Radiolarians in the Sedimentary Record

Radiolarians in the Sedimentary Record PDF Author: P. De Wever
Publisher: CRC Press
ISBN: 9789056993368
Category : Science
Languages : en
Pages : 700

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Book Description
Radiolarians in the Sedimentary Record presents the current state of knowledge on fossil radiolarians. The author discusses the record, as well as new integrated taxonomic systems at the family level. The book provides comprehensive coverage of the fossil record of these unicellular organisms. It also discusses their important role in the history of the Earth and their development of the biosphere. This text will prove indispensable for graduate students and researchers in geology, oceanography and earth sciences.

Radiolarians in the Sedimentary Record

Radiolarians in the Sedimentary Record PDF Author: P. De Wever
Publisher: CRC Press
ISBN: 9789056993368
Category : Science
Languages : en
Pages : 700

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Book Description
Radiolarians in the Sedimentary Record presents the current state of knowledge on fossil radiolarians. The author discusses the record, as well as new integrated taxonomic systems at the family level. The book provides comprehensive coverage of the fossil record of these unicellular organisms. It also discusses their important role in the history of the Earth and their development of the biosphere. This text will prove indispensable for graduate students and researchers in geology, oceanography and earth sciences.

Vertical Flux, Ecology and Dissolution of Radiolaria in Tropical Oceans

Vertical Flux, Ecology and Dissolution of Radiolaria in Tropical Oceans PDF Author: Kozo Takahashi
Publisher:
ISBN:
Category : Marine sediments
Languages : en
Pages : 562

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Book Description
Radiolarians which settle through the oceanic water column were recovered from three stations (western Tropical Atlantic-Station E, central Tropical Pacific-P1 and Panama Basin-PB) using PARFLUX sediment traps in moored arrays at several depths. The taxonomic diversities of the radiolarian assemblages in the sediment traps were very high. A total of 420 taxa, including 23 newly identified taxa, were found at the three stations; of these, 208 taxa were found at station E. The polycystine radiolarians generally reach the sea floor with little change in abundance or species composition, although slight skeletal dissolution occurs throughout their descent. The phaeodarian radiolarians, on the other hand, are largely dissolved within the water column; only a few species reach the sea-floor and these dissolve rapidly at the sediment-water interface. Most radiolarian skeletons sink as individuals through deep water columns without being incorporated into large biogenic aggregates. Because significant numbers of nassellarian and phaeodarian species are deep-water dwelling forms the diversity index of radiolarians increases with increasing depth in the mesopelagic zone. The vertical flux of the total radiolarians arriving at the trap depths (in x 103 individuals/m2/day) ranged from 16-24 (E), 0.6-17 (Pl), and 29-53 (PB). Of these on the average 25 % and 69 % of the total radiolarian flux is transported by Spumellaria and Nassellaria, respectively, while 5 % is carried by Phaeodaria. The measured SiO2 content of the skeletons averaged 91, 98 and 71 % of measured weight for Spumellaria, Nassellaria and Phaeodaria, respectively. The supply of radiolarian silica (mg SiO 2 /m 2/day) to each trap depth ranged from 2.5-4.0 (E), 0.9-3.2 (P), and 5.7-10.4 (PB). The Radiolaria appear to be a significantly large portion of the SiO2 flux in>63 pm size fraction and thus play an important role in the silica cycle. When the radiolarian fluxes at the three Stations are compared with Holocene radiolarian accumulation rates in the same areas it became apparent that several percent or less of the fluxes are preserved in the sediments in all cases and the rest is dissolved on the sea-floor. Estimated excess Si which is derived from SiO2 dissolution on the sea-floor is fairly small relative to advective Si in the western North Atlantic and thus it appears to be insignificant to show any deviation in a simple mixing curve of deep water masses. Weight, length, width, projected area and volume of 58 radiolarian taxa were measured. The density contrast of radiolarians, relative to seawater, generally falls between 0.01 and 0.5 g/cm33. The sinking speed of 55 radiolarian taxa, measured in the laboratory at 3*C, ranged from 13 to 416 m/day. Despite the wide variety of morphology between the species, sinking speeds were best correlated with weight/shell among all the possible combinations of the examined variables. The estimated residence times of these taxa in the 5 km pelagic water column ranged from 2 weeks to 14 months. Large phaeodarians reached the water-sediment interface relatively quickly and ultimately dissolved on the sea floor. Small-sized taxa dissolved en route during sinking. The standing stock of 26 examined abundant taxa is on the order of 1 to 100 shells/m3 . Total radiolarian standing stock ranges from about 450 shells/m3 at Stations P1 and E to 1200 shells/m 3 at Station PB. The rate of production of total Radiolaria is calculated to be 77 to 225 shells/m 3 /day. The turnover time for these species ranges from several days to one month depending on the species and the assumption of the depth interval used for the estimation.

Eocene Radiolarian Faunas from the Mt. Diablo Area, California

Eocene Radiolarian Faunas from the Mt. Diablo Area, California PDF Author: Bruce Lawrence Clark
Publisher: Geological Society of America
ISBN: 0813720397
Category : Paleontology
Languages : en
Pages : 133

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Vertical Flux of Sedimentary Radiolaria

Vertical Flux of Sedimentary Radiolaria PDF Author: Kozo Takahashi
Publisher:
ISBN:
Category : Geology
Languages : en
Pages : 111

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Radiolaria in Pelagic Sediments from the Indian and Atlantic Oceans

Radiolaria in Pelagic Sediments from the Indian and Atlantic Oceans PDF Author: Catherine Anne Clark
Publisher:
ISBN:
Category :
Languages : en
Pages : 106

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Tertiary Radiolaria in Western Pacific Sediments ... With a Note by Hans Petterson: Current Observations Close to the Ocean Bottom

Tertiary Radiolaria in Western Pacific Sediments ... With a Note by Hans Petterson: Current Observations Close to the Ocean Bottom PDF Author: William R. RIEDEL
Publisher:
ISBN:
Category :
Languages : en
Pages : 21

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Radiolaria in surface sediments of the South Atlantic

Radiolaria in surface sediments of the South Atlantic PDF Author: R.M. GOLL
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Radiolaria

Radiolaria PDF Author: Jonathan Aitchison
Publisher: Springer Science & Business Media
ISBN: 3764383445
Category : Science
Languages : en
Pages : 137

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Book Description
Radiolaria are a very diverse marine siliceous microplankton group that have existed at least snice the Cambrian to the recent. This volume gives a representative view of research topics discussed at the 10th International Meeting of Radiolarian Palaeontologists. The articles of this volume cover mainly radiolarian biochronology and radiolarian fauna changes.

Quantitative Radiolarian-based Paleo-oceanography in Late Pleistocene Subarctic Pacific Sediments

Quantitative Radiolarian-based Paleo-oceanography in Late Pleistocene Subarctic Pacific Sediments PDF Author: Harvey Maurice Sachs
Publisher:
ISBN:
Category : Ocean temperature
Languages : en
Pages : 416

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Tertiary Radiolaria in Western Pacific Sediments

Tertiary Radiolaria in Western Pacific Sediments PDF Author: W. R. Riedel
Publisher:
ISBN:
Category : Ocean bottom
Languages : en
Pages : 30

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