Lakes, reservoirs and ponds, vol.

3(2): 120-127, 2009

©Romanian Limnogeographical Association

BAIA VERDE - SLANIC PRAHOVA SALTED LAKES

COMPLEX

Monica SAVA
Grup Şcolar Industrial „1 Mai” – Ploieşti, România
monimo_s@yahoo.com

Abstract
Baia Verde – Slanic Prahova Lakes Complex have been formed by water accumulation resulted out
of infiltrated salted water from bell shaped surface salt mines dated XVII century (1685). Such lakes,
as per their method of formation, can be also found in other places from the SubCarpathians area
(Telega – Prahova, Ocnele Mari – Valcea), Transilvanian Depression (Ocna Sibiului, Turda, Sovata,
Ocna Dejului, etc.). Water contact with diapires, in the places where have always existed such mining
explorations and exploitation, has determined the formation of salted lakes having balneary and
therapeutically qualities and sometimes the development of a heliothermic / mezothermic bed. At
Slanic – Prahova besides the three lakes known as Baia Verde 1, 2 and 3, there is also the lake Baia
Baciului situated at the border of “Salt Mountain” which represented the first objective for
capitalization of the balnear and therapeutically potential of the area.
Keywords: abandoned salt mines, salt lake, balneary locations, turism

1. Introduction

Baia Verde Lakes Complex is formed out of three lakes (Baia Verde 1, 2
and 3), formed after 1850 by collapsing of the old bell shaped salt exploitation
facilities/mines. The lake from Slanic river bed vicinity has been evacuated and
covered due to the assumption that could affect through infiltration the Cantacuzino
salt mine following that in 1998 has been refitted for balneary and tourism purposes.
The salt lakes from Slanic – Prahova can all be all found on the location of
the old abandoned salt mines. From historical documents results that salt
exploitation in the area has begun in 1685.

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 Figure.1 Left bank of Baia Verde 1 lake Figure 2. East bank of Baia Verde 2 lake

On the left side of the Slanic creek can be found the three mine lakes known
as Baia Verde 1, 2 and 3 starting from upstream to downstream. Internal collapsing
processes of the salt breccia layer have greatly contributed in shaping the lakes
form.
The three salted water lakes are affected by logging / colmation process due
to gravity instability resulted out of humectation effect of the yellow clay that forms
creek walls. Same contributions have also the salt spring which feeds the creek and
their surface subject to vaporization.
Baia Verde Complex has a high salinity, over 200g/l, resulted of its salt
banks. Salt concentration at the surface is lower during the spring and after rich
rains (80-120g/l) and is increasing in the rainless periods of time as a result of
vaporization effect. At deep depths the salinity – salt concentration remains
constant.
Slanic Prahova area presents at a first sight the aspect of a petrographical
monotony. The geological formations of the region’s substratum are complex, the
most often found being the salt formations. Slanic salt is particularized by its many
nucleuses and variable thickness lens present in an area of 1.6 km2.
From the geological point of view, Slanic Prahova belongs to Tarcau Unit
and it was formed during neogen and pliocen geographical period of time as
tortonien deposits within quaternary river bed silt.

2. Relief characteristics

The topographical relief is represented by high hills situated in the north -

western part of the area, made out of compact sandstone/slate and micro
conglomerates. Geomorphically considered, Slanic Prahova is situated between the
river beds of Prahova and Teleajen, in the vicinity of Teleajen Mountains – from
which the nearest is Grohotis Mountain.

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 Figure 3. Baia Verde 3 lake Figure 4. Lakes of Slanic Prahova
(morphological sketch, acc. V.Sencu, 1958)

A distinct note in the topographical relief is given by the landslides seen as

2-3 m height sudden soil differences. Landslides and surface soil carried by water
results in monoclay layer removal making place of salt deposits. Due to water action
is developed a micro topographical relief with special shapes that lasts for several
years such as avena type pits and mini caves.
Most of the lake
made depressions is made
out of loosed – cemented
alternant clays and
sandstone/silts.
Topographical shapes that
can normally be found are
pits, wholes and rectilinear
lapiezes. Gypsum can be
very often found and provides
a specific topographical
Figure 5. Baia Verde 2 lake
shape such as rounded peaks
that dominates the few meter
river plateaus.

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3. Limnogegraphical characteristics

The depth of the three lakes variates in time as can be seen in the below
table:

Lake depth / Year 1968 1981 1991 2008

Lake 1 40.0 m 37.0 m 32.0 m 40.0 m
Lake 2 17.5 m 17.0 m 13.0 m 15.0 m
Lake 3 32.0 m 33.0 m 4.5 m 4.5 m

Figure 6. Depth variation of Baia Verde lakes

As it can be seen, Lake 1 and

2 has an almost constant depth during
the studied period of time.
In October 1989, a large
quantity of water of Lake 2 has been
transferred / drained to Lake 3 in
almost 5 hours and from here (Lake 3)
to Slanic Creek.
The level of Lake 2 has been
lowered with app. 2.5 m and by visible
small landfalls and by soil compaction,
the micro system has been separated.
The sudden depth decrease of
Baia Verde 3 lake from 33m to 4.5 m Figure 7. Baia Verde Complex (batimetric
sketches, acc. I.Pisota, 1969)
over 10 years is the result of the mid
lake funnel clogging which had in 1981
a diameter of 6 m.

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 The volume of water present over time variations as can be seeing in Table
2:
Table 2

Lake water volume / Year 1968 1991 2008

Lake 1 13650 m3 10089 m3 9855 m3
Lake 2 6616 m3 5200 m3 5740 m3
Lake 3 4750 m3 705 m3 698 m3

Figure 8. Baia Verde water level variation over time.

Lakes salinity varies over time in close relation with rocks components
where the lakes have been formed. This can be seen is the following Table 3:
Table 3
Lake salinity/Year 1968 1991
Lake 1 240 g/l 230 g/l
Lake 2 210 g/l 220 g/l
Lake 3 203 g/l 200 g/l

Figure 9. Baia Verde lakes – salinity variation over time

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 Lakes salinity varies in depth determining the existence of several layer of
water with different salt concentration, the maximum salt concentration being in the
inferior lower layer – over 250 g/l.
In the lakes that present a draining, such as Baia Verde 3, the lower salinity
layer of water is evacuated so that the remaining richer salt water layers, right at the
surface, will prevent the formation of ice.
According to a research
carried out in February 1969, it was
discovered that while Baia Verde 1
and 2 were covered with an ice
bridge of around 15-20 cm
thickness, Baia Verde 3 was
defrosted due to a very high salinity
(242g/l).
The heliothermal
phenomenon often appears in the
Baia Verde Complex because they
have high depths, small surfaces, a
more diluted water film and salinity
stratification. The number of bays
being more reduced here contributes
to the maintenance of the
heliothermal state.
As a result of thermal
sounding of the three lakes – Baia Figure 10. Baia Verde lakes/ Slanic-Prahova
Verde 1, 2, 3 realized by P. temperature distribution over depth dated July
Gastescu and B. Driga on July 3, 3rd, 1970
1970 – it was acknowledged that in
the Baia Verde lake, the upstream one, where the number of bays is very small, the
heliothermy is better emphasized (29 C on the surface, 38,8 C at 2meters and 22,6
C at 4 meters) whereas in Baia Verde 2 it is almost inexistent. (fig. 10).
The water transparency of the lakes is influenced by the quantity of clay
particles obtained from banks streaming and the existence of a rich organic mass.
One can sequence the lakes according to their antitone order: Lake 1, Lake 2 and
Lake 3.
The water color is provided by water salinity and the quantity of materials
which come from mountainside and banks streaming. Lake 1 is green (due to strong
mineralization), Lake 2 is yellowish - green and Lake 3 is greenish - yellow.
The lakes have sapropelic mud containing different mineral substances such
as chloride, bromine, nitrate, sulfur, carbonate, bicarbonate, calcium, magnesium,
iron and other organic substances.

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 Figure 11. Baia Verde 2 lake – 1911 Figure 12. Baia Verde 2 lake – 1932

 
Figure 13. Baia Verde 2 lake – 2000 Figure 14. Baia Verde 3 lake – 2001

4. Conclusions

The waters of Baia Verde Lake Complex are used in curing/amelioration of

degenerative rheumatic diseases, diatritic diseases (cervical spondilosis–dorsal and
lumbar arthrosis, poliathrosis, tendenites, etc), posttraumatic effects (cricks, sprains,
fractures after arthrosis), peripheral nervous system diseases (poliomyelitis sequels,
light paresis), gynecological diseases (ovarian insufficiency, chronic cervicites, etc.),
dermatological diseases (psoriasis, keratonic dermatitis) and vascular diseases
(varicosity, etc.).
Rehabilitation is mandatory for the banks, same as for side versants and
boundaries situated over the salt deposit exploited in the previous timeframes. The
current geomorphological situation allows surface infiltrations as well as deep
infiltrations to which are added also surface salt domes fissures or the fissures from
the inners side on the caverns situated in the boundaries/versants.
Currently rehabilitation activities are undergoing targeting touristic
improvements for the three salted lakes as well as for the surrounding areas
(development of touristic facilities, access roads and promoting activities).

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 Bibliography

Drăgănescu L. (2002), Istoricul exploatărilor de sare de la Slănic Prahova, SWEMP

2002, Cagliari, Italia.
Gâştescu, P. (1971), Lacurile de România. Limnologie regională, Editura Academiei
Bucureşti.
Petrescu, V. (2003), Slănic Prahova la 470 de ani de atestare documentară, Editura
Premier.
Pişota, I.,Trufaş, V., Ciumpileac,Gh. (1969), Lacurile de la Slănic-Prahova şi Telega,
Hidrobiologia, t.10
Sencu, V. (1968), Muntele de sare de la Slănic-Prahova, Ocrotirea naturii nr.2,t.12.

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