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Show 161 cation, where superb remains of it are seen plastered, as it were, against the foot of the Sierra Madre. The Tertiary- raolassio strata dip towards the foot of the Sierra Madre- that is to say, to the north- northeast, which is a proof that the Tertiary strata have not been dislocated and uplifted by the Sierra Madre, but by another system of upheaval prior to the last upward movement of the Sierra Madre, which took place during the Quaternary period. The mass of Tertiary rooks which is nearest to the Sierra Madre is composed of a gray clay, which fills the bottom of a valley or kind of ditch, extending parallel to the Sierra Madre, all along the foot of the metamorphic rocks. GEOLOGY OF THE VICINITY OF THE SAN FERNANDO MISSION. Just north of the San Fernando mission there is a line of hills, having an elevation of from 150 to 200 feet above the mission; they are composed of limestone and sandstone identical with those found at Los Encinos, on the other side of the San Fernando Plains. The fish- bearing limestone rocks, however, are less thick than at Los Encinos, but they retain the same lithological characteristics, such as nodules of silex with chalcedony, and, as at Los Encinos, scales, vertebra), and other fragments of fossil-fishes are found here, together with fossil- plants, in a bad state of preservation. The sandstone is coarse and hard, of a gray color, and in certain places it becomes a true conglomerate. The direction of the dip of all the strata is to the north- northwest, at an angle of from forty to forty- five degrees; the heads of the strata run from northeast to southwest. Near the Lopez and Bernardi ranches, numerous specimens of the Pecten Cerro-seneis Gabb are found in the sandstone, together with a new species similar to the Pecten Deserti Conrad, which I call the Pecten mmionti, in honor of the San Fernando mission. Grapevine Canon.- In the eastern part of the Sierra of San Fernando, which is called Monte de Pinos on account of the pine trees which cover it, 3 miles to the north of San Fernando, on the right- hand side of the road which leads to the tunnel, the Tertiary rocks reappear toward the foot of the Sierra Madre; they rise higher as we approach the Sierra of San Fernando, which is entirely formed by them. At the points of contact of the molassic Miocene strata with the granite and pegmatite of the Sierra Madre in the Grapevine Cation, the sandstone beds are very aspbaltio in certain parts; and in consequence of folds and ruptures of the strata small springs of petroleum or mineral oil are found. The asphaltum flows over rocks, and in certain parts we find a real covering of pure asphaltum or Mexican " brea," which extends over several square yards around the springs. The rock has been bored unsuccessfully in the hope of finding petroleum, and the following is the geological section at the spot where the bore has been made. After reaching a depth of 50 feet the lead entered the pegmatite and remained there. The sandstone is very friable, nearly of a bluish- gray color, like the molassic rocks of Switzerland, and often becomes a true conglomerate, or " nagelfluh;" it is impregnated with a considerable quantity of asphaltum. The strata are often very much dislocated, raised almost perpendicularly, inverted and folded, while close by they are almost horizontal. Yellow spots of oxidized iron are often seen in some of these beds of sandstone and conglomerate. Fossils are quite frequently found, although generally in a bad state of preservation. Fine specimens of sharks' teeth are found, of the genus Caroharodon, probably the Car-ckarodon rectus Agassiz; also specimens of the Fusue, Pecten, Tellina, Lucina, & c., all of which indicates a Miocene- Tertiary fauna. In general, in the Grapevine Ca& on the direction of the dip of the strata of the Californian " molasse" is south southwest, at an angle of 45°. THE SAN FERNANDO SIERRA. Following the San Fernando road to Lyon's Station or Petroleopolis, almost as soon as one enters the canon to the right of the road in the direction of the Grapevine Ca& on, superb folds in the strata of the Miocene sandstone rocks are seen. The direction of the dip of these molassic sandstone rocks is south, at an angle varying from 10° to 16° ; the following is the geological section: As we go higher up in the cation a repetition is seen of the same strata of sandstone, conglomerate and fish- bearing limestone, in consequence of the numerous foldings to which all this Miocene formation was subjected at the time when the dislocations and elevations of the San Fernando Sierra took place. The San Fernando tunnel.- When we reach the southern extremity of the tunnel the sandstone rocks are found still more massive; they here appear in the form of superb blue molassic rocks, with indistinct stratification, in enormous beds of from 15 to 20 feet in thickness. Here and there, scattered at different heights throughout these rocks, calcareo- sandy nodules are found, containing numerous fossil- shells, and forming the genuine shelly sandstone or muscheUandstein of the 8wiss geologists. * The following is a list of the principal fossils which I have found in the muscheUandstein, the |