. Annual report. Geological and Natural History Survey of Minnesota; Geology; Natural history. 38 TWENTY-FOURTH ANNUAL REPORT a swelling out and northward projection of this sill, although the direct connection could not be traced in the time at com- mand. In it is noticeable an occasional spotting of crystalline red rock like that at Mt. Josephine and on the ridges in the In- dian reservation, and that indicates that it is older than the diabase that cuts the Fig. 4. Section of the Hill-Range, South side of Puckwunge Valley. 2071. Returning toward Puckwunge creek there was en-
. Annual report. Geological and Natural History Survey of Minnesota; Geology; Natural history. 38 TWENTY-FOURTH ANNUAL REPORT a swelling out and northward projection of this sill, although the direct connection could not be traced in the time at com- mand. In it is noticeable an occasional spotting of crystalline red rock like that at Mt. Josephine and on the ridges in the In- dian reservation, and that indicates that it is older than the diabase that cuts the Fig. 4. Section of the Hill-Range, South side of Puckwunge Valley. 2071. Returning toward Puckwunge creek there was en- countered a surface outcrop of the Grand Portage graywacke. It has on casual examination the appearance, as well as the geographic position of a lower bed of rotted trap, and for that it was taken in 1893 when seen in the same place. This indi- cates that the rock 2070 (Grand Portage gra}^wacke) may have a thickness of at least 200 feet. 2072. Fine-grained condition of the sill mentioned as under- lying and cutting the conglomerate and a portion of the Grand Portage graywacke. It is to be remembered that there is a series of dikes of diabase which is later than the great dikes. This is shown by the dike cutting the sill which constitutes the bluff at the south side of South Fowl lake. Many other in- stances could be mentioned. It is quite possible that the later intrusion formed sills as well as the earlier, and the porphyritic condition is not a character which could be depended on to dis- tinguish one from the other. About Grand Portage. The route of the Grand Portage trail runs almost wholly over drift deposits which are underlain, as indicated by occasional exposures, by the rock which above is called Grand Portage Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Geological and Natural History
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