Page:Oregon Historical Quarterly vol. 6.djvu/176

170 170 DR. JOHN SCOULER. these very ruins, by being thrown up in the form of sand banks, defend them from further encroachments. It is, however, obvious that all the sand in the neighborhood of Cape Dissapointment is not from its own disintegration, perhaps more than the half of it is derived from the depo- sitions at the mouth of the Columbia; & this opinion amounts to certainty when we witness the enormous quantity of driftwood which is no doubt derived from the same source. The rocks in the vicinity of the Columbia River appear to be entirely calcareo[u]s, & this character seams to ex- tend from the Cascades to the ocean. To pronounce a decided opinion of the rocks of the Cascades would be exceedingly rash, as I have never had an opportunity of visiting that part of the country ; but from the specimens I have received from there by Mr. Douglass, & from the phenomena of saline springs, there can be little doubt of the character of the prevailing rocks. At the Cascades silicified woods abound, & often very fine specimens are found ; the fibrous texture is still preserved, the colour is pale ferruginous brown, & they are hard, but may be scratched by the knife. Rocks are also found there ap- proaching to the character of calcareous tufa ; they are coarse grained, of a white colour, & easily reduced to grains, & often contains pebbles disseminated through it. The rocks from Cape Dissapointment to Tongue Point were more within the sphere of my observation & their study afforded many interesting facts. These rocks are of a dark leaden colour & of a very soft consistence, & are rapidly worn away by the rains & water torrents. They are of moderate height, & very commonly caverns are ex- cavated in them. It is exceedingly probable that these rocks are connected with the series of magnesian lime- stone formation. They contain imbedded masses of a spherical shape, & varying in size from that of a hazelnut