ANALYSIS OF LINEAR FEATURES MAPPED IN LANDSAT THEMATIC MAPPER AND SIDE-LOOKING AIRBORNE RADAR IMAGES OF THE RENO 1-DEGREES BY 2-DEGREES QUADRANGLE, NEVADA AND CALIFORNIA - IMPLICATIONS FOR MINERAL-RESOURCE STUDIES

Linear tonal features, which reflect topographic and lithologic differ ences, were mapped in Landsat Thematic Mapper (TM) and side-looking ai rborne radar (SLAR) images of the Reno 1 degrees by 2 degrees guadrang le, Nevada and California; combined into a single data set; and compar ed to the distribution of known Tertiary An-Ag vein mineralization. Th e results of analyses of orientation and areal density show that in mo st areas the linear features are expressions of geologic structures th at controlled the mineralization. However, the variability of the spat ial correspondence of the two linear features attributes with mines ne cessitated ranking orientation and areal density values for incorporat ion into a numerical mineral assessment model. The results show that t he combined spatial resolution of the TM and SLAR images permits delin eation of structures that controlled Tertiary precious-metal mineraliz ation in this area. However, the tonal expression of some important st ructures may be below the resolution limit. Other factors that contrib ute to the variability of the results are the unknown age of linear fe atures, illumination-induced biases, and shadowing in high-relief terr ain.