Page:Centennial History of Oregon 1811-1912, Volume 1.djvu/232

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ful eyeads, which combine some of the characteristics of both conifers and ferns with perhaps a still greater likeness to the palms.

If you go to a greenhouse and ask for a cycad palm, they will show you not a true palm, but a diminutive specimen of the beautiful cycad tree of Jurassic days. Its terminal bud unrolls like a fern, the wood and fruit are of the conifer type, but the foliage and general aspect of the tree foreshadowed the palm. Then, too, there grew near the Olalla lake the graceful gingko or maiden hair tree, now a native of Japan and China where its coniferous-like seeds are sold for food.

This same Oregon flora flourished on the northern Sierra of California, where have been found three different genera of conifers, ten species of cycads and per- haps a dozen species of ferns. If this flora grew in northern Sierras and in the Siskiyou region of Oregon, it is but reasonable to suppose that at least the lower slopes of the then majestic Elkhorn and Wallowa mountains, formerly known as Eagle Creek or Powder River mountains, were clothed with the same verdure.

The Jurassic fossils of the Blue mountain region thus far discovered are con- fined to the marine shells living along its sea shore. But there must have been many turtles and great sea lizards or saurians.

There seems to be no reason why the students of Baker or Union or Canyon or some other Blue mountain town may not discover cj'cads, Japanese gingkos and ferns in the sediment of an old Jurassic lake among the Blue mountains or un- earth the fossil bones of a great saurian-like reptile that ruled the seas in Jurassic daj's.

THE CRETACEOUS AGE

The next, or Cretaceous age, is indicated on our map by narrow winding bands of seabeach. A portion of this beach line has been indicated by Professor Condon and Dr. Dlller as entirely surrounding the Siskiyou region, passing up through northern California over the present site of Mount Shasta, north past Jackson- ville into Douglas county and finding the main ocean again near the mouth of the Coquille river. This same Cretaceous sea thrust its long arms in among the moun- tains of the Siskiyou island, leaving its record in fossil shells now found in the older valleys.

Still studying the map we find the Cretaceous rocks skirting the Blue moun- tains on the south and west. This border land has been so covered by later vol- canic floods of lava that it is difficult to determine the eastward extension of the Cretaceous sea, but its shells are found at Mitchell, on Rock creek and in the Crooked river country, and these are considered the last relics of the ocean in Eastern Oregon.

It seems well estalalished among geologists that the great mass of the Cascade mountains within the state of Oregon is built up by volcanic lava. But if it were possible to remove these thousands of feet of later eruptic rock and to ex- amine the fossils in the old sea floor beneath it all, geologists would expect to find shells common in Cretaceous seas.

The Cascade range may have been represented within our state by older islands, but at the close of the Cretaceous a low, broad dome of land was suf- ficiently elevated to exclude the ocean from eastern Oregon, and the bands on our map following the borders of these mountains simply bear record to the