| OCR Text |
Show 169 fossils which I collected at the Arroyo de los Alisos, near Fort Tejon : Fusus { Hemirfusus) Bemondii, Gabb; Tritonium Whitneyi, Gabb; Trit. Califomicum, Gabb; Trachylriion Tejonensis, Gabb; Olicella ifaMeuwonii, Gabb; Fasciolaria ficus, Gabb; Mitioa Uvasana, Gabb ; Lunatia ( gyrodes) Conradiana, Gabb; Neverita globosa, Gabb; Never secta, Gabb; Turritella Uvasana, Gabb; Galerus Excentricus, Gabb ; Ringinella Pinguis, Gabb; Tellina ovideSj Gabb; Tell, aqualis, Gabb; Meretrix Uvasana, Conrad; Merel Hornii, Gabb; Dosiniaelevata, Gabb; Tapes Conradiana, Gabb; Cardium Cooperii, Gabb; Card, Brewerii; Linia multiradiata, Gabb, & c. This fauna does not contain a single one of the cretaceous genera of Central Europe, while it abounds in European and South American Tertiary genera. There is an almost entire absence of polypariaor corals, and of ecbinoderms or radiata. This absence of corals is particularly remarkable, in view of the fact that it extends throughout the whole formation of Tertiary rocks of California, in which only two or three specimens of zoophytes have as yet been discovered, and they were fouud iu the vicinity of Mount Diablo; not a single one has been found in Southern California. Tertiary rocks of California.- The middle and lower portions of the Eocene Tertiary rocks are well represented in California by the lignitic strata of Mount Diablo, which are found immediately beneath the strata of Fort Tejon, after which some beds are found, which bear the name of the Martinez and Chico groups, which succeed each other without discordance of stratification, and the fauna of which ( chiefly Tertiary) contains some cephalopoda badly developed, small, and stunted, as are of ten the last representatives of a great family or genus which is on the point of becoming extiuot. Dr. John B. Tiask, who, with the late Dr. Randall, the discoverer of the fossils at Chico Creek, first called attentiou to these beds at Chico Creek containing cephalopoda, correctly referred them to tqe Eocene Tertiary formation, notwithstanding the presence of the few cephalopods, which he called A mmonites Chicoensis aud BaculitesChicoensis. ( See Description of New Species ef Ammonite and fiaculitefrom the Tertiary Rocks of Chico Creek, in Proceedings of the California Academy of Natural Sciences, vol. L., p. 85, San Francisco, 1854-' 58.) There is absolutely no law in geological science which makes it necessary for cephalopods of the genera known as Ammonites, Baculites, Hamiles, Helio-cera, Turrilitest Ancylocera, & c. to disappear entirely from the surface of the terrestrial flobe with the rocks of the Secondary epochs. Iu Central Europe these cephalopods ave hitherto disappeared with the cretaceous rooks; that, however, is but an empirical law, a negative fact, applicable only to Central Europe, and to extend this fact to the whole earth as a well- established law would be contrary to all that we know of the laws of the geographical distribution of animals. The general zoological, lithological, and stratigraphical characteristics of the California rocks which extend from Chico Creek and San Francisco to San Diego and San Bernardino are such as to render the whole analogous to the great Tertiary rocks of the Americo- European basin of the Atlantic, of which it is the representative and the equivalent iu the great basin of the Pacific; only some Ammonifies, Baculites, Helio-cera, & c, continued to live in the Tertiary seas of the Pacific regions when these genera no longer existed in the Atlautic hemisphere, a fact which is observed in all the geological periods through which the terrestrial globe has passed until the present, time. This is not an exceptiou ; it is, on the contrary, a law of the geographical distribution of beings. Real cretaceous rocks are only found, in California, in the northeastern portion of the State, around Mouut Shasta. But all the southern and central parts,' the real coast range, from San Luis Obispo to Cape Mendocino, the city and peninsula of San Francisco, Mount Diablo, and Fort Tejon, are formed exclusively of stratified rocks of the Tertiary period. Glacial rocks of Southern California and Pike's Peak.- It cannot be doubted that the Sierra Madre, from Mount San Bernardino to Tejon Pass and Tehachipi Pass, was covered with glaciers during the Quaternary period. The long canons of San Gabriel, of the Little and Big Tujunga, of Soledad and San Francisquito, served as receptacles or beds ( lits) for the glaciers which descended from the many high peaks of this chain of mountains, still so little known geographically. In the San Gabriel CaD on we see in several places before reaching Dr. Winson's silver- mines traces of ancient lateral " moraines" on each side of the caGon, and toward the entrance of the cation, a mile from Buell's Hole, heavy blocks of granite or true bowlders are seen, arranged in the form of a crescent, as it for a frontal " moraine." My* exploration of this canon was too superficial to enable me to speak with confidence of the existence of an ancient glacier; it seemed to me, however, that there were some traces of a large glacier which descended from the peak of San Antonio. The traces of glaciers are more visible and striking in the San Francisquito Pass, especially near Jesus Gallejo's ranch, where diorites appear in great masses, and not long after reaching a large lateral valley on the right, as one asceuds the pass, we see a very heavy Quaternary drift, with erratic blocks and indications of glacial stria3, on the dioritio and Miocene sandstone rocks which form the bottom of the valley. I however met with really unn istakable " moraines" only at a single point of my explorations in Southern California, aud that was on the road which runs along the |
