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U.S. Geological Survey Circular 569
Geochemical Anomalies and Metalliferous Deposits Between Windy Fork and Post River,
Southern Alaska Range
By Reed & Elliott

... Bowser Creek drains an area of known lead, zinc. and silver deposits previously described (Reed and Elliott, 1968). The deposits in the area are (1) argentiferous galena-sphalertte or sphalerite-pyrrhotite deposits in limestone, and (2) pyrrhotlte-ephalerite fracture fillings in igneous breccia. The deposits in limestone are replacement bodies and fissure veins; some chip samples show as much as 14.7 percent zinc and 52 ounces of silver per ton. Stream-sediment samples from the creek serve as a basis of reference in interpreting lead-zinc-silver values of other areas sampled.

The location of stream-sediment sampling, areas of sulfide mineralization, and sampling profiles along Bowser Creek are shown in figure 11. The samplling profiles show, in general, an increase in Pb, Zn, Ag, and Cu as the mineralized areas are approached. The sampling profiles also show that metal concentrations diminish rapidly downstream from the known sulfide deposits. Within 1 1/2 miles from the deposits all metal concentrations fall below levels considered anomalous for the region in general. One possible explanation for this short metal train is that Bowser Creek is in an area of high relief, and colluvium from valley slopes is constantly being supplied to the creek. In many places, steep talus slopes feed directly into the creek. Thus, a rapid dilution of the sediment anomaly begins as soon as the stream leaves the source area. Other factors such as the pH of the stream (limestone forms a large percentage of rocks in the drainage area) may also influence the extent of the anomaly,

Most of the high metal values in Bowser Creek are related to areas of known sulfide deposits. However, the highest metal contents (Cu, 500 ppm; Pb, 700 ppm: Ag, 7 ppm; and Zn, 2000 ppm) are from the northeastern-most tributary to Bowser Creek, an area not examined. This drainage area should be investigated.

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