Desert Varnish: The Importance of Clay Minerals

ssell M. Potter and George R. Rossman
 Division of Geological and Planetary Sciences
California Institute of Technology
Pasadena, CA  91125


Abstract. Desert varnish has been characterized by infrared spectroscopy, X-ray diffraction, and electron microscopy. It is a distinct morphological entity having an abrupt boundary with the underlying rock. Clay minerals comprise more than 70 percent of the varnish. Iron and manganese oxides constitute the bulk of the remainder and are dispersed throughout the clay layer

  IR spectrum of clays    
Infrared spectra of desert varnish showing the dominant features attributable to clay minerals.

last updated: 23-Jul-2023