Multi-tracer Study for Groundwater Dating in Southern Oman

This thesis reports on a multi-tracer study to investigate the groundwater system in the Salalah Plain in Southern Oman. Hydrogeological studies in this area are of great significance as extensive groundwater abstraction has led to serious environmental problems. To resolve open questions from former studies, 39Ar was chosen as a dating tracer for its conservative properties and its suitable dating range. To facilitate the purification of argon for its detection with Argon Trap Trace Analysis, a conversion factor for volume estimation of small samples was determined and the pressure readout was automated by a Labview program. In addition to 39Ar, other dating tracers were applied, i.e. noble gases, 14C, CFCs and SF6. While radiogenic 4He served as an initial qualitative dating approach, 14C tracer ages were calculated and corrected yielding mean residence times of up to 7000 years. In contrast, tracer ages derived from CFCs and SF6 data ranged from 20 to 50 years. In a mixing model with two water masses, 14C and CFC-11 data were combined. On average, the contributions of the modern component and a 2000 to 19 000 years old component were found to be almost equal. Combining those findings with prospective 39Ar results sheds light on the so-far contradictive groundwater system in the Salalah Plain.

Level thesis:degree_level

master

Grantor dc:publisher

Universität Heidelberg

Year

2019

Author dc:creator

• Rädle, Viola

Contributors dc:contributor

• Aeschbach, Werner

Repository record source_url

http://www.ub.uni-heidelberg.de/archiv/30882

OAI identifier oai:identifier

oai:archiv.ub.uni-heidelberg.de:30882