Earth Sciences 1490 2009 ICS Proceedings 15th International Congress of Speleology DATING A BIBLICAL LADY: AN UNROOFED SALT CAVE GIVES BIRTH TO LOT’S WIFE AMOS FRUMKIN Department of Geography, e Hebrew University of Jerusalem, 91905, Israel msamos@mscc.huji.ac.il Trying to explain the origin of peculiar geological features has led ancient societies to develop narratives of mythical transformations. Dating geological features supposed to be related to ancient narratives has been virtually impossible until now, because of either the lack of identified, dateable field evidence, or the doubted historicity of the narrative. For at least two thousand years historians and travellers attributed a relict salt pillar in the Dead Sea area to the biblical myth of Lot’s Wife, who “became a pillar of salt” (Genesis 19:26). e formation of the salt pillar and associated cave is analysed and radiocarbon dated, complemented by measurement of its rising rate. Contrary to earlier assumptions that the salt pillar was formed by direct rainfall, the current results attribute the salt pillar to the remains of a wall of a karstic salt cave that collapsed during the period commonly proposed for the Sodom and Gomorrah upheaval. e new evidences suggest that the myth of Lot’s Wife was originally based on one of the earliest geological observations: e sudden appearance of a salt pillar following a catastrophic earthquake which unroofed the cave. e continuous observation of the pillar by travellers must have been coupled with the formulation of the myth which was later documented in the book of Genesis. is is the first field evidence for the origin of such an ancient biblical narrative. 1. Geologic Setting Mt. Sedom is the exposed top of an actively rising salt diapir (ZAK, 1967) at the southwestern shore of the Dead Sea (Fig. 1). Mt. Sedom comprises vertical layers of latest Miocene to Pliocene(?) salt, covered unconformably by residual caprock, composed mainly of anhydrite. e diapir has been rising throughout the Quaternary along its marginal faults (WEINBERGER et al., 2006). Measured mean rising rate for the diapir has been 6–7 mm/yr during the Holocene, and 6.9+0.3 mm/yr for southern Mt. Sedom during the previous decade (PE’ERI et al., 2004; WEINBERGER et al., 2006). is indicates that the present rising rate has persisted for at least thousands of years. e rising is driven by tectonics and buoyancy of low density salt, cutting through the overburden of denser sediments (ZAK, 1967). During the Holocene, salt dissolution has been concentrated mainly where ephemeral streams carrying runoff water sink into the extremely soluble salt (FRUMKIN, 2000), forming (ephemeral) river caves. ese underground voids usually comprise (1) vertical shaſts close to the stream- sink; (2) active sub-horizontal channels, oſten discharging at the foot of the marginal escarpment (Fig. 2); and (3) high, dry cave passages hanging above the active channel (Fig. 3). e oldest, uppermost cave level relates to the initial exposure of salt above base level. As the diapir rises, caves are downcutting, adjusting rapidly to base level changes (FRUMKIN AND FORD, 1995). Subhorizontal dissolution notches are common features in Mt. Sedom caves, formed where flowing aggressive water dissolves the salt wall (in addition to precisely horizontal notches formed by standing water). Low-gradient cave passages accumulate alluvium and some dateable plant remains, derived from the surface of Mount Sedom. 2. Biblical Events Several geologic events, some associated with caves, are described or alluded to in the Bible (BENTOR, 1989). One of the earliest, the biblical story of Sodom and Gomorrah, Figure 1: (a) Location of Mt. Sedom salt diapir; (b) Plan of the study site, showing SSP as a relict between the un- roofed cave and the marginal fault. Figure 3 section line is marked.