The Geography of the Mount of Olives
Sefi Ben Yosef
Location and Borders: The Mount of Olives is a long and narrow mountain that stretches along the eastern edge of Jerusalem in a general north-south direction. Its summit lies in the center of the village of Abu Tor, at an altitude of about 820 meters above sea level, and approximately 100 meters above the Old City of Jerusalem. Its northern border marks the ridge of Augusta Victoria, from which point it connects with Mount Scopus, and together with it constitutes the eastern border of Jerusalem. Its eastern rim is very steep and progresses east towards the Judean Desert, from which the topmost streams of Nahal Og descend. The southern and western borders of the Mount of Olives are defined by the riverbed of Nahal Kidron, in the segment between Wadi al-Joz within Jerusalem’s city limits, and Wadi Sahouri, which joins Nahal Kidron from the southeast to the village of Silwan. This border is cliff-laden and very clear, due to Nahal Kidron’s quick and deep undermining of the solid limestone exposed here.
The tributary of Nahal Kidron, which is called Wadi Sahouri, divides the southern part of the Mount of Olives into two sections – the western branch, also called the Mount of Anointment, on the banks of which sits Silwan, and the eastern portion, which runs to the village of Al Eizariya, upon which are ostensibly the remains of Bethany.
Landscape Units: The Mount of Olives is part of an independent landscape unit in Israel which constitutes a border area between the Judean Hills and the Judean Desert. The Mount of Olives can be discerned by a number of characteristics, both from the area of the Jerusalem Mountains and from the region of the Judean Desert. This expanse is called “The Judean Desert Perimeter,” and the prominent terrain lines within it have a predominantly steeper incline than that of the East. This allows for the existence of lookout points from the Temple Mount over the Judean Desert, the Dead Sea, and the Jordan River Valley.
The rocks in the region are largely solid limestone from the Cenomanian-Turonian Period. In certain parts of the area in which the rock is chalk from the Senonian Period, it is usually covered with calcrete. The chalky mother rock, or the calcrete, makes up the ground foundation that is terra rossa, or alternatively – rendzina. The region is also a climate change unit. Thus, even the natural ground cover within it is transition vegetation from the Mediterranean Sea region to the Irano-Turanian region.
In the Desert Perimeter territory, we find the edge of the intense agricultural area of Judea. As part of this landscape unit, we can detect on the Mount of Olives a number of characteristics that match the model of the region currently being described. Together with this, the terrain of the Mount of Olives is unique in that it does not constitute a gradual transition from the Jerusalem Mountains to the Judean Desert. The presence of the Mount of Olives east of the deep riverbed of Nahal Kidron, as well as its prominence over Jerusalem, establishes the Mount of Olives as a partition between the Mediterranean Sea area of Jerusalem and its desert, and not necessarily a transition region. The Mount of Olives is a distinct boundary between two lithological, morphological, and climatic units that are vastly different from one another.
Morphotectonics: The Mountain is part of the anticlinorium (a large anticline) of Judea. But here it also constitutes a border between structural units and this anticlinorium. In a cross-section running from south to north, the Mount of Olives is in the northeastern extremity of the Hebron anticline. In a cross-section from west to east, it is in the eastern margins of the synclinal ridge of the Judean Mountains, and on the eastern border of the anticline of the Judean Mountains with the syncline of the Judean Desert.
The fault line from west to east, in the southern portion of the Mount of Olives, has elevated the mountain northward and exposed layers of limestone and dolomite from the Cenomanian-Turanian Period in the western section of the mountain, the same section that faces the Judean anticline.
In the interim, the relative deviation westward of the Ramallah anticline, which levels off opposite the Mount of Olives, brings about the permeation of corrugated rock from the Senonian Period to northeast Jerusalem, including the Mount of Olives. A series of faults in the northern section of Mount Scopus, which is a continuation of the Mount of Olives, contributes to the general rise of the mountain range, although most of the extreme cartography on the mountain is observed mainly on the southern side, on which the Kidron’s tributaries deepen the aforementioned morphotectonic line.
Rock: The mass of the Mount of Olives is lithologically divided into a number of units of sedimentary marine limestone:
- The foundation of the mountain’s western slope on the Augusta Victoria-Rockefeller line (northern border) is composed of limestone and dolomite of the Bina formation belonging to the Judea These stones are found at the end of the Cenomanian era and the outset of the Turanian. Their strength reaches about 100 MPa. The foundation of the formation is red dolomite limestone, called “Mizzi Ahmar.” The stone mined from it is good for construction, and indeed there are many quarries from various periods on this exposed rock. The core of the formation is limestone called “meleke.” Its strength is about 20 MPa. It is unlevered, conducive to mining, and the stones were used in the past for building temples and palaces, seeing as they are easy to process and their color is light. The renowned tombstones of the Mount of Olives, like the Tomb of Absalom, the Tomb of Zachariah, and the Tomb of Benei Hezir, were produced from meleke stone. The top of the formation is comprised of layered, dense, and very light colored limestone. This stone is called, “Mizzi Hilu,” and is also used for construction.
- Most of the western, eastern, and southern slopes of the Mount of Olives, as well as the majority of the entire mountain range, are comprised of chalk and “kakula” chalk. The proximity of the mountain to the relatively humid Mediterranean Sea region facilitates creation of the layer of calcrete on the chalk stones. These stones constitute the Menuha formation and belong to the Mount Scopus They are characteristic of the Santonian-Campanian boundary of the Senonian era. The strength of the formation reaches several dozen MPa. The foundation of the formation is composed of reddish-tinged chalk that is called kakula. The stone mined from it was attractive for coating structures and for relatively delicate architectural design. The upper part of the formation is composed primarily of softer chalk and is rich in foraminifera fossils.
- On the ridgeline and the north side of the mountain is a strip of chalk and flint of the Mishash formation, also from the Mount Scopus This is a formation whose rocks are comprised of chalk with layers of solid flint, constituting a coating for the layers from the Menuha formations. The flint is in the form of breccia, although it was originally not in this form. The large amount of fissuring in the flint was created at an early stage, after its sedimentation in the sea. Here it does not appear as a continuous layer, but rather in scattered gravel chunks. The soils of the mountain are the result of exposure of the chalk rocks to principal mother lodes, which are coated with a calcrete crust. Its thickness ranges from several centimeters to about two meters.
In the climatic region of the Desert Perimeter, where it is relatively dry, the temperature is dependent mainly on the elevation above sea level of the ground foundation. Shallow patches of Caesarean rendzina form on the rocky slopes of the mountain. This is a nut-brown color soil with a high percentage of clay. The transition from it to the calcrete rock is pronounced. There is a prominent amount of rocks on the ground. These rocky soil substitutes have a critical influence on the development of vegetation in the area. In the channels that descend the mountain, many chalk rocks are uncovered whose calcite coating was eliminated during the streams’ undermining process. These are pale rendzina soils. They are low in organic matter and minerals, shallow, and easily eroded. They cannot maintain moisture and are not easily permeated. In addition they have no rocky ground from which rain water flow into the soil pockets, and the rock is not fissured. From a geomorphological standpoint, the inferior qualities of these soils and their presence in the steeper and more eroded zones are the reason for poor crop yields, and they have no special value to the vegetation in the region.
The Climate and the Hydrology of the Mount of Olives
The Mount of Olives is located east of the national watershed line that passes within the Jerusalem city limits, even though the mountain is higher than the city. This unique circumstance stems from the stream capture of Wadi al-Joz (the Josaphat Valley) by the main stream of Nahal Kidron. If not for this, these would belong to the drainage basin of Nahal Sorek, thus leaving the Mount of Olives on the national watershed line.
Despite its location east of the watershed line, the western slope of the Mount of Olives is under the climatic influence of the Mediterranean Sea. This reality, and the fact that it is a topographical boundary between Jerusalem and the Judean Desert, are seemingly the reasons for bestowing the mountain with tremendous value in the development of Jerusalem. It protects the city from the damaging effects of eastern desert winds, and for good reason this mountain valued by the city’s residents who took refuge from the Mediterranean Sea region of the west in its shadow.
Together with this, the Mount of Olives-Mount Scopus range is the local watershed line between the drainage basins of Wadi Qelt and Nahal Og (Wadi Mukalik), and the upper drainage basin of Nahal Kidron. The direction of the ridgeline is northwest to southeast.
The majority of the mountain is located in the climatic region of the Mediterranean Sea, and has an annual average rainfall of 380-480mm. Its southeastern portion, in the area of Al Eizariya, already belongs to the Irano-Turanian climatic region, where the multi-year precipitation average is about 250-300mm. The mountain does not have any springs. The limestone structure enables wells to be drilled in the agricultural areas and the pastures. In addition to the wells in the yards of the buildings on the mountain, there are fifteen (15!) large wells for general use on its eastern portion.
Vegetation: The Jerusalem region is a meeting point for southern and eastern desert vegetation with the Mediterranean vegetation of northern and western Israel. This geo-botanical status is linked to the soil – which is a mixture of chalks – with the eroded soil that accompanies it. This mixture is characteristic of the region in which anticline folds expose layers of solid chalk in syncline folds, which are composed of soft chalk stones. This unique geo-botanical status is affiliated with the transition from a temperate Mediterranean Sea climate to an arid Irano-Turonian one.
The transition of the Mount of Olives, as cited above, is still within the zone that is influenced by the Mediterranean Sea region, in which there are still indications that in the past, Mediterranean perimeter forest existed here. The characteristic components of this forest are the Wild Almond, the Azarole, and the Black Hawthorn. This is a sparse forest whose resistance to heat and light rays and dryness are significant, as compared to the more western and northern Mediterranean groves. In the open areas between the trees Mediterranean sub-arid batha – or undergrowth – developed, comprised of various types of Mediterranean and desert vegetation, among them the Prickly Burnet, the Prickly Alkanet, the Strigose Alkanet, the Undulate Horehound, the Noaea Mucronata, and the Echnipos Adenocaulos. As a result of man’s intervention in the growth processes in the area, the thorny shrubs of the Mediterranean sub-arid undergrowth were replaced with fruit trees for consumption and industry. These are the olive, the almond, and the fig trees.
The olive trees of the mountain once had great economic importance. According to tradition, in the past these olive trees were used for religious rituals and lighting oils in the royal and holy institutions of Jerusalem. The olive trees gave the mountain its name, “Mount of Olives,” and the holy “anointment oil” gave its name to the southwestern portion of the mountain, which is the “Mount of Anointment.” Today the trees spread out sparsely. Among the olive trees on the western slope of the mountain, some are more than a thousand years old. A number of large and ancient Atlantic Pistacia trees also grow on the western slope, some of them sacred. It could be speculated that some were planted there for various reasons, but a study of the natural conditions in habitats in the Negev Mountains and Eastern Samaria show that here they grow naturally, and are not planted or taking the place of felled forest trees. Planted orchards of Jerusalem Pines can be found on the exposed chalk of the mountain. In this climatic area, the larger the pine’s roots, the more it develops. Some of the pines are broad, which are reminiscent of the wild pines of the Mediterranean nature reserves in the western Judean Mountains and the Carmel Mountains. We can assume that alongside the Mediterranean undergrowth, a pine forest also grew here naturally in the past, similar to those of which remnants are found today in Judea and Eastern Samaria. Among the chalk stones, which improve the water economy surrounding them, there are Acacia Salicina – or Native Willow trees, which were brought from Australia over the past few generations.
The negative water regime on the calcrete and the chalk rocks, as well as their accompanying soil, induces characteristic desert vegetation to penetrate the western and northern Mount of Olives. These are primarily the White Wormwood and the Norea Mucronata. The eastern slopes of the Mount of Olives are all chalk. They are found on the turn to the Judean Desert and in the “rain shadow” of the Mediterranean Sea Region. The temperature level in the eastern part of the mountain is higher than that of the western portion. This area is characterized by few or no trees, and in their place the Mediterranean sub-arid undergrowth developed. Here, more than likely, is the zenith of the Mediterranean region border. The vegetation groups on the eastern slopes of the Mount of Olives are divided into two, according to the rock criteria. Terra rossa soils, or dark rendzina soils that are similar to the terra rossa, are produced among the chalk rocks. Here the undergrowth is comprised of Prickly Burnet, Undulate Horehound, Phlomis Brachyodon and Eryngium Glomeratum. On the limestone rocks and in the light gray rendzina that develops on them, grow shrubs that have mainly desert or partially desert characteristics, like the Artemisia Sieberi Besser, the Ononis Natrix, the Gypsophila Arabica, the Fagonia Mollis Delile, the Bellevalia Desertorum, the Wavyleaf Mullein, and the Astragalus Deinacanthus.
There appear among them representatives from both types of undergrowth, predominantly in places in which the water economy of the chalk is improved due to concrete coating. In the working fields, there are many slender safflowers and astomae seselifolium, identified as dove’s dung (II Kings VII).
There have not been methodical zoological viewings on the Mount of Olives, but a random survey will uncover an abundance of arthopods, especially those that are acclimated to arid areas and live under rocks, like rough woodlice, centipedes, scorpions, Judean darkling beetles, and various grasshoppers. Different species of rodents, like Cairo spiny mice, nest in the rocky areas. Adjacent to human dwellings nest house mice, field mice, and rats. Various Wheatears, Crested Larks, and Desert Larks represent the bird species in the relatively open and hot areas. In the fields and gardens, as well as in the groves scattered over the mountain, there are various songbirds, according to the seasons. Several Common Kestrels and Hoopoes are identified, which also roost in close proximity to rockier habitats and human dwellings.
Contemporary Settlements in the Mount of Olives
As part of the Desert Perimeter of Judea, there is little settlement on the Mount of Olives. (Additional reasons like expropriation of parts of the mountain for various religious and holy purposes were not taken into account here.) The way of life that developed in the few and relatively small villages is that of farmers who sit on the desert borderland workers, especially of field crops, in accordance with the soil conditions and the climate characteristic of the region. Upon arrival of the winter, a considerable number of the village residents abandon their permanent dwellings and go down to herd sheep and goats in the desert. Herding in the desert during the winter is accompanied by inhabiting caves and tents, like the Bedouin. When the desert dries up in the spring, the herders return to their villages, harvest the crops that grew in their absence, and over the summer once again make their living from limited agricultural work, from crops that were harvested at the commencement of the summer, and even from employment outside of the village. In Judea, from north to south, there is a continuous strip of settlements in which the population there has acted in this manner for thousands of years. This long line of settlements is divided into two ethnic parts. From the Mount of Olives northward and from the outskirts of Mount Halhul southward, these are villagers that function as Bedouin for part of the year. There are permanent residences of Bedouin in the center of the strip whose way of life is nearly identical to that of the farmers. According to various testimonies, it can be assumed that irregular waves of inhabitation of Bedouin, Egyptians, Syrians, and Trans-Jordanians characterized the settling process of the ancestors of the current residents of the villages in this strip, starting from the 12th century and up to the 19th century. In the Mount of Olives itself there are three villages that are reminiscent of the model presented: Issawiya in the northeastern portion of the mountain, Abu Tor at the peak, and Al Eizariya on its southeastern slopes. On the southwestern escarpment, very close to the Nahal Kidron stream, lies a relatively new village – Silwan (Kfar HaShiloah).
Several roads lead out of the Mount of Olives, some ancient, like the Roman Ascent, which descends from the summit of the mountain east towards the Judean Desert, and some modern, like the asphalt road that connects Jerusalem with the Dead Sea and Jericho, and the paved road in the Jewish cemetery. On the descent from the mountain to Nahal Kidron and the southern portion of Jerusalem, and from its northern border on the Augusta Victoria Ridge, there are several additional roads westward towards the center of Jerusalem, and northward, via Mount Scopus to the northern entryways of Jerusalem.
An examination of all the natural data raised here illustrates the existence of a unique landscape factor in East Jerusalem. In spite of its immediate proximity to the city and the ancient link to the way of life in Jerusalem, the Mount of Olives has its own characteristics, based on independent eco-systems, its status in the Judean Mountain area, its location on the boundary of various landscape units, and the influence of the morphotectonical, lithological, and climatic factors of the plant life, the animals, and the human life within it. Together with this, it is impossible to sever the Mount of Olives from Jerusalem and relate to it as an entirely independent and unrelated element. Quite the opposite. Its singular status adjacent to the city, its existence as an influential factor in drawing consistent and significant impact to the city and the people on the mountain, and the fact that there is hardly any area of the Mount of Olives lacking human impact makes it an integral part of Jerusalem.
This is prominent in all its aspects – whether we are speaking about the changing character of the plant life, construction and road building, or the circumstances for changing the water economy in order to correspond with comfortable metropolitan life style. It is clear that all of these actions are pertinent in relating to the Mount of Olives as an ancient and holy place for the three major religions in the Land of Israel.to the Mount of Olives as an ancient and holy place for the three major religions in the Land of Israel.