88 resultados para Weed occurrence
em Publishing Network for Geoscientific
Resumo:
Unusually well preserved Cretaceous radiolarians are observed in the subsurface sections from two drilled sites in the Weddell Sea collected during Leg 113 of the Ocean Drilling Program. Radiolarians from the lithified calcareous chalk of Hole 689B represent the first Campanian-Maestrichtian assemblage which is characterized by abundant Cromyodruppa Iconcentrica, Dictyomitra multicostata, and Protostichocapsa stocki. Abundant Pseudodictyomitra pentacolaensis and Diacanthocapsa sp. 1, on the other hand, are the main constituents of the assemblage from the latest Aptian/earliest Albian diatomite of Hole 693B. These represent the oldest and the highest-latitude reported radiolarian occurrences from the Atlantic sector of the Antarctic Ocean. The assemblages are marked by their low diversity and an absence of low- to mid-latitude zonal indices.
Resumo:
Forty-one samples from the lower section (between approximately 370 and 495.5 mbsf) drilled at ODP Site 738 (southern Kerguelen Plateau) were analyzed for their palynomorph content. The majority proved to be palynologically barren. Twenty-one species and subspecies of dinoflagellate cysts were recorded, however, from the eight samples that proved productive. The irregular distribution of the cysts makes accurate age determinations difficult, particularly for the lower part of the succession. However, species recovered from Cores 119-738C-21R to 119-738C-23R indicate a latest Maastrichtian age.