# AAPG Bulletin

Abstract

Volume: 62 (1978)

Issue: 5. (May)

First Page: 837

Last Page: 844

Author(s): Arie Nissenbaum (2)

Abstract:

Asphalts are present in the Dead Sea basin in three forms: (1) huge blocks, up to 100 tons in weight, composed of extremely pure (>99.99%) solid asphalt occasionally found floating on the lake, (2) veins, seepages, and cavity and fissure fillings in Lower Cretaceous to Holocene rocks, and (3) ozocerite veins on the eastern shore of the lake. Dead Sea asphalts probably have been documented over a longer period of time than any other hydrocarbon deposit--from antiquity to the 19th century. Major uses of asphalt from the Dead Sea have been as an ingredient in the embalming process, for medicinal purposes, for fumigation, and for agriculture. The first known war for control of a hydrocarbon deposit was in the Dead Sea area in 312 B.C. between the Seleucid Syrians and the N batean Arabs who lived around the lake.

Surface manifestations of asphalt are linked closely to tectonic activity. In the lake itself, the asphalt is associated with diapirs. During certain historic periods, tectonic and diapiric activity caused frequent liberation to the Dead Sea surface of semiliquid asphalt associated with large amounts of hydrogen sulfide gas. When the tectonic activity was attenuated, as in the 19th and 20th centuries, the rate of asphalt seepage to the bottom sediments of the Dead Sea was much slower and the asphalt solidified on the lake bottom. The release of asphalt to the surface became much more sporadic, and may have resulted in part from earthquakes. Thus, future asphalt prospecting in the Dead Sea area should be conducted along the boundaries of diapirs or their associated faults.

Text:

INTRODUCTION

The Bible refers to the use of bitumen several times. Various names are given to different types of hydrocarbon, such as zephet, kofer, and heimar. Although the exact classification of the hydrocarbons is not known, there is little doubt that at least the word heimar refers to asphalt. The earliest reference in the Bible to asphalt is its use as a mortar in the construction of the Tower of Babel (Genesis 11:3). This reference agrees with historical and archaeologic evidence on the widespread use of asphalt in ancient Mesopotamia for building purposes (Abraham, 1960; Forbes, 1964).

Dead Sea asphalts (FOOTNOTE 3) are explicitly referred to in the Bible in the story of the war between the kings of the five cities near the Dead Sea (which included Sodom and Gomorrah) and the invading kings of the north (Genesis 14:10). The war ended by the total rout of defenders who fled into the Vale of Siddim (="which is the Dead Sea," Genesis 14:11), where they fell into the "slime pits" of the valley. "Slime pits" is the translation Martin Luther used for the Hebrew word heimar. Because heimar probably refers to asphalt, a more correct rendition of the original text should be "pits of asphalt."

Since Biblical times the asphalt of the Dead Sea has been an important commodity for trade in the region, and a source of numerous stories and legends (Nissenbaum, 1977).

This study is an attempt to review the history of the use of this interesting hydrocarbon deposit, which has been referred to for over 2,000 years. For an extended period of time the asphalt had an important economic role in the regional geopolitics, and the problem of its ownership led to several wars. More recently, its occurrence has been considered an indicator of the possible presence of crude oil in the Dead Sea basin.

Descriptions of various aspects of the Dead Sea asphalts have been given by Clapp (1936), Picard (1954), Abraham (1960), Bentor and Vroman (1960), Langotzky (1963), and Forbes (1964). Some of these reports suffer from inaccuracies, and Longatzky's 1963 work is not readily available. This report therefore summarizes and updates the historical information, and attempts to reevaluate it in the framework of current geologic and geochemical information.

FOOTNOTE 3. The term "asphalt" is used herein to describe brown to black solid and semisolid bituminous substances. This follows the definition given by the Dictionary of Geological Terms (Am. Geol. Inst., 1962). Ozocerite is used to describe a natural mixture of high molecular weight paraffinic hydrocarbons.

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SOLID HYDROCARBONS IN DEAD SEA BASIN

Solid and semisolid hydrocarbons are present in the Dead Sea basin in three major forms: (1) as asphalt blocks floating in the water; (2) in veins, seeps, and as cavity fillings in Paleozoic to recent rocks; and (3) as ozocerite veins on the eastern shore of the Dead Sea.

Type 1. Asphalt Blocks

Blocks of asphalt floating on the lake surface are the most dramatic occurrence, and therefore have attracted most attention. The blocks are of various sizes, some weighing more than 100 tons (90 MT). They may float on the lake surface or, more commonly, are cast up on the shore (Figs. 1, 2). The asphalt is very pure, has an ash content of less than 0.1%, and is characterized by high sulfur content (±10%; Table 1). The blocks are pitch-black, with very high luster on fresh surfaces, and commonly have vesicular structures as well as broad surface striations. The specific gravity of the asphalt is 1.115, and it floats easily in the Dead Sea, whose waters today have a density of 1.230. The exact source of this asphalt is unknown. Surface exposures of asphalts are too small or too im ure to provide the observed quantities of floating blocks so, presumably, the asphalt originates from the bottom sediment of the lake, somewhere between Ein Gedi and the River Arnon (Fig. 1).

Type 2. Veins, Seeps, and Fillings

A second type of asphalt occurs in veins, impregnations, cavity fillings, and seepages (Fig. 2) on the east- and west-central sectors of the lake, particularly between Metzada and Tamar in the west, and south of Ein Humar in the east (Fig. 1). Its host rocks are Nubian sandstones in the east. In the west it is present in rocks ranging from Lower Cretaceous dolomites and limestones to recent wadi gravels. This type of asphalt is more viscous than type 1, and during the hot summer months when ground temperatures reach 50 to 60°C, the asphalt drips from the rock fissures (Fig. 2). Chemical analyses of this type of asphalt show large variations, and some samples are markedly depleted in sulfur compared with type 1.

Type 3. Ozocerite

On the eastern coast of the Dead Sea between the River Arnon and the Lisan Peninsula, deposits of the mineral wax, ozocerite (Nissenbaum and Aizenshtat, 1975), are found in association with asphalt and heavy oil (Picard, 1933). The ozocerite is yellow-brown, rather soft, and occurs as vein fillings. The chemical (Table 1) and gas chromatographic analyses indicate that it is composed almost wholly of straight-chain paraffins between C24 and C45, and possibly up to the C50S (Nissenbaum and Aizenshtat, 1975).

Chemical and isotopic data on solid hydrocarbons are given in Table 1.

In addition to asphalt on the surface most of the boreholes in the central and southern sectors of the Dead Sea have encountered asphalt at various depths.

The source rock for the Dead Sea asphalts is unknown. For many years, it was assumed to be the surface manifestation of buried petroleum, which migrated upward along fissures and faults; however, all holes drilled for oil in the Dead Sea area have been barren. More recent hypotheses relate the asphalt to Upper Cretaceous oil shales on the western shores of the Dead Sea. It is probably relevant that asphalt deposits also are present near Hasbeya in southern Lebanon. The Hasbeya deposit is composed of veins, several feet across, in Upper Cretaceous oil shales, of the same type as near the Dead Sea.

Fig. 1. Asphalt locations in Dead Sea basin.

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Click to view image in GIF format. Fig. 2. [Grey Scale] Asphalts from Dead Sea basin. 1, Floating asphalt blocks cast on Dead Sea shore. 2, Asphalt seeping from recent wadi gravels (N. Heimar). 3, Asphalt seep from Upper Cretaceous dolomite (N. Heimar). 4, Asphalt "dike" in upper Pleistocene carbonate rock near Metzada. 5, Asphalt filling cavity in Upper Cretaceous limestone (N. Heimar). Photographs 3, 4, and 5 by B. Ashley.

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HISTORICAL RECORDS OF DEAD SEA ASPHALT

Ancient World

The earliest historical record of the asphalt from the Dead Sea is in the description by Diodorus Siculus (ca. 50 A.D.; translated 1947) of an attempt, in the year 312 B.C. by Antigonus, king of Syria, to wrest control of the trade in Dead Sea asphalt from the Nabatean Arabs who, at that time, were engaged actively in trading with his enemy, Ptolemy, king of Egypt. A Syrian general, the well-known historian Hieronimus of Cardia, had orders to prepare boats and to collect all the available asphalt. However, he was defeated in a naval battle on the lake. One wonders whether this early war over hydrocarbons was but a foreboding of things to happen in the Middle East 2,300 years later. Internal problems caused the Syrians to give up attempts to control this source of revenue. The importan e of Dead Sea asphalt also was described by Avi-Yona (1974) who stated that the wars of Alexander Jannaeus, king of Judea, with the Nabateans in 99 to 95 B.C., were due in part to an attempt by Alexander to control the Dead Sea trade in asphalt. Many authors (e.g., Hammond, 1959) also have suggested that the conflicts among Queen Cleopatra, King Herod, and the Nabateans were due in large measure to attempts to dominate the Dead Sea and its asphalt. Although this makes sense from the geopolitical point of view, the hypothesis is not corroborated by ancient historians.

The descriptions of Dead Sea asphalts by the ancient historians show remarkable consistency. Diodorus Siculus (ca. 50 A.D.) wrote: "And from its center each year, it sends forth a mass of solid asphalt^hellip When the asphalt is floating on the sea, its surface seems to those who see it from the distance just like an island. It appears that the ejection of the asphalt is indicated twenty days in advance ^hellip the odor of the asphalt spreads with noisome exhalation, and all the silver, gold and bronze in the region lose their proper colour ^hellip" This asphalt was collected by the inhabitants by making a large bundle of reeds on which three people sat. Two were involved in collecting the asphalt while the third was armed with a bow to repel anybody who might interfere with the gathe ing. The asphalt block was cut in situ and loaded on the reed raft. The asphalt then was exported to Egypt.

Strabo (63 B.C. to 20 A.D.) discussed the asphalt in detail. He wrote that the Dead Sea was full of asphalt, which was blown to the surface at irregular intervals from the "middle of the deep." The appearance of asphalt was accompanied by invisible "soot" which tarnished copper, silver, and even gold. The appearance of this "soot," which was probably hydrogen sulfide, preceded the rising of the asphalt to the lake surface. The asphalt then was collected by use of rafts made of reeds. Strabo wrote that the asphalt is "a clod of earth, which is first liquefied by heat, and is blown to the surface and spreads out; then, again by reason of the cold water, ^hellip it changes to a firm, solidified substance."

Josephus (37 to 95 A.D.) wrote: "Moreover in many places it (the Dead Sea) throws up black lumps of asphalt. These, as they float, are in shape and size like headless bulls: The lakeside workers row to the spot, seize the lumps one by one and haul them into the boats^hellip" He wrote further that the asphalt, while fresh, is highly sticky.

Tacitus (55 to 117 A.D.) gave a similar description, that the asphalt is highly viscous, and is

Table 1. Chemical and Isotopic Data on Solid Hydrocarbons from Dead Sea Basin, Utah, and Trinidad

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hardened by exposure to air and heat or by wetting with vinegar.

Although these are the most detailed descriptions, other authors have referred to the Dead Sea asphalt in a cursory way. Among them were Pliny the Elder (23 to 79 A.D.) and Vitruvius (ca. 50 A.D.). A somewhat exaggerated report by Pompeius Trogus (2d century A.D., in Braslavsky, 1943) stated that the Dead Sea was so heavily covered with asphalt that the wind could not raise any waves on its surface.

Middle Ages

Almost no new information was available on the asphalt during the Middle Ages. The collapse of the pagan Kingdom of Egypt led to cessation of embalming (to be discussed later) and this probably led to a decrease in the economic value of the asphalt. Arab historians mentioned the Dead Sea asphalt infrequently and reported that its major use was in agriculture and medicine (Braslavsky, 1943). During this period the asphalt acquired the name "Bitumen of Judea," and Jews from Alexandria were very involved in its trade in the early Middle Ages.

During the period of the Crusades, asphalt was mentioned by the crusader monk Burchard of Mt. Sion (1280). He stated that its main use was for medicine. The fact that the asphalt was of economic value is indicated by the monopoly granted by Fulk, king of Jerusalem, in 1138, to the inhabitants of the village of Tekoa, for the collection of asphalt from the Dead Sea. Other than that, the information during the Middle Ages is very scant. During the Middle Ages, the Dead Sea was reputed to be related to the devil and hell, and the asphalt was associated strongly with such beliefs (Nissenbaum, 1977). Nevertheless, hints in the literature indicate that the asphalt still was collected and exported to Syria, Egypt, and even Europe, although on a smaller scale than before.

Renaissance to Recent Times