versus exploitation. As discussed in the introduction to this chapter, human activities such as mining, power production from fossil fuels and discharges of industrial and municipal wastes not only increase the rate at which metals enter the biosphere but may also drastically alter the speciation of metals from what it would be in the undisturbed geologic cycle. 

Records of past environmental change are preserved in a broad range of Earth materials. Past environments are inferred from "proxy" records, meaning measurements of physical and chemical parameters of marine and terrestrial sediment, polar ice, and other materials that were in some way influenced by their environment during accumulation. Examples of proxy records are the distribution of glacial deposits, the isotopic composition of terrestrial and marine sediments and ice, the abundance and species composition of plant and animal fossils, and the width of tree rings. 

The preservation of biogenic isotopic signals ( C, N) in fossil bones and teeth is critical in order to interpret paleodiets. Some patterns of variation of these biogenic isotopic signals are characteristic of modern mammals, and their recognition in fossil samples provides a clue for the preservation of biogenic paleodietaiy signals. 

BIOGENIC ISOTOPIC SIGNALS USED TO ASSESS THE PRESERVATION OF ISOTOPIC SIGNALS IN FOSSIL SAMPLES FROM C3 PLANT FOOD WEBS... 

The approach proposed to check the preservation of isotopic signatures in Pleistocene samples from cold and temperate areas is to look for these specific signatures whenever possible, by selecting the appropriate specimens in the studied localities, before trying to interpret isotopic variations in fossil samples. The next section will provide examples of this approach in several cases published for Eurasia and Alaska. 

Hare, PE. and von Endt, D. 1990 Variable preservation of organic matter in fossil bone. Annual Report of the Director of the Geophysics Laboratory. Carnegie Institution, Washington. 1989-1990. Washington, D.C., Carnegie Institution ofWashington 115-118. 

Tuross, N., Fogel, M.L. and Hare, P.E. 1988 Variability in the preservation of the isotopic composition of collagen from fossil bone. Geochimica et Cosmochimica Acta 52 929-935. 

Schoeninger, M.J., Moore, K.M., Murray, M.L. and Kingston, J.D. 1989 Detection ofbone preservation in archaeological and fossil samples. Applied Geochemistry 4 281-292. 

Figure 10. SEM photographs of polished, etched thin sections of fossil Acropora palmata coral (after Edwards 1988). The scale bar in a is 10 microns, a depicts sample AFS-12, a last interglacial coral from Barbados. The crystal morphology in this well-preserved sample is indistingnishable from that of a modem sample (see Fig. 9b). The scale bar in b is 100 microns, b depicts sample PB-5B, a fossil coral collected from North Point Shelf on Barbados. The crystal morphology of this sample shows clear evidence of alteration, inclnding a large calcite crystal filling in a macroscopic pore (dark area in npper right portion of photograph).

The criticisms of these results centre on the provenance of the dated faunal material, and the U uptake models employed by Swisher III et al.(1996). In a reply to the paper, Grun and Thome (1997) suggest the river terrace where the material was found had been reworked many times, mixing older with younger material, and that the state of preservation between the hominid remains and the faunal remains was sufficiently different to suggest they had fossilized in a different environment. In addition, they doubt whether the U uptake models employed are appropriate. In the future, direct dating of the hominid remains themselves will address the first problem, a more sophisticated U uptake model would be required to address the second. 

Chemical processes should be designed as part of a sustainable industrial activity that retains the capacity of ecosystems to support both life and industrial activity into the future. Sustainable industrial activity must meet the needs of the present, without compromising the needs of future generations. For chemical process design, this means that processes should use raw materials as efficiently as is economic and practicable, both to prevent the production of waste that can be environmentally harmful and to preserve the reserves of raw materials as much as possible. Processes should use as little energy as is economic and practicable, both to prevent the build-up of carbon dioxide in the atmosphere from burning fossil fuels and to preserve the reserves of fossil fuels. Water must also be consumed in... 

Fossilized primates, especially fossilized humans, are, unfortunately, particularly rare, and this partly explains why the evolutionary history of human beings is incomplete and continuously being revised. Still, the few fossilized human remains that have been preserved provide the main foundations for modem human evolution theories (Reader 1981). 

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