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Show 164 appearance of which calls to mind the marine Miocene fauna of the Helvetian group of Switzerland and Suabia: Neptuna* Humeroaa Gabb, Twrritella in- cd, Venus pertenuii Gabb, Calliata Voy\{\) Gabb, Schizothoru* Californicus, n. sp.; Peoteu oerrosenn* Gabb, Peoten Fernanda, n. sp., very large and beautiful; Cardium Cal\ fornianum( 1) Conrad, • and Lucina Richthoferi Gabb. In consequence of the extreme dryness of the climate and of the dust which results therefrom, the Miocene sandstone rooks of the entire San Fernando Sierra seem to be of a gray color. If a quarry is opened, however, it is seen that the real color of these molassio rocks is a pale blue; and the whole formation presents a general lithologioal, stratigraphioal, and paleontological aspect which reminds one to such an extent of the Miocene " molasse" of Switzerland, as seen from Lausanne to Freiburg, Berne, Lucerne, Zurich, and the Lake of Constance, that I have often thought myself in Switzerland while really in California. The San Fernando Pass.- As we approach the summit of the pass, after passing the Tall House, the strata become more and more inclined, until at the summit the inclination attains an angle of 60°, the direction of the dip being always southerly. It is also remarked that the molasse, the beds of which are from 10 to 15 feet thick, contains pebbles disseminated here and there in the sandstone. These pebbles finally become so numerous that the strata become a true conglomerate or " nageljluh," similar to the " nagelfluh" of Righi, Rosenberg, the Emmenthal, and Appenzell, in Switzerland. Half a mile from the summit of the pass, descending toward Lyon's Station, we find a considerable mass of sandstone and conglomerate rocks of a dingy yellow color, 200 feet in thickness. The direction of the dip is southerly, or rather a little west of south. The direction of the dip of the strata does not change until we reach the secondary chain, only a mile this side of Petroleopolis, or Lyon's Station. The direction of the dip then changes to the north, or rather a little east of north, at an angle of 20°. We must remark that the road from San Fernando to Petroleopolis is very near the point of contact of the San Fernando Sierra with the Sierra Madre, and hence it follows that the inclinations of the strata are slightly different from the normal inclinations of the most western portions of the Sierra, in consequence of numerous plications and setbacks caused by the obstacle of the Sierra Madre. ASPHALTUM AND MINERAL OIL NEAR SAN FRANCISQUITO RANCH. Six miles to the west by south ( ouest- snd) of Lyon's ranch, or San Francisqnito ranch, precisely on the crest or arete* at the point of division from the San Fernando Sierra, there are two springs of petroleum- oil on each side of the summit of the mountain. On the north side Mr. Lyon's petroleum- spring is also known by the name of Pico's Spring, while that on the south side bears the name of Temple's Oil- Wells. Before reaching Pico's Spring we cross two ridges of mountains, very abrupt on the south side, as are the greater part of the mountains of the San Fernando Sierra. These mountains are formed of huge masses of molassio sandstone, of conglomerate, ( nageljluh,) numerous strata of which are thoroughly impregnated with asphaltum, and whose entire thickness varies between 1,500 and 2,000 feet. The direction of the dip of all the strata is toward the bottom of the Santa Clara Valley; that is to say, to the north, a little west of north, at very variable angles, between 20, 85 degrees, and even the perpendicular. Under these asphaltic sandstones, strata of arenaceo, marly schist' mingled with rather thin beds of sandstone and limestone, intercalated here and there in these schistous clays, are seen to crop toward the center of the Sierra, and the petroleum- springs bubble up at the points of contact of these clays with the masses of sandstone and asphaltic conglomerate. These springs are not abundant, for two very simple reasons: first, they are at the very summit of the Sierra, and there are no basins to - fill them; and secondly, the climate is an extremely dry one. During the very short rainy season these springs increase in volume and the petroleum is much more abundant. If these beds of sandstone and asphaltic conglomerate could be flooded, a large quantity of petroleum could be obtained. The only hope of obtaining a good and sufficient flow of this oil is by means of artesian wells bored at the bottom ot the Santa Clara Valley. There, at a great depth- between 2,000 and 3,000 feet- there ifl some prospect of reaching the supply of petroleum and of its flowing in a rich and abundant stream. Hitherto all the boring has been done in the worst localities that could possibly hare been selected. Wherever a few insignificant petroleum- springs gave speculators the hope of making a sudden fortune, they went to boring at once, without thinking of the future. Whoever wishes to succeed must leave the vicinity of the Sierra Madre and the summits of the San Fernando Sierra, and go to the valley of Santa Clara or to that of San Fernando. There will be a better prospect, however, at the bottom of the Santa Clara Valley. * The arete of a mountain is defined by Bescherelle as a curved line which usually separates the principal declivities of a chain of mountains where the highest peaks are found. |