GEOLOGY AND PALEONTOLOGY OF PALOS - Pubs Warehouse

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pi) a tic shale, and limestone in the upper part of the Altamira. The buff siltstone contains Foraminifera typical of the Siphogenerina reedi zone (locality 9). The relations between the buff siltstone and the strata on the crest of the Point Fermin anticline at locality 8 arc obscured by talus in the intervening area, but the siltstone is presumably younger. In San Pcdro, north of the Fort McArthur Upper Reservation and north of the Cabrillo fault, blue- schist sandstone, porcelaneous shale, and silty shale are exposed irt street cuts. These strata appear to grade northwestward into those including diatomaceous silt, described on page 24. WHITES POINT AREA No satisfactory lithologic basis for separating the middle and upper pa.rts of the Altamira was discovered in the Whites Point area. In the preliminary paper 44 pprcelaneous shale and silty shale containing Forami nifera of the Holivina modeloensis zone at localities 14 and 15 were referred on lithologic grounds to a posi tion near the top of the middle part of the Altamira. According to the classification now adopted, however, the strata are assigned to the upper part on the basis of the faunal data. Stratigraphic relations in the strongly deformed rocks at Whites Point and0 nearby are obscure. The schist conglomerate, sandstone, and silty shale in the core of the fan-shaped anticline near Whites Point, shown in figure 14, and in the anticlinal reefs at the point probably represent the middle part of the Alta mira. An incomplete mold of Aeguipecten was col lected from sandstone overlying, schist conglomerate on the north limb of the anticline (locality 12a). In the reefs 2,000 feet northwest of Whites Point rounded masses of basalt are embedded in a limy matrix con taining basaltic .debris and fragments of pectens. This material represents intrusion under a thin cover of unconsolidated sediments or a submarine flow. The oldest rocks exposed on the anticline emerging on the coast half a mile northwest of White"s Point consist of siltstone, mudstone, limestone, and a little porcelaneous shale. These strata, about 100 feet thick, and an overlying unit about 25 feet thick, mostly porcelaneous shale, are thought to represent the middle part of the Altamira. Foraminifera suggestive of the Siphogenerina nuciformis zone were found in calcareous mudstone exposed at low tide 1.2 miles northwest of Whites Point (locality 12b). Loose limestone masses among the reefs at that locality contain cetacean remains. Well- preserved Foraminifera, including Siphogenerina and Valvulineria, were found recently on the extension of Twenty-fifth Street, 0.45 mile southeast of the junction with Palos Verdes Drive South.. In the Whites Point area the WThites Point tunnel penetrated strata consisting of siltstone, some of which contains hard phosphatic nodules, cherty shale, lime stone, and thin beds of clay. The rocks are strongly deformed in the part of the tunnel between the coast and a locality 0.3 mile inland. Poorly preserved Foraminifera of uncertain zonal position in Kleinpell's Luisian stage were collected 250 and 355 feet north of the south portal (localities 12c and 12d, respectively). At the outermost edge of the offshore reefs the open cut exposed buff sandstone underlying basaltic rocks. A diver brought up schist conglomerate about 100 feet beyond the edge of the reefs. « \Voodrinjt, W. P., Bramlctte, M. N., and Klcinpoll, R. M., op. cit., pp. 135,142. MIOCENE SERIES 25 FOSSILS FORAMINIFERA Foraminifera were collected from the middle part 6f the Altamira shale at the localities given in the following table. At many other localities molds of Siphogenerina and large Valvulineria were observed, particularly in limestone interbedded with soft rocks near the horizon of the Miraleste tuff. These forms may be recognized in the field and. are not known to occur in the upper part of the Altamira shale or at higher horizons. The collections from the middle part of the Altamira are assigned by Kleinpell to his Luisian stage. The preservation of much of the material is poor, and the zonal position at many localities is uncertain. According to Kleinpell's identifications, however, the three zones in his Luisian stage in ascending order the Siphogenerina reedi, S. nuciformis, and S. cotlomi are represented. No evidence is apparent for the relative Stratigraphic position of the three zones in the Palos Verdes Hills. The S. reedi zone appears to extend up to about the Miraleste tuff. Foraminifera character istic of that zone were found at locality 5 in diatomace ous silt, evidently near the horizon of the Miraleste tuff. It may be expected that the S. nuciformis and S. collomi zones are in the uppermost part of the middle division of the Altamira. Stratigraphic control at the localities where these two zones are identified is lacking. Locality 10, where a few species suggestive of the S. nuciformis zone were found, appears to be rather low in the section for that zone. (See pi. 3.) The Stratigraphic data at that locality are, however, uncertain. The species identified by Kleinpell are given in the table on the following page. Kleinpell's comments on these fossils are summarized as follows: The Foraminifera from the middle part of the Alta mira shale are generally poorly preserved. The preser vation of the Siphogenerinas, which might give a clue to zonal position, is particularly poor in most of the collections including that genus. The best preserved material may be referred to the Luisian stage (group 2 of preliminary paper) ,45 which corresponds to the unde fined Valvulineria californica zone in its most restricted sense. The collections from localities 3a, 12c, and 12d con sist of a few poorly preserved species. Their zonal position in the Luisian stage is uncertain. Foraminifera from localities 4, 6, and 8 are assigned doubtfully to the Siphogenerina reedi zone (zone B of preliminary paper). Localities 6 and 8 are referable to the S. reedi zone or the underlying S. branneri zone, or possibly to even somewhat older zones. Locality 4 may be referred to either zone just mentioned but hardly to any older horizon. All three localities appear to be referable to the S. reedi zone rather than to older zones on the basis of rather indefinite field relations. A peculiar faunal facies, in which all the species are represented by very small possibly immature specimens, occurs at localities 6 and 8. Assemblages from localities 5 and 9 are typical of the S. reedi zone, and the assemblage from locality 3 appears to represent that zone. A sample that seems to be a duplicate of that from locality 3 contains Valvulineria californica. The assemblages from localities 3, 5, and 9 may be correlated with the typical fauna of the S. reedi zone of the Monterey « Wooclring, W. P., Braralotco, M. N., and Kleinpell, R. M., op. cit., pp. 125-149.
26 GEOLOGY AND PALEONTOLOGY OF PALOS VERDES HILLS, CALIFORNIA Foraminifera from middle part of Allamira shale member of Monlerey shale [Identifications by R. M. Kleinpell. R, rare; F, few; C, common; A, abundant; cf., not certainly identified but resembles the species listed] Species Buliminella brevior Cushman...... __ . ______ ...... Buliminaovatad'Orbigny?-... __ . _ . __ .... __ .... Bolivina advena var. ornata Cushman (including Boliv- Bolivina advena var. striatella Cushman........ _ . __ . Bolivina floridana Cushman...... _ __ . ________ . Uvigerinella californica var. ornata Cushman. ..-.--.-.... Uvigerinella californica var. parva Kleinpell (Uvigerinella cf. U. californica Cushman) .. . __ ...... __ ....... Siphogenerina collomi Cushman _ . ........... _ ........ Siphogenerina nuciformis Kleinpell (Siphogenerina aff. Valvulineria californica var. appressa Cushman-. -------- Valvulineria miocenica Cushman? _ . __ ........... Valvulineria depressa Cushman..... _ .................. Valvulineria ornata Cushman (including Valvulineria? Pulvlnulmella subperuviana Cushman? (Pulvinulinella? Cassidulina panzana Kleinpell (Cassidulina aff. C. crassa d'Orbigny) __ ...-..--.......-...-..-... .. .. Cassidulina williami Kleinpell (Cassidulina cf. C. sub- globosaH. B. Brady). ................................. Pullenia miocenica Kleinpell (Pullenia aff. P. sphaeroides Pullenia miocenica var. globula Kleinpell (Pullenia aff. Planulinacf. P. arimincnsis d'Orbigny. ....... _ ........ ' Apparently same as locality 3. 2 Apparently same as locality 7. Siphogenerina reedi zone (?) shale in Reliz Canyon in Monterey County, 46 with, the fauna from Santa Clara County described by Chap man, 47 and with the fauna of the Claremont shale in the Monterey group of Contra Costa County. 48 Locality 11 represents the S. nuciformis zone (zone C of preliminary paper), which overlies the S. reedi zone. The S. nuciformis zone is particularly well developed in the Monterey on Chico Martinez Creek, on the west side of San Joaquin Valley, where it is known locally as " the Valvulineria flood zone." 49 The assemblages from localities 7, 10, and 12b are suggestive of the S. nuci formis zone rather than the S. reedi zone. A sample that appears to 'be a duplicate of that from locality 7 contains a Siphogenerina that may be S. nuciformis. Locality 12 represents a still higher zone, the S. collomi zone (zone D of preliminary paper). The as semblage from locality 12 may be correlated with that from the frequently cited locality in the lower part of the Monterey shale in the type region near Monterey, « Kleinpell, R. M., Miocene Stratigraphy of California, p. 125, Am. Assoc. Petro leum Geologists, Tulsa, Okla., 1938. «' Chapman, Frederick, Foraminifera from the Tertiary of California: California Acad. Sci. Proc., 3d ser., vol. 1, pp. 241-260, pis. 29, 30,1900. « Kleinpell, R. M., op. cit., p. 56.
Page 1: UNITED STATES DEPARTMENT OF THE INT
Page 4 and 5: IV CONTENTS Stratigraphy and paleon
Page 6 and 7: GEOLOGY AND PALEONTOLOGY OF PALOS V
Page 8 and 9: and paleontology and a general acco
Page 10 and 11: 1902. Arnold, Delos, and Arnold, Ra
Page 12 and 13: 1933. Davis, W. M., Glacial epochs
Page 14 and 15: GEOGRAPHY FIOUIIE 1. Sketch map of
Page 16 and 17: year on the north slope, and small
Page 18 and 19: correlation with the Franciscan of
Page 20 and 21: LITHOLOGIC UNIT MIOCENE SERIES ' 15
Page 22 and 23: shale and porcelaneous mudstone rat
Page 24 and 25: GEOLOGICAL SURVEY PROFESSIONAL PAPE
Page 26 and 27: GEOLOGICAL SURVEY ^ HnMMHMHMHBMHMHM
Page 28 and 29: part of the Altamira shale in the P
Page 30 and 31: slide debris that may conceal a fau
Page 32 and 33: Section of middle part of Altamira
Page 36 and 37: is in the upper part of the sandsto
Page 38 and 39: Section of upper part of Altamira s
Page 40 and 41: Section of Monlerey shale, includin
Page 42 and 43: MIOCENE SERIES Foraminifera from up
Page 46 and 47: GEOLOGICAL SURVEY PKOFESSIONAL PAPE
Page 50 and 51: there appears to be no displacement
Page 52 and 53: oad from Girard to Mohn Spring in t
Page 54 and 55: nose of a spur on the north side of
Page 56 and 57: is used for the formation in that a
Page 58 and 59: spring of 1938. Owing to urban and
Page 60 and 61: y Crickmay u to the Santa Barbara f
Page 62 and 63: The base of the San Pedro sand is d
Page 64 and 65: y Dr. Hampton Smith, Bryozoa and mo
Page 70 and 71: including numerous specimens of Bit
Page 72 and 73: gravel as much as 20 feet thick mad
Page 74 and 75: fossils were found near the seaward
Page 76 and 77: NORTHERN SAN PEDRO In the northern
Page 82 and 83: is at an 1 altitude of 365 feet, mu
Page 84 and 85:
son tod by 43 collections in the ma
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fiocl as M. cf. M. varitosa. M. var
Page 88 and 89:
a width of 3.3 millimeters. Only th
Page 90 and 91:
ased on fossils from San Pcdro, is
Page 92 and 93:
Pedro district, is recognized in th
Page 94 and 95:
According to Arnold's description o
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midellids are on record, half of wh
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fortis is widespread and locally ab
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Progabbia cooperi occurs in the Lom
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ANOM1IDAE The Recent California spe
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opuntia survived from the Pliocene
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millimeters) from Puget Sound. The
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lower Pleistocene units, in deposit
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in interpreting the Pleistocene pal
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PLEISTOCENE SERIES 89 Pleistocene m
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There are no shallow-water Littorin
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localities therefore are inferred t
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locality 70 species of gastropods a
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is better known. Calicantharus is a
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The species in the preceding list b
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It is apparent from the preceding t
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graphic or depth range have taken p
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Pedro district. The close faunal si
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age extend over an entire terrace.
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eludes volcanic agglomerate or brec
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San Pedro district, where those str
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during cutting of the Pleistocene m
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GEOLOGICAL SURVEY PROFESSIONAL PAPE
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GEOLOGICAL SURVEY AIIil'LANE VIEW O
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116 GEOLOGY AND PALEONTOLOGY OF PAL
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G92787 45 10 PLATES 28-37 127
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GEOLOGICAL SUEVEY PROFESSIONAL PAPE
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PLATE 29 [Species and varieties ill
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PLATE 37 [Species illustrated still
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Page Calicantharus fortls..........
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142 INDEX Page kennerlyi, Mercenari
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144 INDEX Page Rissoinidae_________
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