This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...more favorable conditions for wide swings in the stream's course. Both of these conditions are realized in the terraces of Copper River, so that this alternative h'pothesis seems to have a sufficient basis both in theory and in fact to justify its presentation. OUTLINE OF GEOLOGIC HISTORY. Under the above heading that ...
Read More
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...more favorable conditions for wide swings in the stream's course. Both of these conditions are realized in the terraces of Copper River, so that this alternative h'pothesis seems to have a sufficient basis both in theory and in fact to justify its presentation. OUTLINE OF GEOLOGIC HISTORY. Under the above heading that succession of early events in the evolution of this part of the continent which is recorded chiefly in the rock masses that have been described will be discussed. Under the heading of Plsiographic Development those later events whose records are found chiefly in the land forms will be outlined. These two are the ancient and the modern history of geology. They occasionally overlap in time, particularly along that neutral zone in the Tertiary and the Cretaceous, where we sometimes have both land forms and rock records from which to decipher the story of continental evolution; but in general each has its distinct field. Physiographic records of any except the latest events, geologically speaking, are usually not preserved. Stratigraphic records for much more remote periods exist, although even these are more and more imperfect as we delve further into the past. In northwestern America, particularly, the comparatively recent geologic events have been so revolutionary that be'ond the uppermost Paleozoic we generally find ourselves groping blindly. The records are gone or are so obliterated that we can not decipher the story. Upon the same rock palimpsest so many histories have been written that the latest inscription is obscure and the earliest is undecipherable. In the account to follow it must be remembered that the rocks have been described and the evidence has been discussed for their assignment to a particular part of the stratigraphic column....
Read Less