scholarly journals Behavior of hazardous metal(loid)s release from excavated marine sedimentary rock under atmospheric exposure with drying-wetting cycles

2021 ◽  
Vol 9 (7) ◽  
pp. 363-368
Author(s):  
Yuto Yoshida ◽  
Hirofumi Sakanakura ◽  
Toshihiko Miura ◽  
Masahiko Katoh
Keyword(s):  
Sedimentary Rock ◽  
Atmospheric Exposure ◽  
Hazardous Metal ◽  
Marine Sedimentary Rock

scholarly journals Marine mammals through time: when less is more in studying palaeodiversity

2008 ◽  
Vol 276 (1658) ◽  
pp. 887-892 ◽  
Author(s):  
Felix G Marx
Keyword(s):  
Marine Mammal ◽  
Marine Mammals ◽  
Sedimentary Rock ◽  
Rock Outcrop ◽  
Less Is More ◽  
Apparent Correlation ◽  
Mammal Evolution ◽  
Taxonomic Groups ◽  
Mammal Diversity ◽  
Marine Sedimentary Rock

The validity of biological explanations of patterns of palaeodiversity has been called into question owing to an apparent correlation of diversity with the amount of sedimentary rock preserved. However, this claim has largely been based on comprehensive estimates of global marine Phanerozoic diversity, thus raising the question of whether a similar bias applies to the records of smaller, well-defined taxonomic groups. Here, new data on European Caenozoic marine sedimentary rock outcrop area are presented and compared with European occurrences of three groups of marine mammals (cetaceans, pinnipedimorphs and sirenians). Limited evidence was found for a correlation of outcrop area with marine mammal palaeodiversity. In addition, similar patterns were identified in the cetacean and pinnipedimorph diversity data. This may point to the preservation of a genuine biological signal not overwhelmed by geological biases in the marine mammal diversity data, and opens the door to further analyses of both marine mammal evolution and geological bias in other small and well-defined groups of taxa.

Temporal patterns of barren intervals in the Phanerozoic

Paleobiology ◽  
2008 ◽  
Vol 34 (1) ◽  
pp. 155-161 ◽  
Author(s):  
Andrew B. Smith ◽  
A. J. McGowan
Keyword(s):  
Sedimentary Rock ◽  
Western Europe ◽  
Sedimentary Rocks ◽  
Direct Consequence ◽  
Rock Outcrop ◽  
Shallow Marine ◽  
Marine Diversity ◽  
Marine Realm ◽  
Weak Negative Correlation ◽  
Marine Sedimentary Rock

It has recently been argued that barren intervals of marine sedimentary rock are less common in the Cenozoic than in the Paleozoic, and that this arises as a direct consequence of widespread epeiric seas and the prevalence of dysaerobic conditions at such times. We show, using an independent and more direct measure of rock outcrop through time in western Europe, that barren marine sedimentary rocks do become less frequent toward the present, but that this is not linked to any epeiric-seas effect. The proportion of barren to fossiliferous rock outcrop correlates well with the inferred Phanerozoic marine diversity curve (although more so in the Paleozoic than in the post-Paleozoic), and shows no correlation or only a weak negative correlation with area over which the sediments have been deposited. We therefore concluded that the Phanerozoic trend in fossiliferousness most likely records the degree to which space is occupied in the shallow marine realm.

scholarly journals Cyclicity in the fossil record mirrors rock outcrop area

2005 ◽  
Vol 1 (4) ◽  
pp. 443-445 ◽  
Author(s):  
Andrew B Smith ◽  
Alistair J McGowan
Keyword(s):  
Recent Article ◽  
Sedimentary Rock ◽  
Western Europe ◽  
Rock Outcrop ◽  
Marine Diversity ◽  
Marine Fossils ◽  
History Of ◽  
Long Term Trends ◽  
Marine Sedimentary Rock

In a recent article, Rohde & Muller (Rohde & Muller 2005 Nature 434 , 208–210) identified a strong 62 Myr cyclicity in the history of marine diversity through the Phanerozoic. The data they presented were highly convincing, yet they were unable to explain what process might have generated this pattern. A significant correlation between observed genus-level diversity (after removal of long-term trends) and the amount of marine sedimentary rock measured at a surface outcrop in Western Europe is demonstrated. This suggests that cyclicity originates from long-term changes in sedimentary depositional and erosional regimes, and raises the strong possibility that the cyclicity apparent in the record of marine fossils is not a biological signal but a sampling signal.

Stabilization of Hazardous Materials into Ferrites

1991 ◽  
Vol 23 (1-3) ◽  
pp. 399-404 ◽  
Author(s):  
Y. Tamaura ◽  
P. Q. Tu ◽  
S. Rojarayanont ◽  
H. Abe
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Metal Ions ◽  
Present Method ◽  
Hazardous Materials ◽  
Precipitation Process ◽  
Waste Waters ◽  
Formation Reaction ◽  
Coating Method ◽  
Hazardous Metal

Stabilization of the hazardous materials by the Fe3O4-coating method was studied. In the ferrite-formation reaction in the aqueous solution, the adsorption of the metal ions and the oxidation of the adsorbed Fe(II) ions are repeated on the surface of the ferrite particles. This reaction was adopted to the coating of the hazardous materials with the Fe3O4(or ferrite). By repeating the two steps of l)the addition of the Fe(II) aqueous solution into the suspension of the hazardous materials, and 2)the oxidation by passing air through the reaction suspension, with the Fe3O4 layer, we could coat the surfaces of the hazardous materials, such as the heavy metal sludge from the neutralization-precipitation process, the CaF2 precipitates in the treatment of the waste waters containing fluoride ion along with hazardous metal ions, and the soils containing Cd(II) ion. These Fe3O4-coated hazardous materials are very stable and no heavy metal ions are leached under the normal environmental conditions. The ferrite sludges formed in the “Ferrite Process” were highly stabilized by the present method, and by the heat-treatment.

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