This geochemical map shows the distribution and abundance of antimony (Sb) and niobium (Nb) in -80 mesh (177 micrometers) stream sediment samples in the Chandalar quadrangle, Alaska. The map is one of a series of geochemical maps that together with the background information circular (Reiser and others, 1978) comprise the folio on the Chandalar quadrangle, Alaska. The data are plotted on a subdued base map showing the generalized geology, topography, and sample localities. Map symbols showing the ranges of metal values are indicated on the accompanying histograms and all values shown are considered anomalous. An explanation of sampling, preparation, analytical procedures, and geochemical raw data for all samples are discussed by O'Leary and others (1976). The -80 mesh (177 micrometers) stream sediment medium was used in this study because, given the rather restrictive time and manpower constraints, this sample medium combined with panned concentrates were determined to be the most economical and adequate media in this area of the north-central Brooks Range where clastic sediments are derived from local bedrock. 

The study area is generally one of high relief with short fast moving streams and broad glacial valleys. All samples were taken from active streams, as close to the center channel as possible. All sediments were considered to be locally derived. Care was taken, when sampling an obviously glaciated terrane, to sample above or upstream from morainal material, wherever possible. Most samples were taken in areas where bedrock was within 30 m of the sample site.

Due to the high limit of determination for antimony by spectrographic analysis (100 parts per million), all samples collected in 1975 for this study were analyzed for antimony by the atomic absorption method. Spectrographic antimony values for samples collected prior to this study were not used. Most of these previously collected samples are from the area between the North Fork and the Middle Fork of the Chandalar River and south of the Squaw Lake-Grove Creek Valley in the central part of the quadrangle and are discussed by Brosge and Reiser, 1970, 1972.