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191.
Thermal maturity information has been compiled for one of the deepest parts of the Central European Basin system, the Schleswig-Holstein
area in northern Germany. New vitrinite reflectance data were obtained and old data were evaluated from a total of 31 wells.
Furthermore, numerical 1D basin modelling was performed in order to interpolate/extrapolate vitrinite reflectance data to
base Zechstein and base Keuper. For these two horizons, maturity maps were finally compiled revealing large differences in
present-day thermal maturity within the basin. For example, vitrinite reflectance at base Zechstein ranges from greater than
4.5% in the Glueckstadt Graben to less than 1% in the northern part of the study area. Highest thermal maturity of base Keuper
occurs in the West Holstein Trough and in the northern part of the Glueckstadt Graben. The timing of maturation is greatly
affected by the complex tectonic evolution of the area. For six key wells distributed over the entire study area, burial and
temperature histories as well as evolution of maturity were evaluated using 1D basin modelling. Deepest burial and maximum
temperatures occurred either during Jurassic, Upper Cretaceous or Neogene times in these wells. Only some parts of the sedimentary
package in Schleswig-Holstein show a significant increase in maturity during the Tertiary leading to additional hydrocarbon
generation and entrapment. 相似文献
192.
An assessment of marine pollution due to metals was made in the Caspian Sea based on coastal sediment collected in Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan. Despite the high carbonate content, the distribution of most metals was largely controlled by terrigenous inputs. Several metals (As, Cr, Ni) exhibited concentrations that exceed sediment quality guidelines. Such metals have a high natural background but anthropogenic activities, notably mining, may further enhance concentrations. This would explain hot spots for Cu and Zn in Azerbaijan and Iran, and Cr at the mouth of the Ural River in Kazakhstan. Contamination by Hg was observed to the south of Baku Bay, Azerbaijan. Some anomalously high concentrations of Ba in the central Caspian are probably from offshore drilling operations, but the elevated U concentrations (up to 11.1 microg g(-1)) may be natural in origin. Several metals (Ag, Cd, Pb) have relatively low levels that pose no environmental concerns. 相似文献