[en] Radon concentrations of rock formations (and soils) were measured directly at more than 70 sites, representing stratigraphic units which constitute the main rock exposures in Israel. In order to meet local conditions, a modified alpha-track detection system was implemented, consisting essentially of a polycarbonate foil within a PVC pipe. The radon source in the Mount Scopus Group rock units is the apatite (calcium phosphate) content - from ∼ 2 Wt.% P₂O₅ up to ∼ 30% in the phosphate layers, corresponding to uranium concentrations of up to 150 ppm. These rock units, which are down-faulted and buried along the Dead Sea Rift Zone, are believed to be also the source for high radon emanations in the vicinity of some faults and thermal water springs in this area. 1 fig

[en] Phosphorites are attractive as an additional source of uranium for many reasons, the main being that uranium can be produced there as a by-product. Two hundred and fifty-four samples from nine phosphate fields and one oil shale deposit overlying phosphorites were examined for U, P₂O₅ and organic matter. Statistical treatment of the normalized results (U/P₂O₅) showed that the different phosphorite fields probably represent different populations as far as uranium content is concerned. The fields showed significant differences in uranium content; there are fields relatively rich in uranium, like Zefa with a normalized mean of 5.9 ppm uranium per 1% P₂O₅, while others such as Saraf have only a mean of 3.5 ppm. These fields have about 28% P₂O₅ (Zefa) and 25% P₂O₅ (Saraf). It is suggested that the uranium concentration of the sea-water (interstitial water) was the dominant factor in uranium precipitation and concentration. Furthermore, on the basis of these findings, it should now be possible to choose and reserve the appropriate raw material to obtain the highest yields of phosphoric acid and uranium, and to use other phosphorites less rich in uranium for other purposes. (author)

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[en] Delayed neutron counting for uranium assay was coupled with γ-ray spectrometry in order to measura redionuclides of F, Al, Ca, and V produced by neutron activation. For this measurement, the delay time required for U determination was exploited. Calibration of the method was provided by standards based on a CaCO₃ matrix and validity of results was verified against other analytical methods. A single sample can be analyzed for the five elements in 3 min with a precision of ∼ +-10%. The method developed was applied in the exploration of phosphate ores. The measured total concentrations permitted the disclosure of correlations between various elements and constituents in the samples. Chemical and mineralogical properties were obtained as well. (author)

[en] Abstract only

[en] Delayed neutron counting for uranium assay was coupled with γ-ray spectrometry in order to measure radionuclides of F, Al, Ca and V produced by neutron activation. For this measurement, the delay time required for U determination was exploited. Calibration of the method was provided by standards based on a CaCO₃ matrix and validity of results was verified against other analytical methods. A single sample can be analyzed for the five elements in 3 min with a precision of approximately +-10%. The method developed was applied in the exploration of phosphate ores. The measured total concentrations permitted the disclosure of correlations between various elements and constituents in the samples. Chemical and mineralogical properties were obtained as well. (author) 11 refs.; 5 figs

No abstract available