Growth ages of ferromanganese crusts from the western and central Pacific: Comparison between nannofossil analysis and 10Be dating.

Based on results of nannofossil analysis and ¹⁰Be dating in ferromanganese crusts M1-1 and A1-1 (no nannofossils were found in it), from the western and central Pacific respectively, it is found that the crust growth ages from nannofossil biostratigraphy agree well with those based on ¹⁰Be isotope analysis. Both crusts have three growth layers, and the oldest layer was deposited in Miocene at about 12.80 Ma. The maximum, minimum, and average growth rates of crust A1-1 (from the central Pacific) are 8.11, 1.92 and 3.47 mm/Ma, and those of crust M1-1 (from the western Pacific) are 2.93, 0.47, and 0.94 mm/Ma. [ABSTRACT FROM AUTHOR]