Ge/Si record of marine biogenic opal ...
We have determined germanium/silicon ratios in purified diatoms and radiolarians from siliceous sediments in Holocene core tops, one late Pleistocene piston core, and four high-latitude Southern Ocean Deep Sea Drilling Project (DSDP) sites ranging in age from Holocene to Oligocene. High-latitude Hol...
| Main Authors: | , , |
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| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
PANGAEA
1989
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.1594/pangaea.726997 https://doi.pangaea.de/10.1594/PANGAEA.726997 |
| Summary: | We have determined germanium/silicon ratios in purified diatoms and radiolarians from siliceous sediments in Holocene core tops, one late Pleistocene piston core, and four high-latitude Southern Ocean Deep Sea Drilling Project (DSDP) sites ranging in age from Holocene to Oligocene. High-latitude Holocene diatoms in the 10- to 38-µm size fraction ([Ge/Si]opal = 0.693 +/- 0.039 * 10**-6) faithfully record the present oceanic ratio ([Ge/Si]seawater = 0.699 +/- 0.004 * 10**-6). This confirms that diatoms from siliceous oozes are monitors of seawater Ge/Si and may record past changes in rates of delivery of weathering products to the sea from continental and seafloor weathering. Large diatoms and radiolarians display ratios much lower than (Ge/Si)seawater, suggesting that (Ge/Si)opal, to some extent, displays the effects of biological fractionation. From 0 to 2.5 m.y.B.P., (Ge/Si)opal in diatoms from DSDP sites ranges from about 0.54 to 0.70 * 10**-6, similar to the range observed in one late Pleistocene piston ... : Supplement to: Shemesh, Aldo; Mortlock, Richard A; Froelich, Philip N (1989): Late Cenozoic Ge/Si record of marine biogenic opal: implications for variations of riverine fluxes to the ocean. Paleoceanography, 4(3), 221-234 ... |
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