864 resultados para Deep-Ocean
Resumo:
An analysis of earlier measurements and author's data serves as a basis for a discussion of origin of deep-sea hydrogen. High hydrogen concentrations (0.001 ml/l or higher) in geothermal brines of the Atlantis II Deep depression are of abiogenic origin.
Resumo:
Calcareous and siliceous biogenic components have been studied in deep-water iron-manganese nodules from the northern and southern Pacific Ocean. Calcareous material consists of foraminifera remains, calcareous algae, and coccolithophorids, whereas siliceous material consists of remains of radiolarians and diatoms, as well as sponge spicules. Structures similar in morphology to coccal and filiform bacteria have been found in both outer and inner sections of the nodules indicating that microorganisms may be directly or indirectly involved in their development.
Resumo:
The monograph presents results of comprehensive geological and geophysical studies carried out in 1973 and 1976 during Cruises 54 and 58 of R/V "Vityaz" in the Eastern Indian Ocean. On the base of obtained data a description of topography, magnetic and gravity fields, structure of the sedimentary series and deep crustal structure of the East Indian Ridge, Central, West Australian and Cocos Basins, the Sunda Trench has been done. Materials on petrography, petrochemistry and geochemistry of igneous rocks in the region have been summarized. New geological and geophysical information has been compared with with DSDP materials. Tectonics and geological history of the Eastern Indian Ocean are under consideration.
Resumo:
Abyssal agglutinated foraminifers allow biostratigraphic correlation of Upper Cretaceous brown zeolitic claystones in Deep Sea Drilling Project Holes 196A and 198A and Ocean Drilling Program Holes 800A and 801 A. Three agglutinated foraminiferal zones subdivide the strata overlying the Campanian to Cenomanian cherts. The lower zone is characterized by Hormosina gigantea, which is a Campanian zonal marker in the North Atlantic Ocean and western Tethys. A major correlation level, which was observed in all holes studied, is based on the acme of evolute Haplophragmoides spp. This acme zone was observed in Sample 129-801A-6R-CC, about 9 m above the first occurrence of H. gigantea in Sample 129-801A-7R-1, 62-67 cm (approximately middle Campanian). The uppermost zone is characterized by dominant Paratrochamminoides spp. and in some instances common Bolivinopsis parvissimus (late Campanian to Maestrichtian). The available biostratigraphic data for the Upper Cretaceous of Sites 196, 198, 800, and 801 are correlated with the biochronologic framework of the North Atlantic, western Mediterranean, and Carpathians. Additionally, we use quantitative estimates of the diversity and abundance of agglutinated foraminiferal species to monitor general faunal trends with time in the western Pacific.
Resumo:
The present volume contains the planktological data collected during the expedition of the "Meteor" to the Indian Ocean in 1964/65. It was the main objective of the expedition to study the up- and downwelling conditioned along the western and eastern coasts of the Arabian Sea by the northeastern monsoon. It is from these areas that the greater part of the data here presented was obtained. A few values from the Red Sea have been added. As the title "Planktological-Chemical Data" implies, it was chiefly with the help of chemical methods that the planktological investigations, with the exception of the particle size analysis and phytoplankton counting conducted optically, were carried out. These investigations were above all devoted to a quantitative survey of particulate matter and plankton, the latter being sampled by water-bottle and net. The zooplankton hauls were taken with the Indian Ocean Standard Net according to the international guidelines laid down for the expedition. As a rule, double catches were made at every station, one sample being intended for laboratory analysis at the Indian Ocean Biological Centre in Ernakulam, South India, and the other for the Institut für Meereskunde in Kiel. In addition to determining the standing stock, the production rate of phytoplankton was measured by the 14C method. These experiments were mainly conducted during the latter half of the expedition. The planktological studies primarily covered the euphotic zone, extending into the underlying water layers up to a depth of 600 m. The investigations were above all directed towards ascertaining the quantity of organic substance, formed by primary production, in its relation to environmental conditions and determining whether or not organic substance is actively transported from the surface into the deeper layers by the periodically migration organisms of the deep scattering layers. Depending on the station time available, a few samples could now and then be taken from deeper layers. The present volume of planktological-chemical data addresses itself to all those concerned processing the extensive material collected during the International Indian Ocean Expedition. As a readily accessible work of reference, it hopes to serve as an aid in the evaluation and interpretation of the expedition results. The complementary ecological data such as temperature, salinity, and oxygen content as well as the figures obtained on abundance and distribution in depth of the nutrients essential for primary production may be found in the volume of physical-chemical data published in Series A of the "Meteor"-Forschungsergebnisse No. 2, 1966 (Dietrich et al., 1966).