(K %)

eTh/eU

eU/eTh

eTh (ppm)

eU (ppm)

The study areas

Av.

Range

Av.

Range

Av.

Range

Av.

Range

Av.

Range

3.9

2.6 - 5.9

1.04

0.4 - 1.8

1.3

0.5 - 2.3

15.73

6 - 28.5

21.4

4.5 - 41.8

Umm Seleimat (n = 17)

5.5

2.4 - 7.8

0.8

0.3 - 2.1

1.7

0.4 - 2.8

3.2

1.3 - 7.7

4.3

2.7 - 5.1

Sikait (n = 15)

3.9

2.8 - 4.9

1.6

1.2 - 2.9

0.6

0.3 - 0.8

9.5

3.2 - 15

6.9

2.9 - 11.5

Umm El Kheran (n = 12)

2.8

1.4 - 3.9

0.4

0.2 - 0.6

2.7

1.5 - 6.5

4.2

1.5 - 6.9

10.5

4.9 - 15.7

Umm Addebaa (n = 15)

-

-

-

-

0.25

0.33

19

18 - 20

4

1 - 9

Adams et al., 1959 ; Clarke et.al., 1966

4

-

-

-

0.25

0.1 - 0.5

18

5 - 20

4.5

1 - 12

Crustal acidic igneous rocks (after IAEA, 1979 and Boyle, 1982 ).