Chemical remanent magnetism related to the Dead Sea Rift: evidence from Precambrian igneous rocks of Mount Timna, southern Israel

A palaeomagnetic and mineralogical study of shallow intrusive basement rocks on Mount Timna shows that although all the igneous rocks are of late Precambrian age, a remanent magnetic direction similar to the subrecent field (Miocene to present) is identified in samples of quartz-monzodiorite, monzodiorite, dikes of various composition, and altered gabbro. The "subrecent' direction appears both as an overprint direction and as the sole stable vector in dolerite, rhyolite, and andesite dikes. The subrecent direction is interpreted to have been acquired as a chemical remanent magnetization (CRM) by hydrothermal activity and circulation of thermal brines through fractures related to the adjacent Dead Sea transform. The hydrothermal activity occurred before uplift and erosion exposed the basement rocks, i.e., in the middle Miocene, during the early stages of activity of the Dead Sea rift. -from Authors