Volume VI No. 4 - September, 1933

Wizard Island affords a great deal of interesting material for both geological and biological reflection. Many feet tread the trail up the extremely fascinating cinder cone of the island. Relatively few, aside from an occasional fisherman seeking the Skell Channel, tread the rock-piled ramifications of the island to the west of the cone. On this portion of the island erosion has made but little progress. Rough folds of lava rocks have cracked into innumerable jagged blocks of stone that have tumbled into loose jumbled masses. So sharp and angular are the blocks that the whole mass permits the water falling on it to drain readily through it down to the lake level. This same condition permits the waters of the lake to flow through there rock masses at the level of the lake.

As a result of this water table or level, a level fluctuating with the level of the lake, there exist in the hollows between the jagged lava rock piles a number of pools, the size and especially the depth of these pools being determined by the extent to which the collapsed sputter cones developed depressions with a base below the present water level.

On looking at these pools from the Watchman or from the Rim Drive, one observes light green patches which would indicate to the observer the possibility of the existence of beds of algae such as Spirogyra. A visit to the pools, however, reveals a lack of green algae. The patches turn out to be an accumulation of a creamy white mud and ooze. Similar accumulations occur in Skell Channel and between the rocks off the shore of Wizard Island. A carefully examination of samples from a number of these accumulations indicates that they are a highly diatomaceous pumicite sediment.

During the latter part of July the White bark pines (Pinus albicaulis) throw off to the wind a vast amount of pollen. This pollen accumulates in floating bands of yellow which moved about the lake, eventually contacting the shore, where the pollen tended to adhere to the rocks at the shoreline. As the waters of the lake evaporate the pollen is left in rings on the shore rocks. A small amount of the pollen apparently becomes water-logged, or by wave action, gets entangled in the diatomaceous slime on the rocks as a microscopic examination of the rock scrapings indicates their occasional presence. Samples two or three feet down do not show the presence of pollen, hence the reasonable conclusion that the coloration in the shallow portions of the lake is the result of diatomaceous ooze or slime mingled with pumice dust.