Cave
CAVE. A hollowed-out place in the earth, whether formed by nature or by man. In a mountainous land such as Palestine, where there is much limestone, caves are likely to be quite numerous. Caves were often used for regular human habitation, for hiding from the law or from enemies in warfare, for securing precious treasure (such as the Dead Sea Scrolls), for storehouses and cisterns, for stables and cattle, and for burial (Gen.19.30; 1Kgs.19.9).
CAVE (מְעָרָה, H5117, cave; חֹרִ֖ים, holes; Gr. σπηλαι̂ον, cave) a hollow extending beneath the surface of the earth. Caves have been used by mankind of all ages for habitation (Gen 19:30), refuge (Josh 10:16) and burial (John 11:38), and many legends and superstitions are attached to them. Some caves have been cut by wave action (sea caves), other scoured by wind action, particularly in desert regions (eolian caves) and still others result from glacial melt-water (glacial caves). The largest and most common types of caves, both worldwide and in the Holy Land in particular, are solution caves which result from the action of underground water. Most of these caves are in limestone because no other rock equally abundant at the earth’s surface is so readily dissolved. Calcite (calcium carbonate), which is the chief constituent of limestone, including the Judean Limestone which crops out over large areas of Israel and Jordan, is dissolved by ground water containing carbon dioxide. Some of this carbon dioxide is taken up by rain water falling through the air, but much comes from the air in soil containing decaying humus which contains 300 times more carbon dioxide than the air of the atmosphere. As dissolved carbon dioxide reacts with water to form carbonic acid, water passing through soil rich in humus may become strongly acidic. It is by the action of this water that most caves in limestone have been formed. Particularly in dense, jointed limestone, water is concentrated along restricted planes rather than being disseminated throughout the rock. In this way much solution takes place along joints and bedding planes by the reaction of the carbonic acid in the ground water with the calcium carbonate to give a solution of calcium bicarbonate.
Caves are formed just below the water table in regions where the water table remained stable for a long time. They have a characteristic pattern of passages which are usually horizontal, even where the limestone beds are steeply inclined, except in regions where the originally horizontal attitude of the cavern network has been tilted during later mountain building deformation. The development of most caves just below the water table, in rocks saturated with water, rather than at random depths within the water saturated part of the earth’s crust, is prob. the result of a nonlinear relation between calcium carbonate solution and the partial pressure of carbon dioxide. The result is that the mixing of water percolating down from the surface with slowly moving ground water below the water table constantly produces an undersaturated solution capable of dissolving more calcium carbonate.
Most caverns are composed essentially of horizontal and some vertical passageways. Passage width and height varies from upwards of 30 meters to the smallest penetrable dimensions. Where not modified by collapse, the cave cross sections are tubular or rectangular in shape, but others are irregular in cross section. The pattern of their ground plan varies: a grid of intersecting passageways is referred to as a network cave, a dentritic branching pattern of increasingly smaller passages make up a branching cave and one tube with numerous twists and turns is an angulate cave. The vertical passageways are the active recharge points of ground water into the limestone. Often these are roughly cylindrical vertical shafts with smooth walls and heights of 100 meters or more.
Collapse of the roof of a cavern or the downward solution of limestone or other soluble materials (e.g. dolomite—calcium magnesium carbonate, or gypsum—hydrated calcium sulphate), results in the development of depressions at the surface commonly referred to as sinkholes. Typically they are circular and 10-20 meters deep and often of the order of 100 meters in diameter. Coalescence of sinkholes is common, particularly the coalescence of a linear series. In this way access from the surface to some caverns is provided.
Lowering of the water table makes the caverns accessible and in many the process of deposition of calcite dominates over solution. As water drips from the cavern ceilings, it evaporates, loses carbon dioxide, and calcium carbonate (calcite) is precipitated. Progressively icicle-like forms, stalactites, develop hanging down from the ceiling. Calcite precipitated when water drips to the floor is built up as stalagmites. Continued precipitation of calcite may result in the meeting of stalactites and stalagmites to form columns.
Bibliography
R. W. Fairbridge (ed.) The Encyclopedia of Geomorphology (1968), 652, 653, 1036-1039; E. M. Blaiklock (ed.), The Zondervan Pictorial Bible Atlas (1969), 438-452; D. J. Easterbrook, Principles of Geomorphology (1969), 256-265.
International Standard Bible Encyclopedia (1915)
([me`arah] (compare Arabic magharah), chor (Job 30:6 the King James Version), mechilloth (Isa 2:19); ope (Hebrews 11:38), spelaion (Joh 11:38); chor, more often rendered "hole," is akin to Arabic khaur, "gulf" or "inlet," but is also related to me`arah (compare also Arabic ghaur "low-land," especially of the Jordan valley and Dead Sea). Mechilloth (root, chalal, "to pierce" (compare Arabic khall, "to pierce")) occurs only in Isa 2:19, where the King James Version has "caves" and translates me`aroth in the same verse by "holes." In the Revised Version (British and American) these words are very properly changed about. Spelaion is a common Greek word for "cave"; ope means rather "hole"): In Palestine as in other limestone countries, caves are of frequent occurrence, and not a few of large size are known. Water from the rain and snow, seeping down through cracks, enlarges the passages through which it goes by dissolving away the substance of the rock. Just as upon the surface of the land the trickling streams unite to form brooks and rivers, so many subterranean streams may come together in a spacious channel, and may issue upon the surface as a bold spring. The cave of the Dog River near Beirut and that of ’Afqa (perhaps Aphek (Jos 13:4)) in Lebanon are excellent examples of this. Not infrequently after forming a cave the stream of water may find some lower outlet by a different route, leaving its former course dry. In some cases the hinder part of the roof of the cave may fall in, leaving the front part standing as a natural bridge. Numerous shallow caves, especially in the faces of cliffs, are formed not by seeping water, but by atmospheric erosion, a portion of a relatively soft stratum of rock being hollowed out, while harder strata above and below it are but little worn away. Many of the hermits’ caves originated in this way and were artificially enlarged and walled up at the mouth. The principal caves mentioned in the Bible are those of MACHPELAH, MAKKEDAH and ADULLAM (which see).
See Den.