134
U. Shavit et al.
2.3 Geochemistry
Water samples were analyzed for major chemical constituents at the laboratory of
the Israel Geological Survey and University of Amman. Strontium was separated
by ion-exchange columns and the isotopic composition was measured using a
MAT-261 mass spectrometer at the laboratory of US Geological Survey, Menlo
Park, California. Boron isotopes were measured by negative thermal ionization
mass spectrometry (Vengosh et al. 1999) using a MAT-261 at US Geological
Survey, Menlo Park. Oxygen isotope ratio measurements were made on a VG
SIRA-II mass spectrometer at the Geological Survey of Israel. Results for oxygen
and boron isotopes are given in per-mil values with respect to SMOW (Craig
1961) and NBS-SRM 951 standards, respectively. Analytical reproducibility of
duplicates and replicate analyses are 0.1, 1, and 0.025%0 for 0, B, and Sr isotopes,
respectively.
3 Results and Discussion
The results reported here are preliminary. However, data collected since
September 1999 provides a broad reliable picture of the river hydrochemistry. It
should be noted that the hydrological year 1999 - 2000 followed two consecutive
drought years, and hence the results represent base flow with minimal contribution
of runoff.
3.1 Chemical and Isotope Analysis
The chemical and isotope analysis reveals three geographically distinguished
zones (Figs. 5,6): the upper zone (first 30 km, from Alumot to Shifaa), the central
zone (30 - 70 km), and the lower zone (from 70 km down to the Dead Sea) .
. ~
II
c
i
..,
~
Fig.S. The three river zones
U. Shavit et al.
2.3 Geochemistry
Water samples were analyzed for major chemical constituents at the laboratory of
the Israel Geological Survey and University of Amman. Strontium was separated
by ion-exchange columns and the isotopic composition was measured using a
MAT-261 mass spectrometer at the laboratory of US Geological Survey, Menlo
Park, California. Boron isotopes were measured by negative thermal ionization
mass spectrometry (Vengosh et al. 1999) using a MAT-261 at US Geological
Survey, Menlo Park. Oxygen isotope ratio measurements were made on a VG
SIRA-II mass spectrometer at the Geological Survey of Israel. Results for oxygen
and boron isotopes are given in per-mil values with respect to SMOW (Craig
1961) and NBS-SRM 951 standards, respectively. Analytical reproducibility of
duplicates and replicate analyses are 0.1, 1, and 0.025%0 for 0, B, and Sr isotopes,
respectively.
3 Results and Discussion
The results reported here are preliminary. However, data collected since
September 1999 provides a broad reliable picture of the river hydrochemistry. It
should be noted that the hydrological year 1999 - 2000 followed two consecutive
drought years, and hence the results represent base flow with minimal contribution
of runoff.
3.1 Chemical and Isotope Analysis
The chemical and isotope analysis reveals three geographically distinguished
zones (Figs. 5,6): the upper zone (first 30 km, from Alumot to Shifaa), the central
zone (30 - 70 km), and the lower zone (from 70 km down to the Dead Sea) .
. ~
II
c
i
..,
~
Fig.S. The three river zones