부산대학교 도서관

Abstract: Distribution of 10Be in systematically collected (degree×degree interval at 10 to 16 °S; 73.5 to 76.5 °E) surficial siliceous ooze, siliceous clay and pelagic clay sediments (top 2cm) from the abyssal Central Indian Basin and the Andaman Sea is used to evaluate sources and to decipher the transport pathways of sediment particles, demarcate sediment depocenters and erosional areas. While 10Be concentrations display a wide variation (0.12–5.56×109 atomsg−1) with an average of 3.58×109 atomsg−1 in the Central Indian Basin, the values in the Andaman Sea are uniform with an average of 1.49×109 atomsg−1. The 10Be/9Be values in the Central Indian Basin sediments range between 0.06 and 2.99×10−8 atomsatoms−1 and average to ∼1.56×10−8 atomsatoms−1. Correlation of 10Be data with some selected major (Al, Mn, Ti) and trace (Rb and Ba) elements suggest that large part of the isotope has been supplied through direct atmospheric fallout from the water column and minor part from lithogenic detrital flux. Significantly lower 10Be accumulation rates in the Central Indian Basin and an order of magnitude higher in the Andaman Sea sediments compared to the estimated global average production rates indicate removal of the isotopes at the continental margins. Bottom topography seems to exert control on local 10Be variation, where sediments deposited in valleys or topographic depressions contain higher 10Be concentrations in contrast to the probably erosion-dominated areas at the slopes and troughs. [Copyright &y& Elsevier]