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PROVENANCE OF THE NEOPROTEROZOIC OCOEE SUPERGROUP, EASTERN GREAT SMOKY MOUNTAINSChakraborty, Suvankar 01 January 2010 (has links)
The Ocoee Supergroup is a sequence of Neoproterozoic, immature, continental rift facies clastic sediments. Potential source rocks were tested by analyzing modes of detrital framework minerals, detrital mineral chemistry, whole rock geochemistry and detrital zircon U/Pb geochronology by LA-ICP-MS for Ocoee siltstone-sandstone dominated formations. Ocoee units are arkosic to subarkosic siltstones/sandstones, and ternary tectonic discrimination diagrams confirm a continental basement uplift source. Alkali feldspar predominates over plagioclase feldspar. Detrital feldspar compositions of Ocoee sediments as a group are similar to feldspar in local basement granitic rocks except for high-Ca plagioclase grains present locally in basement granitic rocks. The high alkali content of the detrital feldspars in the Ocoee Supergroup is consistent with derivation from an A-type granite source terrane. Normative Q-A-P values, calculated from wholerock chemistry, and trace element diagrams are also supportive of an A-type granite source for these rocks. The siltstones and sandstones of the Snowbird Group contain high abundances of heavy minerals (zircon, titanite, ilmenite, epidote and apatite), which are dispersed among other detrital grains and as concentrations of heavy minerals in discrete laminae. ZTR index and titanite mineral chemistry suggest a granitic source for these sediments. Detrital zircon geochronology in Ocoee sediments indicates a dominantly Grenville (1000 to 1300 Ma) source for these sediments. The youngest zircon age in the basal Ocoee Wading Branch Formation (639±8 Ma) is related to rift magmatism and provides a minimum depositional age for the Ocoee Supergroup.
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Determinants of Clinal Variation in Life History of Dusky Salamanders (Desmognathus Ocoee): Prey Abundance and Ecological Limits on Foraging Time Restrict Opportunities for Larval GrowthBernardo, Joseph, Agosta, Salvatore J. 01 April 2003 (has links)
Recent models argue that thermal environments are the major cause of ectotherm life-history clines. However, elevational clines in body size in the mountain dusky salamander Desmognathus ocoee (family Plethodontidae) shift from positive at hatching, to negative at metamorphosis to positive again as adults, and so are not consistent with this explanation. The clinal shift from hatching to metamorphosis was investigated by examining the clinal and seasonal feeding patterns of larval salamanders at high and low elevation sites in rockface and woodland habitats. Repeated cohort sampling was also used to examine clinal and seasonal patterns in body size and to estimate average growth rates. Larval growth in both rockface and woodland habitats was tightly correlated with feeding activity. Although temperature was found to vary between high and low elevation sites, the greatest growth occurred in a cold woodland habitat with a high elevation, and the lowest growth occurred in an adjacent rockface habitat. Because this difference in growth cannot be attributed to thermal differences, we conclude that local food resource levels are the predominant source of local differences in growth. These findings, clinal patterns of variation in other predatory salamanders, and experimental analyses in which both food and temperature are orthogonally manipulated, indicate that general models that single out temperature as the principle cause of ectotherm life-history clines should be viewed with caution.
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Constructing African American Histories In Central FloridaParry, Katherine 01 January 2008 (has links)
From the time of their occurrence up to the present, people have constructed and revised narratives about violent racial events in Florida. In the case of the racial violence in Ocoee and the lynching of July Perry, multiple accounts coexisted until one particular group in the 1990's contested earlier conservative white Southern narratives with new public memories containing African American perspectives of the events, demanding racial justice and memorialization of the events. A struggle over the power to construct this narrative resulted in compromises between the two sets of memories. While some goals were attained, the landscape of memorization remains undeveloped. The construction of a narrative concerning the meaning of Harry T. Moore's life and death entered the public domain at his death and remained unchanging, carried forward by the collective memories of African Americans in Florida. Historians reassessed his role as a martyr for civil rights to the first martyr of the Civil Right's Movement. A group of African Americans in Brevard County were successful in attaining resources that included landscape and a memorial complex during the 1990's and the first decade of 2000. The construction of public memories and the power to gain landscape and resources for commemoration reflected the aims and power of each group. Because the public memories of July Perry were contested, the group could not attain commemorative landscapes. However, the narratives about Harry T. Moore had consensus, allowing significant commemorations.
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