the knight mohsen
جيو محترف
العمر : 22
سجّل في : 20 سبتمبر 2007
عدد المساهمات : 86
Localisation : كفر الدوار
 |  موضوع: Geochemical characteristics of Thorium (Th)  2007-12-07, 9:55 am | |
| Geochemical characteristics of Thorium (Th):-
1- Atomic no:
90, atomic wt: 232.04
2- Igneous rocks:
Ultramfic rocks: 0.004, Mafic: 207, Granite (20).
3- Sedimentary rocks:
Limestone 1.7, Sandstone (5.50 and Shale (12), Soils (13), Plant ash 20 ppb, Fresh water 0.1 ppb
4- Associations:
lithophile, occurring principally in accessory minerals of igneous rocks, in placer deposits, Th minerals occur for a radioactive decay series ending in He & Pb.
5- Rock minerals:
monazite (RE,Th)PO4, and as a minor constituent of allanite (hydrated silicate of Ca, Fe, Al), sphene (CaTiSiO5), and zircon (ZrSiO4).
Industrial source: monazite in placer deposits.
6- Mobility:
very low, determined by the extremely refractory character of the principal primary Th minerals.
7- Geochemical prospecting
applications: He has been suggested as a guide to Th deposits, a low Th/U ratio in kimberlites has been reported as favorable for the occurrence of diamonds.
to be containued:lol!: |
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