排序方式: 共有2条查询结果,搜索用时 15 毫秒
1
1.
Saioa Elordui-Zapatarietxe Núria Moraleda Joan Albaigés 《Marine pollution bulletin》2010,60(10):1667-1673
Spills from wrecks are a potential major source of pollution in the deep ocean. However, not much is known about the fate of a spill at several kilometers depth, beyond the oceans continental shelves. Here, we report the phase distribution of hydrocarbons released from the wrecks of the Prestige tanker, several years after it sank in November 2002 to depths between 3500 and 3800 m. The released oil reached the surface waters above the wrecks without any signs of weathering and leaving an homogenous signature throughout the water column. At depths of several kilometers below the sea surface, the occurrence and spread of the deep sea oil spill could be evaluated better by quantifying and characterizing the dissolved hydrocarbon signature, rather than just the investigation of hydrocarbons in the suspended particulate matter. 相似文献
2.
Saioa Suárez Hazel M. Prichard Francisco Velasco Peter C. Fisher Iain McDonald 《Mineralium Deposita》2010,45(4):331-350
The distribution, mineralogy and mobility of the platinum-group elements (PGE) in the surface environment are poorly understood.
This study of the lower, less altered and upper, more altered gossan, overlying the Aguablanca Ni–Cu-(PGE) magmatic deposit
(Spain), has shown that the platinum-group minerals (PGM) are progressively oxidised and dispersed into iron oxides that form
the gossan. A combination of the characterization of PGE in host PGM, using a scanning electron microscope, and measurement
of PGE at lower concentrations in host iron oxides, using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS),
has for the first time allowed the total distribution of the PGE within a gossan to be documented. This study has revealed
a complete in situ alteration and dispersion sequence of the PGM including (1) breakdown of both the more stable Pt-arsenides,
Pt/Pd-tellurides and the less stable bismuthotellurides, (2) formation of partially oxidised PGM, (3) development of a wide
range of oxidised Pt- and Pd-bearing phases, (4) subsequent formation of Fe–PGE-oxides and PGE-hydroxides, (5) incorporation
of PGE into ferruginous supergene products and lastly (6) concentration of PGE at the edges of veins and iron oxides. Dispersion
of Pd is greater than for the other PGE with Pd being widely distributed throughout the iron oxides. This oxidising environment
produced PGE-oxides rather than PGE-alloys, also commonly found in the surface environment, especially in placers. These results
provide critical evidence for the stages of mineralogical change from PGE host mineralogy in magmatic ores to surface weathering
producing PGE-oxides. 相似文献
1