Permanent Link:

https://digital.lib.usf.edu/SFS0069959/00001

Material Information

Title:

Geochemical and isotopic (oxygen, hydrogen, carbon, strontium) constraints for the origin, salinity, and residence time of groundwater from a carbonate aquifer in the Western Anti-Atlas Mountains, Morocco

Series Title:

Journal of Hydrology

Creator:

Ettayfi, N.
Bouchaou, L.
Michelot, J.L.
Tagma, T.
Warner, N.
Boutaleb, S.
Massault, M.
Lgourna, Z.
Vengosh, A.

Publication Date:

2012-05-17

Language:

English

Subjects

Subjects / Keywords:

Isotopes ( local )
Geochemistry ( local )
Groundwater ( local )
Salinity ( local )
Residence Time ( local )
Semi-Arid ( local )

Genre:

serial ( sobekcm )

Notes

Abstract:

Groundwater in many arid basins, particularly in developing countries, is the only available water resource that sustains local communities. Yet, information on the basic hydrological parameters and the sustainability of the groundwater exploitation are often lacking. This study investigates the origin of groundwater from the Lower Cambrian carbonate aquifer of the Lakhssas Plateau in the Anti-Atlas Mountains of southwestern Morocco. The study aims to reveal the origin of the groundwater, salinity sources, and the residence time of the water. The study is based on a comprehensive geochemical and isotopic (oxygen, hydrogen, carbon, and strontium) investigation of groundwater from different parts of the basin. The hydrochemical and isotopes results indicated three types of groundwater in the Lakhssas Plateau: (1) thermal water in the southern part of the basin with solute composition that reflects dissolution of calcium–sulfate and calcium carbonate minerals; (2) low-temperature groundwater at the southern margin of the basin with low salinity (chloride content up to 100 mg/L) and chemical composition that is expected from equilibrium with limestone–dolomite rocks; and (3) low-temperature groundwater in the northern, western, and eastern margins of the basin with a wide range of salinity (chloride up to 800 mg/L). The different water types had also different stable isotope composition; the thermal water was depleted in 18O and 2H (δ18O as low as −7.6‰) relative to the southern (−5.9 to −5.3‰) and northern waters (−5.7 to −3.8‰). The differences in δ18O and δ2H between the southern and northern waters are related to elevation that induced fractionation of oxygen and hydrogen isotopes in recharge water originated from coastal moisture. The data suggest that the high salinity in groundwater from the northern, western and eastern margins of the Lakhssas Plateau is related to the presence of schist rocks in these areas. The distinctive low Na/Cl and Br/Cl ratios, coupled with high silica contents and high 87Sr/86Sr rati

Original Version:

Journal of Hydrology, Vol. 438-439 (2012-05-17).

Record Information

Source Institution:

University of South Florida Library

Holding Location:

University of South Florida

Rights Management:

This object is protected by copyright, and is made available here for research and educational purposes. Permission to reuse, publish, or reproduce the object beyond the bounds of Fair Use or other exemptions to copyright law must be obtained from the copyright holder.

USFLDC Membership

Aggregations:

University of South Florida
Karst Information Portal

Postcard Information

Format:

serial