Siegl-Farkas, Á. 1988: Az Ajkai Koszén Formáció palynosztratigráfiája és fejlödéstörténete (Palynostratigraphy and evolution history of the Ajka Coal Formation, W Hungary). - Ann. Rep. Hung. Geol. Inst., 1986, pp. 179-209.
Authors:J. Somlai, B. Kanyár, R. Bodnár, CS. Németh and Z. Lendvai
A significant dose contribution on the population could be derived from coal slags used as isolation material. Extremely high natural activities are measured in the coal slag, derived from the region of the settlement Ajka, Hungary. In some buildings monitored, the elevated -doses were nearly 5–10 times higher than the world average ones. The annual average indoor radon concentrations from the slag exceeded 400 Bq/m3 and in some cases up to 1200 Bq/m3. Due to the elevated exposure and the radon concentrations in the dwellings the annual dose was estimated to 8–24 mSv/y more than 5–10 times of the world average one.
The heavy mineral assemblages and chemistry of detrital spinel grains from the Senonian basin of the Transdanubian Range (TR) were examined and compared with previous results from Jurassic and Lower Cretaceous successions of the Gerecse Mountains of the Transdanubian Range Unit. The heavy minerals recorded that in the area of Transdanubian Range the sedimentary cover, low-grade metamorphic and granitic rocks of the continental crust were eroded in the Coniacian and Santonian. Detritus of high-grade metamorphics was transported to the bathyal basin during Campanian time. The ophiolitic source area indicated by the presence of chrome spinel, ilmenite and magnetite still existed and persisted through the Late Cretaceous. Compared to the low TiO2 content (lower than 0.2 wt%) of detrital spinels from Jurassic and Lower Cretaceous sediments of the Gerecse Mountains, the most characteristic features of spinels in the Senonian sediments are as follows: exceptionally high TiO2 content (about 0.5-4.7 wt%), relatively high amount of Cr2O3 (about 33-50.8 wt%) and high total iron (sumFeO=15-36 wt%). The data on detrital spinels from the Ajka Coal and Csehbánya Formations suggests that xenoliths (mainly dunites), which previously enclosed the spinel grains, may have been formed from alkalic-tholeiitic magma as crystal accumulates. This was the potential source rock of high TiO2-bearing spinel grains.
Radioactivity of the nuclides238U(235U),232Th,226Ra,137Cs and40K was measured in soil by direct -ray spectrometry using Ge(Li) detector. Relative laboratory method was used. Soil was dired, powdered, sieved and put into hemetically sealed container. CCRMP certified reference materials and compounds of the above nuclides mixed with fine quartz sand were used as references. Five and four -lines were used for the determination of232Th and226Ra, respectively, to obtain more accurate results. The most significant interferences, caused by the limited energy resolution of the detector, were resolved. In the case of ordinary soils, using one day duration of measurement and 1 kg mass of soil,232Th,226Ra and40K can be determined with less than 10% relative random error. Elevated concentrations of238U(235U) and226Ra were observed in soil samples collected around a coal-fired power plant in Ajka town, Hungary.