Publication Date:
2023-02-08
Description:
Despite the important role that volcanogenic aluminosilicate (VA) alteration has on elemental cycles in marine sediments, there is no mechanism to arrive at a global assessment of this process. To quantify the VA alteration rates from Japan, New Zealand (NZ), and Costa Rica, we developed a mass balance approach that is constrained by the strontium concentration and 87Sr/86Sr ratios in pore fluid, authigenic carbonates, and VA. We derived VA alteration rates ranging from 101 to 103 nmole Sr/m3 bulk sediment/yr with the highest rate obtained for Tuaheni, NZ (Site GeoB80202), which has the youngest sediment. We showed that 87Sr/86Sr ratios of VA derived from this mass balance approach are significantly higher than the reported ratios from volcanic glass samples, indicating a concomitant role of volcanogenic feldspar dissolution and/or authigenic clay formation. Most of the strontium released during VA alteration is precipitated as authigenic carbonate, with important implications for carbon inventories. The VA alteration rates derived from this approach can also be used to quantify the release of other critical elements, such as release of iron that can stimulate formation of Fe‑carbonates and/or fuel microbial activity at depth.
Type:
Article
,
PeerReviewed
Format:
text
Format:
text
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