A simple method for the rapid determination of biogenic opal in pelagic marine sediments
In: Deep-Sea Research (1953). Pergamon: Oxford; New York. ISSN 0146-6291; e-ISSN 1878-2485, meer
|  |
| Trefwoorden |
Analysis > Chemical analysis
Analysis > Sediment analysis
Chemical compounds > Silicon compounds > Silica
Fossils
Minerals > Silicate minerals > Opal
Sedimentation > Pelagic sedimentation
Sediments > Biogenic deposits
Separation > Chemical extraction
Marien/Kust |
| Auteurs | | Top |
- Mortlock, R.A.
- Froelich, P.N.
|
|
|
| Abstract |
Biogenic opal in marine sediments is determined with a single extraction of silica into 2 M Na2 CO3 solution at 85 degree C for 5 h. The method has been applied to sediments of varied opal contents (3-100% opal) and age (Recent to Pliocene). It is sufficiently simple, precise and rapid to be used routinely for high resolution spatial and temporal mapping of the biosiliceous component in deep-sea sediments. Evidence from timed dissolution experiments, germanium/silicon ratios, and comparisons with other methodologies demonstrates that systematic errors produced by leaching of silica from aluminosilicates or by incomplete dissolution of siliceous microfossils are small compared to the range of opal contents in biogenic sediments. When estimating mass accumulation rates, the authors report sedimentary biogenic opal both as %SiOPAL (silicon content) and as %OPAL (2.4 x %SiOPAL). This conversion accounts for the average water content of diatomaceous silica (about 10% water = SiO2 multiplied by 0.4 H2O). |
|
