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Chapter Four
Geology And Soil

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Geology

Rock outcrops in Nablus area range in age from Cretaceous to Quaternery. Jurassic rocks also have limited outcrops. Cretaceous and Tertiary rocks are marked by marine carbonate sediments such as limestone, dolomites, chalks and marls (Rofe and Raffety, 1965). Table 4.1 shows the geological rock formations and the hydrostratigraphic units and their aquifer potentiality and lithology.

 

Table 4.1: Lithology, aquifer potentiality and thickness of different geologic formations of Nablus area."

Geological Time Scale					Series		Formation	Lithology	Thickness Range (m)	Aquifer Potentiality
Era	System	Epoch			Rofe and Raffety		Rofe and Raffety
C E N O Z O I C	Quaternary	Holocene			Recent		Alluvium	"Marl, alluvium, gravel"	Variable	Good Aquifer
		Pleistocene			Lisan		Gravel and fans
							Lisan	"Laminated marl and gypsum, L.S."	200+	Good with soluble mineral content
	Tertiary	Miocene Pliocene			Bayda		Bayda	Conglomeratic rocks	200+	Good Aquifer
		M.Eocene Palaeocene			B A Y D A	Jenin sub series	"Reef L.S numulitic L.S with chalk, chalk with numulitic L.S"	"Reef, L.S., bedded L.S., chalk with L.S., undifferentiated"	0 - 470	Aquifer in L.S. zones. An aquiclude in chalk zones
M E S O Z O I C	EOUTA CECRS	Senonian					"Chalk, Cherts"	"Chalk, chert"	"0 - 450 ,0 - 40"	Poor aquiclude
	C R E T A C E O U S	Turonian			Ajlun		Jerusalem	L.S. and dolomite	50 - 100	Very good aquifer
		C E N O M A N I A N	Upper				Bethlehem	"Dolomitised L.S., dolomite, chalk"	30 - 115	Very good aquifer
			Middle	Upper			Hebron	"Limestone,dolomitic, cherts, chalky"	105 - 260	Excellent aquifer
				Lower
			Lower	Upper			Yatta	"Dolomitic L.S.,marl, chalky,clay"	50 - 150	Poor aquiclude
				Lower
							Upper Beit Kahil	"Chalky L.S., dolomite, organic L.S."	110 - 190	Good aquifer
							Lower Beit Kahil	"Dolomitised, marly L.S.,shale"	250 - 290	Poor aquiclude
		Neocomian - Albian			Kurnub		Ramali	"Sandstone, sandy lime"	260 - 290	Excellent
	JURASSIC	Bajocian - Bthonian			Zerqa		Upper Maleh	"Marl, chalky L.S."	190	Poor aquiclude
							Lower Maleh	"Limestone,oolitic L.S.,marl"	>55	Good
							Igneous	Basic igneous variable
L.S. Lime Stone

 

Geological Formations

 

1- Jurassic Rocks:

They are exposed in wadi Maleh, and composed mainly of limestone. Jurassic rocks are divided into the following formations (Table 4.1)

• Lower Maleh formation: It consists mainly of limestone which is affected by instrustive basalt. The limestone is massive and it has a light-brown color which is due to limonate. The formation is marked with vertical joints.
• Upper Maleh Formation: The lower part of this formation is marked with marl and chalky limestone, while chalk and chalky limestone mark the upper part. The limestone of the lower formation is suddenly transformed from massive to a sharp topographic feature. Weathered limestone and Karst caves make the formation a minor aquifer.

 

2- Cretaceous Rocks:

They are divided into the following formations:

• Ramali Formation: The Ramali Formation, in Nablus area, consists of sandstone series occurring between the base of the Beit Kahil and the Maleh formations. The Ramali formation is exposed in the core of the Judean anticline in three distinct areas. The most extensive outcrop is in wadi Maleh area where the sandstone is the main component. The two other exposures of this formation are in wadi Far'a and Luhuf Jadir and are composed mainly of a prominent craggy limestone. Ramali formation is an excellent aquifer, the cemented sandstone is well jointed and the bulk of the sand is porous (Table 4.1).
• Lower Beit Kahil Formation: It forms the lower part of lower Cenomanian. The main outcrops are in wadi Far'a and in the north of the anticline axis area. The lower part of the formation consists mainly of thick, massive iron-stained limestone. The formation passes up through sandy marls and shales into thin-bedded porcellanous limestone. The formation has a thickness of 230 m (Table 4.1).
• Upper Beit Kahil Formation: This formation is considered to be as equivalent to the upper part of the lower Cenomanian. The main outcrops are in wadi Far'a and Beit Furik and in the core of Ein Qinya anticline. It consists of dolomitic and sometimes chalky, and marly limestone. This formation has a small outcrop area because of its steep dips. It has a thickness of about 120-250 m. The formation is marked by joints and includes Carvenous limestone, thus forming a good aquifer (Table 4.1).
• Yatta Formation: It forms the lower part of the middle Cenomanian and is exposed on both the east and west sides of the Judean anticline. This formation consists mainly of marl, chalky limestone, clay and thin interbedded dolomitic limestone. It has a thickness of about 150 m (Table 4.1).
• Hebron Formation: This formation is regarded as equivalent to the upper part of the middle Cenomanion. It is exposed in the west, southwest and southeast of Nablus district, and consists mainly of blue-green limestone and dolomitic limestone. The lower part of its outcrop is massive while the upper part is well bedded. The Hebron formation rocks have karst caves and joints, therefore it is an excellent aquifer (Table 4.1).
• Bethlehem Formation: It is approximately equivalent to the upper Cenomanian and is exposed on the flanks of both the Far'a and Anabta anticlines. The bottom of the formation consists of dolomite, limestone, chalk and marl. It has a thickness of about 30-100 m (Table 4.1) (Rofe and Raffety, 1963).
• Jerusalem Formation: This formation belongs to the Turonian period. It is exposed in the west along the axial area of the Anabta anticline and in narrow strips flanking the Far'a anticline. It consists mainly of massive limestone, dolomite and, sometimes chalk. The formation varies in thickness and lithology and has a thickness of about 50-100 m (Table 4.1).

 

3- Rocks of the Cretaceous-Tertiary Transition Chalk with Chert:

This formation is composed mainly of chalk and ranges in age from approximately Coniacian at the base to Palaeocene at the top. The chalk is usually cream, buff or white, and occasionally dark colored due to the presence of bituminous materials. In some places of the formation, the chalk is associated with chert, therefor it tends to be phosphatic with some fish remains.

 

4- Tertiary Rocks:

These consist of the following formations.

• Jenin subseries: It consists of Eocene aged rocks which are found in Nablus and Jenin areas. Outcrops are widely spread covering one third of the total area. Rocks of the Palaecene age consist mainly of chalk. In this formation, five facies of limestone and chalk have been described. These facies are chalk with minor chert, chalk with interbedded limestone, limestone with minor chalk, bedded massive limestone and Reef limestone. The total thickness of this formation is about 500 m. Rocks of the Jenin subseries are caved and have joints, therefore they are considered as a major aquifer (Table 4.1).
• Bayda Formation: It consists mainly of conglomerate resting on the exposed formations of the Cretaceous rocks. The formation is marked by rounded features. The area of Bayda was subjected to folding, faulting and uplifting. Recent erosion has cut down the solid rocks leaving capping on the interfluves (Table 4.1).

 

5- Quaternary rocks:

They are divided into the following formations :

• Lisan formation: It consists mainly of laminated marls and gypsum, marginally of gravels and poorly sorted pebble beds, occasionally calcareous and limestones. Total thickness is about 200 m (Table 4.1).
• Alluvium: This formation is composed of alluvium consisting of unconsolidated marls with some siliceous sand. The derivation of the alluvium from the limestone gives it the red color and fine texture (Table 4.1).
• Nari formation: It occurs over all rocks especially in areas of high rainfall, where the carbonate rocks are dissolved by percolating water penetrating the upper zone of the outcrops. It forms a thin coating over the limestone with a thickness of about l0 m.
• Igneous rocks: There was two periods of igneous activity. The first occurred between the Maleh and Ramali formation, at the end of the Jurassic to the early Cretaceous, and the second post-dates nummultic limestones of Eocene age. Outcrops are found in both wadi Far'a and wadi Maleh. In wadi Far'a basaltic layers are inter bedded with yellow-red sandstone.

 

Structural patterns:

 

Folds:

The following folds exist in Nablus district:

• Anabta Anticline:

  It extends to about 25 km, and trends north-south. Its northern part has southerly pitch but the southern part is broken by faults. The Anabta anticline is symmetrical in structure.

   

• Nablus-Beit Qad Syncline:

  It covers an area of about 1500 km. The axis trends NNE-SSW, but near Jammaa'in it bends sharply westwards. The northern part has a northerly pitch except for the last few kilometers where it tilts southwards. The syncline is symmetrical with a gentle dipping west limb and a steep east limb (Figure 4.1).

   

  

   

• Ein Qinya Anticline:

  It passes through the area around Deir Es Sudan, then swings sharply eastwards to pass through Khirbet Qeis. It trends NE-SW and it is symmetrical in structure (Figure 4.1).

   

• Far'a Anticline:

It is considered as one of the main folds in Nablus district. It trends NNW and extends to about 10 km. The east and west limbs of the anticline form two minor folds, Rujeib Monocline and Khirbet Fasayil Monocline. It's board axial area is distinguished from the flanks. The anticline has a symmetrical structure (Figure 4.1).

 

Faults:

In Nablus district, the main depressed areas, like Far'a, Tubas and Tayasir Grabens are boarded by complex fault systems. Majdal Bani Fadil fault and Beit Furik fault also form major structures in the district. Most of faults trend NW - SE (Figure 4.1). Towards the west, the faults become more hummock and their impact therefore, becomes less visible.

 

Joints:

Joints and solution channels are best developed in the lower Maleh, Hebron, and Jerusalem formations, as well as Nummulitic limestone facies.

 

Earthquakes:

Several earthquakes happened during the last 2,000 years. Records show that about 500 persons were killed and more others injured. In Nablus district, at least 33 earth movements have been recorded, some of these earthquakes were severe, others are moderate or weak.

 

Soil

The soil characteristics and references to major vegetation were adopted from the document entitled, The Soil of Israel (1976). The major soil associations found in Nablus district are as follows (Table 4.2 and Figure 4.2).

 

 

Table 4.2: Major soil types and characteristics in Nablus district

no	Soil Association	Area Hectares	American Classification	FAO Soil Unit Classification	Location	General Characteristics	Natural Vegetation	Rainfall (mm)	Mean temperature (c)
1	Grumusols	"9,461.57"	Xererts	Vertisols	Area with smooth to gently sloping topography	Parent material are fine textural alluvial or aeolien sediments	Prosopis farcata-Scolymus maculatus	300-700	19-21
2	"Terra rossas, brown and pale rendzinas"	"78,409.75"	Xerochrepts Haploxerolls	"Luvisols, Cambisols, Lithosols, and Rendzinas"	central mountainsSmall plateau of the mountains	"Terra rossa type, the parent materials are dolomite and hard limestone, the soil depth varies from shallow to deep (0.5-2m) Xeric moisture regime, deep in hilltops and shallow in sloppy mountainous areas. Soil has a reddish brown color with subangular blocky structure. Same as Xerochrepts with the exception that it has a base saturation of 75%"	"Quercus calliprinos, Pistacia palaestina and Pistacia lentiscus. Pistacia atlantica, Amygdalus korschinskii and Pistacia palaestina."	400-700	15-20
3	Brown & pale rendzinas	"35,884"	Xerorthents	Rendzinas and Lithosols	Hilly slopes	"Xeric moisture regime, it has a reddish brown color. Soil structure is crumby. Texture is loamy or clay, about 30% is stony. Parent material is soft calk and marl."	Pinus halepensis and Pistacia palaestina.	600-700	15-19
			Haploxerolls		Valleys and depressions	Xeric moisture regime. It has dark reddish brown color with clay and with gentle slope. Parent rocks are marl and chalk.	"Quercus ithaburensis, Pistacia lentiscus, Ceratonia siliqua and Ballotetalia undulatae."	300-700	18-20
4	Brown lithosols & loessial arid brown soils	"5,052.81"	Haploxeralfs Torriorthents Xerochrepts	Lithosols and Xerosols	Eastern slopes	"marl, chalk, limestone and conglomerates parent rocks.Xeric moisture regime, the soil has ochric surface epipedon with low organic matter < 0.6% and massive structure. Parent material is loessial sediments."	"Ballotetalia undulatae, Artemisietea herbae-albae."	200-350	19-21
5	Regosols	"11,427.86"	Xerochrepts Calciorthids Gypsiorthids	Regosols	Badlands along terraceescarpment in the Jordan Valley	"The soil has Pale brown color, loamy texture. Parent materials are sands, clays and loess."	"Anabasis articulata, Salsola vermiculata and Salsola tetrandra"	150-200	22-24
6	Dark Brown soils	"5,642.45"	Xerochrepts Haploxeralfs	Luvisols and cambisols	Slopy areas	"It is characterized by coarse textural residual dark brown soils. The parent rocks are aeolian sediments, calcareous sandstone and medium to fine textured alluvial deposits."	Prosopis farcata - Scolymus maculatus	350-500	19-20
7	Alluvial Arid Brown soils	"3,148"	Haplargids Camborthids	Xerosols	Alluvial fans and plains	Formed as a result of erosion of calcareous silty and clay materials.	Herbaceous vegetation of desert annual halophytes and glycophytes	150-200	23
8	Loessial Arid Brown soils	311.92	Palexeralfs Haploxeralfs Xerochrepts	Xerosols	Gently sloping plateau and dissected plateau	Parent rocks are conglomerate and chalk.	Achilleetum santolinae	150-250	20-21
9	Calcareous serozems	"4,571.20"	Xerochrepts Calciorthids Gypsiorthids	"Cambisols, Xerosols, Yermosols"	Flood plains	"The soil is highly calcareous with greyish-brown color. The texture is medium to fine. Parent rocks are limestone, chalk and marl."	Salsoletum villase	100-400	21-24
10	Solonchalk	"3,148"	Salorthids	Solonchalk	Occupy the drainage valleys and closed basins where the groundwater table is near the soil surface.	"Texture ranges from sand to clays, some cases is extremely saline, with up to 50% salts. The parent materials are recent alluvial deposits. "	"Tamarix, Suaeda and Nitraria"	50	23-25
11	Pale Rendzinas	325.83	Xerortherts Haploxerolls	Lithosols and Rendzinas	"Jammain, O’rif and Sabastiya(hilly slopes)"	It is a highly calcareous and greyish-brown alluvial soil. Parent material are soft chalk and marl	Pinus halepensis	600-700	15-19

1. Grumusols

This soil association covers approximately 9,461 hectares of the district. It is found in areas with smooth to gently sloping topography. The soil is originally formed from fine textured alluvial or aeolien sediments. Primary natural vegetation has been destroyed. Presently, what appears is segetal vegetation of the Prosopis farcata-Scolymus maculatus association. The use of this soil type for production purposes is currently limited to wheat cultivation. The American Great Classification that represents this soil is Xererts.

2. Terra Rossa, Brown and Pale Rendzinas

These types of soil associations occupy approximately 78,409 hectares, or 49% of Nablus district. Rock outcrops in these soils cover between 30-50%. The major native vegetation cover include Quercus calliprinos, Pistacia palaestina, Pistacia lentiscus, Pistacia atlantica, and Amygdalus korschinskii. The dominant land use pattern on these soils is the cultivation of field crops, mainly wheat, barley, grapes, olive and fruit trees, particularly on valley shoulders. The American Great Group Classification that represents these soil associations is Xerochrepts and Haploxerolls.

 

3. Brown Rendzinas and Pale Rendzinas

This soil association occupies an area of approximately 35,884 hectares. Similar to the previous soil types, rock outcrops in these soils are 30­50%. Major vegetation cover includes Pinus halepensis, Pistacia lentiscus, Pistacia palaestina, Quercus ithaburensis, Ceratonia siliqua and Ballotetalia undulatae. On such areas, cultivation of grapes and olives, field crops (wheat and barley), and grazing are the main land uses, especially in shallow and steep sloping areas. According to the American Great Group classification, these soils represent the association of Xerorthents, and Haploxerolls.

 

4. Brown Lithosols and Loessial Arid Brown Soils

This type of soil association covers an area of approximately 5,052 hectares of Nablus district. It characterizes the southern parts of the eastern slopes of the district and is mainly found on steep to moderate rocky and eroded slopes. Brown lithosols are found in the pockets among the rocks. Loessial arid brown soils are found on flat hilltops, plateau and foot­slopes. The parent rocks of this soil association are chalk, marl, limestone and conglomerates. Major vegetation is Ballotetalia undulatae and Artemisietea herbae­albae. The American Great Classifications that represent this soil are Haploxeralfs Terriorthents and Xerochrepts

 

This type of soil association characterizes the eastern border of Nablus district. It is found as badlands along terrace escarpments in the Jordan Valley, covering an area of approximately 11,427 hectares. The soil parent materials are sand, clay and loess. The dominant vegetation found in this region are Anabasis articulata, Salsola vermiculata and Salsola tetrandra. The area is used for grazing. The American Great Group Classifications that represent this soil, are Xerochrepts, Calciorthids and Gypsiorthids.

 

6. Dark Brown Soils

This type of soil association covers an area of approximately 5,642 hectares of Nablus district. This soil is distributed as elongated polygons on the eastern slopes of the district. The parent rocks of this soil association are aeolian sediments, calcareous sandstone (Kurkar), and medium to fine textured alluvial deposits. Primary natural vegetation was destroyed in this area, except segetal vegetation of the Prosopis farcata-Scolymus maculatus. The American Great Group classifications that represent this soil association are Xerochrepts, and Haploxeralfs.

 

7. Alluvial Arid Brown Soils

This type of soil association is located mainly in the Fasayil area. It covers an area of approximately 3,148 hectares. It exists as an alluvial fans and plains, which formed as a result of erosion of calcareous silty and clay materials. This soil type supports herbaceous vegetation of desert annual halophytes and glycophytes, and responds well to irrigation, producing various crops, mainly subtropical and tropical fruits, such as citrus, bananas, and dates, as well as winter vegetables. The American Great Group Classifications that represent this soil association are Haplargids and Camborthids.

 

8. Loessial arid Brown Soils

This type of soil association is found on moderate slopes to the east of Kh. Kardala at the north-eastern part of the district. It covers an area of approximately 311 hectares. The soil was formed originally from conglomerate and/or chalk. The major vegetation type found in this region is Achilleetum santolinae, and the primary land use includes cultivation of various field crops and some irrigated horticultural crops. Wheat, barely, and sorghum are grown as dry­farming crops. The American Great Group Classifications that represent this soil association are Palexeralfs, haploxeralfs and Xerochrepts.

9. Calcareous Serozems

This type of soil association is found on the eastern slopes of Nablus district. It was formed mainly as a result of flooding of the Jordan River. The soil covers an area of approximately 4,571 hectares. It was originally formed from limestone, chalk and marl. The vegetation is restricted to Salsoletum villase. The current land use is restricted to winter grazing. The American Great Group Classifications that represent this soil are Xerochrepts,Calciorthids and Gypsiorthids.

 

10. Loessial arid Brown Soils

This type of soil association is found in the south eastern part of the district, covering an area of about 3,148 hectares. It occupies the drainage valleys and closed basins where the groundwater table is near the soil surface. The soil parent rocks are recent alluvial deposits ranging in texture from sand to clays. Major vegetation is halophytic with dominant species being Tamarix, Suaeda, and Nitraria. Some dates are grown on the periphery of the depressions, where the ground water is still relatively fresh. The American Great Group Classification that represents this soil is Salorthids.

 

11. Pale Rendzinas

This soil association covers the areas of Jammaa'in, O'rif, and Sabastiya, covering an area of about 325.83 hectares. It is a highly calcareous grey and greyish brown alluvial soil. Parent materials are soft chalk and marl. Major vegetation is Sponyaneous woods of Pinus halepensis. Various rainfed orchards are grown especially olives. Rainfed field crops are also widespread. The shallow soils are used for grazing. The American Great Group Classifications that represent this soil are Xerortherts and Haploxerolls.

 

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Copyrighted © Applied Research Institute - Jerusalem (ARIJ), 1996