Jökull - 01.12.1967, Síða 68

0.8 1/s, and the temperature 36—38° C. Prior
to the second pumping test (Fig. 3) some
change in the water discharge into the well
must have occurred, since the water level had
to be lowered to a depth of 38 m to obtain the
same discharge rate as in the first test. Most
likely mud and chippings have blocked water
yielding fissures that were open, when the well
was 900 m deep.
Finally in October—November 1965 the third
pumping test was carried out with a new pump
that was sunk down to a depth of 94 m. The
water level was not recorded during this test
because of a technical failure, but at the end
of it the water level was at a depth of 88 m.
Regular analyses of the chloride content of the
water were made during the periocl of pump-
ing. The relation between discharge rate, tem-
perature and chloride content is shown in
Fig. 4.
i/s Temp. Water
level
,t i
I
I
I
I
io J
—-----Water level
■ ■ Discharge during pumping
------Temperature
/
/
/
Days -
THE CHLORIDE AND CALCIUM
CONTENT OF THE WATER,
ITS ISOTOPIC COMPOSITION
AND ORIGIN
All available data for the chloricle, calcium
and isotopic composition (8-value) of the water
from the well are given in Table I. The
samples analysed were collected cluring the
pumping tests. An analysis of sea-water and of
the circulation fluid from the water tank of
the town used during drilling is included. On
the basis of its isotopic composition the water
was divided into two groups, firstly water with
8-value between — 52 and — 56%c ancl secondly
between — 60 and — 63%0. The high 8-value of
the first samples from the second pumping
test is due to contamination by circulation
drilling water (also supported by the relatively
low chloride content of the sample).
As can be deduced from Fig. 5, the water
Ti 1 25 1 35 ' 4.5^
1964
Fig. 2. A diagram of the first pumping test. Temperature of water discharged, water level
and discharge rate are each plotted against time (days). Date of pumping April 28 to May 4,
1964. By then the well was 900 m deep.
Mynd 2. Linurit yfir fyrstu dœlingu. Dœlt var frá 28. aþríl—4. mai 1964, og var holan 900 m
djúp. A linuritinu sýna lóöréttu ásarnir hita, vatnsborð og rennsli, en lárétti ásinn sýnir tima.
302 JÖKULL 17. ÁR