Internal deformation and uplift-rate of salt walls detected by a displaced dissolution surface, Dead Sea basin

Abstract

Despite numerous studies examining salt tectonics, relatively little is known regarding the internal movements of salt units that build diapirs such as the Mount Sedom salt wall. In this study we focus on the recent deformation processes of southern Mount Sedom. We choose a fossilized dissolution surface known as the “salt mirror” of Mount Sedom as a structural datum, in order to understand and resolve the deformation processes during the last 14 ka. Surveying the salt mirror surface from outcrops and natural dissolution “chimney” caves, sets constraints for the structural map. Our results indicate that the salt wall rises as a telescopic antenna, with the internal salt units sliding across each other along bedding-plane slip faults, influenced by the subsiding Dead Sea basin. The flow of the rising salt forms an elongated ridge, distinctly asymmetric across its short dimension. The uplift rate of the Southern part of Mount Sedom throughout the last 14 ka is at least 11 mm/yr. This result is somewhat higher but in a fair agreement with the results of previous studies that assessed the rates in a variety of methods. The telescopic behavior of the salt wall represents a mode of internal deformation that might be applicable to other salt diapirs worldwide.