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A comparison of the eastern and western sides of the Sea of Galilee and its implication on the tectonics of the northern Jordan Rift Valley
Tectonophysics, 141 (1987) 125-134 Elsevier Science Publishers B.V., Amsterdam - Printed in The Netherlands
125
A comparison of the eastern and western sides of the Sea of Galilee and its implication on the tectonics of the northern Jordan Rift Valley H. MICHELSON
I, A. FLEXER 2 and 2. EREZ 3
’ TAHAL Water Planning for Israel, 54 Even Gevirol, Tel Aviv (Israel) 2 Department of Geophysics and Planetary Sciences, Raymond and Beverly Sackler Fatuity of Exact Sciences, Tel Aviv University, Tel Aviv (Israel) 3 Geoiogy Department, Everyman’f University, Ramat Aviv (Israel)
(Received November 14,1985; accepted May 5,1986)
Abstract Michelson, H., Plexer, A. and Erez, Z., 1987. A comparison of the eastern and western sides of the Sea of Galilee and its impli~tion on the tectonics of the northern Jordan Rift Valley. In: Z. Ben-Avraham (Editor), Sedimentary Basins within the Dead Sea and Other Rift Zones. Tectonopkys~cs, 141: 125-134. The Sea of Galilee divides two Neogene basins which are characterized by largely continental elastic sequences and basalt flows. Stratigraphic differences between the two basins are discerned. A comparison of the stratigraphy of both sides of the Sea of Galilee does not support the postulated 107 km left-lateral movement. Although some small strike-slip faults might exist, most faults are of a gravity dip-slip type. A postulated ridge trending NNE, buried under the Sea of Galilee, might have had a stratigrapbic influence on sediment distribution between the eastern and western sides.
Introduction This paper examines the tectonic and stratigraphic evolution of the Neogene basin in the southern Golan Heights and compares it to the Neogene basin on the opposite side of the Jordan Rift Valley in order to determine if there are any indications of lateral movements. The Golan Heights (Fig. 1) is a typical basalt plateau formed by fissure eruptions. The northern border of the Golan Heights is at the contact with the flanks of the Hermon anticline whereas the southern border is the Yarmouk gorge which cuts into Senonian-Eocene beds near the southern extent of the basalt. These Senonian-Eocene beds form the southern flank of the Irbid syncline which continues beneath the Golan Heights. The eastern extension of the Golan Heights is HO-1951/87/~03.50
0 1987 Elsevier Science Publishers B.V.
the Hauran Plateau, a younger basalt plateau with numerous prominent volcanic cones and fresh basalt sheets. The western border of the Golan Heights is the Jordan Rift Valley. The main border fault has a N-S strike but turns N35 * E at Sheikh Ali (Figs. 2 and 4). From that point north to the Hula Valley, the rift valley faults are undetectable by surface mapping, although the Golan Plateau is separated from the Jordan and Hula Valleys by one main or several smaller cliffs. These cliffs are the morphological expression of either a main border fault or a series of step faults. The border fauit on the western side of the rift valley is obvious at the Naftali mountains. It’s extension further south, between Rosh Pinna and Tabigha, is unclear. The western side of the Sea of Galilee and its southern extension to the Bet Shean
Jordan
Fig. 1. General location map illustrating the morphotectotic
Valley is distinguished by a series of tilted blocks separated by transversal faults (Fig. 2).
units surrounding
the Golan Heights.
The Zora Fm. is built of profusion of planktonic foraminifera (“Globigerina ooze”) while nummulites are absent. The planktonic assemblage of the Adulam Mbr. includes Acarinina b~~~br~uki (Boli), Spaeroidinellopsis
senni (Beckmann)
and Morzo-
vek
Over 900 m of Early Eocene to Pliocene formations are exposed in the southern Golan Heights (Fig. 3). These include two newly described formations: the Fiq and Susita Formations (Michelson and Lipson, 1987). Zora Formation (Early-Middle
Eocene, 400 m)
formation exposed is the Eocene It is composed of bedded chalk and flint (Adulam Mbr) and massive chalk (Maresha Mbr). The
oldest
Zora Formation.
indicating upper Early Eocene age. The Maresha Mbr, contains six standard biozonesfrom ME11 with Hantkenina arugonensis to UEl with Gobigerinatheka semiinuahtu indicating a Middle Eocene to early Late Eocene age. Fiq and Susita Formatictns (Late Eocene, Oligocene, to Lower Miocene, about 2UQ m)
The Fiq and Susita Formations by a new marine cycle limited to of the Jordan Valley. The Fiq Fm. glauconitic and detritic limestone,
were deposited the eastern side is composed of white chalk and
127
tDlfERRANEAN
Tartirry
bedimoou
($
Tel Rakkat
03
Tfberisil Mt Hordoa
L
01
Zemnkh
Fig. 2. Schematic geological map of the Jordan Rift Valley in northern Israel (after Picard, 1965).
128 LEGEND:
FORMATION
AGE
-
UNCONFORMITY
2
CLAY
COVER
“CIOCENE
‘= -
SILTSTONE
BASALT
%
7
QIOCENE
OOLitlC
LIMESTONE
i
CONGLOMERATE
& Z
CALCAREOUS SANDSTONE
r? !.‘.:.
SANDSlbNE
W Z w 0
MlD0l.E
TO
0 LATE LLI MIOCENE Z
-
MlDOLE
OLIGOCENE EARLY
LL Z LL c C LL
EN
MIOCENE
MIOCENE
EOCENE
L! P’z CI
TO - LATE
EOCENE
I
_A
c
EARLY
SANDS
TO
a.
MIDDLE
GEV
s
mza *
,-15ofisn” z r
4 a EARLY-MIDDLE
r
MARESHA .‘I.
= -
QUARTZITE
Ia”
FOSSILS
/.g
LUMACHELLE
s -i
EARITE CONCRETIONS
wrxi
Gi_AUCONITE
3 -
MARLY
CHALK
E -
CHALKY
LIMESTONE
I 4
FLINT
HORIZONS
i--i
FLINT
LENSES
DOLOMITE
B
LIMESTONE
j--L/
CHALK
g
MARL
EOCENE
Fig. 3. Composite columnar section of the eastern cliff of the Sea of Galilee (after Michelson, 1972).
some marl, and the Susita Fm. is built of yellowish sandy marl, calcareous sandstone, bioclastic dolomite and limestone and chalky limestone. Both the Fiq and Susita Formations are very rich in fauna. Fossils include mainly planktonic foraminifera in the Fiq Fm., and planktonic and benthonic foraminifera as well as megafauna in the Susita Fm. The joint occurrence of Cassigerinella chipolensis and Gfobanomalina micra in the Fiq Fm. indicates Early Oligocene age. It is, however, possible
that the sedimentary cycle responsible for the Fiq Fm. had started as early at the Late Eocene. The important megafossils of the Susita Fm. are: Conw sp., Bithium sp., Cerithium sp., Turritella sp., Lucina sp., Arca sp., Cardium sp., Pecten sp., Ostrea sp., Phacoides sp., Venus ~Omphaioc~~thrurn~,cf. aglaurae (determined by S. Rothman, in Michelson and Lipson, 1987). Among the microfossils it is worthy to note the rich association of Miliolidae and Peneroplidae. Numerous sections of Tr~~~u~ina sp., Archaias sp., Quinguelo-
129
culina sp., and Austrotrillina sp. are encountered,
together with Peneroplis sp., small Rotalidae, coralline Algae and bryozoan fragments. The presence of Austrotrillina bears paleogeographical significance since this fossil occurs in the Oligocene-Miocene of the Indo-Pacific province, the Mediterranean basin (Adams, 1967, 1968) and notably in the Iran-Iraq basin (Asmari Limestone -Adams, 1968; Sampo, 1969). As Austrotrillina is lacking in the Oligocene-Miocene beds of the other areas in Israel, the Susita Fm. most likely was connected with the Iran-Iraq basin via the Wadi Sirhan depression. In addition, a shallow marine sequence similar to the Fiq and Susita Formations has been described by Bender (1968, fig. 90) approximately 90 km southeast of Azraq, and by Wetzel and Morton (1959) at Wadi Taiyiba opposite the Bet-Shean Valley and by Wiesemann (1969) near Esh Shuna on the eastern side of the Jordan River, about 10 km south of the Sea of Galilee. The similarity of the fauna and lithofacies of these sequences indicates that they were deposited by the same ingression that came from the Persian Gulf through the Sirhan depression and reached the southern Golan Heights. En Gev and Hordos Miocene; 250-3.50 m)
Formations
(Middle-Late
The En Gev Fm. was deposited in a restricted depression east of En Gev. It consists of mainly fine-grained eolian sands and was probably deposited in a local lake. The Hordos Fm. unconformably (mostly angular) overlies all of previously mentioned formations. This unconformity is regional (Bender, 1968). The Hordos Fm. is composed mostly of elastics -boulders, pebbles, sand, silt and marl that were deposited in lakes and flood plains of internal basins produced by differential uplift. Indicative fauna has not been found in either formation. Basalt flows and dikes found in the Hordos Fm. are equivalent to the Lower Basalt exposed on the western side of the Sea of Galilee. The isopachs of the En Gev and Hordos Fms. (Fig. 4) indicate thickening towards the west, i.e., progressive sinking of the Miocene basin. Angular unconformities within the Hordos Formation also indicate tectonic activity.
Bira and Gesher Formations (Pliocene, 80 m)
The last marine ingression in the area originated from the Mediterranean Sea through the Yizreel Valley during the Pliocene. It reached the southern Golan Heights and left behind relics of an Ostreae lumachelle (equivalent of the Bira Fm. to the west) (Michelson, 1972). Subsequently shallow freshwater lakes occupied the area, and continental calcareous sandstone, marl, lacustrine and oolithic limestone were deposited forming the Gesher Fm. (Fig. 3). Basalt flows are also found in the Gesher Formation (“Intermediate Basalt”, Schulman, 1962). Cover Basalt (Lute Pliocene, 50-150
m)
Tectonic and volcanic activity in the Late Pliocene terminated the Neogene sedimentary cycles. An angular unconformity separates the Gesher and older formations from the lava flows (Cover Basalt) in the Hauran Plateau, Golan Heights, southeastern Galilee and parts of northwestern Jordan. The Cover Basalt is built of flows of hard, coarse-grained, olivine rich basalt. It has been dated at between 3.1 m.y. (top) and 3.7 m.y. (bottom) (Mor and Steinitz, 1982). In the Golan, the Cover Basalt is overlain by younger Quatemary basalt with cinder cones and can form a sequence of over 500 m. The Cover Basalt becomes thinner towards the Sea of Galilee. The major faulting phase which formed the present Jordan Valley occurred after the lava flows of the Cover Basalt were extruded. Stratigraphy of the western rim of the Sea of Galilee A deposit of 1800 meters of Cenomanian to Pleistocene Formations are exposed on the western rim of the Sea of Galilee. (Fig. 5). The Cretaceous Formations (550 m)
The Upper Cenomanian Sakhnin Fm., 200 m thick, is built mainly of coarse crystalline dolomite. The overlying Turonian Bina Fm. consists of 50 m
130
--
H
.-
210 .7-‘.--
____.._ ____~.^.qL -__
-____y,,,
SEA OF
t GALILEE
f
Fig. 4. Isopach map of the Miocene Hordos and En Gev Formations after Michelson (1972).
131
East
West
MORE THAN 300 m
I
BAIIALT
1 hlID.-UC
tOLKIOCENE-
z
LIMESTONE
CHALKY-MARLY
FACIES
..ZYICI.LI
*a*-
Iad!
MlOCENEIl
lz!
FACIES
LEQLND USACT hn
AND
FLOWIINTRA CESHER
HORODS
Fm.i
I I
I I
9 =
9 : ‘. : : q.
l.lMLSTONe
FAUNA -
CACCAREOUS
SANDSTONE
Fig. 5. SItratigrapbic relationships between the western (Poriyya Heights) and the eastern (southern Golan Heights) sides of the Sea of Galilee.
of limestone. The Senonian-Paleocene Mt. Scopus Group is composed of 290 m of ,cha.lk and marl with abundant planktonic foraminifers, ostracods and nannofossils. The Timrat and Bar Kokhba Middle Eocene, 400 m)
Formations
(Lower-
The lower formation consists of well-bedded limestone (“Timrat Fm.“) and the upper one is a
massive karstic limestone rich in nummulites (((Bar Kokhba Fm.“). Hordes Formation (Miocene, 400-500
m)
The Hordos Fm. is composed of continental, fluviatile-lacustrine beds. The formation includes several intercalated basalt sheets which thicken southwards to form a continuous basalt sequence -the Lower Basalt (S~hulman, 1962). This formation is limited to the Neogene basins.
132
Bira Marl (Pliocene, 200 m)
The Bira Frn. is mostly composed of marl and dark clays, containing a few thin chalk, dolomite and limestone interbeds (brackish lagoonal series), followed by evaporites (gypsum and rock salt). A very thick sequence of evaporites was drilled by the Zemakh well (Marcus and Slager, 1985). Gesher Formation (Pliocene, 80 m)
The Gesher Fm. consists of white chalk at the base, oolitic chalk or Hydrobia fraasi bearing freshwater limestone in the middle and variegated clay at the top.
there is no significant strike-slip movement in the Jordan Valley, the ridge might continue to the structural high at Shamir in the Golan Heights. At the southern edge of the Sea of Galilee, the Zemakh well penetrated a very thick Neogene to Pleistocene sequence of basalts, evaporites and carbonates. A sequence which is believed to be Hordos Formation was encountered at a depth of 4200 m. indicating the existence of a very deep basin during the Miocene (Marcus and Slager, 1985). Discussion The origin of the Sea of Gaii~ee segment of the Jordan Valley
Cover Basalt (Pliocene, 50-150
m)
The Cover Basalt is similar to the same formation exposed on the eastern side of the Sea of Galilee. Structure
Normal dip-slip graben faults are the dominant tectonic element on both sides of the TiberiasHula graben system. The Haon cliffs (Fig. 4), stretching along the eastern border of the Sea of Galilee, are regarded as the mo~holo~cal expression of the main border fault having a vertical throw of several hundred meters. North of Wadi Samakh and the Sheikh Ali crescentic fault, there are several normal faults with small throw of 50 to 100 m. The Sheikh Ali crescentic fault is the continuation of the main border fault and has a similar throw. Neither pronounced slickensides, fault breccia nor mylonite that indicate strike slip movement have been observed on any fault planes. The border faults located on the opposite side and along the Naftali Mts. are again characteristic gravity faults (Picard, 1967). The main faulting phase is post-Cover Basalt-Late Pliocene and Pleistocene. The structural highs exposed at Mt. Hordos, Tel Rakkat, Tabigha and the buried high drilled at Rosh Pinna (numbers 6, 5 and west of numbers 2, 4 in Fig. 2) might be connected to form a continuous ridge with a strike of N15’E (Saltzman, 1964, Michelson, 1972). Assuming that
Two schools of thought exist regarding the origin of the Jordan Valley. One school claims that the main faults bordering it are normal with essential vertical displacement and thus the Jordan Valley is a graben (Picard, 1967). The other, dominant one claims that the faults are strike-slip faults with a cumulative lateral displacement of 107 km (Quennell, 1958; Freund et al., 1970; Bandel, 1981). Much of the evidence for a lateral shift of 107 km is based on displacement of features from the opposite sides of the Rift Valley. The features compared are usually from the southern segment of the Rift Valley in the Sinai Peninsula, Gulf of Elat and Arava. We will compare the Neogene sections exposed in northern Israel, on either side of the Sea of Galilee- the Poriyya Heights and southern Golan Heights-to determine whether or not they correlate (Fig. 5). Features common to the eastern (southern Golan Heights) and western (Poriyya Heights) graphic sections
strati-
(1) A thick Miocene continental section (Hordes Formation) with three to four basalt flows (Lower Basalt). (2) Freshwater deposits of oolitic and lacustrine limestone, marl and conglomerates about 80 m thick (Gesher Fm.) with a few basalt flows. (3) The Neogene sedimentary section is uncon-
133
formably overlaid by 150 m of Cover Basalt, the last pre-rift formation. (4) Basalt dikes penetrate the Neogene section. The differences between eastern and western sections (1) The facies of the Eocene formations differ -a nummulitic limestone-was deposited on the western side while a planktonic marly chalk was deposited on the eastern side. (2) The Fiq and Susita Formations are absent on the western side. (3) The maximum thickness of the Hordos Formation is 250 m in the southern Golan Heights. It is over 400 m thick in the Poriyya Heights. (4) A very thick section of Lower Basalt overlaid by a local conglomerate of basalt fragments forms the foundation of the Neogene basin on the western side, to the south and east of the Poriyya Heights. This thick section and local conglomerate is absent on the eastern side of the rift. (5) The Bira Formation is almost missing in the southern Golan Heights except for several Ostrea lumachelle relics. Most proponents of the lateral shift theory suggest that a displacement of 107 km has occurred since the Late Oligocene or Neogene. One would therefore expect to find traces of the Neogene basin of the southern Golan Heights up to 107 km south of the Sea of Galilee on the western side. Such outcrops have not been positively identified along the western side of the Rift. The western Neogene basin continues 15-20 km south of the Sea of Galilee. However, the Fiq and Susita Formations are not present there either. The Hordos Formation at the southeastern corner of the western basin might be similar to that in the southern Golan basin; however there it is “continuously exposed from the mountain border in the west to the mountain border in the east”. (Schulman and Rosental, 1968). The only formations found further south on the western side that might match the formations in the eastern Neogene Basin are the Gesher and Cover Basalt Formations. Therefore, a 15-20 km Pliocene-Pleistocene shift might have occurred. Freund et al. (1968) has correlated the Lower Basalt on both sides of the Jordan Valley. How-
ever, Michelson (1979) subsequently mapped the Lower Basalt referred to by Freund as Cover Basalt. If very little lateral shift occurred, the differences in stratigraphy between the Poriyya Heights and southern Golan could be explained by the existence of a structural ridge buried underneath the Sea of Galilee. This ridge formed in the Late Senonian and acted as a barrier separating two depositional basins during the Eocene, Oligocene and Miocene periods. The Jostulated existence of this structural ridge can explain: (1) The facies differences in the Eocene. (2) The reason that the Late Eocene-Early Miocene transgression from the Persian Gulf that deposited the Fiq and Susita Formations did not reach the western side. (3) The reason that the Pliocene transgression from the Mediterranean that deposited the Bira Formation barely reached the eastern side. The structural ridge was covered during the Pliocene and, subsequently, the Gesher Formation was deposited on both sides. It is noteworthy that many of the geologists who have done field work in the area of the northern Jordan Valley have maintained that the valley is bordered by normal faults (Picard, 1965; Bender, 1970; Schulman, 1962; Saltzman, 1984; Horowitz, 1973; Michelson, 1972; Dubertret, 1967; Darghawth, 1975). The Miocene horizontal displacement measured in the Gulf of Elat (Bartov et al., 1980; Eyal et al., 1981) might have dispersed along transversal and crescentric faults on both sides of the graben (Jericho fault, eastern Samaria faults, Gilboa-Carme1 fault system, etc.), thus reducing the lateral net displacement in the northern part of the Jordan Valley to only several kilometers (Freund, et al., 1970) and producing local basins like the one revealed by the Zemakh well. Concluding remarks
(1) Lithostratigraphic and facies analysis show that the initial tectonic phases of the graben commenced during the Early-Mid Miocene. (2) There is no observed physical evidence of
134
mylonites, major lateral slickenslides or fault breccia that speak for any important lateral movements. (3) The eastern cliff of the Sea of Galilee is a morphological feature caused by a normal fault. The Poriyya cliff was also formed as a result of a normal fault (Schulman, 1962). (4) The stratigraphy of the southern Golan Heights does not match the stratigraphy found on the western side of the rift further south, particularly 107 km further south, in the Judean desert, which has no Eocene-Neogene formations. (5) Stratigraphic and lithofacies analysis of the area under review does not support the existence of a large scale strike-slip movement. (6) The differences that exist between the Eocene, Oligocene and Miocene formations on either side of the graben are explained by the existence of a buried ridge unde~eath the present-day Sea of Galilee. References Adams, C.G., 1967. Tertiary Fora~~fera in the Tethyan, American and Indo-Pacific provinces. Aspects of Tethyan Biogeography. Syst. Assoc. Publ., 7: 195-217. Adams, C.G., 1968. A revision of the foraminiferal genus Ausrrotrdha PARR. Bull. of the Br. Mus. (Nat. Hist.), Geol., 16(2): 1-97. Bandel, K., 1981. New stratigraphical and structural evidence for lateral dislocation in the Jordan Rift Valley connected with a description of the Jurassic rock column in Jordan. Neues Jahrb. Geol. Palaeontol., Abh., 161(3): 271-308. Bartov, Y., Steinitz, G., Eyal, M. and Eyal, Y., 1980. Sinistral movement along the Gulf of Aqaba (Elat)-its age and relation to the opening of the Red Sea. Nature, 285: 220-221. Bender, F., 1968. Geologie von Jordanien. Bomtraeger, Berlin, 230 pp. Bender, F., 1970. The shear along the Dead Sea Rift-Discussion. Philos. Trans. R. Sot. London, Ser. A, 267: 127-129. Darghawth, B.R., 1975. The structural geology of the eastern flank of Mount Lebanon and the Western part of the Bekaa Graben in the Hazerta-Qabb Eliass Region. MSc. Thesis, University of Beirut. Dubertret, L., 1967. Remarques sur le fosse de la Mer Morte et ses prolongements au Nord jusqu’au Taurus. Rev. Geogr. Phys. Gtol. Dyn., (2). 9(l). Eyal, M., Eyal, Y., Bartov, Y. and Stein&, G., X981. The tectonic development of the western margin of the Gulf of Elat (Aqaba) Rift. Tectonophysics, 80: 39-66.
Freund, R., Zak, I. and Garfunkel, Z., 1968. Age and rate of the sinistral movement along the Dead Sea Rift. Nature, 220: 253-255. Freund, R., Garfunkel, Z., Zak, I., Goldberg, M., Weissbrod, T. and Derin, B., 1970. The shear along the Dead Sea Rift. Philos. Trans. R. Sot. London, Ser. A, 267: 107-127. Horowitz, A., 1973. Development of the Hula Basin, Israel. Isr. J. Earth Sci, 22: 107-139. Marcus, E. and Slager, J., 1985. The ~d~rnenta~-ma~atic sequence of the Zemakh I well (Jordan-Dead Sea Rift, Israel) and its empiacement in time and space. Isr. J. Earth Sci., 34: l-10. Michelson, H., 1972. The hydrogeology of southern Golan Heights. Tahal Rep. HR/72/37, 89 pp. Michelson, H., 1979. The Geology and Paleogeography of the Golan Heights. Ph.D. Thesis, Tel-Aviv Univ. 163 pp. (in Hebrew with English Abstr.}. Michelson, H. and Lipson, S.P., 1973. The litho and biostratigraphy of the southern Golan Heights. Isr. J. Earth Sci., 35(3/4). Mor, D. and Steinitz, G., 1982. K-Ar age of the Cover Basalt surro~ding the Sea of Galilee-Interim Report. Isr. Geol. Surv., Rep. ME/6/82. Picard, L., 1943. Structure and evolution of Palestine. Bull. Geol. Dep. Hebrew Univ., Jerusalem, 4: 1-134. Picard, L., 1965. The geological evolution of the Quatemary in the central-northern Jordan graben. INQUA Congr-Isr. Geol. Sot. Am., Spec. Pap., w 336-337. Picard, L., 1967. Thoughts on the graben system in the Levant. Geol. Surv. Can., Prof. Pap., 66-14: 22-32. Quennell, A.M., 1958. The structure and geomorphic evolution of the Dead Sea Rift. Q. J. Geol. Sot. London, 64: 1-24. Saltzmann, U., 1964. The geology of Tabigha-Huqoq-Migdal area. Tahal Rep. No. 347. MSc. Thesis, Hebrew Univ., Jerusalem, 55 pp. (in Hebrew ,with English abstr.). Sampo, M., 1969. Microfacies and microfossils of the Zagros area, Southwestern Iran (from the Permian to Miocene). In: J. Cuvillies and M.E. Schurmanns (Editors), Int. Sediment. Petrogr. Ser., Vol. 7. Brill, Leiden, 102 pp. Schulman, N., 1962. The geology of the Central Jordan Valley. Ph. D. Thesis, Hebrew Univ., Jerusalem, 103 pp. (in Hebrew with English abstr.) Schulman, N. and Rosenthal, E., 1968. Neogene and Quatemary of the Marma Feiyad area south of Bet She’an. Isr. J. Earth Sci, 17(2): 54-62. Wetzel, R. and Morton, D.M., 1959. Contribution a la Gtologie de la Transjordanie. Notes M&m. Moyen Orient, 7: 95-191. Wiesemann, G., 1969. Zur Tektonik Gebietes iistlich des Grabenabschnittes Totes Meer-Jordantal. Geol. Jahrb., Beih., 81: 215-247. Wolfart, R., 1964. Hydrogeology of the Damascus Basin (southw~t-Sy~a). General Assembly of Berkeley, Publ. No. 64.
125
A comparison of the eastern and western sides of the Sea of Galilee and its implication on the tectonics of the northern Jordan Rift Valley H. MICHELSON
I, A. FLEXER 2 and 2. EREZ 3
’ TAHAL Water Planning for Israel, 54 Even Gevirol, Tel Aviv (Israel) 2 Department of Geophysics and Planetary Sciences, Raymond and Beverly Sackler Fatuity of Exact Sciences, Tel Aviv University, Tel Aviv (Israel) 3 Geoiogy Department, Everyman’f University, Ramat Aviv (Israel)
(Received November 14,1985; accepted May 5,1986)
Abstract Michelson, H., Plexer, A. and Erez, Z., 1987. A comparison of the eastern and western sides of the Sea of Galilee and its impli~tion on the tectonics of the northern Jordan Rift Valley. In: Z. Ben-Avraham (Editor), Sedimentary Basins within the Dead Sea and Other Rift Zones. Tectonopkys~cs, 141: 125-134. The Sea of Galilee divides two Neogene basins which are characterized by largely continental elastic sequences and basalt flows. Stratigraphic differences between the two basins are discerned. A comparison of the stratigraphy of both sides of the Sea of Galilee does not support the postulated 107 km left-lateral movement. Although some small strike-slip faults might exist, most faults are of a gravity dip-slip type. A postulated ridge trending NNE, buried under the Sea of Galilee, might have had a stratigrapbic influence on sediment distribution between the eastern and western sides.
Introduction This paper examines the tectonic and stratigraphic evolution of the Neogene basin in the southern Golan Heights and compares it to the Neogene basin on the opposite side of the Jordan Rift Valley in order to determine if there are any indications of lateral movements. The Golan Heights (Fig. 1) is a typical basalt plateau formed by fissure eruptions. The northern border of the Golan Heights is at the contact with the flanks of the Hermon anticline whereas the southern border is the Yarmouk gorge which cuts into Senonian-Eocene beds near the southern extent of the basalt. These Senonian-Eocene beds form the southern flank of the Irbid syncline which continues beneath the Golan Heights. The eastern extension of the Golan Heights is HO-1951/87/~03.50
0 1987 Elsevier Science Publishers B.V.
the Hauran Plateau, a younger basalt plateau with numerous prominent volcanic cones and fresh basalt sheets. The western border of the Golan Heights is the Jordan Rift Valley. The main border fault has a N-S strike but turns N35 * E at Sheikh Ali (Figs. 2 and 4). From that point north to the Hula Valley, the rift valley faults are undetectable by surface mapping, although the Golan Plateau is separated from the Jordan and Hula Valleys by one main or several smaller cliffs. These cliffs are the morphological expression of either a main border fault or a series of step faults. The border fauit on the western side of the rift valley is obvious at the Naftali mountains. It’s extension further south, between Rosh Pinna and Tabigha, is unclear. The western side of the Sea of Galilee and its southern extension to the Bet Shean
Jordan
Fig. 1. General location map illustrating the morphotectotic
Valley is distinguished by a series of tilted blocks separated by transversal faults (Fig. 2).
units surrounding
the Golan Heights.
The Zora Fm. is built of profusion of planktonic foraminifera (“Globigerina ooze”) while nummulites are absent. The planktonic assemblage of the Adulam Mbr. includes Acarinina b~~~br~uki (Boli), Spaeroidinellopsis
senni (Beckmann)
and Morzo-
vek
Over 900 m of Early Eocene to Pliocene formations are exposed in the southern Golan Heights (Fig. 3). These include two newly described formations: the Fiq and Susita Formations (Michelson and Lipson, 1987). Zora Formation (Early-Middle
Eocene, 400 m)
formation exposed is the Eocene It is composed of bedded chalk and flint (Adulam Mbr) and massive chalk (Maresha Mbr). The
oldest
Zora Formation.
indicating upper Early Eocene age. The Maresha Mbr, contains six standard biozonesfrom ME11 with Hantkenina arugonensis to UEl with Gobigerinatheka semiinuahtu indicating a Middle Eocene to early Late Eocene age. Fiq and Susita Formatictns (Late Eocene, Oligocene, to Lower Miocene, about 2UQ m)
The Fiq and Susita Formations by a new marine cycle limited to of the Jordan Valley. The Fiq Fm. glauconitic and detritic limestone,
were deposited the eastern side is composed of white chalk and
127
tDlfERRANEAN
Tartirry
bedimoou
($
Tel Rakkat
03
Tfberisil Mt Hordoa
L
01
Zemnkh
Fig. 2. Schematic geological map of the Jordan Rift Valley in northern Israel (after Picard, 1965).
128 LEGEND:
FORMATION
AGE
-
UNCONFORMITY
2
CLAY
COVER
“CIOCENE
‘= -
SILTSTONE
BASALT
%
7
QIOCENE
OOLitlC
LIMESTONE
i
CONGLOMERATE
& Z
CALCAREOUS SANDSTONE
r? !.‘.:.
SANDSlbNE
W Z w 0
MlD0l.E
TO
0 LATE LLI MIOCENE Z
-
MlDOLE
OLIGOCENE EARLY
LL Z LL c C LL
EN
MIOCENE
MIOCENE
EOCENE
L! P’z CI
TO - LATE
EOCENE
I
_A
c
EARLY
SANDS
TO
a.
MIDDLE
GEV
s
mza *
,-15ofisn” z r
4 a EARLY-MIDDLE
r
MARESHA .‘I.
= -
QUARTZITE
Ia”
FOSSILS
/.g
LUMACHELLE
s -i
EARITE CONCRETIONS
wrxi
Gi_AUCONITE
3 -
MARLY
CHALK
E -
CHALKY
LIMESTONE
I 4
FLINT
HORIZONS
i--i
FLINT
LENSES
DOLOMITE
B
LIMESTONE
j--L/
CHALK
g
MARL
EOCENE
Fig. 3. Composite columnar section of the eastern cliff of the Sea of Galilee (after Michelson, 1972).
some marl, and the Susita Fm. is built of yellowish sandy marl, calcareous sandstone, bioclastic dolomite and limestone and chalky limestone. Both the Fiq and Susita Formations are very rich in fauna. Fossils include mainly planktonic foraminifera in the Fiq Fm., and planktonic and benthonic foraminifera as well as megafauna in the Susita Fm. The joint occurrence of Cassigerinella chipolensis and Gfobanomalina micra in the Fiq Fm. indicates Early Oligocene age. It is, however, possible
that the sedimentary cycle responsible for the Fiq Fm. had started as early at the Late Eocene. The important megafossils of the Susita Fm. are: Conw sp., Bithium sp., Cerithium sp., Turritella sp., Lucina sp., Arca sp., Cardium sp., Pecten sp., Ostrea sp., Phacoides sp., Venus ~Omphaioc~~thrurn~,cf. aglaurae (determined by S. Rothman, in Michelson and Lipson, 1987). Among the microfossils it is worthy to note the rich association of Miliolidae and Peneroplidae. Numerous sections of Tr~~~u~ina sp., Archaias sp., Quinguelo-
129
culina sp., and Austrotrillina sp. are encountered,
together with Peneroplis sp., small Rotalidae, coralline Algae and bryozoan fragments. The presence of Austrotrillina bears paleogeographical significance since this fossil occurs in the Oligocene-Miocene of the Indo-Pacific province, the Mediterranean basin (Adams, 1967, 1968) and notably in the Iran-Iraq basin (Asmari Limestone -Adams, 1968; Sampo, 1969). As Austrotrillina is lacking in the Oligocene-Miocene beds of the other areas in Israel, the Susita Fm. most likely was connected with the Iran-Iraq basin via the Wadi Sirhan depression. In addition, a shallow marine sequence similar to the Fiq and Susita Formations has been described by Bender (1968, fig. 90) approximately 90 km southeast of Azraq, and by Wetzel and Morton (1959) at Wadi Taiyiba opposite the Bet-Shean Valley and by Wiesemann (1969) near Esh Shuna on the eastern side of the Jordan River, about 10 km south of the Sea of Galilee. The similarity of the fauna and lithofacies of these sequences indicates that they were deposited by the same ingression that came from the Persian Gulf through the Sirhan depression and reached the southern Golan Heights. En Gev and Hordos Miocene; 250-3.50 m)
Formations
(Middle-Late
The En Gev Fm. was deposited in a restricted depression east of En Gev. It consists of mainly fine-grained eolian sands and was probably deposited in a local lake. The Hordos Fm. unconformably (mostly angular) overlies all of previously mentioned formations. This unconformity is regional (Bender, 1968). The Hordos Fm. is composed mostly of elastics -boulders, pebbles, sand, silt and marl that were deposited in lakes and flood plains of internal basins produced by differential uplift. Indicative fauna has not been found in either formation. Basalt flows and dikes found in the Hordos Fm. are equivalent to the Lower Basalt exposed on the western side of the Sea of Galilee. The isopachs of the En Gev and Hordos Fms. (Fig. 4) indicate thickening towards the west, i.e., progressive sinking of the Miocene basin. Angular unconformities within the Hordos Formation also indicate tectonic activity.
Bira and Gesher Formations (Pliocene, 80 m)
The last marine ingression in the area originated from the Mediterranean Sea through the Yizreel Valley during the Pliocene. It reached the southern Golan Heights and left behind relics of an Ostreae lumachelle (equivalent of the Bira Fm. to the west) (Michelson, 1972). Subsequently shallow freshwater lakes occupied the area, and continental calcareous sandstone, marl, lacustrine and oolithic limestone were deposited forming the Gesher Fm. (Fig. 3). Basalt flows are also found in the Gesher Formation (“Intermediate Basalt”, Schulman, 1962). Cover Basalt (Lute Pliocene, 50-150
m)
Tectonic and volcanic activity in the Late Pliocene terminated the Neogene sedimentary cycles. An angular unconformity separates the Gesher and older formations from the lava flows (Cover Basalt) in the Hauran Plateau, Golan Heights, southeastern Galilee and parts of northwestern Jordan. The Cover Basalt is built of flows of hard, coarse-grained, olivine rich basalt. It has been dated at between 3.1 m.y. (top) and 3.7 m.y. (bottom) (Mor and Steinitz, 1982). In the Golan, the Cover Basalt is overlain by younger Quatemary basalt with cinder cones and can form a sequence of over 500 m. The Cover Basalt becomes thinner towards the Sea of Galilee. The major faulting phase which formed the present Jordan Valley occurred after the lava flows of the Cover Basalt were extruded. Stratigraphy of the western rim of the Sea of Galilee A deposit of 1800 meters of Cenomanian to Pleistocene Formations are exposed on the western rim of the Sea of Galilee. (Fig. 5). The Cretaceous Formations (550 m)
The Upper Cenomanian Sakhnin Fm., 200 m thick, is built mainly of coarse crystalline dolomite. The overlying Turonian Bina Fm. consists of 50 m
130
--
H
.-
210 .7-‘.--
____.._ ____~.^.qL -__
-____y,,,
SEA OF
t GALILEE
f
Fig. 4. Isopach map of the Miocene Hordos and En Gev Formations after Michelson (1972).
131
East
West
MORE THAN 300 m
I
BAIIALT
1 hlID.-UC
tOLKIOCENE-
z
LIMESTONE
CHALKY-MARLY
FACIES
..ZYICI.LI
*a*-
Iad!
MlOCENEIl
lz!
FACIES
LEQLND USACT hn
AND
FLOWIINTRA CESHER
HORODS
Fm.i
I I
I I
9 =
9 : ‘. : : q.
l.lMLSTONe
FAUNA -
CACCAREOUS
SANDSTONE
Fig. 5. SItratigrapbic relationships between the western (Poriyya Heights) and the eastern (southern Golan Heights) sides of the Sea of Galilee.
of limestone. The Senonian-Paleocene Mt. Scopus Group is composed of 290 m of ,cha.lk and marl with abundant planktonic foraminifers, ostracods and nannofossils. The Timrat and Bar Kokhba Middle Eocene, 400 m)
Formations
(Lower-
The lower formation consists of well-bedded limestone (“Timrat Fm.“) and the upper one is a
massive karstic limestone rich in nummulites (((Bar Kokhba Fm.“). Hordes Formation (Miocene, 400-500
m)
The Hordos Fm. is composed of continental, fluviatile-lacustrine beds. The formation includes several intercalated basalt sheets which thicken southwards to form a continuous basalt sequence -the Lower Basalt (S~hulman, 1962). This formation is limited to the Neogene basins.
132
Bira Marl (Pliocene, 200 m)
The Bira Frn. is mostly composed of marl and dark clays, containing a few thin chalk, dolomite and limestone interbeds (brackish lagoonal series), followed by evaporites (gypsum and rock salt). A very thick sequence of evaporites was drilled by the Zemakh well (Marcus and Slager, 1985). Gesher Formation (Pliocene, 80 m)
The Gesher Fm. consists of white chalk at the base, oolitic chalk or Hydrobia fraasi bearing freshwater limestone in the middle and variegated clay at the top.
there is no significant strike-slip movement in the Jordan Valley, the ridge might continue to the structural high at Shamir in the Golan Heights. At the southern edge of the Sea of Galilee, the Zemakh well penetrated a very thick Neogene to Pleistocene sequence of basalts, evaporites and carbonates. A sequence which is believed to be Hordos Formation was encountered at a depth of 4200 m. indicating the existence of a very deep basin during the Miocene (Marcus and Slager, 1985). Discussion The origin of the Sea of Gaii~ee segment of the Jordan Valley
Cover Basalt (Pliocene, 50-150
m)
The Cover Basalt is similar to the same formation exposed on the eastern side of the Sea of Galilee. Structure
Normal dip-slip graben faults are the dominant tectonic element on both sides of the TiberiasHula graben system. The Haon cliffs (Fig. 4), stretching along the eastern border of the Sea of Galilee, are regarded as the mo~holo~cal expression of the main border fault having a vertical throw of several hundred meters. North of Wadi Samakh and the Sheikh Ali crescentic fault, there are several normal faults with small throw of 50 to 100 m. The Sheikh Ali crescentic fault is the continuation of the main border fault and has a similar throw. Neither pronounced slickensides, fault breccia nor mylonite that indicate strike slip movement have been observed on any fault planes. The border faults located on the opposite side and along the Naftali Mts. are again characteristic gravity faults (Picard, 1967). The main faulting phase is post-Cover Basalt-Late Pliocene and Pleistocene. The structural highs exposed at Mt. Hordos, Tel Rakkat, Tabigha and the buried high drilled at Rosh Pinna (numbers 6, 5 and west of numbers 2, 4 in Fig. 2) might be connected to form a continuous ridge with a strike of N15’E (Saltzman, 1964, Michelson, 1972). Assuming that
Two schools of thought exist regarding the origin of the Jordan Valley. One school claims that the main faults bordering it are normal with essential vertical displacement and thus the Jordan Valley is a graben (Picard, 1967). The other, dominant one claims that the faults are strike-slip faults with a cumulative lateral displacement of 107 km (Quennell, 1958; Freund et al., 1970; Bandel, 1981). Much of the evidence for a lateral shift of 107 km is based on displacement of features from the opposite sides of the Rift Valley. The features compared are usually from the southern segment of the Rift Valley in the Sinai Peninsula, Gulf of Elat and Arava. We will compare the Neogene sections exposed in northern Israel, on either side of the Sea of Galilee- the Poriyya Heights and southern Golan Heights-to determine whether or not they correlate (Fig. 5). Features common to the eastern (southern Golan Heights) and western (Poriyya Heights) graphic sections
strati-
(1) A thick Miocene continental section (Hordes Formation) with three to four basalt flows (Lower Basalt). (2) Freshwater deposits of oolitic and lacustrine limestone, marl and conglomerates about 80 m thick (Gesher Fm.) with a few basalt flows. (3) The Neogene sedimentary section is uncon-
133
formably overlaid by 150 m of Cover Basalt, the last pre-rift formation. (4) Basalt dikes penetrate the Neogene section. The differences between eastern and western sections (1) The facies of the Eocene formations differ -a nummulitic limestone-was deposited on the western side while a planktonic marly chalk was deposited on the eastern side. (2) The Fiq and Susita Formations are absent on the western side. (3) The maximum thickness of the Hordos Formation is 250 m in the southern Golan Heights. It is over 400 m thick in the Poriyya Heights. (4) A very thick section of Lower Basalt overlaid by a local conglomerate of basalt fragments forms the foundation of the Neogene basin on the western side, to the south and east of the Poriyya Heights. This thick section and local conglomerate is absent on the eastern side of the rift. (5) The Bira Formation is almost missing in the southern Golan Heights except for several Ostrea lumachelle relics. Most proponents of the lateral shift theory suggest that a displacement of 107 km has occurred since the Late Oligocene or Neogene. One would therefore expect to find traces of the Neogene basin of the southern Golan Heights up to 107 km south of the Sea of Galilee on the western side. Such outcrops have not been positively identified along the western side of the Rift. The western Neogene basin continues 15-20 km south of the Sea of Galilee. However, the Fiq and Susita Formations are not present there either. The Hordos Formation at the southeastern corner of the western basin might be similar to that in the southern Golan basin; however there it is “continuously exposed from the mountain border in the west to the mountain border in the east”. (Schulman and Rosental, 1968). The only formations found further south on the western side that might match the formations in the eastern Neogene Basin are the Gesher and Cover Basalt Formations. Therefore, a 15-20 km Pliocene-Pleistocene shift might have occurred. Freund et al. (1968) has correlated the Lower Basalt on both sides of the Jordan Valley. How-
ever, Michelson (1979) subsequently mapped the Lower Basalt referred to by Freund as Cover Basalt. If very little lateral shift occurred, the differences in stratigraphy between the Poriyya Heights and southern Golan could be explained by the existence of a structural ridge buried underneath the Sea of Galilee. This ridge formed in the Late Senonian and acted as a barrier separating two depositional basins during the Eocene, Oligocene and Miocene periods. The Jostulated existence of this structural ridge can explain: (1) The facies differences in the Eocene. (2) The reason that the Late Eocene-Early Miocene transgression from the Persian Gulf that deposited the Fiq and Susita Formations did not reach the western side. (3) The reason that the Pliocene transgression from the Mediterranean that deposited the Bira Formation barely reached the eastern side. The structural ridge was covered during the Pliocene and, subsequently, the Gesher Formation was deposited on both sides. It is noteworthy that many of the geologists who have done field work in the area of the northern Jordan Valley have maintained that the valley is bordered by normal faults (Picard, 1965; Bender, 1970; Schulman, 1962; Saltzman, 1984; Horowitz, 1973; Michelson, 1972; Dubertret, 1967; Darghawth, 1975). The Miocene horizontal displacement measured in the Gulf of Elat (Bartov et al., 1980; Eyal et al., 1981) might have dispersed along transversal and crescentric faults on both sides of the graben (Jericho fault, eastern Samaria faults, Gilboa-Carme1 fault system, etc.), thus reducing the lateral net displacement in the northern part of the Jordan Valley to only several kilometers (Freund, et al., 1970) and producing local basins like the one revealed by the Zemakh well. Concluding remarks
(1) Lithostratigraphic and facies analysis show that the initial tectonic phases of the graben commenced during the Early-Mid Miocene. (2) There is no observed physical evidence of
134
mylonites, major lateral slickenslides or fault breccia that speak for any important lateral movements. (3) The eastern cliff of the Sea of Galilee is a morphological feature caused by a normal fault. The Poriyya cliff was also formed as a result of a normal fault (Schulman, 1962). (4) The stratigraphy of the southern Golan Heights does not match the stratigraphy found on the western side of the rift further south, particularly 107 km further south, in the Judean desert, which has no Eocene-Neogene formations. (5) Stratigraphic and lithofacies analysis of the area under review does not support the existence of a large scale strike-slip movement. (6) The differences that exist between the Eocene, Oligocene and Miocene formations on either side of the graben are explained by the existence of a buried ridge unde~eath the present-day Sea of Galilee. References Adams, C.G., 1967. Tertiary Fora~~fera in the Tethyan, American and Indo-Pacific provinces. Aspects of Tethyan Biogeography. Syst. Assoc. Publ., 7: 195-217. Adams, C.G., 1968. A revision of the foraminiferal genus Ausrrotrdha PARR. Bull. of the Br. Mus. (Nat. Hist.), Geol., 16(2): 1-97. Bandel, K., 1981. New stratigraphical and structural evidence for lateral dislocation in the Jordan Rift Valley connected with a description of the Jurassic rock column in Jordan. Neues Jahrb. Geol. Palaeontol., Abh., 161(3): 271-308. Bartov, Y., Steinitz, G., Eyal, M. and Eyal, Y., 1980. Sinistral movement along the Gulf of Aqaba (Elat)-its age and relation to the opening of the Red Sea. Nature, 285: 220-221. Bender, F., 1968. Geologie von Jordanien. Bomtraeger, Berlin, 230 pp. Bender, F., 1970. The shear along the Dead Sea Rift-Discussion. Philos. Trans. R. Sot. London, Ser. A, 267: 127-129. Darghawth, B.R., 1975. The structural geology of the eastern flank of Mount Lebanon and the Western part of the Bekaa Graben in the Hazerta-Qabb Eliass Region. MSc. Thesis, University of Beirut. Dubertret, L., 1967. Remarques sur le fosse de la Mer Morte et ses prolongements au Nord jusqu’au Taurus. Rev. Geogr. Phys. Gtol. Dyn., (2). 9(l). Eyal, M., Eyal, Y., Bartov, Y. and Stein&, G., X981. The tectonic development of the western margin of the Gulf of Elat (Aqaba) Rift. Tectonophysics, 80: 39-66.
Freund, R., Zak, I. and Garfunkel, Z., 1968. Age and rate of the sinistral movement along the Dead Sea Rift. Nature, 220: 253-255. Freund, R., Garfunkel, Z., Zak, I., Goldberg, M., Weissbrod, T. and Derin, B., 1970. The shear along the Dead Sea Rift. Philos. Trans. R. Sot. London, Ser. A, 267: 107-127. Horowitz, A., 1973. Development of the Hula Basin, Israel. Isr. J. Earth Sci, 22: 107-139. Marcus, E. and Slager, J., 1985. The ~d~rnenta~-ma~atic sequence of the Zemakh I well (Jordan-Dead Sea Rift, Israel) and its empiacement in time and space. Isr. J. Earth Sci., 34: l-10. Michelson, H., 1972. The hydrogeology of southern Golan Heights. Tahal Rep. HR/72/37, 89 pp. Michelson, H., 1979. The Geology and Paleogeography of the Golan Heights. Ph.D. Thesis, Tel-Aviv Univ. 163 pp. (in Hebrew with English Abstr.}. Michelson, H. and Lipson, S.P., 1973. The litho and biostratigraphy of the southern Golan Heights. Isr. J. Earth Sci., 35(3/4). Mor, D. and Steinitz, G., 1982. K-Ar age of the Cover Basalt surro~ding the Sea of Galilee-Interim Report. Isr. Geol. Surv., Rep. ME/6/82. Picard, L., 1943. Structure and evolution of Palestine. Bull. Geol. Dep. Hebrew Univ., Jerusalem, 4: 1-134. Picard, L., 1965. The geological evolution of the Quatemary in the central-northern Jordan graben. INQUA Congr-Isr. Geol. Sot. Am., Spec. Pap., w 336-337. Picard, L., 1967. Thoughts on the graben system in the Levant. Geol. Surv. Can., Prof. Pap., 66-14: 22-32. Quennell, A.M., 1958. The structure and geomorphic evolution of the Dead Sea Rift. Q. J. Geol. Sot. London, 64: 1-24. Saltzmann, U., 1964. The geology of Tabigha-Huqoq-Migdal area. Tahal Rep. No. 347. MSc. Thesis, Hebrew Univ., Jerusalem, 55 pp. (in Hebrew ,with English abstr.). Sampo, M., 1969. Microfacies and microfossils of the Zagros area, Southwestern Iran (from the Permian to Miocene). In: J. Cuvillies and M.E. Schurmanns (Editors), Int. Sediment. Petrogr. Ser., Vol. 7. Brill, Leiden, 102 pp. Schulman, N., 1962. The geology of the Central Jordan Valley. Ph. D. Thesis, Hebrew Univ., Jerusalem, 103 pp. (in Hebrew with English abstr.) Schulman, N. and Rosenthal, E., 1968. Neogene and Quatemary of the Marma Feiyad area south of Bet She’an. Isr. J. Earth Sci, 17(2): 54-62. Wetzel, R. and Morton, D.M., 1959. Contribution a la Gtologie de la Transjordanie. Notes M&m. Moyen Orient, 7: 95-191. Wiesemann, G., 1969. Zur Tektonik Gebietes iistlich des Grabenabschnittes Totes Meer-Jordantal. Geol. Jahrb., Beih., 81: 215-247. Wolfart, R., 1964. Hydrogeology of the Damascus Basin (southw~t-Sy~a). General Assembly of Berkeley, Publ. No. 64.