HR: 14:45h
AN: U12A-04    [PDF]
TI: Trace Elements in Interstitial Waters: From Carbonate to Siliceous Environments
AU: * De Carlo, E H
EM: edecarlo@soest.hawaii.edu
AF: Dept. of Oceanography, 1000 Pope Road University of Hawaii, Honolulu, HI 96822
AB: Similarities in the characteristics of depth-profiles of major constituents in IW from boreholes drilled during DSDP and ODP cruises indicate that the same set of diagenetic reactions controls porewater compositions at many sites. Depending largely on sediment deposition rates porewater profiles are dominantly mediated by alteration of volcanics (basalts of layer II or volcanic matter dispersed throughout sediments) or by reactions involving sulfate reduction and methanogenesis (e.g., Gieskes, 1981). Largely as a result of analytical diffulties, however, trace elements in IW have generally not received the attention that has been afforded to major species. Trace element concentrations, particularly those in non-diffusional profiles, although also governed in part by the main diagenetic reactions taking place in the sediment column, also reflect the existence of localized reaction zones. This is particularly true in sediments where episodic changes in the depositional regime lead to the isolation of pockets of highly reactive material. Such reaction zones can then exert a more dominant control on the trace element composition of IW. In this contribution we will compare and contrast profiles of various trace elements (e.g., Sr, Li, Rb, Cs, Fe, Mn, and selected transition metals) determined in IW recovered from passive and active continental margins, carbonate platforms, and pelagic settings.
DE: 4825 Geochemistry
DE: 4835 Inorganic marine chemistry
DE: 4875 Trace elements
SC: U
MN: 2003 Fall Meeting