959 resultados para upper-semicontinuity
Resumo:
This report contains the occurrence data for dinoflagellate cysts recorded from 163 samples taken from Sites 902 through 906, during Ocean Drilling Program (ODP) Leg 150. The dinoflagellate cyst (dinocyst) stratigraphy has been presented in Mountain, Miller, Blum, et al. (1994, doi:10.2973/odp.proc.ir.150.1994), and was based on these data. This report provides the full dinocyst data set supporting the dinocyst stratigraphic interpretations made in Mountain, Miller, Blum, et al. (1994). For Miocene shipboard dinocyst stratigraphy, I delineated 10 informal zones: pre-A, and A through I, in ascending stratigraphic order. These zones are defined in Shipboard Scientific Party (1994a, doi:10.2973/odp.proc.ir.150.103.1994), and are based on my studies of Miocene dinocyst stratigraphy in the Maryland and Virginia coastal plain (de Verteuil and Norris, 1991, 1992; de Verteuil, 1995). This zonation has been slightly revised (de Verteuil and Norris, 1996), and the new formal zone definitions are repeated below. Each new zone has an alpha-numeric abbreviation starting with "DN" (for Dinoflagellate Neogene). The equivalence between the informal zones reported in Mountain, Miller, Blum, et al. (1994), and the new DN zones is illustrated in Figure 1. For clarity, I delineated both zonations in the range charts that accompany this report (Tables 1-6). De Verteuil and Norris (1996a), using these and other data, correlated the DN zonation with the geological time scale of Berggren et al. (1995). Figure 2 summarizes these correlations and can be used to check the chronostratigraphic position of samples in this report, as determined by dinocyst stratigraphy. A thorough discussion of the basis for, and levels of uncertainty associated with, these correlations to the Cenozoic time scale can be found in de Verteuil and Norris (1996a). The Appendix lists all the dinocyst taxa recorded during shipboard analyses of Leg 150 samples. Open nomenclature is used for undescribed taxa. The range charts and Appendix also include reference to several new taxa that de Verteuil and Norris (1996b) described from Miocene coastal plain strata in Maryland and Virginia. Names of these taxa in Tables 1 through 6 and in the Appendix of this report are not intended for effective publication as defined in the International Code of Botanical Nomenclature (ICBN, Greuter et al., 1994). Therefore, taxonomic nomenclature contained in this report is not to be treated as meeting the conditions of effective and valid publication (ICBN; Article 29).