caa a22 4500 445814462 CHVBK 20180317145221.0 cr unu---uuuuu 170323e20110201xx s 000 0 eng 10.1007/s10040-010-0673-2 doi (NATIONALLICENCE)springer-10.1007/s10040-010-0673-2 Using geochemical indicators to investigate groundwater mixing and residence time in the aquifer system of Djeffara of Medenine (southeastern Tunisia) [Elektronische Daten] [Kamel Zouari, Rim Trabelsi, Najiba Chkir] Utilisation d'indicateurs géochimiques pour l'étude du mélange et du temps de résidence dans le système aquifère de Djeffara de Medenine (Tunisie du Sud-Est) Stable isotopes (δ2H, δ18O and δ13C) and radiocarbon (14C) have been used in conjunction with chemical data to evaluate recharge mechanisms and groundwater residence time, and to identify inter-aquifer mixing in the Djeffara multi-aquifer in semi-arid southeastern Tunisia. The southern part of this basin, the Djeffara of Medenine aquifer system, is comprised of two main aquifers of Triassic and Miocene sandstone. The Triassic aquifer presents two compartments; the first one (west of the Medenine fault system) is unconfined with a well-defined isotope fingerprint; the second compartment is deeper and confined. Multi-tracer results show groundwater of different origins, ages and salinities, and that tectonic features control groundwater flows. Fresh and brackish groundwater from the unconfined part of the Triassic aquifer was mostly recharged during the Holocene. The recharge rates of this aquifer, inferred by 14C ages, are variable and could reach 3.5mm/year. Brackish water of the deep confined part of the Triassic aquifer has stable isotope composition and 14C content that indicates earlier recharge during late Pleistocene cold periods. Brackish to saline water of the Miocene aquifer presents variable isotope composition. Groundwater flowing through the Medenine fault system is mainly feeding the Miocene aquifer rather than the deep confined part of the Triassic aquifer. Springer-Verlag, 2010 Stable isotopes nationallicence Carbon 14 nationallicence Groundwater recharge nationallicence Flow rate nationallicence Tunisia nationallicence Zouari Kamel Laboratory of Radio-Analysis and Environment, National School of Engineers of Sfax, BP 1173, 3038, Sfax, Tunisia aut Trabelsi Rim Laboratory of Radio-Analysis and Environment, National School of Engineers of Sfax, BP 1173, 3038, Sfax, Tunisia aut Chkir Najiba Laboratory of Radio-Analysis and Environment, National School of Engineers of Sfax, BP 1173, 3038, Sfax, Tunisia aut Hydrogeology Journal Springer-Verlag 19/1(2011-02-01), 209-219 1431-2174 19:1<209 2011 19 10040 https://doi.org/10.1007/s10040-010-0673-2 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-010-0673-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zouari Kamel Laboratory of Radio-Analysis and Environment, National School of Engineers of Sfax, BP 1173, 3038, Sfax, Tunisia aut NATIONALLICENCE 700 1- Trabelsi Rim Laboratory of Radio-Analysis and Environment, National School of Engineers of Sfax, BP 1173, 3038, Sfax, Tunisia aut NATIONALLICENCE 700 1- Chkir Najiba Laboratory of Radio-Analysis and Environment, National School of Engineers of Sfax, BP 1173, 3038, Sfax, Tunisia aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/1(2011-02-01), 209-219 1431-2174 19:1<209 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer