Mobilization of beryllium in the sedimentary column at convergent margins

Geochimica et Cosmochimica Acta
By: , and 

Links

Abstract

Studies of Be distributions in subduction zone sediments will help to understand questions regarding the enrichments of cosmogenic Be-10 in arc volcanic rocks. Analyses of Be-10 and Be-9 in sediments of Ocean Drilling Program Site 808, Nankai Trough and Be-9 in porewaters of Site 808 and Sites 671 and 672, Barbados ridge complex, show significant decreases in solid phase Be-10 and large increases of porewater Be-9 at the location of the décollement zone and below or at potential flow conduits. These data imply the potential mobilization of Be during pore fluid expulsion upon sediment burial. Experiments involving reaction between a décollement sediment and a synthetic NaCl-CaCl2 solution at elevated pressure and temperatures were conducted in an attempt to mimic early subduction zone processes. The results demonstrate that Be is mobilized under elevated pressure and temperature with a strong pH dependence. The Be mobilization provides an explanation of Be-10 enrichment in arc volcanic rocks and supports the argument of the importance of the fluid processes in subduction zones at convergent margins.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Mobilization of beryllium in the sedimentary column at convergent margins
Series title Geochimica et Cosmochimica Acta
DOI 10.1016/0016-7037(94)90219-4
Volume 58
Issue 22
Year Published 1994
Language English
Publisher Elsevier
Description 11 p.
First page 4887
Last page 4897
Country Japan
City Nankai Trough, Pacific Ocean
Google Analytic Metrics Metrics page
Additional publication details