Helium in Porewater and Rocks of Crystalline Bedrock from the Fennoscandian Shield, Olkiluoto (Finland)

Rufer, Daniel; Waber, Niklaus; Pitkänen, Petteri; Eichinger, Florian (2017). Helium in Porewater and Rocks of Crystalline Bedrock from the Fennoscandian Shield, Olkiluoto (Finland). Procedia earth and planetary science, 17, pp. 762-765. Elsevier 10.1016/j.proeps.2017.01.019

[img]
Preview
Text
Rufer_etal_PEPS_2017.pdf - Published Version
Available under License Creative Commons: Attribution-Noncommercial-No Derivative Works (CC-BY-NC-ND).

Download (375kB) | Preview

Dissolved noble gases in matrix porewaters of low-permeable crystalline rocks are useful tracers for investigating porewater migration and interactions between porewater and groundwater. Samples from the 1160 m deep OL-KR56 borehole, drilled at the Olkiluoto site (southwestern Finland), have been analysed for concentrations and isotope signatures of helium in porewater, groundwater and in the rock matrix. These are the first 3He/4He ratios combined with 4He concentrations in porewaters and rocks from the Fennoscandian Shield. High 4He porewater concentrations suggest long porewater residence times, while concentration differences of one order of magnitude between porewater and groundwater indicate a transient state between these reservoirs. Concentrations of 4He in porewater show small variations with depth, which are mimicked in the concentrations of conservative chemical tracers as well as in 4He concentrations of groundwaters from various regional boreholes. 3He/4He ratios in porewaters are higher than in the rock matrix, requiring either fractionation during redistribution of He between these reservoirs or the addition of an isotopically light component.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Institute of Geological Sciences > Rock-Water Interaction

UniBE Contributor:

Rufer, Daniel and Waber, Niklaus

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

1878-5220

Publisher:

Elsevier

Language:

English

Submitter:

Daniel Rufer

Date Deposited:

30 Jan 2017 17:17

Last Modified:

30 Jan 2017 17:17

Publisher DOI:

10.1016/j.proeps.2017.01.019

BORIS DOI:

10.7892/boris.93908

URI:

https://boris.unibe.ch/id/eprint/93908

Actions (login required)

Edit item Edit item
Provide Feedback