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DEPARTMENT OF THE INTERIOR

BULLETIN

UNITED STATES

GEOLOGICAL SURVEY

No. 19

NOTES ON THE STRATIGRAPHY OF CALIFORNIA

WASHINGTON

OOVKBNMKNT PRINTING OFFICE

1885

A.T> VlflR T I S B5 M1B3 N'T.

[Bulletin No. 19.]

The publications of the United States Geological Survey are issued in accordance with the statute, 

approved March 8,1879, which declares that 

" The publications of the Geological Survey shall consist of the annual report of operations, geological 

and economic maps illustrating the resources and classification of the lands, and reports upon general 

and economic geology and paleontology. The annual report of operations of the Geological Survey 

shall accompany the annual report of the Secretary of the Interior. All special memoirs and reports 

of said Survey shall be issued in uniform quarto series if deemed necessary by the Director, but other- 

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ehall be the property of the United States and form a part of the library of the organization: And the 

money resulting from the sale of such publications shall be covered into the Treasury of the United 

States."

On July 7,1882, the following joint resolution, referring to all Government publications, was passed 

by Congress:

" That whenever any document or report shall bo ordered printedj,by Congress, there shall be printed 

in addition to the number in each case stated, the 'usual number' (1,900) of copies for binding and 

distribution among those entitled to receive them."

Under these general laws it will be seen that none of the Survey publications are furnished to it for 

gratuitous distribution. The 3,000 copies of the Annual Report are distributed through the document 

rooms of Congress. The 1,900 copies of each of the publications are distributed to the officers of the 

legislative and executive departments and to stated depositories throughout the United States.

Except, therefore, in those cases where an extra number of any publication is supplied to this office 

by special resolution of Congress, as has been done in the case of the Second, Third, Fourth, and Fifth 

Annual Eeports, or where a number has been ordered for its use by tho Secretary of the Interior, as in 

the case of Mineral .Resources and Dictionary of Altitudes, the Survey has no copies of any of its publications for gratuitous distribution.

ANNUAL REPORTS.

Of the Annual Reports there have been already published:

I. First Annual Report to the Hon. Carl Schurz, by Clarence King. 1880. 8°. 79 pp. 1 map. A 

preliminary report describing plan of organizati^ and publications.

II. Report of the Director of the United States Geological Survey for 1880-'81, by J. W. Powell. 

1882. 8°. Iv, 588 pp. 61 pi. 1 map.

in. Third Annual Report of the United States Geological Survey, 1881-'82, by J. "W". Powell. 1883 

8°. xviii, 564 pp6 67 pi. and maps.

IV. Fourth Annual Report of the United States Geological Survey, 1882-'83, by J. "W. Powell. 1884. 

8°. xii, 473 pp. 85 pi. and maps.

The Fifth Annual Report is in press.

MONOGRAPHS.

Of the Monographs, Nos. n, HI, IV, V, VI, VH, and VIII are now published, viz:

n. Tertiary History of the Grand Canon District, with atlas, by Clarence E. Button, Capt., U. S. A.

1882. 4°. xiy, 264 pp. 42 pi. and atlas of 24 sheets folio. Price $10.12. 

HI. Geology of tho Comstock Lode and the Washoo District, with atlas, by George F. Decker.

1882. 4°. xv, 422 pp. 7 pi. and atlas of 21 sheets folio. Price $11.

IV. Comstook Mining and Miners, by Eliot Lord. 1883. 4°. xiv, 451 pp. 3 pi. Price $1.50.

V. Copper-bearing Rocks of Lake Superior, by Roland D. Irving. 1883. 4°. xvi, 464 pp. 15 1. 

29 pi. Price $1.85.

VI. Contributions to the Knowledge of the Older Mesozoio Flora of Virginia, by "Wra. M. Fontaine. 

1883. 4°. xi, 144 pp. 541. 54 pi. Price $1.05.

Vn. Silver-lead Deposits of Eureka, Nevada, by Joseph S. Curtis. 1884. 4°. xiii, 200 pp. 16 pL 

Price $1.20.

VUI. Paleontology of the Eureka District, by Charles D. Waloott. 1884. 4°. xiii, 208 pp. 241. 

24 pi. Price $1.10.
ADVERTISEMENT.

The following are in press, viz:

IX. Brachiopoda and Lamellibranchiata of the Raritan Clays and G-reensand Marls of New Jersey, 

by Robert P. Whitfield. 1885. 4°. ix, 338pp. 35 pi.

X. Dinocerata. A Monograph of an Extinct Order of Gigantic Mammals, by Othniel Charles Marsh. 

1885. 4°. -, pp. 56 pi.

XL Geological History of Lake Lahontan, a Quaternary Lake of Northwestern Nevada, by Israel 

Cook Russell. 1885. 4°. , pp. 46 pi.

The following are in preparation, viz:

I. The Precious Metals, b'y Clarence King.

Geology and Mining Industry of Leadville, with atlas, by S. F. Emmons.

Geology of the Eureka Mining District, Nevada, with atlas, by Arnold Hague.

Lake Bonneville, by G. K. Gilbert.

Sauropoda, by Prof. 0. C. Marsh.

Stegosauria, by Prof. 0. C. Marsh.

BULLETINS.

The Bulletins of the Survey will contain such papers relating to the general purpose of its work as 

do not properly come tinder the heads of ANNUAL REPORTS or MONOGRAPHS.

Bach of these Bulletins will contain but one paper and will be complete in itself. They will, however, be numbered in a continuous series, and will in time be united into volumes of convenient size. 

To facilitate this each Bulletin will have two paginations, one proper to itself and another which be 

longs to it as part of the volume.

Of this series of Bulletins Nos. 1 to 19 are already published, viz:

1. On Hypersthene-Andesite and on Triclinic Pyroxene in Augitic Rocks, by Whitman Cross, with 

a Geological Sketch of Buffalo Peaks, Colorado, by S. F. Emmons. 1883. 8°. 42 pp. 2 pi. Price 10 cents.

2. Gold and Silver Conversion Tables, giving the coining value of Troy ounces of fine metal, etc., by 

Albert "Williams, jr. 1883. 8°. ii, 8 pp. Price 5 cents.

3. On the Fossil Faunas of the Upper Devonian, along the meridian of 76° 30', from Tompkins County,' 

New York, to Bradford County, Pennsylvania, by Henry S. Williams. 1884. 8°. 36 pp. Price 5 cents

4. On Mpsozoic Fossils, by Charles A. White. 1884. 8°. 36pp. 9 pi. Price 5 cents.

5. A Dictionary of Altitudes in the United States, compiled by Henry Gannett. 1884. 8°. 325pp. 

Price 20 cents.

6. Elevations in the Dominion of Canada, by J. W. Spencer. 1884. 8°. 43 pp. Price 5 cents.

7. Mapoteca Geologica Americana. A catalogue of geological maps of America (North and South), 

1752-1881, by Jules Marcou-and John Belknap Marcou. 1884. 8°. 184pp. Price 10 cents.

8. On Secondary Enlargements of Mineral Fragments in Certain Hocks, by R. D. Irving and C. R. 

Vanhise. 1884. 8°. 56 pp. 6 pi. Price 10 cents.

9. A Report of work done in the Washington Laboratory during the fiscal year 1883-'84. F. W. 

Clarke, chief chemist; T. M. Chatard, assistant. 1884. 8°. 40pp. Price 5 cents.

10. On the Cambrian Faunas of North America. Preliminary studies by Charles Doolittle Walcott. 

1884. 8°. 74pp. 10 pi. Price 5 cents.

11. On the Quaternary and Recent Mollusca of the Great Basin; with Descriptions of New Forms, by 

R. Ellsworth Call; introduced toy a sketch of the Quaternary Lakes of the Great Basin, by G-. -K. 

Gilbert. 1884. 8°. 66 pp. 6 pi. Price 5 cents. ^

12. A Crystallographic Study of the Thinolite ofmake Lahontan, by Edward S. Dana. 1884. 8°, 

34 pp. 3 pi. Price 5 cents.

13. Boundaries of the United States and of the several States and Territories, by Henry Gannett. 

1885. 8°. 135 pp. Price 10 cents.

14. The Electrical and Magnetic Properties of the Iron-Carburets, by Carl Barus and Vincent 

Strouhal. 1885. 8°. 238 pp. Price 15 cents.

15. On the Mesozoic and Cenozoic Paleontology of California, by Dr. C. A. White. 1885. 8°. 33pp. 

Price 5 cents.

16. On the higher Devonian Faunas of Ontario County, New York, by. J. M.. Clarke. 1885. 8°. 

86 pp. 3 pi. Price 5 cents.

17. On the Development of Crystallization, etc., by Arnold Hague and J. P. Iddings. 1885. 8°. 

44 pp. Price 5 cents.

18. On Marine Eocene, Fresh-water Miocene, and other Fossil Mollusca of Western North America, 

by Dr. C. A. White. 1885. 8°. 26 pp. 3 pi. Price 5 cents.

19. Notes on the Stratigraphy of California, by George F. Becker. 1885. 8°. 28 pp. Price 5 cents. 

Numbers 1 to 6 of the Bulletins form Volume I, and numbers 7 to 14 Volume IT. Volume m is not 

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The following are in press, viz:

20. Contributions to the Mineralogy of the Rocky Mountains, by Whitman Cross and W. F. Hillebrand. 1885. 8°. 114 pp. 1 pi. Price 10 cents.

21. The Lignites of the Great Sioux Reservation, by Bailey Willis. 1885. 8°. pp. 6 pi. Price 

 cents.
ADVERTISEMENT.

'22. On Mew Cretaceous Fossils from California, by Charles A. White, M.D. 1865. 8°. pp. 5pL 

Price cents.

STATISTICAL PAPERS.

A fourth series of publications having special reference to the mineral resources of the United States 

is contemplated.

Of that series the first has been published, viz:

Mineral Resources of the United States, by Albert Williams, jr. 1883. 8°. xvii, 813pp. Price 60 

cents.

The second volume of this series, Mineral Resources 1883 and 1884, is in preparation and will soon 

be put to press.

Correspondence relating to the publications of the Survey, and all remittances, which must be by 

POSTAL NOTE or MONET OBDBB, should be addressed

To THK DIRECTOR OP THB

UNITED STATES GEOLOGICAL SUBVET, 

Washington, D. (7. WASHINGTON, D. C., May 25,1885.

DEPARTMENT OF THE. INTERIOK

BULLETIN

OF T1-U-:

UNITED STATES

GEOLOGICAL SURVEY

30236

No. 1©

WASHINGTON

GOVERNMENT PRINTING OFFICE 

/

1835

UNITED STATES GEOLOGICAL SURVEY

J. W. POWELL DIRECTOR

NOTES

OX THE

STRATIGRAPHY OF CALIFORNIA

BY

i' ftM 236 V< .'.feD

F. BECKEH

WASHINGTON

GOVERNMENT PRINTING OFFICE

CONTENTS.

Page.

Introductory................................................................ 7

Metamorphic rocks of the Coast Ranges...................................... 7

Age of the metamorphic rocks of the Coast Ranges............................ 8

Nonconformity between the Kuoxville beds and the Chico.................... 12

Identity of the Mariposa and Knoxville beds................................. 18

Relation of the Cascades to the Sierra and the Coast Ranges of California..... 20

Other Mesozoic beds ...... ................................................... 20

Paleozoic rocks of California................................................. 21

The Coast Ranges members of the Western Cordillera system.'................ 23

Index .........................................._......................... 27

(195)

NOTES ON THE STRATIGRAPHY OF CALIFORNIA.

BY GEORGE F. BECKER.

. INTRODUCTORY. A complete examination of the Coast Ranges ot 

California can hardly be undertaken by the Geological Survey for some 

years to come, consistently with the plans at present formed. The detailed study of certain small areas in these ranges, however, raised a 

number of questions as to'the age and stratigraphical relations of the 

various series'of beds, which it seemed necessary to answer as well as 

circumstances permitted. Having reached certain conclusions, for themost part on structural grounds, it became indispensable for me to 

obtain the co-operation of an expert paleontologist. At my solicitation, 

and with the approval of the director, Dr. C. A. White consented to visit 

the field with me. f !e passed several months of the summer of 1884 in 

studying my collections and the occurrence of fossils in place with reference to the points at issue. His results appear in Bulletin No. 15, 

that and this being complementary to one another. I had the great satisfaction of finding that Dr. White was led from a purely paleontological 

position to conclusions entirely accordant with those at which I had 

already arrived on structural grounds. His long experience.as a general geologist also made his agreement; with .me as to the structural indications a welcome confirmation of my opinions. These studies, in 

.conjunction with many observations made by earlier workers on the 

Pacific Coast, particularly those of the State Geological Survey of California, under Prof. J. D. Whitney, have led to some seemingly well established general conclusions of interest. The more purely geological 

results will be presented in the following pages, in the imperfect form 

in which alone it will be possible to give them until an immense amount 

of additional work shall have been done.

METAMORPHISM IN THE COAST RANGES. Throughout the Coast 

Ranges of California there occur large irregular areas of rocks in the 

condition ordinarily regarded as metamorphic. They are characterized 

lithologically by the presence of serpentine (perhaps accompanied by 

some other magnesian minerals) or silica, or both. Of the secondary

(197) ' 7
8 STRATIGRAPHY OF CALIFORNIA. [BULL. 19.

nature of the silicification there can be no doubt, since the quartz and 

opal occur mainly in the form of veins and stringers, for the most part 

occupying tiny cracks in the rock. The serpentine was also regarded 

as an alteration-product by Professor Whitney and his assistants, and 

with this opinion I am compelled to agree, after a careful study of the 

phenomena, both structural and microscopic, the details of which will 

be published on another occasion. Where the stratification of the met- 

. amorphic rocks is not obliterated, they are seen to be greatly disturbed, 

having been sometimes broken up into a chaotic mass of fragments, 

since cemented by silica or serpentine, and sometimes thrown into sharp 

plications. In the latter class of cases it is often clear that plication 

has not.been effected by flexure, but by innumerable fractures, the re- 

.sultiug fragments often averaging less than one-quarter inch cube. 

These particles were retained in approximately their original position 

by mutual pressure, and have been recemented by silica. The most 

striking instances of this character are seen among thin-bedded rocks, 

either sandstones or sandy shales, and such are remarkably frequent in 

this series; indeed they might be said to be characteristic of it, though 

occasionally met with in formations which appear to be later than the 

most important era of metamorphism.1

Besides the rocks referred to above, the Coast Eanges include others 

which have been subjected to more or less complete alteration. Thus 

along the shore of Carmelo Bay, Miocene schists have been locally 

changed to a ciudery mass, as if by the action of heat, but these rocks 

bear no resemblance to the serpentinized and silicified material just doscribed. More or less complete induration is common even in the most 

recent rocks of the coast, and oxidation and impregnations with calcite 

and gypsum occur abundantly in rocks of all ages. In the present 

paper, however, the term metamorphism, unless specially qualified, must 

be understood to refer to serpentinization, silification, and associated 

changes.

AGE OF THE METAMORPHIC ROCKS OF THE COAST EANGES. Eocks

of the metaraorphic series often pass over into unaltered beds under 

such circumstances as to preclude a doubt that they are of the same 

age; but nnfortunately the unchanged strata seldom contain determinable fossils, and only a small number of occurrences are known in 

which the age can be satisfactorily established by direct evidence. In 

addition to these cases, however, there is a considerable amount of 

tolerably satisfactory indirect evidence available, when all the circumstances are taken into consideration. The neighborhood of Kuoxville, 

Napa Oounty. atlbrds an excellent opportunity for the study of the 

metaraorphic rocks. This region has also been mapped and examined 

in detail as a portion of a series of studies which, with abundant illus1 The peculiarity of these thin-bedded, plicated, inetamorphic rocks was observed 

and frequently referred to by Professor Whitney.

(198)
BKCKEB.J METAMORPHICS OF THE COAST KANGES. . 9

trations, will appear hereafter. A section. across the north fork of 

Da vis Creek, a little north of the Reed mine, a short distance from Knox-. 

ville, shows that the ravine occupies an eroded anticlinal of which the 

western portion is highly metamorphic, while the eastern consists in 

part of highly fossiliferous strata, containing Aucclla of two varieties, 

with other molluscan remains. A map of the region shows that the 

strike of the unaltered strata throughout is tolerably constant, but that 

areas of inetamorphic and unaltered rocks, the latter nearly all containing a few fossils, are interspersed in the most irregular manner. While 

the passage from metamorphosed to fresh rock is usually rather sudden, 

there are also clear cases of transition. The whole structure and the 

stratigraphical relations are such as.to preclude every supposition except 

that the metamorphic rock is an alteration product of the same beds 

which contain Aucella and the accompanying fossils. These fossils, and 

these only, occur over a strip of country several miles in length, in 

which Knoxville is -the only town. Dr. White and I have therefore 

agreed to call these characteristic beds the Knoxville group. Their age, 

as may be seen from Dr. White's bulletin, is near the limits of the 

Jurassic and the Cretaceous, and it is not quite certain to which they 

belong, if indeed they are not intermediate or transitional.

Close to the Manzanita gold and quicksilver mine on Sulphur Creek, 

in Colusa County, the metamorphic rocks contain impressions ofAucella 

PiocMi, and close by are beds of limestone full of Bhynconella WMtneyi.2 

The metamorphic rocks of this region are serpentinized and silicified, 

and the thin-bedded strata show the characteristic contortions accompanied by a fine network of veins of silica. At Mount Diablo, too, there 

is abundant proof of the Knoxville age of the metamorphic rock! Professor Whitney, writing before Mr. W. M. Gabb-had made his final 

divisions of the California Cretaceous, mentions the occurrences at Mount 

Diablo as conclusive of the Cretaceous age of the metamorphic rocks, 

but withont enumerating the associated fossils. From an examination 

of the fossil localities in Mr. Gabb's work, however, it appears certain 

that these were Aucella, etc. An examination which Dr. White and I 

undertook for the purpose shows that in Bagley Creek, about a mile 

from the summit, Aucella occurs abundantly close to the edge of metamorphosed strata; indeed, in partially metamorphosed strata conformable with those extremely altered, and in structural relations to them, 

which clearly indicate the same age. My assistant, Mr. H. W. Turner, 

subsequently found a series of beds, some of which had escaped action 

and contained Aucella, though inclosed on both sides by highly -metamorphic strata. Mr. Gabb also mentions 3 an Aucella locality near the 

New Almaden mine which I have not thus far been able to identify.

3 These specimens -were determined by direct comparison with specimens in the collection of the State survey. The figure given in Pal. Cal., Vol. II, Plate XXXIV, is 

incorrect in important particulars.

"Pal. Cal., Vol. II, p. 247.

(199)
10 STEATIGEAPHY OF CALIFORNIA. [DULL. 19.

So far as is known, that part of the country consists of metamorphic 

rocks overlain by Miocene strata, and there can be little doubt that the 

Aucella beds belong to the metamorphic series. Alcatraz Island, close 

to San Francisco, consists of metamorphic sandstone and shales not 

distinguishable from those of San Francisco or of Mount Diablo. Here 

Major Elliott discovered an Inoceramus, considered by Mr. Gabb and 

Dr. White as establishing the Cretaceous age of these rocks, though 

indecisive of the portion of this formation to which they should be referred. The above comprise all the instances known in which the age 

of the silicified and serpentinized metamorphic rocks is directly determinable by paleontological evidence.

Of other cases of alteration of rocks known not to belong to the 

Knoxville beds I have already mentioned the very remarkable but 

utterly different change in the Miocene strata near Monterey. In the 

Arroyo de la Penitencia above Alum Eock, near San Jose', there is also 

an area of altered Miocene sandstones referred to by Professor Whitney.4 

The rock here is much indurated and is full of veins of calcite. No objection can be made to its description as metamorphic by Professor Whitney, but it is not serpentinized and silicified, and does not partake of 

the characteristics so strongly marked in the highly metamorphosed 

recks of the Knoxville group. On the other hand, there are plenty of 

rocks of this group no more altered than the Miocene of the Arroyo de 

la Penitencia and some areas still less modified. The Tertiary of the 

Arroyo has been subjected to influences seemingly identical with those 

which have affected portions of the Knoxville beds, but not to those 

which have produced in the older strata the characteristic serpentinization and silification. Professor Whitney also refers 5 twice to altered 

beds in the San Francisquito Pass, which, indeed is to the south of the 

Coast Eanges as usually defined. In the first reference he states that 

" this belt of metamorphic is referred by us to the Cretaceous formation, 

from general analogy rather than from any direct evidence of fossils." 

In the second reference they are mentioned as " Miocene rocks turned 

upon edge and so much metamorphosed as to be converted into mica 

slate." No statement of the means of determination of the age of these 

beds accompanies this remark, which, however, occurs in a brief summary of the geology of the Coast Eanges. Whatever the evidence may 

be upon which the change of reference was made, it can have little 

bearing upon the age of the metamorphics in the central Coast Eanges, 

nor is serpentinization referred to as forming a part of the phenomena.

So far as is known, therefore, no beds in the Coast Ranges of California younger than the Knoxville group have experienced the peculiar 

magnesian and silicious rnetainorphisinso characteristic of these ranges. 

No fossils antedating the Knoxville period have anywhere been discov4 Geol. Cal., Vol. I, p. 51.

6 Geol. Cal., Vol. I, p. 196. Aur. Grav., p. 19.

(200)
DECKEU.] .METAMORPHOSED KNOXVILLE BEDS. 11

ered in the Coast Eanges. For the most part it would seem that rocks 

indistinguishable in habitus from the Knoxville group rest directly upon 

the granite. In the Gavilan Eange, however, an extremely crystalline 

limestone is the lowest sedimentary formation.6 It is so highly metamorphosed where thus far'seen as to offer no hope of fossils, and its 

general appearance is such as to suggest a far greater age than the 

Jurassic. Nothing of the kind is known to exist between this point and 

Clear Lake. A portion, at least, of the characteristic metamorphism of 

the Coast Eanges took place before the beginning of the Chico period. 

Metamorphic pebbles are common in the Chico conglomerates, but these 

are usually wholly silicious. This is in no way inconsistent with their 

having been derived from areas of metamorphosed Kuoxville beds, for 

serpentine is easily abraded and easily decomposed, so that it readily 

escapes redeposition. These pebbles might also, however, have been 

derived from some earlier metamorphic area not now exposed. But in 

the Wallala7 beds, a series extending along the coast from near Fort Boss 

at least to Wallala, and which Dr. White regards as probably prior to 

the Chico, serpentine pebbles from the adjoining metamorphic area are 

tolerably abundant. This area is a large one and no Knoxville fossils 

have been found as yet near Wallala, but the metamorphic is continuous 

with that of Colusa and Napa Counties, where we know that the magnesian metamorphism involved the Knoxville beds: These pebbles, 

then, are probably of Knoxville age. New Idria lies at the southern extremity of the Mount Diablo range, which takes its name from its most 

northerly peak. The range is essentially a metamorphic ridge flanked 

by inclined strata not altered. The metamorphic axis can be followed 

almost continuously, and perhaps quite so, but while at the northern 

end the metamorphic rocks are certainly of Knoxville age, at the southern end the externally indistinguishable material contains, so far as 

known, only a few indeterminable plant remains. It appears to me almost beyond reasonable doubt that the metamorphic of New Idria includes Knoxville beds.

Similarity of lithological and physical character may, I think, be 

given too much weight in geological diagnosis. I cannot conceive, for 

example, that any degree of similarity between the rocks of California 

and those of Switzerland should properly be considered as even tending to prove the age of either. I go farther, and refuse to regard the 

metamorphism of the rocks of Butte County as necessarily contemporaneous with that of the strata of Napa County in spite of external 

similarity. On the other hand, within properly limited areas, observations show that the same fauna is associated with similar rocks; while 

if it were impracticable to draw any conclusions as to age, except where

6 Cf. Dr. Antisell's paper in Pacific Railroad Survey, Vol. VII.

7 This name is variously spelled Gualala, Guadala, Walhalla and Wallala. The last 

is the spelling adopted by the Coast and Geodetic Survey after careful scrutiny and 

consideration.

(201)
12 STRATIGRAPHY OF CALIFORNIA.

the rock is fossiliferous, or where absolute continuity with fossiliferous 

localities, uninterrupted by faults, could be proved, geological mapping 

would be impossible. In California great use can be made of resemblances. Thus the Tejon strata of -New Idria are mostly heavy bedded 

sandstones of a peculiarly light color, which there distinguishes them 

from the tawny Chico sandstones. Both are fossiliferous there as 

also near Mount Diablo, where, at a distance of 125 miles from New 

Idria, they preserve the same external characteristics. Similarly, the 

Knoxville beds of Knoxville and Mount Diablo are externally indistinguishable and, in their typical development, even when unaltered, very 

different from most of the later rocks.

Excepting the peculiar limestones of the Gavilan Eange, there is no 

occurrence known in the Coast Eanges which suggests the presence of 

beds older than the Knoxville. Such may nevertheless be included in 

the metamorphic series, and may have undergone upheaval and metamorphisin at the same date. There is also a possibility that older rocks 

not only exist, but were metamorphosed before the deposition of the 

Knoxville, so that the metamorphic areas in contact with the Wallala 

beds on the coast and with the Chico'strata at New Idria may conceivably be earlier than the Knoxville. Even this supposition, which, in the 

absence of any evidence tending to it, seems rather far-fetched, would 

have no effect on the conclusions drawn in this paper, unless it could 

be maintained, not only that such was'the case, but also that the violent 

upheaval and metamorphism which followed the Knoxville left the supposed older areas undisturbed. This would conflict with all analogy.

It is, perhaps, worth while to note that as a rule the character of the 

topography of the areas occupied by Shasta rocks differs widely from 

that of regions in which only the more recent beds are laid bare. In 

the metamorphic areas the valleys usually occupy anticlinals, though 

the erosion appears to have been partially controlled by the extent of 

the metamorphism.8 Such surfaces necessarily indicate extremely prolonged exposure. On the other hand, where the surface is occupied by 

rocks of the Chico or later groups, erosion has often approximately 

followed the bedding.

The foregoing facts and the necessary inferences from them appear 

to justify the statement that the silicified and serpentinized metamorphic rocks of the Coast Eanges include a portion of the Knoxville beds, 

and do not include any portion of the Chico or of the Wallala series, 

while if there were pre-Knoxville rocks within the metamorphic areas 

they must have undergone at least a fresh disturbance at the time when 

the Knoxville beds were broken up and metamorphosed.

NONCONFORMITY BETWEEN THE KNOXVILLE BEDS AND THE 

CHICO. Had the proof of this nonconformity been a simple matter, it 

could not have escaped attention of some one of the several able geol-

*Cf. Dana's Manual, p. 750. 

(202)
BECKER.] NON-CONFORMITY BELOW THE CHICO. 13

ogists wl*o have done more or less work in the Coast Eanges. The 

difficulty is in part due to the rarity of fossils in the older groups over 

a great portion of the area in question, which often leaves the observer 

without absolute proof of the age of the rocks about him; but the main 

obstacle arises from the complexity of structure. Few geological phenomena are more striking than a nonconformity where the overlying 

strata are nearly horizontal, the underlying rocks greatly inclined and 

the exposure tolerable. This combination is rare in the Coast Eanges, 

and no such case is known where the Shasta and Chico beds meet. 

The post-Miocene uplift traced by Professor Whitney has folded, faulted, 

and broken the later Cretaceous and the Tertiary rocks as well as 

the earlier strata upon which they were unconformably deposited, so 

that it is usually far from easy to make out the effects ascribable to 

the earlier and later disturbances respectively, and still more difficult 

to prove that no explanation except that of a nonconformity before the 

Chico will account for the facts. I believe that the structural evidence 

to-be presented amounts to a demonstration of this nonconformity, but 

even after having delayed publication for a considerable time in order 

to secure more data, the proof, though convincing, is less abundant 

than I could wish it. The paleontological argument for this nonconformity is a very strong one, as will be seen from Dr. White's paper, 

but I had detected the gap before he joined me and while in ignorance 

that an'hiatus existed in the succession of organic forms. The evidence 

will, therefore, be presented here chiefly from a purely structural standpoint.

In the neighborhood of the New Idria mine the nietamorphic rocks 

have been greatly disturbed, while the Chico strata though tilted at a 

high angle are remarkably regular. Owing to the steepness of the contact, however, I was unable to find any exposures showing both series 

together from, which thoroughly satisfactory inferences could be drawn 

as to the relations of the underlying and overlying rocks. I therefore 

resorted to a study of the exposures of each separately, for which the 

region offers unusual facilities. It was found possible to follow single 

strata of the Chico uninterruptedly for a large part of a mile, and in 

favorable cases to recover the croppiugs with substantial certainty after 

passing intervals -covered with detritus, by the aid of lithological peculiarities combined with topographical indications and the strikes observed at the exposures.9 The contact with the nietamorphic rocks 

was also laid down and a great number of dips were observed in the 

nietamorphic area. In order to eliminate the irregularities clue to the 

varied topography of the lines of croppiugs, and the contact as laid 

down on the map, each line of croppings was reduced to its intersection 

with a plane of the mean altitude of these croppings, following the in9 This -would have been excessively difficult, if not impossible, but for the aid afforded by an almost ideally good contour map on a scale of 800 feet to the inch prepared for me by Mr. J. D. Hoffrnann.

(203)
14 STRATIGRAPHY OF CALIFORNIA. [BULL. 19.

dication of the local dips. The results showed that the Chico strata 

are parallel in strike and thrown into extremely gentle undulations, 

while the rnetainorphic area is a mere shattered mass. The contact has 

approximately the same general direction as the Chico beds, but does 

not entirely coincide with their strike. It is a rough line, but not 

rougher than one which would represent the vertical section of an ordinary sea-bottom near the coast. The dip of the Chico strata decreases as the distance from the contact increases.

This structure either represents a nonconformity or else the metaraorphism and accompanying disturbances occurred after the,deposition 

of the Chico beds but ended sharply at a certain line. It might at first 

sight seem impossible that an area several miles in width should be 

crumpled, broken quite as thoroughly as a representative area of the 

Archaean along the eastern coast, and further for the most part converted into serpentine and chert, but that both mechaniqal and chemical action should cease abruptly at a given line. Nevertheless instances 

 of which the above might pass for a description actually occur and are 

perhaps more frequent in the Coast Ranges than elsewhere. All 

geologists who have visited this region are aware of the very irregular, 

distribution of the metamorphic areas and it has already been pointed 

out that, for example at Knoxville and at Mount Diablo, the metamorphic passes over into unaltered or very slightly altered Knoxville beds 

suddenly, though under circumstances which preclude the supposition 

that the adjoining areas represent different formations. There are, 

however, significant differences between these occurrences and the conditions at New Idria. The Jimits of metamorphism in areas consisting of 

Knoxville beds, however sharp they may be, are'exceedingly irregular, 

the outline being substantially independent of stratification, cutting 

strata more often than following them, and presenting all sorts of convolutions. There are almost invariably also outlying areas of metamorphic 

rock and included masses of unaltered rock. Furthermore at least here 

and there are distinct transitions between unaltered and metamorphic 

rock. At New Idria, on the other hand, a section of the contact normal 

to the surface extends over at least several miles (as far as it was followed ) in a tolerably straight line. There are no outlying patches of 

metamorphic rocks; the included masses of comparatively unaltered 

rock seem wholly different from the Chico strata above them and, though 

there is a considerable alteration of a portion of the overlying mass, 

this alteration is not of the same character as the magnesian and silicious metamorphism of the underlying rock; nor could I find any distinct case of transition. Finally, in the Chico conglomerates a part o, 

the pebbles seem entirely to resemble the silicified or jaspery portions of 

the present metamorphic area while a few appear both macroscopicallj 

and microscopically identical with the serpentinized rocks of Knoxvill^ 

age.

(204)
BECKER.] . NON-CONFORMITY AT NEW IDUIA. 15

Some farther evidence of the relation of the two series was found a 

few miles to the southeast of New Idria, where a branch of Cautua 

Creek cuts through a portion of the range. Here the heavy-bedded, 

tawny Chico sandstones, lying at an angle of about 45°, cap the hills 

which are intersected by the brook, while in the bed of the stream the 

thin-bedded metamorphic strata stand vertically. No actual contact, 

however, could be found, the interval being covered with detritus.

There seems no reasonable explanation of the structure at and near 

New Idria, except by the existence of a non-conformity. Though the 

evidence may seem less satisfactory than that which would be presented by an ideal exposure, it is derived from the correlation of the 

structural evidence along the contact for miles, and in this respect is 

superior to any but the very best local exposures of unconformable 

contacts; for every geologist must have observed cases where unconformable exposures were closely simulated by local faults. Could it 

be proved that the underlying mass is of greater age than the Kuoxville the evidence would nevertheless indicate a non-conformity between 

the Chico and the Kuoxville, unless it could be shown that the convulsion which has so marvelously crushed the Knoxville beds, at least from. 

Clear Lake to the neighborhood of New Almaden, was uufelt at New 

Idria, while the comparatively gentle post-Miocene upheaval certainly 

extended throughout the Coast Ranges of California and Oregon.

Mount Diablo and the surrounding country consist of a core of metamorphic rock inclosed nearly or quite quaquaversally by rock of Chico 

and Tertiary age. The core is highly contorted, and for the most part is 

in an extremely metamorphosed condition, though here and there it is 

comparatively fresh, and in some cases contains Aticella and associated 

fossils. The overlying Chico, Tejon, and Miocene strata are tilted, but 

otherwise comparatively undisturbed. Over wide areas these three 

series seem to be perfectly conformable, nor is there any case known on 

the Pacific coast where there seems any ground for suspecting a nonconformity within these limits. Mr! H. W. Turner, my assistant, spent 

several days in this region, collecting fossils from various beds and 

searching for some exposure in which the relations of the Kuoxville 

beds and the Chico could be well made out. The result was negative, 

no exposure being detected from which a non-conformity could be estab. 

lished beyond a question. On the other hand, the structure is much 

more easily accounted for by supposing a non-conformity to exist than 

by assuming conformity. The upturned edges of the more recent strata 

form long, smooth curves enveloping the plicated and metamorphosed 

core, and nowhere was there any inetamorphism in the strata identified 

as Chico. The pebbles of the Chico conglomerates were metamorphic, 

but entirely silicious, and neither distinctly the same as the core of the 

mountain nor essentially different.

From about a mile south of Fort Boss northward for an unknown 

distance the sea-coast of California is formed by a terrace separated from.

(205)
16 STEATIGEAPHY OF CALIFORNIA. |BULL. 19.

the beach by cliffs.10 The rock exposed on these cliffs arid at croppings 

on the terrace is composed of soft tawny sandstones, like those of the 

Chico, dark shales, and coarse conglomerates. The sandstone predominates. About a mile north of Wallala several fossils were found, and 

careful search at many points to the southward disclosed a few more 

from the same beds. These Dr. White regards as probably older than 

the Chico, but younger than the Knoxville group. At the chief fossil 

locality, near Wallala, the shells were found in part in sandstones and 

in part in the matrix of a conglomerate the pebbles of which are serpentine and other metamorphic rocks, (exactly similar to those of typical 

nietarnorphic areas of Knoxville and Mount Diablo) and granite. The 

metamorphic pebbles are considered as valid evidence that the metaniorphism and accompanying disturbances took place before these 

Wallala beds were deposited.

At the southern extremity of this terrace, below Fort Boss, there is 

a sharp contact between the Wallala beds and the metamorphic serpeutinized rock which extends from this point to below the Eussian Eiver, 

if not to the Golden Gate. Passing back into the hills, the Wallala 

beds are found capping the first range of elevations opposite portions 

of the shore which are composed of the metamorphic rocks. 1 believe 

no one could examine this locality without being convinced that the 

Wallala beds rest unconforinably upon the metamorphic, nor could any 

one pass inland from the mouth of the Eussian Eiver to Kuoxville without feeling sure that the metamorphic is uniform in character and substantially continuous, though occasionally masked by eruptive rocks and 

possibly by a few patches of unaltered strata.

There is furthermore much indirect structural evidence that a nonconformity must exist between the Kuoxville beds and the Chico. The 

exposures at Mount Diablo show that there, at least, no deposits were 

formed between the Knoxville and the Chico. . Were the fauna of the 

Wallala beds more decisive as to age, it might therefore at once be maintained that during the Wallalti period the Knoxville beds of Mount Diablo must have been above water. But this argument is not necessary. 

Upon the Chico lies the Tejou (I omit the Martinez u as a mere subdivision), and next follows the Miocene. The stratigraphical relations, as

10 This terrace appears to ine beyond question a raised beach. A careful comparison 

of its topography with that of the beaches more or less exposed at low tide showed 

a correspondence in character seemingly perfect. Still better evidence was the discovery of rock in place on the terrace at two points separated by several miles, in 

which were unmistakable Pholas borings indistinguishable from those frequent at the 

present water-level. Some of them were filled with hardened earth which had preserved their interior surfaces perfectly smooth. One locality was by estimation about 

100 feet above tide water, the other more than double this elevation. As is well 

known, there have been differences of opinion as to the character of the terraces on 

the California coast.

11 This name has crept into geological literature under the entirely incorrect form 

Martinez.

(200)
BROKER.] NON-CONFOBM1TIES AT VARIOUS LOCALITIES. 17

well as organic forms, show a continuous sedimentation and a continuity of life between the Chico and Tejon. Between the Tejon and Miocene there is nowhere any suggestion of a non-conformity. 12 Near New 

Idria and ut Mount Diablo, for example, the Miocene seems as strictly 

conformable with the Tejon as this with the Chico. So, too, along the 

flank of the Sierra Nevada, both Chico and Miocene remain almost perfectly horizontal.' There is, in fact, evidence that the country was sinking at the period of time which separates the two eras. Had there been 

a great upheaval, accompanied by intense inetamorphism, between the 

Tejon and the Miocene, it seems impossible not only that no trace of a nonconformity between these beds should have-been detected, but also that 

no Chico or Tejon strata should have been found metamorphosed. But 

somewhere between the end of the Knoxville and the beginning of the 

Miocene there was a great upheaval, accompanied by silicious and magnesiau metamorphism and followed by enormous erosion; for at ninny 

points the unaltered Miocene rests un conform ably upon the metamorphic rocks. This I have observed on San Bartolo Creek and in the valley of the Sati Benito, to which the other is tributary. Professor Whituey found the Miocene resting uuconformably upon the metamorphic between the G-uadalupe Mine and Forbes's Mill, also near McCartysville, 13 

as well as north of the Golden Gate; 14 for instance, near Tomales, 15 

while, in speaking of the neighborhood of Suscol, he says 16 "it is probable that the most extensive disturbances of the Cretaceous, as also the 

larger portion of the metamorphic action upon it, had taken place before the Tertiary marine and volcanic beds were deposited."

There being nothing whatever to indicate any upheaval between the 

Tejon and the Miocene, this indirect evidence alone is sufficient to establish the fact of a non-conformity between the close of the Knoxville 

and the beginning of the Chico. Add to this the direct evidence at New 

Idria and Fort Boss, and to this again the paleontological evidence of 

an hiatus in the organic succession, probably amounting to the entire 

period represented by the sum of all the Cretaceous rocks of the country east of the Rocky Mountains, and it appears to me that the conclusion is irresistible. The precise time at which the Kuoxville strata 

were upheaved and metamorphosed cannot be determined from any 

known facts. It must have been long before the first of the Wallala 

beds were deposited, and still longer before the opening of the Chico period. In the absence of any strata intermediate in age between the 

Knoxville and the Wallala beds it seems more probable that the upheaval took place soon after the close of the Knoxville period than at 

a later date or neither long before nor long after the Neocomian.

12 Professor Whitney (Aur. Grav., p. 26) writes: " The Miocene and the Cretaceous 

seem everywhere to be conformable with each other." The Cretaceous here referred 

to is, of course, the Tojon.

13 Geol. Cal., 1, p. 69. '< Id., p. 79. « Id.-, p. 83. >« Id., p. 103.

Bull. 19 2 (207)
18 STEATIGRAPHY OF CALIFORNIA. [BULL. 19.

IDENTITY OF THE MARIPOSA AND KNOXVILLE BEDS. The gold belt 

of California, as hitherto traced out by miners and geologists, is an area 

of peculiar form. From Mariposa County to Nevada City, in Nevada 

county, a distance of about 150 miles, the belt is a strip of country 

nearly parallel to the crest of the Sierra, and about 30 miles in width. 

To the northward of Nevada City it rapidly widens, becoming at the 

same time less well defined. To the north it is finally terminated by 

extensive lava fields, while towards the northwest the country gradually 

loses its auriferous character as the coast is approached. Within the 

gold-bearing regijon three fossiliferous areas are known to exist. From 

the McCloud Eiver to Pence's Eanch extends a belt of highly inetamorphic limestone containing Carboniferous fossils. At Genesee Valley the State survey found fossils regarded as Triassic. Both of these 

localities are far removed from the narrow strip of country lying along 

the foot-hills from Mariposa to Nevada, and which is often known as 

the gold belt proper. In this narrow portion of the auriferous area, 

though the rocks are for the most part highly metamorphosed, a number 

of fossils have been found belonging to Aucella, Belemnites, etc., which 

are discussed in Dr. White's paper. Meek first described these fossils 17 

and ascribed them to the Jurassic chiefly on the ground that Aucella 

"is, so far as is known, entirely confined to the Jurassic rocks."

Previous to the discovery of fossils on the Mariposa estate in the 

series which I shall call the Mariposa beds, Professor Whitney and his 

associates had collected in the Coast Ranges Belemnites, a shell determined as Inoceramus Piocliii, and some others from the strata which I 

have entitled the Knoxville beds in this paper. Mr. Gabb described 

them as Cretaceous forms. 18 Some years after Mr. Meek had referred the 

Mariposabeds to the Jurassic, Mr. Gabb redescribed Inoceramus Piocliii as 

Aucella Piochii a change of genus which I understand to be unquestionably correct. This correction would seem to have been of evident importance to the stratigraphy of the State, for through it the fauna of a 

large part of the known rocks supposed to belong to the Shasta group 

of the Cretaceous acquired the strongest resemblance to that of the 

Jurassic of Mariposa County. Indeed there seems scarcely room left 

for a distinction; if Aucella, is distinctively Jurassic, the Aucella-lw&ring beds of the Coast Ranges must be members of that system, while 

if these Aucella beds are Cretaceous, Aucella is not a distinctively Jurassic genus even in the State of California, and Mr. Meek's principal 

reason for assigning the Mariposa beds to the Jurassic loses its validity.20 Professor whitney states that while the Mesozoic age of the

17 Geol. Cal.,Vol.I, p. 477. 

«Pal. Cal., Vol. J.

19 Pal. Cal., Vol. II.

20 This argument first suggested itself to me on a preliminary visit to Knoxville, 

two years since. From an inquiry on the subject addressed to Dr. White through 

one of our colleagues, eventually resulted his visit to this coast.

(208)
BECKEB.J KNOXVILLE AND M4RIPOSA BEDS IDE^7TICAL. 19

Mariposa beds is proved by their fossils the pre-Cretaceous age of these 

strata is demonstrated from their stratigraphical relations. Professor 

Whitney has indeed shown that Cretaceous strata rest unconformably 21 

upon (he upturned edges of the auriferous slates along the foot-hills of 

the Sierra at several points; but I find no record of any such bed so low 

as the Knoxville group.22 All the fossils recorded in this position are 

Chico. This does not indeed preclude the possibility that the Mariposa 

beds are Jurassic, and the Aucella beds.of the Coast Eanges Cretaceous, 

for the former might have been above water during the Shasta epoch. 

But were Cretaceous strata containing the so-called Aucella Piochii to 

be found resting in a nearly horizontal position upon the Mariposa beds, 

it would prove not only that the genus had persisted from Jurassic into 

Cretaceous times, but that in essentially the same locality the genus was 

represented immediately after a great and wide-spread upheaval by a 

species nearly or quite indistinguishable from one which had inhabited 

it prior to this convulsion and the attendant metamorphism. Zoologists 

would probably think such a survival very strange if it could be proved, 

and very improbable unless the proof were ample.

On the other hand, if the Mariposa beds are considered as equivalent 

to the Knoxville beds of the Coast Eanges, the non-conformity between 

the Chico beds and those of Mariposa is the same which has been traced 

in j:he preceding pages as existiug in the Coast Eanges. Dr. White, 

after examination of Meek's tvpes and new and better specimens which 

we collected together, is unable to draw any specific distinction between 

the Aucella of the Mariposa beds, and that of the Knoxville beds. Were 

it otherwise the upheaval and metamorphism of the two series would 

still be referable to nearly the same period, and would be presumptively 

simultaneous.

The lithological resemblance of the rocks of the Mariposa estate to 

those of many portions of the metamorphic rocks of Knoxville age is 

very strong. There is a similar prevalence of thin-bedded strata which 

silicih'cation and serpentinizatiou are equally the predominant characteristics. Plication and fracture are less noticeable than in the Coast 

Eauges. One geologist has maintained that the fossiliferous rocks of 

this locality did not form an integral portion of the auriferous series. 

Neither Dr. White nor I was able to see any ground for this assertion. 

The fossiliferous rocks are metamorphic like the whole series; they 

have the same dip and strike; they are unquestionably auriferous, gold

21 1 am perfectly satisfied of the existence of this non-conformity, though the localities where the Chico beds have been found resting on the upturned edges of the auriferous slates are not near those in which Meso/oic fossils have been found in the 

older rocks. The Chico beds, where they occur along the foot-hills, have suffered little 

if at all from the post-Miocene uplift in the Coast Ranges and are nearly horizontal. 

The Mariposa beds are almost vertical.

22 The shell from Tuscan Springs recorded, Geol. Cal., Vol. I, p. 207, as Ivocrramus 

PiocUii, is redetermined as a Alylilus iu Pal. Cal., Vol. II, p. 191.

(209) .
20 STRATIGRAPHY OF, CALIFORNIA. [BULL. 19.

quartz veins occurring between fossil-bearing strata and not simply 

near them. In short we could see no means of separating the strata 

Containing shells from the remainder of the immense thickness of similar and apparently conformable slates.

KELATION OF THE CASCADES TO THE SIERRA AND THE COAST 

EANG-ES OF CALIFORNIA. It seemed highly desirable to institute some 

slight comparison between the California ranges and the Cascades. For 

this purpose we visited EoseburgfcOregou,and made several trips into the 

mountains. These are evidently underlain by granite, which forms a 

great portion of the stream pebbles, though we met none of this rock 

in place. In a great number of localities we found upturned, crumpled, 

silicified, and metamorphosed rocks exactly similar to those of Mount 

Diablo, but our search for Aucella was not rewarded. Upon the inetamorphic rocks lie non-conformably somewhat tilted unaltered sandstones. These are certainly Miocene, for though we found no fossils 

ourselves, Dr. White examined extensive collections of Miocene shells 

in entirely similar rock collected by the Eev. Thomas Coudou, who gave 

us full information as to their occurrence in precisely similar positions 

but somewhat north of Eoseburg. Overlying the sandstones are large 

areas of volcanic rocks.23

In the section made by the Columbia Eiver no metamorphic rock or 

granite appears, but at least the southern portion of the range h^s a 

foundation similar to that of the California ranges and probably due to 

the same upheaval. Dr. White points out that since Chico fossils occur 

to the east of the Cascades the site of the Cascades was at least in part 

covered by the western sea. This, however, is no objection to the proposition just made, for the interior of Oregon may have been a gulf similar to the present Gulf of California.

OTHER MESOZOIC BEDS. The Horsetown beds, as it seems convenient to call the group which occurs near Cottonwood Creek, Shasta 

County, so far as known are confined to that locality, and their relation to the Knoxville series is unknown. The solution is very probably 

to be found in the eastern Coast Eanges in Tehama County, but this 

region is not known to have been geologically explored, and it probably will not be examined until a special study of the Coast Eanges as a 

whole is undertaken. The Horsetown beds are somewhat altered, but 

at the points visited by Dr. White and myself do not show the characteristic serpeutiuization and silieificatiou of the metamorphosed Kuoxville beds. It cannot by any means be asserted definitely, however, 

that they were not involved in- the upheaval and inetainorphism which 

took place after the Kuoxville and before the Wallala period, because 

much of the Knoxville series is also little altered. On the other hand,

23 l;i ati answer to an inquiry, Prof. Joseph Le Conte states that histfemarks concerning the lower portion of the Cascade range in the Am. Jour, of Science, 3d s., Vol. 

VII, p. 177, were not from personal observation. He there suggested that the Cascades were a continuation of the Sierra.

(210)
DECKER, j OTHER FOSSILIFEROUS STRATA. 21

the Horsetown beds rest unconforrnably upon the auriferous slates of 

that region, which are of unknown age, though apparently continuous 

with the Carboniferous of Pence's Kanch. Professor Whitney detected 

this nonconformity, though expressing the result in somewhat guarded 

terms.24 The mining operations which have since been prosecuted have 

so exposed the rocks as to leave no room for any possible difference of 

opinion. The slates upon which the Horsetown beds lie are somewhat 

peculiar, and differ physically from those of the Mariposa beds, showing a very thin cleavage and a peculiar silver-gray luster. They give 

to the eye an impression of great geological age.

Genesee Valley, in Plnrnas County, is the only known locality west 

of the crest of the Sierra at which Triassic fossils have been discovered. 

The fossiliferous rocks seem to belong to the Jura-Trias area of Nevada, 

and this reference is strengthened by topographical considerations, for 

though Genesee Valley lies to the westward of the highest crests of the 

Sierra in this latitude, it lies to the east of a lower range, which is more 

directly in the line of the general trend of the Sierra. This neighborhood is auriferous, but, as already explained, gold is disseminated 

through a very wide area north of Nevada County. Dr.'White and I 

did not visit Genesee Valley, its geographical position being such as 

not to conflict with any of our conclusions.

PALEOZOIC BOOKS OF CALIFORNIA. Dr. Trask long since showed 

that Carboniferous limestones make up the McCloud Range, which 

stretches along the McCloud River; and near Pence's Ranch, in Butte 

County, Professor Whitney's party found similar limestones also fossiliferous and clearly of the same age. Professor Whitney infers, on 

lithological grounds, that the more westerly limestones of the gold belt 

further south may also be Carboniferous.

Near Baird post-office, on the McCloud River, a considerable area of 

granite occurs about half a mile west of the fossiliferous limestone. The 

interval is occupied by extremely metamorphosed sandstones, in which 

my party failed to find any trace of fossils. These sandstones underlie 

the limestone, and are probably older, but there is no evidence to show 

whether they belong to the Carboniferous or to some preceding formation. To the northwest of Baird thin-bedded, plicated, metarnorphic 

shales occur, bearing a strong resemblance to those of theKnoxville 

series in central California. Their structure and position are such as to 

suggest nonconformity with the Carboniferous, but, owing to the difficulties of traversing the country, we were unable to test this relation 

satisfactorily in a hasty visit to the neighborhood. Not a trace of a 

fossil could be found even in the least altered portions of the shales, 

and their age is therefore entirely uncertain, the lithological resemblance 

to the Knoxville group amounting to a mere suggestion at such a distance from well-ascertained members of that series.

24 Gcol. of Cal., Vol. I, p. 321. 

(211)
22 STRATIGRAPHY OF CALIFORNIA. [BULL. 19.

Near Pence's Eanch the shales are auriferous as well as certainly Carboniferous, at least in part. They also come in contact with Chico beds, 

which lie horizontally upon their upturned edges. The slates have a , considerable similarity to those of the Mariposa group, and furthermore they are nearly vertical and strike in nearly the same direction as 

those of the gold belt proper. The question therefore at once arises 

whether their upheaval and metamorphism is ascribable to the same 

period as the uplift and alteration of the Mariposa and Knoxville beds. 

This is a subject which can be discussed only tentatively until a great 

amount of detailed work has been done in a somewhat unpromising 

field; but it is not too early to make some suggestions.

I think it may be asserted, as a result of all the geological work done 

from the Eocky Mountains to the Pacific, that there has been throughout geological time a definite tendency in the structural development of 

this area. The geologists of the fortieth parallel exploration showed that 

a fault began upon the west flank of the Wahsatch in the Archaean, the 

same fault which Mr. Gilbert has traced as still in progress! The lastnamed geologist has also detected a similar fracture on the east side of 

the lower portion of the Sierra. The eastern portion of the Great Basin 

was lifted above the surface of the ocean after the close of the Carboniferous, the western portion of the same area followed before the Cretaceous, and at one or both of these epochs the country was laterally 

compressed, an action no doubt closely connected with the progress of 

the great faults. About the time of the Neocomian, California experienced an east and west compression, and again following the Miocene 

was an uplift throwing the horizontal strata of the coast into north and 

south folds. From the Wahsatch to the Pacific Coast there thus appears to have been a recurrent, if not a constant tendency to lateral 

compression, in substantially one and the same direction. Now Dr. 

White points out that an extraordinary difference has existed between 

the marine fauna of the Pacific Coast and that of the waters east of the 

Sierra from a time prior to the Cretaceous onward, and hence that a 

land barrier must throughout have occupied substantially the position 

of the Sierra Nevada, which must therefore have experienced repeated 

upheavals to compensate for constant erosion. There are also said to 

be some paleontological grounds for supposing at least a partial separation of these areas during the Carboniferous. This supposition is in 

entire accord not only with the structural analogies of the region but 

with the detailed observations of Mr. Clarence King 25 and his colleagues, who were led to infer the existence of a continental area during 

the Paleozoic west of long. 117030', lat. 40°. Such a range as the 

Sierra, though partaking in the general compression and movement of 

the whole country, must offer a tremendous resistance, and at any one 

of the active periods during which the physical conditions permitted

26 Systematic Geology, p. 534. 

(212)
BBCKKB.I PALEOZOIC BEDS. 23

contortion of strata along the western flank of the Sierra, these must 

have been driven against the barrier until they could yield no more. 

Thus if a pile of cloths were compressed from their edges (as in Hall's 

famous experiment) with enormous energy, they would be forced into 

plications so sharp that the dip at any point would be nearly vertical. 

It seems to follow that at different upheavals, some of them perhaps as 

yet untraced, strata to the west of the great Sierra may have been 

driven into the nearly vertical position of the gold slates and their 

original stratigraphical relations completely obscured. I do not consider it certain, therefore, or even probable that the Carboniferous slates 

near Pence's Eatich first assumed their present position subsequently 

to the Knoxville period. It may be that they have stood nearly as now 

ever since the Carboniferous of Utah was raised above water, while the 

slates of Horsetown, of the age of which nothing is known, so far as I 

can see, may possibly owe their vertical dip to still earlier convulsions.

The Carboniferous slates of Pence's Kanch are serpentmoid, and, 

though distinctions between them and the metamorphosed Knoxville 

beds might perhaps be drawn, they are very similar. But just as it 

seems to me that successive upheavals may have produced similar results, I think the association of a certain uplift with a particular series 

of chemical changes in an argument for the supposition that analogous 

dynamical conditions might lead to molecular changes of the same kind. 

It seems therefore not at all impossible that both upheaval and metamorphism at Pence's Eanch were in the main earlier phenomena than 

those traced in the Coast Eanges. If so, their effect must have been 

felt throughout a great portion of California, though the results may 

have long since been obliterated. On the other hand, the post-Knoxville disturbance must have been felt at Pence's Eauch, though its effects 

may have been trifling as compared with those of earlier convulsions.

THE COAST EANGES MEMBERS OF THE WESTERN CORDILLERA 

SYSTEM. As has already been stated, I am unable to see any reason for 

dissenting from Professor Whitney's opinion that the fossiliferous beds 

of Mariposa form an integral portion of the modern Sierra Nevada Eange. 

It seems simply impossible that they should have assumed their present vertical position with a strike parallel to the crest, and that they 

should have been profoundly modified by chemical action except under 

conditions of disturbance amply sufficient to have brought about essential modifications of the whole range. That there were at the time, or 

at least had been previously, mountains in nearly the same position does 

not impair the claim of this addition to be considered as much a part of 

the modern Sierra as any older portion. If the conclusions thus far stated 

are accepted, it follows at once that subsequent to the close of the Knoxville, but long before the beginning of the Chico, both the Sierra and 

the Coast Eanges experienced an upheaval. This was in all probability 

not the first in the line of the Sierra and very possibly did not actually 

originate the Coast Eanges, but for the latter it is the first distinctly

- (213)
24 STRATIGRAPHY OF CALIFORNIA. [BULL. 19.

traceable movement. It is conceivable that within the limits of time 

indicated two upheavals should have taken place, one affecting only the 

Sierra, the other only the Coast Eanges; but the probability of this alternative will scarcely be seriously maintained. The earlier determinable portion of the Coast Eanges must therefore be considered as due 

to the same disturbance which added the gold belt proper to the Sierra 

Nevada. There is much probability that a portion at least of the Cascade Eange was elevated and metamorphosed at the same time. The 

relationship thus established is brought out more clearly by a comparison of the history of the ranges so far as it can be traced.

Both the Sierra Nevada and the Coast Eanges were above water and 

underwent erosion during the interval between the Knoxville and the 

Chico epochs. Both ranges also sank just before the beginning of the 

Chico, admitting the ocean over a great part of the Coast Eanges and over 

considerable areas at the base of the Sierra. Both appear to have risen 

partially before the Tejon, particularly toward the north; at least, the 

rocks of this epoch, so far as is known, are confined to the southern extremity of the Sierra and to the Coast Eanges south of Martiuez. A subsidence would appear to have taken place before the Miocene; rocks of this 

age extending along the Sierra far to the north of the Tejon localities, 

while in the Coast Eanges they lie directly upon the metamorphic at a 

great number of points, clearly indicating a lower general level than 

during the preceding epoch. During the Pliocene very little of either 

range was below water.

Not only was an important uplift of the Sierra Nevada contemporaneous with the first known upheaval of the Coast Eange, but, even with 

the imperfect information at command, it is clear that the successive 

fluctuations of level of the country, since the close of this disturbance 

have affected these ranges substantially in the same manner, and I cannot bat conclude, that the new facts brought forward necessitate the 

reference of the Sierra Nevada and the Coast Eanges to a single mountain system. The Coast Eanges are, and probably always have been, 

of less altitude than the great Sierra, and they have consequently been 

more extensively immersed, just as would be the case if both were now 

to sink any given number of thousand feet. Between the Miocene and 

Pliocene periods the Coast Eanges also suffered disturbances, in which 

at least the western base of the Sierra seemed not to have shared. The 

Sierra, too, has undergone some faulting in which neither the Coast 

Eanges nor the Basin Eanges have shared; but these differences do not 

appear to me sufficient to counterbalance the important coincidences in 

the history of the ranges.

In portions of the Cascades the Miocene rests directly upon the metamorphic as it so often does in the California Coast Eanges, but to the 

east of the Cascades Chico beds occur, showing that the range was at 

least broken through at certain points. I greatly incline to the belief,

(214)
SKCKKR.] CONCLUSIONS. ' 25

however, that this range is structurally one of the northern continuations of the united Coast Eanges and Sierra Nevada, though but a portion of it may have emerged from the sea at the same time as the more 

southern ranges. The great valley of California was evidently covered 

by water in comparatively recent times, as eastern Oregon was in the 

Chico, and as the Gulf of California is now. Dr. White points out that 

the occurrence of fossils of the eastern zoological province west of the 

Sierra Madre, shows that the peninsula of California was at one time the 

line of the barrier between the eastern and western seas. This appears 

to me conclusive, and yet there is much remaining to be settled as to the 

relations between the Sierra and the ranges from Arizona southward. 

They may still turn out to belong to a single system, though at some 

time the eastern members of the chain may have been broken sufficiently to admit the ocean while the western ranges were intact, just 

the reverse of the present condition.

The views taken in the foregoing pages have a perhaps not inconsiderable advantage in more closely harmonizing the topography and geology of the west coast. Any good topographical map of the Western 

United States seems to indicate some such structural relations as those 

which have been presented here from a geological point of view. Or 

conversely, if the conclusions reached are accepted, it appears that 

just as comparatively small fissures, such as are met in mines, are 

almost never simple, but branch or divide and meet again while following one dominant course, so the great lines of disturbance which 

have determined the geographical features of a large portion of the 

country unite, divide, and throw out shoots with an irregularity in detail underlying which a dominant tendency is clearly perceptible. I do 

not believe that such a system could have come into existence.piecemeal, but rather that all its main outlines originated, like the great 

Wahsatch fault, long before the earliest of our fossiliferous strata.

SAN FRANCISCO, CALIFORNIA, February. 1885.

(215)

INDEX.

Psge.

Aucella, occurrence at various localities in the Coast Ranges .................. 9

occurrence on the gold-belt ......................................... 18

Piocfcii of Gabb..................................................... 18

Alcatraz Island, Inoceramus found at............................ ..'........ 10

Baird post-office, Carboniferous near ........................................ 21

Cantua Creek, Exposures at............... .................................. 15

Carboniferous on McCloud Eiver .................................... ..... 21

at Pence's Ranch ............................................. 21

Cascades, Relation of, to the Sierra Nevada and the Coast Ranges . . 20

Chico andTejon conformable............................................. 17

conglom erates contain metamorphio pebbles.......... .............. 14

fossils east of the Cascades ............................................ 20

Coast Ranges members of the Cordillera system.............................. 23

Condon, Prof. Thomas, Information furnished by ............................ 20

Fort Ross, Exposures and non-conformity at................................. 15

Gabb W. M., redetermination of Inoceramu8 Ptochii. .......... .......... *.. 18

Gavilan Range, Crystalline limestone of....................................... 11

Genesee Valley, Trias of..................................................... 21

Gold-belt, Geographical position of .......................................... 18

Gualala. (See Wallala.)

Hoffmann, Mr. J. D., Map by ............................................... 13

Horsetown beds unconformable on auriferous slates.......................... 21

Inoceramus found at Alcatraz Island ......................................... 10

Piochii. .......................................................... 18,19

Jurassic, supposed, on the Mariposa estate................................... 18

King, Mr. Clarence, on limits of Paleozoic ocean.............................. 22

Knoxville and Mariposa beds, Identity of.................................... 18

group, why so named..................................... .... 9

Opportunities for study at .............. _....................... 8

Lithological characteristics of some groups of b eds........................... 12

resemblances, applicability in mapping ...... ................... 11

Manzanita mine, Age of metamorphics at.................................... 9

Mariposa and Knoxville beds, Identity of........................... ...... 18

Mariposa beds actually a portion of the auriferous series............ _....... 19

beds, determination as Jurassic by Meek ........................... 18

Martinez, Orthography of ................................................... 16

Meek,Prof. F. B., determined Mariposa beds................................. 18

Metamorphic limestone in Gavilan Range.................................... 11

pebbles in Chico conglomerates ................................ 14

rocks, Age of at Knoxville, Sulphur Creek, and Mount Diablo... 9

Metamorphism in the Coast Ranges.......................................... 7

Date of .................................. 12

in the Sierra Navada......................................... 11

of Knoxville beds, Probable date of .......................... 17

Miocene at Monterey..................... ................. 8

at the Arroyo de la Penitencia................................ 10

(217) 27
28 INDEX.

Page.

Miocene, Metamorphosed...........................,.. ................... 8,10

of Oregon......................................................... 20

unconformable upon metamorphics................................. 17

Mount Diablo, Age of metamorpliicsat....................................... 9

Structure of, best explained by non-conformity, . ........ 15

New Almaden, ducella near...... ............................................ 9

Non-conformity above Knoxville beds, Indirect evidence of.......... ....... 16

at New Idria................................................. 13

between Chico and Mariposabeds ............................ 19

between Knoxville and Chico beds............................ 12

paleontologicalevidence of.................................... 13

Paleozoic rocks of California ................................................ 21

Pence's Eanch, Carboniferous near...................................... .. 21

Plication by fracture ............................................_......... 8

Roseburg, Oreg., Metamorphics at........................................... 20

San Francisquito Pass, Metamorphic rock of.... ...1.............. ......... 10

Separation between Pacific and Great Basin provinces........................ 22

Serpentinization, Secondary nature of.................................. .*.... 8

Sierra Nevada and Coast Eanges, their history compared...................... 24

Silicification, Secondary..................................................... 8

Tejon and Chico conformable................................................ 17

Terraces along California coast,Origin of .................................... 16

Topography,Character of, inmetamorphicareas.................... ....... 12

Trias of Genesee Valley ..................................................... 21

Turner, Mr. H.W., Fossils found by........................................... 9

Wallala beds, Age of......................................................... 11

Wallala, Correct spelling of.................................................. 11

Wallala beds, Position of.................................................... 16

White, Dr. A. C., Joint investigation by the author and ....................... 7

on aucella .................................................. 19

on separation of Great Basin and Pacific provinces .......... 23

Whitney, Prof. J. D., on non-conformity between Miocene and metamorphic series 17

on Miocene metamorphics ............................... 10

on secondaiy nature of serpentine ....................... 8

(218) 28

N O TI C 1C.

The bulletins of the United States Geological Survey will be numbered in a continuous series and will be bound in volumes of convenient size. 

This bulletin will be included in Volume III.