Geochemical analyses of Boom Clay pore water and underlying aquifers in the Essen-1 borehole

Mieke De Craen, Isabelle Wemaere, Serge Labat, Maarten Van Geet

Research outputpeer-review

Abstract

This report presents the results of the geochemical analyses of Boom Clay pore water and underlying aquifers in the Essen-1 borehole. A comparison is made with the reference Boom Clay pore water composition at the Mol site. In Essen, the Boom Clay pore water is a NaCl-type solution. It is characterised by a relatively high salinity, increasing towards the bottom of the clay deposit, and further into the underlying aquifers. This is clearly different from the reference Boom Clay pore water composition at the Mol site. The most important differences are the type of pore water, the salinity, and the vertical variations in chemical composition. The stable isotope composition was also studied. With increasing salinity towards the bottom of the clay, both 2H and 18O are enriched in the pore water. These data suggest that these pore waters are mainly from meteoric origin, but some mixing with water of marine origin is visible (most likely from underlying aquifers). The mixing with water of marine origin explains the higher salinity and the enrichment in 2H and 18O in the Essen pore waters compared to the pore waters in Mol.
Original languageEnglish
PublisherSCK CEN
Number of pages23
Volume1
Edition0
StatePublished - Nov 2006

Publication series

NameSCK•CEN Reports
PublisherStudiecentrum voor Kernenergie
No.ER-19

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