Butte County CA Archives History - Books .....Geology Of Butte County 1882 ************************************************ Copyright. All rights reserved. http://www.usgwarchives.net/copyright.htm http://www.usgwarchives.net/ca/cafiles.htm ************************************************ File contributed for use in USGenWeb Archives by: Joy Fisher sdgenweb@yahoo.com January 27, 2006, 3:17 am Book Title: History Of Butte County GEOLOGY OF BUTTE COUNTY. BY A. L. KNOWLTON. Butte county, though not represented by all the geological formations, is nevertheless an interesting field. That the subject may be better understood by those who have not the time to investigate the science of geology, I will give a brief statement of the names and position of the geological formations as accepted by the best geologists. The names of formations, and their subdivisions, are arranged in a descending order; or, as we should find them were we to make a perpendicular descent into the earth's crust, and find them all in place: First, the Tertiary—divided into the Recent, Pliocene, Miocene and Eocene; second, the Secondary formation—divided into the Cretaceous, Jurassic and Triassic periods; third, the Primary Fossiliferous formation—divided into the Permian, Carboniferous, Devonian, Silurian and Cambrian periods; fourth, the Eozoic, or non-fossiliferous and metamorphic rocks, which in turn rest upon the granite which is at the base of the series. The granite and metamorphic slates are well represented in this county—the eastern portion being composed of these rocks. The slate strata are nearly perpendicular; and their strike, or direction of the upturned edges of the slates, is about N. 30° "W., S. 30° E. In these slates are found beds of magnetic and chrome iron-ore, limestone and marble, and well-defined and rich quartz-veins. In the ascending series we find the whole of the primary fossiliferous formation, and the Triassic and Jurassic of the secondary formation missing in Butte—at least I have never found what I regarded as a representative of either. In the Coast Range, near Allen's Springs, is found a fossiliferous stone, which may be of the Jurassic period, which may extend eastward as far as the foot-hills of the Sierra, but being covered by newer formations, is not seen. The Cretaceous period is well represented. Probably the whole western portion of the state, from the base of the Sierra, is of this period. During this period the western part of the county was beneath the ocean. The eastern shore of the Pacific of that period passed northward from a point near Oroville —probably west of the town; is seen again at Pence's ranch on Dry creek, at Mineral slide on Little Butte, at or near Hell town on Big Butte, near the old toll-gate on Little Chico, and near Harris' place on Big Chico. It is again seen on Deer creek in Tehama county. Large portions of Tehama and Shasta counties are composed of sandstones of this period. The characteristic fossils are Ammonites, Belumnites. and Orthoceratites, besides many of more simple form. These fossils are very numerous and interesting. Of the land and its living tenants little is known. We have reason to believe that the country was more even than at the present time. At the close of the Cretaceous period, or during the early portions of the Tertiary, there was a vast change. The country was elevated, the floor of the cretacous ocean became dry land as far west as the Coast Range, or perhaps farther. During this period (Tertiary) those mighty rivers that deposited the gold-bearing gravels flowed in a southwest direction down the west slope of the Sierra, and out over the nearly level plains of the old cretaceous ocean beds, to the shore of the Pacific, then as far west as the Coast Range. In Butte county alone there are five of these old river-channels, varying in width from 200 to 1,300 feet, with well-defined shores or banks of slate-rock, with gravel deposits from a few feet to two and three hundred in depth, all containing gold. One of two conditions must have prevailed during this period. Either there must have been a greater amount of rainfall then than now, or the rivers must have taken their rise further inland, and have drained a larger extent of country. It is likely that the latter condition prevailed, and the old tertiary rivers took their rise far beyond the present summit of the Sierra, draining the county known as the "Great Basin," in Nevada and Utah; and the Sierra themselves were but a chain of comparatively low hills. There is a variety of porphyry, having a grayish-green base, with large square and rectangular crystals of feldspar, found in Little and Big Butte, Little and Big Chico, and in Deer creek, evidently carried down from its .original beds by those old streams; for in no part of Butte county can this porphyry be found in place. Further geological investigation will alone settle this fact. The fossils of this period are in many respects similar to living animals and plants. During this period a mighty volcanic eruption occurred, by which the country, from Central California to British Columbia, was buried from 200 to 3,000 feet beneath accumulations of lava. This eruption was not the work of a day; it must have required ages to accomplish it. The first material ejected from these monster volcanos was vast accumulations of volcanic ashes; and the old rivers bore this material down their channels and deposited it along their courses in the form of beds of pipe clay, varying from a few feet to fifty in thickness. Following this came the more' hard and compact lavas— not always in a molten state, but in most instances composed of material having all the appearance of a mass of loose volcanic stones—mingled with sand and ashes, and all subsequently cemented in one solid mass, often containing animal and vegetable remains. We are justified in the belief that during this period the country, as far east as the foot-hills of the Sierra, was successively submerged beneath the ocean, and raised above it; for we find the lava outflow as far west as the foot-hills on the east flank of the Coast Range. This must have flowed out over a country having a moderate slope, and lying above the ocean. Again, we find the deposits lying nearly horizontal, and bearing unmistakable evidence of being deposited under water; the isolated buttes near Pence's are fine examples. But why no fossil remains in. these deposits, if they were laid down beneath the ocean? During this lava epoch the waters must have been an ocean of mud from the streams carrying down deposits of volcanic ashes, thus destroying every vestige of life in these waters. This eruption covered all the old river channels, destroyed all animal life within its reach, and left the country a waste, to be repaired and re-peopled during the succeeding ages. Following this eruptive period was ushered in that of the glacial, when the whole northern hemisphere, as far south as the fourth degree of north latitude, was covered with a moving mass of ice. All along the western slope of the Sierra were sent down moving streams of ice, cutting canons from Oregon to Yosemite that challenge the world for magnitude and sublimity. In many places these canons were cut through the lava that covers the country like a great mantle, deep into the underlying slates and granites, thus cutting across the old tertiary rivers and scattering their golden treasures along the new-made channels. Thus we have access to those rich gravel deposits which are rewarding the toiling miner. To the glacial epoch are we indebted for much of that beauty and grandeur of scenery for which this coast, and California in particular, is so justly noted. All the rivers flowing through deep mountain gorges were given their channels by the action of the glaciers. The summits of the Sierra chain of mountains bear evidence in the polished and stiriated slates and granites of their action; quartz-veins are smoothed and polished like marble; and all mountain lakes above an altitude of 5,000 feet may be safely claimed as glacial. During this epoch the canons along the base of the Sierra and foot-hills sent great icebergs rolling and rocking over the present Sacramento Valley and the Coast Range, for there was no Coast Range of mountains then; but they have been reared to their present position since that period, for nowhere upon their summits can we find the stiriations and grooving that are found upon the Sierra. Since the uplifting of the Coast Range, the Sacramento Valley has been filled to its present level with sediment from the surrounding mountains, and covered with a rich and productive soil, thus fitting it for the habitation of civilized man. The result of all these changes gives to Butte county varying topographical features. The western portion, from the Sacramento river to the base of the foot-hills, varies from eight to twenty miles, and is an almost level plain, having an average altitude of 200 feet above the ocean. Leaving the foot-hills, the country commences to ascend with a very evenly-distributed ascent, averaging about 200 feet to the mile, and attaining an altitude of 7,000 feet at the summit of the Sierra. This slope, though uniform, is by no means unbroken. Crossing it at various angles are canons and ravines, some 3,000 feet in depth, many of which have perpendicular walls of lava near their edges from 20 to 300 feet. Fine examples of this may be seen along Butte creek, from the Butte Mills to Helltown, and along Chico creek, from the old dump to Harris' place; also on Dry Creek, along the Magalia and Oroville road. These ravines and gorges give shape to the course of travel and commerce through the eastern portion of the county. All the roads and stage-lines cross the mountains on ridges that are flanked by these ravines. To cross at right angles to the streams would be a physical impossibility. Thus in brief we have only glanced at the successive changes that have taken place in our county during vast ages of the past. Additional Comments: Extracted from: HISTORY OF BUTTE COUNTY, CALIFORNIA, IN TWO VOLUMES. I. HISTORY OF CALIFORNIA FROM 1513 TO 1850. BY FRANK T. GILBERT. The Great Fur Companies and their Trapping Expeditions to California. Settlement of the Sacramento Valley. The Discovery of Gold in California. BY HARRY L. WELLS. II. HISTORY OF BUTTE COUNTY, From its Earliest Settlement to the Present Time. BY HARRY L. WELLS AND W. L. CHAMBERS. BOTH VOLUMES ILLUSTRATED WITH VIEWS AND PORTRAITS. HARRY L. WELLS, 517 CLAY STREET, SAN FRANCISCO 1882. Entered, according to Act of Congress, in the year 1882, by HARRY L. WELLS, in the office of the Librarian of Congress, at Washington, D. C. 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