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in the south of Ireland ninety years ago, came to America with his parents when a boy, hunted rabbits in Central Park, New York, when it was waste wild land, worked hard with his own hands to pay for his own education, studied Theology and came around Cape Horn in a clipper ship with his young wife to labor in Oregon as a missionary, finally settled at the Dalles to preach the gospel where it was much needed, became interested in fossils and fossil rocks that the army officers brought in from the frontier posts in Harney valley, and in this way took up the study of Oregon geology, and in his book, "The Two Islands," edited and revised by his daughter, Ellen Condon McCornack, and published as "Oregon Geology," has told us how the Creator of the world built up that part of it called Oregon. It is a wonderfully interesting work, and no boy or girl in any high school or college in Oregon, or who hungers for an education, ought to think they know anything if they have not read and mastered Condon's Geology. This life work of Thomas Condon is monumental. Like Oregon's history and pioneer state builders, there is nothing like it, or equal to it to be found elsewhere; and the name of Thomas Condon will live to enlighten the world and honor the state when all its millionaires are wholly forgotten. (The biography of Prof. Condon may be found in the biographical volumes of this work.)
The geological history contained herein is largely the work of Mrs. McCornack, for which, as for many other suggestions, in connection with this work, hearty acknowledgment is made here. The engraved geological map printed herein is all the work of Mrs. McCornack. That young readers may more readily comprehend how the crust of the earth has been built up in all the millions of years that have passed since it became material substance condensed from gaseous vapor, a diagram of the different and succeeding layers of rock is also given which was taken from Dana's Geology.
THE PRE-CRETACEOUS AGE
If the reader will turn to the geological map he will find the oldest parts of Oregon represented by two areas indicated in the legend as Pre-Cretaceous. The one in southwestern Oregon and extending into California is Professor Condon's Siskiyou island. The other in the northeastern section of the state, following the outline of the Blue mountains, represents his Shoshone region.
These oldest parts of the state each contain within itself several different geological ages.
Lindgren tells us: "The oldest rocks of the Blue mountains are represented by the relatively small area of gneiss northwest of Sumpter and just north of Bald mountain. This rare spot of ancient Oregon history takes us back to a most ancient period in the earth's history, to the very dawn of plant and animal life and perhaps even before the vital spark of life had been kindled upon the earth.
All through the paleozoic or most ancient life period, the ocean covered the Blue mountain region, but a portion of this deep sea bed with its fine mud of clay and quartz material reached the sunlight above the surface of the ocean at the close of the carboniferous or coal period, for the argillite series of rocks into which it was changed is found from the head of the John Day valley southeast nearly to Huntington on the Snake river. These rocks contain but few fossils.
The same watery waste covered most of Oregon through the next or Triassic
