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13.
藏南白垩系黑-红层沉积岩有机质组成分布特征 总被引:1,自引:0,他引:1
对藏南江孜县床得剖面白垩系黑层和红层沉积岩进行的有机地球化学研究表明,黑层有机碳含量高于红层5~10倍,红层和黑层饱和烃主峰碳数分别为nC25和nC23;黑层和红层沉积有机质的母质来源都以水生植物和菌藻类等低等生物为主,陆源有机质的输入非常有限;但饱和烃的分布和主峰碳数的差异可能反映了有机母源物质在种群方面的差异,而这种差异可能主要是水体温度存在差异造成的,即红层发育时期水体温度可能高于黑层沉积时期.而在高温度条件下,水生生物和陆生植物的生长发育受到限制,造成原始有机质产率和有机质沉积保存量低可能是红层沉积岩形成的主要原因. 相似文献
14.
Multivariate analysis of heavy metal contents of sediments from Gumusler creek, Nigde, Turkey 总被引:2,自引:0,他引:2
In this study, heavy metal contents of samples from Gumusler creek in Turkey were studied and the metal contamination characteristics
were investigated. In this respect, considering the pollutant sites in the area, systematic sediment samples were collected
in a zone starting from the manifestation part of the water to the entrance of the Karasu creek in Gumusler town. Samples
were taken from lower section of the river bed at 30 stations along Gumusler creek, 13 km in length and their heavy metal
contents were analyzed with XRF Spectrometer. Correlation coefficients, element coefitic coefficient correlation, dendogram
hierarchical cluster, model summary and Annova analysis statistical methods were applied to data. Strong positive correlations
were determined for some elements which are believed to have possibly the same origin. In addition, mineralizations in the
area are thought to cause variation in metal contents. Results of chemical analysis show that soil limit values and clark
values were exceeded. The heavy metal accumulation in the creek is believed to be derived from non-operated Sb-Hg-W and Fe
quarries. 相似文献
15.
In an attempt to delineate heavy metal contamination precincts and to evaluate the extent and degree of toxic levels, besides
their possible sources, 38 water samples from Ankaleshwar Industrial Estate, south Gujarat, India were analyzed. By clutching
geochemical analyses and GIS-based colour composites areas depicting anomalously high concentration of heavy metals (Mo, Zn,
Pb, Ni, Co, Cd, etc.) in the groundwater were revealed. The multicomponent overlays in grey-scale facilitated in identifying
situates of heavy metal ‘hot spots’, and lateral protuberances of the contamination plume around defile stretch of the main
stream Amla Khadi flowing through the area. The multiple pollution plumes emerging from other parts of the area further coincide
with effluent laden streams and small channels indicating industrial establishments as major sources of groundwater contamination.
Influent nature of the streams, accelerated infiltration process, high mass influx and shallow groundwater table are the factors
conducive for easy access of heavy metals to the phreatic aquifers affecting over 20 km2 area. On the basis of P/U ratios (concentration of metals in polluted water to unpolluted water), geogenic and anthropogenic sources have been identified.
Very high levels of technogenic elements present in the ground water raise concerns about possible migration into food crops,
as the area is an important horticultural locale and is highly cultivated. 相似文献
16.
Soil contamination from urban and industrial activity: example of the mining district of Linares (southern Spain) 总被引:1,自引:0,他引:1
J. Martínez J. F. Llamas E. de Miguel J. Rey M. C. Hidalgo 《Environmental Geology》2008,54(4):669-677
The Linares region (southern Spain) has been subjected to two important sources of pollution: the intensive mining works and
the urban-industrial activity. To obtain a geochemical characterisation of the soil, 31 trace elements were analysed and 669
soil samples were collected. By means of clustering analysis, we identified groups of elements and grid squares in which relations
could be established concerning soil lithology, urban and industrial activities and the degree of pollution impact; in addition,
we were able to characterise the geochemical background of the study area. The multivariate study led us to identify four
factors. Particularly important was factor 2, which represented the elements associated with mineral paragenesis (Cu, Pb,
As, Co, Mn, Zn, Sn, Ba). This factor also contains elements related with an urban-industrial activity, such as Pb, Cu, Zn,
As and Ba. Furthermore, we identified factor 4, associating Ni, V and Cr, and which is related to the use of fuels. 相似文献
17.
Correlations between heavy metals and organic carbon extracted by dry oxidation procedure in urban roadside soils 总被引:1,自引:0,他引:1
Xue Song Wang 《Environmental Geology》2008,54(2):269-273
The organic fraction in soils has a significant influence on heavy metal transport. In this study, the organic carbon content
was measured by dry oxidation procedure from 21 Xuzhou urban roadside soils to assess the relationships between the concentrations
of heavy metals (Pb, Cu, Zn, and Cr) and the amount of organic carbon. The anthropogenic heavy metals (e.g. Pb, Cu, Zn) were
strongly correlated with organic carbon (denoted by Corg−c) extracted by dry oxidation while natural heavy metal (e.g. Cr) showed no correlation to the Corg−c. The anthropogenic heavy metals were also strongly correlated with the amount of the total carbon. These results show that
the anthropogenic heavy metals are mainly enriched in the organic matter in the Xuzhou urban roadside soils. 相似文献
18.
Georadiochemical evidence to weathering of mining residues of the Mansfeld mining district,Germany 总被引:1,自引:0,他引:1
Mining heaps are used as archives for the investigation of weathering processes. Aim of this work was to investigate the different
weathering behavior of heap materials derived from Kupferschiefer mining with respect to environmental hazard. For this purpose,
Kupferschiefer and slag material of two heaps of different age were examined regarding to the radionuclide distribution and
geochemical composition. By measuring of the local dose rate, performing digital autoradiography and gamma spectrometry the
radiological load of the heaps and the heap materials was determined. The geochemical characterization of the samples was
performed by XRF, ICP–OES and ICP–MS. The results show a clear higher radionuclide load of the younger slag heap. A depletion
of chalcophile and lithophile elements in the older slag was determined. Apart from a homogeneous radionuclide distribution,
considerable radionuclide enrichments in fossil fragments could be proven. The results reveal a different weathering behavior
of slag material in comparison to the Kupferschiefer depending on the chemical binding of the elements on organic and inorganic
species. Natural organic matter as well as apatite in Kupferschiefer act as retention barrier for some metals. 相似文献
19.
Distribution of Cd,Pb, Zn and Cu and their chemical speciations in soils from a peri-smelter area in northeast China 总被引:2,自引:0,他引:2
An exploratory study on soil contamination of heavy metals was carried out surrounding Huludao zinc smelter in Liaoning province,
China. The distribution of total heavy metals and their chemical speciations were investigated. The correlations between heavy
metal speciations and soil pH values in corresponding sites were also analyzed. In general, Cd, Zn, Pb, Cu and As presented
a significant contamination in the area near the smelter, comparied with Environmental Quality Standards for Soils in China.
The geoaccumulation index showed the degree of contamination: Cd > Zn > Pb > Cu > As. There was no obvious pollution of Cr
and Ni in the studied area. The speciation analysis showed that the dominant fraction of Cd and Zn was the acid soluble fraction,
and the second was the residual fraction. Pb was mostly associated with the residual fraction, which constituted more than
50% of total concentration in all samples. Cu in residual fraction accounted for a high percentage (40–80%) of total concentration,
and the proportion of Cu in the oxidizable fraction is higher than that of other metals. The distribution pattern of Pb and
Zn was obviously affected by soil pH. It seemed that Pb and Zn content in acid solution fraction increased with increasing
soil pH values, while Cd content in acid soluble fraction accounted for more proportion in neutral and alkaline groups than
acidic one. The fraction distribution patterns of Cu in three pH groups were very similar and independent of soil pH values.
And the residual fraction of Cu took a predominant part (50%) of the total content. 相似文献
20.
Eleven surface soil samples from calcareous soils of industrial areas in Hamadan Province, western Iran were analyzed for
total concentrations of Zn, Cd, Ni, Cu and Pb and were sequentially extracted into six fractions to determine the bioavailability
of various heavy metal forms. Total Zn, Cd, Ni, Cu and Pb concentrations of the contaminated soils were 658 (57–5,803), 125.8
(1.18–1,361), 45.6 (30.7–64.4), 29.7 (11.7–83.5) and 2,419 (66–24,850) mg kg−1, respectively. The soils were polluted with Zn, Pb, and Cu to some extent and heavily polluted with Cd. Nickel values were
not above regulatory limits. Copper existed in soil mainly in residual (RES) and organic (OM) fractions (about 42 and 33%,
respectively), whereas Zn occurred essentially as RES fraction (about 69%). The considerable presence of Cd (30.8%) and Pb
(39%) in the CARB fraction suggests these elements have high potential biavailability and leachability in soils from contaminated
soils. The mobile and bioavailable (EXCH and CARB) fractions of Zn, Cd, Ni, Cu, and Pb in contaminated soils averaged (7.3,
40.4, 16, 12.9 and 40.8%), respectively, which suggests that the mobility and bioavailability of the five metals probably
decline in the following order: Cd = Pb > Ni > Cu > Zn. 相似文献