Studies on water movements and sediments in Southern Lake Michigan : part 1[-3] ... / by John C. Ayers.

SUMMARY AND CONCLUSIONS

1. Five hundred and twenty-four samples of the surficial sediments taken in 1962-63 are the basis of this report. The
coverage represented is good, though not complete.
2. Comparison of this survey to that-of Hough (1935) does not
demonstrate changes in sediment type as such over the 30 -year intervening period. -
3. Seven samples in the southern extremity of the lake (off —
Calumet Harbor, Indiana Harbor, Gary, and Burns Ditch) give
olfactory evidence that organic materials are being incorporated into the sediments, though the process appears to
have not yet gone to the point of causing changed sedimenttype or changed sediment color.
4. Six of these seven samples indicate the incorporation of
oil into the sediment.
5. It is suggested that the region where oil odor is now
present is one -that should be watched for evidences of
future definitive eutrophic deterioration.

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