Description, Beryllium characteristics and chemical composition of manganese nodules from the Pacific Ocean

Mean accumulation rate of these manganese nodules ranges from 2.7 to 8.0 mm/m.y.. The variation of 10Be and 10Be/9Be with depth or time is found to be less than ±30% for periods from 0.4-1.0 m.y. back to 6 m.y.

B.P. Surface 10Be/9Be atomic ratio is found to be (9-13) x 10**-8, that shows authigenic nature of manganese nodule acuumulation by comparison with (12-31) x 10-8 for deep-sea water, (2-7) x 10**-8 for clay sediments and (7-9) x 10**-8 for fossil-rich sediments.