This series of geochemical maps shows the distribution of tin in three sample media: (A) the oxide residue (the oxalic-acid-leachable fraction) of the stream sediment, (B) the minus-80-mesh stream sediment, and (C) the ash of aquatic bryophytes (mosses). The geochemical data are plotted on a base map that shows generalized geology and the drainage pattern. The map symbols show the sample sites and ranges of values in the following manner: (1) open symbols denote background, (2) small black symbols represent weakly anomalous values, and (3) large black symbols denotes strongly anomalous values. Because the small black symbols represent weakly anomalous values, they are considered to be significant only where they correlate with strongly anomalous metal values either in the same or other sample media. The ranges of values were determined from the histograms and other statistical data shown for each of the sample media. An explanation of sampling, preparation, and analytical procedures is given in Circular 734, which accompanies this folio. Complete analytical data for geochemical samples collected by the U.S. Geological Survey in the Tanacross quadrangle are available in a U.S. Geological Survey open-file report (O'Leary and others, 1976).
