- GeoRef, Copyright 2008, American Geological Institute. Reference includes data from Bibliography and Index of Geology Exclusive of North America, Geological Society of America, Boulder, CO, United States
Clay minerals of the sediments of the Negev region, Israel, are essentially from one source area, the Precambrian Arabian-Nubian massif to the south, and although deposited from early Cambrian to late Tertiary, the climatic conditions of deposition are considered to have been relatively constant. No relationship to depth of burial or tectonic position has been observed, but a gradual transition with time from one clay mineral assemblage to the next is noted. Transition periods between equilibrium assemblages are characterized by minerals with mixed-layer structures. The localities of distinct clay mineral species are related to the environment of deposition.