Sedimentary and 

Igneous Rocks of the 

Grays River Quadrangle, 

Washington 

By EDWARD W. WOLFE and EDWIN H. McKEE 

GEOLOGICAL SURVEY BULLETIN 1335 

Prepared in cooperation with 

the State of Washington 

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1972 
UNITED STATES DEPARTMENT OF THE INTERIOR 

ROGERS C. B. MORTON, Secretary 

GEOLOGICAL SURVEY 

W. A. Radlinski, Acting Director 

Library of Congress catalo~t-card No. 74-180661 

For sale by the Superintendent of Documents, U.S. Govemment Printing Office 

Washington, D.C. 20402- Price 40 cents (paper cover) 

Stock Number 2401-1193 
CONTENTS 

Page 

Abstract -------------------------------------------------------- 1 

Introduction ----------------------------------------------------- 2 

Tertiary System ------------------------------------------------- 4 

Eocene Series ----------------------------------------------- 4 

Crescent Formation ------------------------------------- 4 

Lithology -------------------------------------------- 4 

Age and correlation --------------------------------- 7 

Paleogeologic setting -------------------------------- 10 

Unrt A ------------------------------------------------- 10 

Lithology -------------------------------------------- 10 

Age and correlation --------------------------------- 13 

Paleogeologic setting -------------------------------- 14 

Unrt B ------------------------------------------------- 15 

Lithology ----·--·------------------------------------- 15 

Siltstone ---·------------------------------------- 15 

Sandstone -------------------------------------- 16 

Volcanic roeks ---------------------------------- 18 

Age and correlation --------------------------------- 26 

Paleogeologic setting --------------------------------- 28 

Intrusive rocks ---·--------------------------------------- 29 

Lithology ----·--·------------------------------------- 29 

Age and geologic relations --------------------------- 30 

Eocene (?) to Miocene Series --------------------------------- 30 

Lincoln Creek Formation -------------------------------- 30 

Lithology ______ ------------------------------------- 32 

Siltstone -·--------------------------------------- 32 

Lower basaltic and glauconitic sandstone __________ 32 

Upper basaltic and glauconitic sandstone __________ 36 

Interlaminated sandstone and siltstone ------------ 36 

Age and correlation -·-------------------------------- 38 

Paleogeologic setting -------------------------------- 42 

Miocene Series ----------------------------------------------- 43 

Astoria Formation -------------------------------------- 43 

Lithology ------------------------------------------ 44 

Unit I ---·--------------------------------------- 44 

Unit II ------------------------------------------ 45 

Unit III -·--------------------------------------- 4 7 

Age and correlation ---------------------------------- 48 

Paleogeologic setting --------------------------------- 49 

Miocene to Pliocene ( ?) Series --------------------------------- 54 

Basalt flows and intrusive rocks -------------------------- 54 

III 
IV CONTENTS 

Page 

Tertiary System-continued 

Miocene to Pliocene ( ?) Series-continued 

Lithology ------------------------------------------- 54 

Extrusive and intrusive basalt of Three Tree Point 

type ---------------------------------------- 54 

Extrusive and intrusive basalt of Altoona type _____ 57 

Pack Sack type intrusive rocks ------------------- 59 

Age and correlation ---------------------------------- 64 

Paleogeologic setting --------------------------------- 65 

Quaternary deposits --------------------------------------------- 65 

Referencescited ------------------------------------------------- 66 

Index ---------------------------------------------------------- 69 

ILLUSTRATIONS 

Page 

FIGURE 1. Map of western Washington showing the location of the 

Grays River quadrangle ----------------------------- 3 

2. Photograph of pillow basalt in the Crescent Formation __ 5 

3. Photomicrograph of Crescent basalt -------------------- 6 

4. .Generalized geologic map of the Grays River quadrangle _ 8 

5. Photograph of rhythmically alternating sandstone and 

siltstone of unit A ---------------------------------- 11 

6. Diagram showing relative proportions of quartz, potassium feldspar, and plagioclase in unit A sandstone ____ 12 

7. Photomicrograph of unit B siltstone-------------------- 16 

8. Diagram showing relative proportions of quartz, potassium feldspar, and plagioclase in unit B sandstones ___ 18 

9. Photomicrograph of unit B subaerial basalt ------------- 19 

10. Photograph of well-bedded aquagene tuff of unit B ______ 20 

11. Photomicrograph of unit B aquagene tuff --------------- 20 

12. Graph showing chemical relationships among basaltic 

rocks of the Grays River area ----------------------- 23 

13. Photomicrograph of Lincoln Creek tuffaceous siltstone ___ 33 

14. Photomicrograph of lower basaltic sandstone of the Lincoln Creek Formation ------------------------------- 34 

15. Diagram showing the relative proportions of quartz, potassium feldspar, and plagioclase in Lincoln Creek Formation sandstones ---------------------------------- 35 

16. Diagram showing relative proportions of quartz, 

potassium feldspar, and plagioclase in the Astoria Formation -------------------------------------------- 45 

17. Photomicrograph of basalt of Three Tree Point _________ 55 

18. Silica variation diagrams-basalt flows and intrusive 

rocks ---------------------------------------------- 58 

19. Photomicrograph of basalt of Altoona type ------------- 60 

20. Photomicrograph of basalt of Pack Sack type ----------- 62 
CONTENTS v 

Page 

TABLE 1. Chemical analyses: and normative compositions of basalt of 

Crescent Formation and Siletz River Volcanics ________ _ 

2. Foraminifera from Crescent Formation ------------------ 9 

3. Foraminifera from unit A ------------------------------ 13 

4. Chemical analyseg and normative compositions of unit B 

basalt ---------------------------------------------- 22 

5. Foraminifera from unit B ------------------------------ 24 

6. Megafossils from unit B ------------------------------- 27 

7. Chemical analyses and normative compositions of Eocene 

intrusive rocks -------------------------------------- 31 

8. Foraminifera from Lincoln Creek Formation ------------- 38 

9. Megafossils from Lincoln Creek Formation -------------- 40 

10. Average compositions of Astoria Formation sandstones ___ 45 

11. Heavy-mineral composition of the Astoria Formation _____ :46 

12. Foraminifera from Astoria Formation ------------------- 50 

13. Megafossils from Astoria Formation -------------------- 52 

14. Chemical analyses and normative compositions of basalt of 

Three Tree Point type ------------------------------- 56 

15. Chemical analyses and normative compositions of basalt of 

Altoona type ----·------------------------------------ 61 

16. Chemical analyses and normative compositions of basalt of 

Pack Sack type ·--------------------------------------- 63 

SEDIMENTARY AND IGNEOUS ROCKS 

OF THE GRAYS RIVER QUADRANGLE, 

W1!\SHINGTON 

By EDWARD W. WOLFE and EDWIN H. McKEE 

ABSTRACT 

The Grays River quadrangle in southwestern Washington is underlain by 

a thick sequence of Eocene to Miocene or younger marine sedimentary rocks 

and basaltic lavas that are part of a eugeosynclinal accumulation in western 

Washington and the Oregon Coast Range. 

The oldest exposed rock unit, the Crescent Formation, consists mainly of 

tholeiitic pillow basalt of middle Eocene (Ulatisian) or possibly earliest late 

Eocene age (early Narizian). The basalt is chemically similar to the lower 

unit of the Siletz River Volcanics (lower and middle Eocene) of the Oregon 

Coast Range. 

Unit A, overlying and perhaps intertonguing with the Crescent Formation, consists of about 2,000 feet of siltstone with some rhythmically interbedded sandstone probably deposited by turbidity currents. Likely source 

rocks are metamorphic and volcanic rocks such as those exposed in northcentral Washington and adjacent British Columbia and Vancouver Island. 

Foraminifera indicate a late middle Eocene (late Ulatisian) or possibly 

earliest late Eocene age (early N arizian) . 

The next younger unit, B, comprises several thousand feet of marine tuffaceous siltstone, basaltic volcanic rocks, and a few beds of sandstone. Massive subaerial basalt flows, 2,000 feet thick or more, occur in the upper 

Grays River drainage area. In the Naselle River valley to the west, basaltic 

rocks of submarine origin interfinger with the tuffaceous siltstone. Foraminifera suggest a late Eocene age ( N arizian and early Refugian). The uppermost part of the unit (Refugian) may be correlative with the lower part of 

the Lincoln Creek Formation, as mapped elsewhere in western Washington. 

Unit B accumulated in an offshore marine setting. The Grays River area 

was a volcanic center in the late Eocene. 

Porphyritic basalt dikes, similar in lithology to unit B basalt, and larger 

bodies of diabase or gabbro intrude the Crescent Formation and units A and 

Bin the northern part of the quadrangle. A late Eocene age is inferred. 

The Lincoln Creek Formation, which overlies unit B, consists of two successive units of marine tuffaceous siltstone, each with a basal .zone of basaltic and glauconitic sandstone. Fossils indicate an open-sea, offshore, sublittoral to bathyal depositional setting. Prior to its submergence in early 

Oligocene time, a subaerial mass of pre-Oligocene rock provided the basaltic 

detritus which makes up the lower part of the formation in the eastern part 

of the area. Foraminifera indicate that the Lincoln Creek is of latest 

1 
2 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

Eocene ( ?) and Oligocene age (Refugian and Zemorrian). Mollusks are referable to the Oligocene "Lincoln Stage" and to the "Blakeley Stage" of late 

Oligocene and early Miocene age. 

The Astoria Formation (lower to middle Miocene) unconformably overlies 

the Lincoln Creek Formation. The predominant rock type (unit I), extensively exposed in the valleys of the Grays and Deep Rivers, is soft, argillaceous, carbonaceous, micaceous siltstone to very fine grained sandstone interpreted as an open-sea offshore facies. In the more eastern outcrops, the 

Astoria (unit II) consists of slightly coarser, more distinctly bedded, more 

fossiliferous strata with local accumulations of well-sorted crossbedded sandstone. These rocks are interpreted as a nearshore shallow-water facies. Interbedded sandstone and siltstone in the southwestern part of the Grays 

River quadrangle (unit III) may have accumulated in a deep-water, offshore 

setting. 

Miocene to Pliocene(?) basalt flows overlie the Astoria Formation, and related dikes and sills intrude the Astoria Formation and older rocks. The 

flows and intrusives include the three petrochemical types recognized by others elsewhere in western Oregon and Washington as similar to basalt of the 

Yakima, late Yakima, and Pomona types of the Columbia Plateau. 

INTRODUCTION 

The Grays River quadrangle is in southwestern Washington, 

approximately 20 miles upstream from the mouth of the Columbia River (fig. 1). Mild climate and heavy rainfall (approximately 115 inches per year at Naselle, about 3 miles west of the 

map area) foster lush vegetation and deep and intensive weathering that impede geologic investigation. Outcrops are largely limited to stream courses and to roadcuts along the complex of logging roads that penetrates most of the quadrangle. 

Geologic mapping of the Grays River quadrangle was 

undertaken by the U. S. Geological Survey during the summers of 

1963 to 1966, as part of a cooperative program with the State of 

Washington. The resulting map, with a brief descriptive text, has 

been published by the State (Wolfe and McKee, 1968) . This report is intended as a companion to that map. 

Previously published literature on the geology of the Grays 

River area is limited to the pioneering stratigraphic and paleontologic studies of Weaver (1912, 1937). His monograph on the 

Tertiary stratigraphy and paleontology of western Washington 

and Oregon (1937) includes a generalized geologic map of the 

Grays River area. More recent detailed geologic studies of nearby 

areas in western Washington (Henriksen, 1956; Pease and Hoover, 

1957; Rau, 1958, 1966, 1967; Snavely and others, 1958; Gower and 

Pease, 1965; Livingston, 1966; Wagner, 1967a, b) deal with stratigraphic sequences closely related to the succession in the quadrangle. In addition, accounts of the geologic history of western 
INTRODUCTION 

125° 124° 123° 122° 121° 

49° ~-----------.--r. 

VANCOUVER 

ISLAND 

SKAGIT 

48° 

KING I 

/,.. 

47" 

' \.. ~ t::J fAcoMl l :; () '-....,...r_';'f~ 

MflA - Aberdeen P I E R C E " 

W A S 1H I N G'\J' 0 N 

THURSTON\.Mount Rainier~/- "YAKIMA 

---- ~ '"""\. ... ,, ,-

460 0 

(") 

~ 

South 

Bend 1 -oChehalis ------....,--.._I' ~ ,J 

PACJFICI LEWIS ) 

0 10 20 30 40 50 60 MILES 

FIGURE 1.-Loca.tion of the Grays River quadrangle. 

3 

Washington and Oregon (Snavely and Wagner, 1963) and Washington (Wagner and Snavely, 1966) provide a regional historical 

framework for the geology of the Grays River area. 

Weldon W. Rau of the ·washington Division of Mines and Geology made all foraminiferal determinations and age designations; 

Warren 0. Addicott of the U.S. Geological Survey made all molluscan identifications and correlations. Field assistance was ren-
4 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

dered by A. R. Brown in 1963, M. D. Himes in 1964, and W. G. 

Gilbert in 1965. Special credit is due N. S. MacLeod, who mapped 

parts of the Astoria Formation and the basalt flows and intrusive 

rocks unit in 1966. 

Petrographic analyses consisted largely of examination of thin 

sections and grain mounts, supplemented by X-ray diffraction 

where appropriate. Most of the modal analyses of igneous rocks 

are based on counts of 1,000 points in a thin section. Modal analyses of sandstones were determined by thin-section counts of 200 

points. Because consistent distinction among feldspar types and 

quartz was difficult, point counts were supplemented by 200-grain 

counts on mounts stained to facilitate recognition of plagioclase 

and potassium feldspar. Grain counts were made with transmitted light to permit distinction of feldspars from clay minerals 

and lithic fragments that took the stains. Heavy minerals from 

the very fine sand (62-124 micron) fraction or from the coarse 

silt to very fine sand (30-124 micron) fraction were concentrated in tetrabromethane (sp gr 2.96), and 100 nonmicaceous, 

nonopaque grains per sample were identified. Little difference in 

heavy mineral distribution exists between the very fine sand fraction and the coarse silt to very fine sand fraction where these 

were compared for sandstone samples from the Grays River 

quadrangle. 

TERTIARY SYSTEM 

EOCENE SERIES 

CRESCENT FORMATION 

The oldest rock unit exposed in the Grays River quadrangle is 

a sequence of basaltic rocks called the Crescent Formation in accordance with the usage of Gower (1960). The sequence crops out 

in the relatively rugged highland areas in the northwestern and 

northeastern parts of the quadrangle and is probably more than 

5,000 feet thick. 

LITHOLOGY 

The Crescent Formation consists mainly of aphanitic to finegrained pillow basalt but also includes massive and columnarjointed basalt, as well as small amounts of aquagene tuff and siltstone, locally with abundant radiolarian tests. 

Pillows are well defined and range from about 1 to 3 feet in 

diameter. They are characterized in cross section by well-developed radial jointing and are rudely circular to elliptical in outline 
EOCENE SERIES 5 

(fig. 2). In fresh exposure the pillow basalt looks greasy, and locally it is amygdaloidal. 

Thin sections of typical Crescent basalt reveal that the rock is 

hypocrystalline and contains ophitic to subophitic plagioclase and 

augite (fig. 3). Point counts of several samples give the following 

compositional ranges: plagioclase 40 to 46 percent, augite 26 to 37 

percent, olivine 0 to 3.5 percent, opaque minerals 2 to 8 percent, 

and fine-grained interstitial material, including altered glass and 

vesicle fillings, 14 to 22 percent. 

Plagioclase (An57-7o) occurs as anhedral to subhedral laths 

ranging from about 0.1 to 1.5 mm (millimeter) in length. Some 

of the larger laths occur in cumulophyric clots as wide as 2.5 mm. 

Twinning and normal progressive zoning are common. Some plagioclase is altered to green Inontmorillonitic or chloritic clay minerals. Commonly, the feldspar core is intensely altered and the 

rim relatively fresh. Other types of alteration occur locally and 

include replacement of the plagioclase by analcite and alteration 

to oligoclase (about An3.o) and heulandite. The known occurrences 

of the heulandite alteration are near faults. 

Augite (2V approximately 50°; NY approximately 1.70) occurs 

as fresh anhedral to subhedral grains. Olivine, completely altered 

to clay minerals, makes up a small part of some specimens. 

FIGURE 2.-Pillow basalt in the Crescent Formation (SW14 sec. 11, T. 11 N., 

R. 7 W.). 
6 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

FIGURE 3.-Photomicrograph of Crescent basalt. Basalt consists predominantly of ophitic intergrowth of plagioclase and augite and contains scattered plagioclase phenocrysts, small crystals of magnetite and altered 

olivine, and patches of residuum with chlorophaeite ( ?) in part. Plane-polarized light. 

Interstices are filled with altered glass, some of which encloses 

vesicles filled with a green to brown isotropic mineraloid ( chlorophaeite?) that in places surrounds a core of montmorillonitic 

clay. The glass, partly altered to clay minerals, contains feldspar 

microlites and crystallib~s. Magnetite or ilmenite crystals are 

very abundant in the altered glass; they crosscut all parts of the 

basalt except the vesicle fillings. 

Aquagene tuffs, exposed at the north edge of the quadrangle in 

the SW%. sec. 24, T. 12 N., R. 8 W., and at the east edge of the 

quadrangle in the SW14 sec. 12, T. 11 N., R., 6 W., consist of 

granules ranging from altered amygdaloidal glass to glassy basalt. Amygdule fillings, alteration products, and cementing agents 

include analcite, thomsonite, calcite, and montmorillonitic clay. 

Chemical analyses and normative compositions of three samples of typical Crescent basalt are listed in columns 1 to 3 of 

table 1. As shown in figure 4 the samples are from widely separated localities. The basalts of the Crescent are typical tholeiites 

and are chemically similar to basalts of the lower unit of the Siletz 

River Volcanics of the Oregon Coast Range (table 1, columns 4A, 
EOCENE SERIES 7 

TABLE 1.-Chemical analyses and normative compositions, in weight percent, of 

basalt of Crescent Formation and Siletz River Volcanics 

[Analyses recalculated to water-free basifl. Nos. 1 to 3 (location shown in fig. 4) were analyzed by methods described by Shapiro and Brannock (1962), supplemented by X-ray fluorescence. Analysts: P. L. D. Elmore, S. D. Botts, G. W. Chloe, Lowell Artis, Hezekiah Smith] 

SiOz ___________________________ _ 

Alz03 __ ------------------------- Fez03_- ____ - _______ ------------ FeO ___________________________ _ 

MgO ______________ ------------- CaO ____ ______________________ _ 

N azO ________________ - ___ -------

KzO ___ -- - - - -- - - - -- - - - - - - - - - - - - - TiOz __________________________ _ 

PzOs ___ ------- ___________ ----- - Mn 0 _______________ - - --- - - - - - - -

COz __ -------------------------- H20- _________________________ _ H20 + _________________________ _ 

Or Q_- - - - - - - - - - - - - - - - - - - - - - - - - - - - - ____________________________ _ 

Ab ______________________ ------ _ An ____________________________ _ 

Wo _______ ------------- _______ _ En ____________________________ _ 

Fs ____________________________ _ Fo ____________________________ _ Fa ____________________________ _ 

M t ___________________________ _ 

II __ ---------------------------- Ap ____ ------------------------- Cc ____________________________ _ 

Normative plagioclase ___________ _ 

2 

Chemical analyses 

49 . 3 15.8 

5 . 1 6 . 9 5.2 

12.6 

2.4 

.30 

2.1 

.25 

.25 

1.2 

1.1 

4 .3 1.8 

19.9 

31.5 

12.2 

13.0 

5.4 

7.4 

3.9 

.6 

Ans1 

48.6 

14.9 

6.2 

6.3 

5.1 

13.4 

2.5 

.17 

2.3 

.30 

.34 

.05 

1.7 

1.2 

Norms 

4.4 

1.0 

21.0 

28.9 

14.7 

12.6 

3.3 

9.0 

4.3 

.7 

. 1 Anss 

3 4A 4B 

49 .2 49.0 48.3 14.9 14.5 14.6 4.2 3.9 5.3 7.1 7.7 8.5 8.1 8.3 5.8 12.1 12.2 11.5 2.0 2.3 2.6 .17 .17 .14 1.7 1.6 2. 7 .31 .15 .31 .20 .19 .25 

2.2 

2 . 0 

2 . 4 2.8 1.0 1.0 .8 16.9 19.5 22.0 31.2 28.7 27 . 8 11.1 12.9 11.4 20.1 19.7 14.4 7.2 8.2 7 . 2 .7 

.3 6.1 5. 7 7. 7 3.2 3.0 5.1 .7 .4 . 7 

Anss An so Anss 

1. Pillow basalt from quarry in NE_liSW~ sec. 16, T. 11 N., R. 7 W. Field No. WGR63-379; USGS Lab. No. 162220. 2. Pillow basalt from quarry in NW_liNW;\1! sec. 1, T. 11 N., R. 9 W. Field No. WoGR64-479; USGS Lab. No. 164283. 3. Massive basalt from NE_li NE_li sec. 26, T. 12 N., R. 7 W. Field No. WoGR64-704; USGS Lab. No. 164294. 4. Tholeiitic basalt, lower unit of Silet:T. River Volcanics, central part of Oregon Coast RangP. 4A, av- erage of 3 analyses from older part of lower unit; 4B, average of 5 analyses from younger part of lower unit (from Snavely and others, 1968, table 3). 

4B; fig. 12). Analysis 3 is nearly identical with average basalt 

from the older part of the lower unit of the Siletz River Volcanics (column 4A); analyses 1 and 2 are more similar to average 

basalt from the younger part (column 4B). 

AGE AND CORRELATION 

Foraminifera from siltstone interbeds in the Crescent Formation of the Grays River quadrangle (table 2) indicate a middle 

Eocene (Ulatisian of M:allory, 1959) or possibly earliest late 

Eocene age (early Narizan of Mallory, 1959). The Crescent Formation is lithologically correlative with the lower part of the 

Siletz River Volcanics (lower and middle Eocene) of western 

Oregon (Snavely and others, 1968). 
8 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

0 4 MILES 

FIGURE 4.-Generalized geologic map of the Grays River quadrangle 

showing location of samples collected for fossils, for chemical analysis. 

or for heavy minerals. 
EOCENE SERIES 

EXPLANATION 

Basalt flows and intrusive rocks 

~ 

ITT]~ 

l__L_Lj ~ 

Unit I Unit II Unit III 

Astoria Formation 

Contact, approximately located ______ ,_,_,_ 

Fault, approximately located 

Queried where probable or hypothetical 

• M-3 

Megafossil Foraminifera 

Fossil locality 

See tables 2, 3, 5, 6, 8, 9, 12, 13 

9 

Lincoln Creek Formation 

Shading shows approximate outcrop of interlaminated sandstone and siltstone. Dashed 

line marks base of upper glauconitic and 

basaltic sandtone 

Foraminiferal stages: Rz, Relizian; S, 

Saucesian; Z, Zemorrian; R,Rejugian; N, 

Narizian; LN, Lower Narizian; U, Ulatisian; ?, evidence for stage designation weak 

C-1 

Location of chemically analyzed sample 

See tables 1, 4,7,14,15,16 

Unit B, siltstone 

and sandstone 

Intrusive rocks . 22 

Heavy-mineral sample locality 

Unit B, volcanic 

rocks 

Number shows percentage of hornblende 

plus ex pidote among nonopaque and nonmicaceous heavy minerals in the Astoria 

Formation 

-9-

Exploratory test well 

Unit A 

Atlantic Richfield Oil Co. Weyerhaeuser 1 

SWU sec. 31, T. 10 N., R. 8 W. 

Crescent Formation 

FIGURE 4.-Continued. 

TABLE 2.-Foraminifera from the Crescent Formation, Grays River quadrangle, 

Washington 

[Identifications by W. W. Rau. Fossil localities shown in fig. 4. C, common; F, few; R, rare] 

Locality (fig. 4) ___________________ __ ______________________________________ _ F-1 F-2 Washington Div. Mines and Geology Lab. N o ________________________________ _ S-433 S-444 

A no mali na s p ________ ____ __ __ __________ ______ ______________ _ R 

Asterigerina crassiformis Cushman and Siegfus __ __ _____ ________ _ F 

Bulimina cf. B. lirata Cushman and Parker __________ ________ __ _ R 

Cibicides sp ______ ___ ____ __ __ _____ _______________ __ _________ _ R 

Cibides martinezensis malloryi Smith __ __________ __ ____________ _ c 

Dentalina spp _____ __ __________ _____________________ ___ _____ _ R 

Epistomina eocenica (Cushman and Hanna) __ ___ ___ ______ ____ __ _ F 

Eponides cf. E. mexicana (Cushman) ___________ ___ ____________ _ R 

Gaudryina coalingensis (Cushman and G. D. Hanna) ____________ _ c 

Globigerina spp _____ _______ ____ ________ ___ ___ _________ ___ __ _ _ F c 

Gyroidina orbicularis planata Cushman ________ __ _____ ________ _ _ R Robulusspp _____ ___________ _______ ______ __ __ __ __ _______ ___ _ F R 

Valvulineria cf. V. jacksonensis welcomensis Mallory _____ _______ _ R 
10 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

PALEOGEOLOGIC SETTING 

Volcanic rocks of the Crescent Formation in the Grays River 

area are part of a thick sequence of low~r to middle Eocene basaltic volcanic rocks that accumulated in the axial part of a eugeosynclinal trough that extended from Vancouver Island to the 

Klamath Mountains. The thickness of the sequence is probably 

more than 10,000 feet in many parts of western Washington and 

Oregon and exceeds 15,000 feet in the Olympic Mountains (Snavely 

and Wagner, 1963, p. 3,4) . 

Qualifying the available microfauna! evidence as poor, W. W. 

Rau (written commun., 1966) noted that Foraminifera suggest 

accumulation of the Crescent Formation in shallow water, perhaps 

300 feet deep, in an open-sea, offshore environment. The absence 

of basaltic sandstones and conglomerates and the predominance of 

pillow basalt suggest that the water was too deep for local volcanic 

accumulations to reach above sea level within the mapped area. 

UNIT A 

A unit of siltstone and interbedded sandstone, which may be as 

thick as 2,000 feet, overlies and perhaps intertongues locally with 

the upper part of the Crescent Formation. The unit, informally 

designated unit A, is exposed in the northwestern and northeastern parts of the quadrangle. 

LITHOLOGY 

Siltstone, the predominant type of rock in unit A, is well indurated, thin bedded, and dark gray where freshly exposed. It consists of angular silt-sized quartz, feldspar, and lithic grains, as 

well as minute mica flakes in a chlorite or vermiculite matrix. 

Sandstone beds, rhythmically alternating with siltstone, range 

in thickness from less than a foot to more than 10 feet (fig. 5). 

In fresh exposures the sandstone is greenish gray, but in most 

outcrops it is weathered to shades of yellow or brown. The sandstone is very fine to medium grained with abundant interstitial 

clay and randomly scattered mica flakes. Coarser sand and granules occur locally. Typically, the sandstone beds have no visible 

internal structure. Graded bedding is visible in some outcrops, 

but it is usually difficult to recognize where coarse detritus is absent. Small-scale crossbedding occurs locally. The basal contacts 

of the sandstone beds are always sharp; sole marks are uncommon. 

Inspection of thin sections indicates that the sandstone is angular very fine to fine sand in a clay-rich matrix. In some rocks the 
EOCENE SERIES 11 

FIGURE 5.-Rhythmically alternating sandstone and siltstone of unit A 

(SW14SE 14 sec. 33, T. 12 N., R. 8 W.). 

sand is coarser, and grains become more rounded as grain size increases. 

Modal analyses of seven unit A sandstone samples have the average composition shown below. Typically, quartz constitutes 

about one-quarter to one-third of the rock. Monocrystalline 

quartz, commonly strained, is slightly more abundant than the 

polycrystalline varieties, which range from cryptocrystalline fragments (chert?) to coarser interlocking mosaics of probable metamorphic origin. Feldspar, also one-quarter to one-third of the 

rock, consists primarily of sodic plagioclase and a smaller amount 

of potash feldspar. Much of the feldspar does not show twinning 

Volume 

percent (avg.) 

Monocrystalline quartz --------------~---------------------------- 16 

Polycrystalline quartz -------------------------------------------- 11 

Potassium feldspar ---------------------------------------------- 5 

Plagioclase ----------------------------------------------------- 21 

Mica and chlorite ------------------------------------------------ 7 

2 

8 

Metamorphic rocks -----------------------------------------------

Volcanic rocks ---------------------------------------------------

Volcanic(?) rocks ----------------------------------------------- 10 

Matrix ------------------------------------------------ --------- 15 

Other ---------------------------------------------------------- 4 

99 
12 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

in thin section, and consistent distinction among feldspar types 

and quartz is difficult. Relative proportions of quartz and the 

feldspars, determined from stained grain mounts, are plotted in 

figure 6. Lithic fragments include small quantities of schistose 

metamorphic grains, fairly abundant obviously volcanic clasts, 

and clasts whose alteration, small size, and (or) fine texture preclude unequivocal classification. Many of the latter are probably 

of volcanic origin. Muscovite flakes and chlorite clasts are scattered, and crumpled biotite grains are abundant. 

Although sharp grain boundaries occur, many clasts have 

vague or intricately interdigitated boundaries with the matrix. 

Biotite and volcanic clasts grade into the matrix, which to some 

extent is a product of the alteration of unstable clasts. X-ray diffraction analyses indicate that the matrix is predominantly a clay 

mineral intermediate between chlorite and vermiculite. In a few 

specimens the matrix is calcite. 

The heavy mineral suite is characterized by an abundance of 

epidote, or epidote and green or blue-green hornblende. In 15 of 

17 samples, epidote and hornblende total more than 80 percent of 

the nonopaque, nonmicaceous heavy minerals. The other heavy 

Quartz 

.. 

. . . . 

FIGURE 6.-Relative proportions of quartz, potassium feldspar, and plagioclase in unit A sandstone. 
EOCENE SERIES 13 

minerals are zircon, garnet, tourmaline, sphene, apatite, staurolite, 

and rutile. 

Interbedded siltstone and volcanic sandstone which occur north 

of the headwaters of Sweigiler Creek, near the eastern border of 

the quadrangle, are included in unit A. The sandstones are volcanic wackes with clasts of plagioclase and basalt. Beds, some of 

which are graded, are massive and range from a few inches to 

about 2 feet in thickness. 

AGE AND CORRELATION 

Foraminifera from siltstones in unit A (table 3) in the northcentral part of the quadrangle indicate an age of late middle 

Eocene (late Ulatisian of Mallory, 1959) or possibly earliest late 

Eocene (early Narizian of Mallory, 1959). Unit A is continuous 

with strata mapped as rhythmically bedded sandstone and siltstone in the Raymond quadrangle (Wagner, 1967a) and at least in 

part is also continuous with strata included with the lower member of the Mcintosh Formation in the southwestern corner of the 

Doty-Minot Peak area (Pease and Hoover, 1957). Close ternTABLE 3.- Foraminifera from unit A, Grays River quadrangle, Washington 

[Identifications by W. W. Rau. F ossil localities shown in fig. 4. C, common; F, few; R, rare; ?, identifi- cations questionable] 

Locality (fig. 4) _ _ _ _ _ _ _ _ __ _ _ _ _ __ _ __ _ __ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ __ _ _ __ _ __ _ __ _ _ _ _ _ F-3 F-4 F-5 

Washington Div. Mines and Geology Lab. No _____ _________ __ ___ __ ___ ____ 4010 3921 426R 

Alabamina wilcoxensis Toulmin _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ R 

Allomorphina macrostoma Karrer __ __ __ ___ _______ _________ _ Anomalina sp_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ F 

Asterigerina crassiformis Cushman a nd Siegfus _ _ _ _ _ _ _ _ _ _ _ _ _ _ R 

Bulmina pupoides d'Orbigny _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ F 

C assidulina globosa Han tken _____ ____ _____ ____ ___ ________ _ 

Cibicides sp _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ R 

cf. C. venezuelanus NuttalL ___________ _______________ _ ? 

Dentalina spp _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ F 

Dorothia principiensis Cushman and Bermudez ___ _____ _____ _ 

Epistomina eocenica (Cushman and Hanna) __ ______ _____ ___ _ Globigerina spp ___ _ _ _ _ _ _ __ __ __ _ _ __ _ _ _ _ __ _ _ _ _ _ _ __ _ _ _ _ __ __ _ C 

Gyroidina orbicularis planata Cushman ________ _______ ___ __ _ 

simiensis Cushman and McMa sters __ ___ ___ ___ ____ ____ _ 

Nodosaria cf. N. arundinea Schwager ___ _______ ___ __ ______ _ 

Pleurostomella acuta Hantken _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ R 

Pullenia eocenica Cushman and Siegfus ______ ______ ____ __ __ _ Robulus spp _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ F 

Silicosigmoilina californica Cushman and Church_ ____ _____ __ R 

Spiroplectammina directa (Cushman and Siegfus) _ _ _ _ _ _ _ _ _ _ _ _ C 

Tritaxilina co lei Cushman and Siegfus ___ ____ ___ __ _______ __ _ 

Uvigerina cf. U. churchi Cushman and Siegfus ____ _______ __ _ _ 

garzaensis Cushman and Siegfus ___ _____ __ ________ ____ R 

Valvulineria cf. V . jacksonensis welcomensis Mallory _ _ ______ _ 

R 

F 

F 

? 

F 

F 

R 

F c 

R F 

F 

F 

R 

F c 

R c 

c 

R 

? 
14 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

poral affinity with the Crescent Formation of the southern part 

of the Olympic Peninsula is suggested by the occurrence in unit 

A of the following Foraminifera, restricted to the Crescent in the 

Satsop area (Rau, 1966, p. 23, 24) and in the Wynoochee Valley 

quadrangle (Rau, 1967) : 

Cibicides cf. C. venezuelanus Nuttall 

Do1·othia principiensis Cushman and Bermudez 

Gyroidina simiensis Cushman and McMasters 

Pullenia eocenica Cushman and Siegfus 

Silicosigmoilina californica Cushman and Clark 

Spiroplectammina dire eta (Cushman and Siegfus) 

Tritaxilina colei Cushman and Siegfus 

Uvigerina cf. U. churchi Cushman and Siegfus 

Except for Epistomina eocenica (Cushman and Hanna), none 

of the 41 species appearing first in sedimentary rocks of late 

Eocene age in the Satsop area (Rau, 1966, p. 25-27) are present 

in unit A. Many of these Foraminifera do occur in unit B. 

Unit A is superficially similar to the Tyee Formation (middle 

Eocene), which overlies the Siletz River Volcanics in the central 

part of the Oregon Coast Range (Snavely and others, 1964); it 

may be approximately correlative with either the Tyee or the 

overlying mudstones, which are assigned to Mallory's ( 1959) 

upper Ulatisian or lower Narizian Stages (Snavely and others, 

1964, p. 465). 

PALEOGEOLOGIC SETTING 

Rhymthmic repetition of sandstone beds, some of which are 

graded, suggests that the unit A sandstones may have been deposited by turbidity currents. Although he considered the evidence 

poor, Rau (written commun., 1966) noted that the presence of 

certain Foraminifera suggests deposition of unit A siltstone in 

an open-sea, offshore environment at 600- to 3,000-foot depths 

which would be compatible with a turbidity current origin for the 

sandstones. 

The mineralogy of unit A suggests that the source areas included volcanic and metamorphic rocks, such as the amphibolites 

and hornblende gneisses common in the pre-Tertiary orogenic 

belt exposed in the Klamath Mountains of southwestern Oregon 

and in the Cascade Range in northern Washington and British 

Columbia. 

Since the composition of unit A is different from that of the 

Tyee Formation, a turbidite sequence derived mostly from the 

Klamath Mountains, unit A probably had a different source. Ac-
EOCENE SERIES 15 

cording to Snavely, Wagner, and MacLeod (1964) the Tyee contains 3 to 20 percent plagioclase, compared with 18 to 28 percent 

in unit A. Plagioclase in the Tyee is commonly euhedral and shows 

pronounced oscillatory zoning, unlike plagioclase in unit A, and 

hornblende is the only nonopaque heavy mineral recognizable in 

more than trace amounts in thin sections of Tyee sandstone 

(Snavely and others, 1964, p. 469-471). Cursory examination of 

several heavy mineral separates from the Tyee indicates that epidote, while common, is not preponderant as in unit A. 

Likely sources for unit A sandstone are north-central Washington and adjacent British Columbia and Vancouver Island. Wagner 

and Snavely ( 1966, p. 40-42) suggest that middle Eocene turbidites in southwestern Washington (unit A) may share the 

Vancouver Island source of sandstones of the northern Olympic 

Peninsula. Because heavy mineral separates from a suite of sandstones that H. D. Gower collected in the northern Olympic Peninsula commonly show a preponderance of epidote, they support this 

suggestion. 

UNIT B 

The next younger map unit, informally designated unit B, consists of several thousand feet of marine tuffaceous siltstone, a few 

beds of sandstone, and volcanic rocks. The absence of distinctive 

marker beds and lack of information about structural details prevent a precise determination of the thickness, but more than 

5,000 feet seems likely. The contact with the older rocks, where 

observed, is a fault. 

LITHOLOGY 

SILTSTONE 

The most widespread rock type in unit B is marine tuffaceous 

siltstone, which is well indurated, well stratified, and generally 

some shade of gray or greenish gray. Common calcareous concretions range from spheres about an inch in diameter to elongate 

lenticular masses as much as 1 foot thick and many feet long. 

The siltstone (fig. 7) contains silt to very fine sand-sized detritus occurring as dispersed gr ains as lenticular laminae in a montmorillonitic matrix. The most abundant constituents of silt and 

sand size are quartz, feldspar, volcanic fragments, and glass 

shards altered to heulandite. Megafossils are rare, but Foraminifera are abundant and are commonly visible in hand specimens. 
16 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

FIGURE 7.-Photomicrograph of unit B siltstone. Contains quartz, feldspar, 

lithic fragments, and glass shards in a matrix of montmorillonitic clay. 

Opaque fragments are iron-sulfide nodules and carbonaceous clasts. Planepolarized light. 

SANDSTONE 

Sandstone is a minor constituent of unit B. It includes a massive, fine- to medium-grained, friable arenite approximately 200 

feet thick that rests on the subaerial volcanic rocks in the eastern 

part of the quadrangle and grades upward into marine tuffaceous 

siltstone in the upper part of unit B. Similar sandstone, as well 

as basaltic and glauconitic sandstone, occurs in scattered outcrops 

elsewhere. In a few localities, particularly in the north-central 

part of the quadrangle and in the Naselle River channel near the 

west edge of the quadrangle (sec. 12, T. 10 N., R. 9 W.) a very 

fine grained sandstone is interlaminated with siltstone. Parallel 

lamination with concentrations of mica and carbonaceous detritus 

on the bedding surfaces is characteristic. Small-scale crossbedding and structures produced by sedimentary loading occur locally. 

Unit B sandstone is predominantly angular very fine to medium-grained quartz and feldspar with abundant mica flakes and 

sparse lithic fragments. An estimate of average composition 
EOCENE SERIES 17 

based on point counts on 10 thin sections supplemented by results 

from stained grain mounts is shown below: Volume 

percent (avg.) 

Monocrystalline quartz ------------------------------------------- 18 

Polycrystalline quartz -------------------------------------------- 13 

Potassium feldspar ---------------------------------------------- 10 

Plagioclase ----------------------------------------------------- 15 

Mica and chlorite ---------------------------------------------- 9 

Metamorphic rocks ---------------------------------------------- 2 

Volcanic rocks -------------------------------------------------- 3 

Volcanic(?) rocks ----------------------------------------------- 4 

Matrix -------------------------------------------------------- 24 

Other ---------------------------------------------------------- 2 

100 

Matrix, including detrital silt and clay and altered unstable 

clasts, constitutes from less than 1 to more than 40 percent of the 

volume of unit B sandstones. Hence, the average percentages 

shown here represent a wide range of values; however, they are 

representative of the relative proportions that occur among the 

clastic components of unit B sandstones. Except for local basaltic 

sandstones, in which the volcanic clasts resemble unit B basalt, 

unit B sandstones have significantly fewer volcanic clasts than 

unit A sandstones. Comparison of figure 8, a triangular plot of 

quartz, potassium feldspar, and plagioclase, with a similar plot for 

unit A (fig. 6) shows that unit B sandstones are more varied in 

composition and significantly richer in potassium feldspar relative 

to quartz and plagioclase than unit A sandstones. 

Generally, the sandstones can be separated into two distinct 

groups on the basis of heavy mineral composition. In one group, 

represented by 14 of 22 samples counted, epidote constitutes from 

25 to 95 percent of the heavy mineral fraction. Other heavy minerals in this group, which includes the mapped sandstone unit 

overlying the subaerial volcanic rocks, are green or blue-green 

amphibole, zircon, garnet, sphene, apatite, tourmaline,_ rutile, and 

staurolite. In the second group, represented by six samples, amphibole is absent, and epidote constitutes 2 percent or less of the 

nonopaque heavy minerals. In this group zircon, garnet, sphene, 

and apatite are the most abundant heavy minerals) constituting 

62 to 92 percent of the nonopaque heavy minerals. Other heavy 

minerals include tourmaline, staurolite, rutile, and monazite. Figure 8 indicates that the epidote-rich sandstones have relatively 

less quartz and more feldspar than the epidote-poor sandstones. 
18 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

Quartz 

I 

. : 

. 

EXPLANATION 

~ Hornblende plus epidote 

:S 2 percent 

Hornblende plus epidote 

>30 percent 

FIGURE 8.- Relative proportions of quartz, potassium feldspar, and plagioclase in unit B sandstones. 

VoLCANIC RocKs 

The volcanic rocks of unit B are mainly massive lava flows of 

subaerial origin in the upper reaches of Grays River and aquagene tuff and flow breccia of probable marine origin in the N aselle River valley. The massive flows of the upper Grays River 

drainage area are relatively fresh porphyritic basalt and andesitic basalt with a small amount of tuff and volcanic breccia. 

Bright red zones of oxidized tuff or altered lava, some as thick as 

15 feet, occur locally. At the base of the sequence the massive 

flows grade downward into volcanic breccia, tuff, and volcanic 

sandstone that are interbedded with marine siltstone of unit B. 

Oyster fragments occur in the tuffaceous marine rocks immediately below the subaerial basalt. The total thickness of massive 

basalt is unknown, but it is probably at least 2,000 feet. 

Typical massive basalt in the upper Grays River drainage area 

contains phenocrysts of plagioclase (An75-s5 ) that are twinned, 

progressively zoned, and up to 3 mm long (fig. 9), as well as subhedral augite (NY approximately 1.70; 2V=4l0 -56°) and subhedral to euhedral olivine altered to clay minerals and chlo-
EOCENE SERIES 19 

FIGURE 9.- Photomicrograph of unit B subaerial basalt. Plagioclase phenocrysts in intergranular groundmass of small subparallel crystals of 

plagioclase with interstitial clinopyroxene, magnetite or ilmenite, and 

minor residuum. Crossed polarizers. 

rophaeite ( ?) . The groundmass is intergranular in texture and is 

commonly trachytic. It consists of subhedral plagioclase crystals 

(An4 o-.'i:! ), interstitial granules of clinopyroxene and opaque minerals, and a small amount of residuum largely represented by clay 

minerals and mineraloids. The phenocrysts, particularly plagioclase and augite, often occur in cumulophyric clots and are commonly slightly embayed by the groundmass. Relative proportions 

of the mineral constituents vary slightly, but an average of five 

specimens gives the following approximate compositions: plagioclase phenocrysts, 4 percent; groundmass plagioclase, 38 percent; 

augite phenocrysts, 1 percent; clinopyroxene microlites, 35 percent; olivine phenocrysts, 1 percent; opaque minerals, 17 percent; 

residuum, 4 percent. 

Basaltic rocks of submarine origin interfinger with marine tuffaceous siltstone in the valleys of the Naselle River and Salmon 

Creek. They also crop out in the North N emah River valley in the 

northwest part of the quadrangle and in and near the headwaters 

of Hull Creek in the east-central part of the quadrangle. The lowest rocks penetrated by the Atlantic Richfield Co.-Weyerhaeuser 
20 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

FIGURE 10.-Well-bedded aquagene tuff of unit B exposed in the bank of the 

Naselle River (NW74,SE 14 sec. 17, T. 11 N., R. 8 W.). 

T<'IGURE 11.-Photomicrograph of unit B aquagene tuff. Clasts of amygdaloidal glassy basalt in a matrix of comminuted glass-rich basaltic debris. 

Plane-polarized light. 
EOCENE SERIES 21 

1 well on the west shore of Grays Bay consist of approximately 

800 feet of alternating siltstone and porphyritic amygdaloidal 

basalt, which is interpreted as submarine volcanic rock of unit B. 

The submarine volcanic rocks are mainly massive to well-bedded dark-gray to olive-gray well-indurated aquagene tuff (fig. 10) 

exposed in steep-sided gorges along the Naselle River and its 

tributaries. The tuff is mostly angular clasts of extremely amygdaloidal volcanic rock ranging from. altered basaltic glass to 

glassy or very fine grained porphyritic basalt (fig. 11) . Crystals 

of plagioclase and augite also occur as clasts. Some plagioclase occurs as cumulophyric masses similar to those in the massive flows 

of the Grays River valley. Calcite and analcite are the cementing 

agents; calcite, analcite, or montmorillonitic clay fill the amygdules and occur as alteration products of the glass. In some specimens plagioclase has been replaced by analcite. 

Locally the volcanic sequence contains extremely amygdaloidal 

pillow basalt resembling basalt clasts in the aquagene tuff. The 

volcanic sequence also contains a small amount of basaltic sandstone that differs from the tuff mainly in that the clasts are 

rounded. The aquagene tuff interfingers with tuffaceous siltstone 

and grades laterally through siltstone rich in coarse volcanic debris to normal marine tuffaceous siltstone. 

Relatively unaltered nonamygdaloidal basalt similar in lithology to the massive flows of the Grays River valley is present locally among the submarine volcanic rocks. It occurs most 

commonly as flow breccia, but in places it is pillowed or massive 

and may include some small intrusive bodies. Typically the basalt 

is porphyritic, often cumulophyric, with phenocrysts of plagioclase 

(An,.o-s5), augite (NY approximately 1.70; 2V=43°-52°), and altered olivine in an intergranular, often strongly trachytic groundmass of plagioclase (approximately An50 ), clinopyroxene, and 

opaque minerals. An approximate average composition is plagioclase phenocrysts, 4 percent; groundmass plagioclase, 33 percent; 

augite phenocrysts, < 1 percent; clinopyroxene micro lites, 30 percent; olivine, < 1 percent; opaque minerals, 19 percent; residuum, 

12 percent. 

Chemical analyses of unit B basalt are shown in table 4. Columns 5 to 9 are analyses of the massive subaerial basalts from 

the upper Grays River drainage area. Columns 10 to 13 are analyses of relatively unaltered nonamygdaloidal basalt from volcanic 

breccia and pillow basalt in the submarine volcanic rocks. Column 

14 is an analysis of altered porphyritic to cumulophyric basalt at 

a depth of approximately 8,530 feet in the Atlantic Richfield Co.-
22 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 4.-Chemical analyses and normative com positions, in weight percent, of unit 

B basalt 

[Analyses recalculated to water-free basis. Analyses were done by methods described by Shapiro and Brannock (1962), supplemented by X-ray fluorescence. Analysts: P. L. D. Elmore, S. D. Botts, G. W. Chloe, Lowell Artis, Hezekiah Smith. Location of Nos. 5-8, 10-13 shown in fig. 4] 

5 6 7 8 9 10 11 12 13 14 

Chemical analyses 

Si02---- ______________ 50.6 51.1 50.8 48.6 49.4 49.1 49.0 48.3 46.7 47.7 Ah03 ____________ ----- 16.8 15.4 15.7 15.8 15.2 13.8 16.4 16.0 15.8 16.4 

F€203---------------- 6.3 7.1 6.0 5.5 3.4 3. 7 3.8 4.9 6.6 6.6 FeQ __________________ 6.3 6.5 6.8 7.6 9.9 11.6 7.4 8.4 7.6 6.8 

MgQ ___ - ------------- 2.7 3.2 3.3 4. 7 4.7 4.1 5.5 4.6 5.0 5.7 CaO _________________ 8.6 8.1 8.2 10.3 10.4 9. 7 11.9 10.6 10.4 9.4 Na20 _________________ 3.6 3.2 3.6 2.8 2. 7 2.9 2.6 2.8 2.5 3.9 K20 __________________ 1.1 .93 1.2 .86 .59 .36 .29 .36 .28 .29 Ti02- ________________ 3.1 3.6 3.6 3.3 3.3 3.8 2.6 3.4 4.0 2.6 

P20s_- _-------------- .64 .60 .75 .46 .46 . 77 .39 .46 .60 .47 MnO _________________ .22 .22 .19 .21 .18 .22 .15 .21 .53 .14 C02- _________________ .10 .18 .07 .07 .09 H20- ________________ .75 .84 1.4 1.0 .66 .68 .85 .90 2.0 1.0 

H20+----- ----------- .95 .94 .80 .67 1.2 1.3 1.1 1.3 1.0 4.6 

Norms 

Q_----------- -------- 7.0 11.2 6.8 3.8 3.7 5.1 2.6 4.0 5.6 Or ___________________ 6.6 5.5 7.3 5.1 3.5 2.1 1.7 2.1 1.6 1.7 Ab ___________________ 30.2 26.7 30.3 23.3 22.4 24.2 21.6 23.4 20.9 33.4 An ___________________ 26.6 25.1 23.0 28.2 27.8 23.7 32.5 30.2 31.1 26.2 Wo __________________ 4.6 4.1 5.3 8.3 8.5 7.9 10.1 8.0 6. 7 7.2 En ___________________ 6.6 7.9 8.2 11.7 11.7 10.2 13.7 11.5 12.3 10.7 Fs ___________________ 1.8 .6 1.9 4.5 10.3 12.5 6.6 6.2 2.9 2.4 Fo ___________________ 2.4 Fa ___________________ .6 Mt __________________ 9.2 10.3 8.8 8.0 4.9 5.3 5.5 7.1 9.6 9.6 

II_------------------- 5.8 6.8 6.8 6.2 6.2 7.2 4.8 6.4 7.6 4.9 

Ap ___ ---------------- 1.5 1.4 1.8 1.1 1.1 1.8 .9 1.1 1.4 1.1 Cc ___________________ .2 .4 .2 .2 .2 

Normative plagioclase __ An47 An4s An43 Anss Anss An so An so Ansa An so An44 

5. Massive basalt from NE}iNE~i sec. 34, T. 11 N., R. 7 W. Field No. WGR63-383; USGS Lab. No. 162222. 

6. Massive basalt from SW~;lSE~ sec. 26, T. 11 N., R. 7 W. Field No. WGR63-384; USGS Lab. No. 162223. 7. Massive basalt from SE~NW~4 sec. 2, T. 10 N., R. 7 W. Field No. WGR64-430; USGS Lab. No. 162873. 

8. Massive basalt from NE~NW~ sec. 34, T. 11 N., R. 7 W. Field No. WGR63-382; USGS Lab. No. 162221. 9. Columnar basalt from center of sec. 30, T. 11 N ., R. 6 W., Skamokawa quadrangle. Field No. WG R63- 402; USGS Lab. No. 162225. 10. Basalt breccia from NW~NEH sec. 20, T. 11 N., R. 7 W. Field No. WGR63-137; USGS Lab. No. 162216. 

11. Basalt breccia from quarry in SE~iSE~4 sec. 23, T. 11 N., R. 8 W. Field No. WGR63-355; USGS Lab. No. 162219. 12. Basalt breccia from SE~SW~,4 sec. 2, T. 11 N., R. 8 W. Field No. WGR63-410; USGS Lab. No. 162226. 

13. I:>olated pillow in basalt breccia from NE~SE~ sec. 9, T. 11 N., R. 8 W. Field No. WoGR64-504; USGS Lab. No. 164286. 

14. Zeolitized porphyritic basalt from depth of approximately 8,530 feet in Richfield-Weyerhaeuser 1 well, SE~4SWH sec. 31, T. 10 N., R. 8 W. Field No. SR61-187; Lab. No. 160087. (Published with permission of Atlantic Richfield Co.). 

Weyerhaeuser 1 well on the west shore of Grays Bay. In this 

rock, phenocrysts of augite, altered olivine, and plagioclase extensively altered to thomsonite occur in a fine-grained, somewhat 

trachytic, intergranular groundmass with scattered amygdules. 

The rock is fractured; calcite, thomsonite, and chlorite fill fractures and amygdules. The undersaturated normative composition 
EOCENE SERIES 23 

presumably reflects addition of soda, suggested by the unusually 

high soda content (3.9 percent Na20) in the chemical analysis. 

As a group, unit B volcanic rocks most nearly approximate 

normal tholeiitic basalt and average tholeiitic andesite in the 

chemical grouping of Nockolds (1954, tables 6 and 7). Although 

tholeiitic basalt occurs in both the submarine and subaerial flows, 

the latter include some slightly more silicic and alkalic rocks that 

might be distinguished as andesitic basalts (columns 5 to 7, table 

4 this report). These contain more normative quartz (6.8 to 11.2 

percent) than the associated rocks (2.6 to 5.6 percent); more normative potash feldspar (5.5 to 7.3 percent) than the associated 

rocks (1.6 to 5.1 percent); a more sodic normative plagioclase 

(An43-47) than the associated rocks (An5 o--6o) ; and more normative 

salic minerals (67.4 to 70.4 percent) than the associated rocks 

( 55.0 to 60.3 percent). 

Unit B volcanic rocks are richer than Crescent basalt (table 1) 

in alkalis, titania, and phosphate, and poorer in calcium and magnesium oxides. However, they range from tholeiitic basalt (table 4, 

column 11) chemically very much like Crescent basalt to andesitic 

basalt (table 4, columns 5 to 7). Figure 12 illustrates some of the 

chemical relationships among the igneous rocks of the Grays 

River area. Except for three rocks altered by addition of soda, 

basaltic rocks of the Crescent Formation, unit B, and the intru-

~ 0 0 

"'+ 

0.5 ,-------,-----rl---,--- 1-r-1-----,1-----,-1----r----. 

0.4 

Three Tree Point type 

o I Altoona I 0 

ty,Pe I o 

EXPLANATION 

Averages for Three Tree Point, 

Altoona, and Pack Sack types 

(table 14, column 25; table 

15, column 35; table 16, column 42) 

0 

Intrusive rocks (table 7) 

~ON 0 :.::: 0.3 

Albitized 

1

/ 0 

Unit B basalt (table 4) N + "' 0 z ; 

z Pack Sack type 

0.2 

0 I 

o oo/ o 0 /0 

I o 

0 .. .~ 

..---.lOt. 

b. 

Basalt of Crescent Formation 

(table 1, columns 1 to 3) 

... Lower unit of Siletz River Vol-

- canics (table 1, columns 4A, 

4B) 

0.1 L__------1----'----'---L----L-. _ __L__--'--___j 

0.5 0.6 0.7 0.8 0.9 

Fe 2 0 3 +FeO+MgO 

FIGURE 12.-Chemical relationships among basaltic rocks of the Grays 

River area. 
24 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 5.-Foraminifera from unit 

[Identifications by W. W. Rau, Fossil localities shown in fig. 4, except 

Fossil localities __________________ F-6 F-7 F-8 F-9 F-10 F-11 F-12 F-13 F-14 F-15 

Washington Div. Mines and Geology Lab. No ______________ S-431 S-428 4024 S-430 4020 4021 4019 4243 4014 4251 

Alabamina wilcoxensis Toulmin ___ _ Allomorphina macrostoma Karrer __ Angulogerina hannai Beck________ F Astacolus cf. A. barksdalei Beck ___ _ 

Asterigerina crassaformis Cushman and Siegfus _________ _ Baggina teninoensis Rau _________ _ 

Bolivina basisenta Cushman and Siegfus ______________________ _ 

cf. B. jacksonensis Cushman and Applin ______________ _ 

Bulimina corrugata Cushman and Siegfus ______________________ _ 

cf. B. jacksonensis Cushman __ microcostata Cushman and Parker __________________ _ 

pachecoensis Smith __________ _ pupoides d'Orbigny _________ _ schencki Beck ______________ _ 

sculptilis laciniata Cushman and Parker ______________ _ 

Cancris joaquinensis Smith _______ _ Cassidulina globosa Hantken _____ _ cf. C. globosa Hantken _______ _ 

Chilostomella cf. C. oolina Schwager ____________________ _ Cibicides sp. ____________________ _ elmaensis Rau ______________ _ 

hodgei Cushman and Schenck _ cf. C. laimingi Mallory ______ _ cf. C. pachecoensis Smith _____ _ Dentalina spp __________________ _ 

sp. B of Rau, 1948 __________ _ sp. C of Rau, 1948 __________ _ 

consobrina d'Orbigny _______ _ 

cf. D. consobrina d'Orbigny __ _ dusenburyi Beck ____________ _ 

cf. D. jacksonensis (Cushman and Applin) ______________ _ 

Dorotlda priJncipensis Cushman and Bermudez ________________ _ 

Ellipsonodosaria cf. E. cocoaensis (Cushman) _____ ---------- ___ _ Eponides sp ____________________ _ 

duprei ciervoensis Cushman and Simonson ____________ _ 

umbonatus (Reuss) __________ _ Globigerina spp _________________ _ 

Globobulimina pacifica Cushman __ _ Guttulina sp ____________________ _ 

problema d'Orbigny _________ _ 

Gyroidina condoni (Cushman and Schenck)_ ___________________ _ 

orbicularis planata Cushman __ Karreriella cf. K. contorta Beck ___ _ cf. K. elongata Mallory ______ _ washingtonensis Rau ________ _ Lagena sp ______________________ _ 

Listerella communis (d'Orbigny) __ _ M arginulina subbullata Hantken __ _ Nodosaria cf. N. arundinea Schwager ____________________ _ grand is Reuss ______________ _ Planularia sp __________________ _ 

cf. P. markleyana Church ____ _ 

Plectofrondicularia billmani Rau __ _ cf. P. jenkinsi Church _______ _ 

packardi Cushman and Schenck _________________ _ 

packardi multilineata Cushman and Simonson ____________ _ 

searsi Cushman, R. E. and Stewart, K. C ____________ _ 

cf. P. searsi Cushman, R. E. and Stewart, K. c ________ _ cf. P. vaughni Cushman _____ _ 

c 

c 

c 

F 

R 

R 

R 

R 

R 

c 

c 

c 

c 

c 

R 

c 

R 

R 

F 

F 

R 

F 

F 

F 

c 

c 

R F 

c 

R 

R 

R F 

R 

R 

F 

R 

F 

F 

R 

F 

R 

R 

F 

? 

R 

R 

F 

F F 

c R 

F R 

26 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 5.-Fo1·aminifera from unit 

[Identifications by W. W. Rau, Fossil localities shown in fig. 4, except 

Fossil localities __________________ F-6 F-7 F-8 F-9 F-10 F-11 F-12 F-13 F-14 F-15 Washington Div. Mines and Geology Lab. No ______________ S-341 S-428 4024 S-430 4020 4021 4019 4243 4014 4251 

Pseudoglandulina conica (Neugeboren) _________________ 

injlata (Bornemann) _________ 

Pullenia bulloides (d'Orbigny) _____ Quinqueloculina rninuta Beck ______ 

F R ? ? Robulus spp _____________________ c R R F R c R F R sp. (compressed, many chambers) ________________ 

cf. R. pseudovortex Cole _______ -f R welchi Church _______________ R Siphonodosaria frizzelli Rau _______ 

Spiroloculina cf. S. wilcoxensis Cushman and Garrett_ _________ c Spiroplectarnrnina cf. S. warrani (Cushman and Ellison)_ ________ R Uvigerina sp ____________________ 

atwilli Cushman and Simonson _________________ c F cocoaensis Cushman __________ 

garzacnsis Cushman and Siegfus ___________________ F F c cf. U. yazooensis Cushman ____ 

Valvulineria cf. V. jacksonensis welcornensis Mallory ____________ F R F turneyensis Cushman and Simonson _________________ c F willapaensis Rau _____________ Virgulina sp ____________________ 

Vulvulina curta Cushman and Siegfus _______________________ R cf. V. rnississippiensis (Cushman) _______________ 

1 SE~iNEh sec. 30, T. 11 N., R. 6 W., Skamokawa quad.; Narizian Age. 

sive rocks of the northern third of the quadrangle (see p. 29) 

show a trend (dashed line in figure 12) from the more basic tholeiitic basalt of the Crescent to the andesitic basalt of unit B in 

the upper Grays River drainage area. 

AGE AND CORRELATION 

Foraminifera from unit B (table 5) represent the Bulimina cf. 

B. jacksonensis, Uvigerina cf. U. yazooensis, and Plectofrondicularia cf. P. jenki.nsi-BuiimZ:na schencki zones of Rau (1958), of 

late Eocene age (Narizian Stage of Mallory, 1959), and possibly 

the Sigmomorphina schencki zone (Rau, 1958; Snavely and others, 

1958). Rau (written commun., 1967) refers the latter zone to the 

lower part of the Refugian Stage of Schenck and Kleinpell 

(1936) and now tentatively regards it as late Eocene in age. 

Megafossils are rare in unit B, but collections that contain mollusks and crustaceans (table 6) were made from basaltic or glauconitic sandstone in the Grays River valley above the subaerial 

volcanic rocks (locality M-1, fig. 4) and on the Naselle River 

channel near the west edge of the quadrangle (locality M-2, fig. 
EOCENE SERIES 27 

B, Grays River Area, Washington-Continued 

as noted. C, common; F, few; R, rare;?, identification questionable] 

F-16 F-17 F-18 F-19 F-20' F-21 F-22 F-23 F-24 F-25 F-26 F-27 F-28 F-29 F-30 

4011 4195 S-436 S-438 3846 4192 4256 S-417 S-412 S-413 S-411 S-435 3913 4030 4027 

R 

R F ? R 

R c F c R R F c F R 

c 

R R R 

R 

R c R 

R F 

c F 

? 

F c c R F R R F 

F c R F R R 

F c ? 

F R F F 

F 

4). Gastropods from locality M-1 are distinctive species restricted to the Cowlitz Formation (W. 0. Addicott, written commun., 1965) The Cowlitz fauna is correlated with the fauna of 

the late Eocene "Tejon Stage" (Clark and Vokes, 1936) of the 

the Pacific coast. 

TABLE 6.-Megafossils from unit B, Grays River area, Washington 

[Identifications by W. 0. Addicott. Fossil localities shown in fig. 4. X, present as identified) 

Locality (fig. 4)_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ M -1 M -2 

USGS Cenozoic locality__________________________________________________ M2562 M2785 

Pelecypods: Acila sp___ _ _ ___ _ _ _ __ _ _ _ _ _ _ __ __ _ _ _ _ __ _ _ _ _ ____ _ _ __ _ _ _ _ _ X 

Delectopecten sp _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ X 

Pitar sp_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ X 

Gastropods: Fulgurofusus washingtonianus (Weaver) _________________ _ Siphonalia sopenahensis (Weaver) ______________________ _ trochid ______________________________________________ _ 

Crustaceans: 

Raninoides sp ________________________________________ _ 

Zanthopsis vulgaris Rathbun ___________________________ _ 

X 

X 

X 

X 

X 
28 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

The massive basalt of the Grays River valley is lithologically 

similar to basalt of the Goble Volcanic Series (upper Eocene) of 

Wilkinson, Lowry, and Baldwin (1946), which is exposed along 

the Columbia River south of Kelso, Wash. Unit B is at least partially equivalent to the Goble Volcanic Series and the associated 

sedimentary strata of the Cowlitz Formation. The Mcintosh, 

Northcraft, and Skookumchuck Formations of the Centralia-Chehalis district (Snavely and others, 1958), considered as a group, 

are approximately correlative with most of unit B. The foraminiferal data (fig. 4) suggest that the uppermost part of unit B includes strata of Refugian Age that may be correlative with the 

lower part of the Lincoln Creek Formation as mapped elsewhere 

in southwest Washington. Sedimentary rocks of late Eocene age 

mapped by Rau (1966, 1967) in the southern part of the Olympic 

Peninsula are equivalent to at least part of unit B. The Nestucca 

Formation (Snavely and Vokes, 1949) and the associated volcanic 

rocks in the Oregon Coast Ranges are also approximately correlative with unit B. 

PALEOGEOLOGIC SETTING 

According to a paleogeographic summary by Snavely and Wagner (1963, fig. 9), the upper Eocene rocks of western Washington 

and Oregon accumulated in a north-south-trending eugeosynclinal 

trough with scattered volcanic centers that produced local basaltic islands. In southern Washington, the eastern margin of the 

basin was probably about 50 miles inland from the present coast. 

The predominance of siltstone among the sedimentary rocks is 

consistent with the offshore marine setting indicated by Snavely 

and Wagner (1963) for the Grays River area. Foraminifera from 

siltstones throughout unit B are typical of offshore, open-sea conditions (W. W. Rau, written commun., 1966). Water depths of 

1,000 to 5,000 feet are suggested by Foraminifera from unit B 

rocks of the Naselle valley area; Foraminifera from siltstones 

overlying the subaerial volcanic rocks in the Grays River valley 

suggest water depths of 500 to 2,500 feet. 

The great thickness of unit B volcanic rocks and the abundance 

of related intrusive rocks (see Intrusive Rocks, p. 29) indicate 

that the Grays River area was a local center of late Eocene basaltic volcanism. In the central and western part of the area, the 

volcanic rocks are entirely of submarine origin, indicated by the 

occurrence of pillow basalt, flow breccia, and aquagene tuff intercalated with marine sedimentary rocks. However, a large volcanic 

pile was built above sea level near the eastern edge of the quad-
EOCENE SERIES 29 

rangle. Eventual submergence of the subaerial volcanic mass and 

its burial by marine sediments are recorded by the friable massive sandstone overlying the subaerial volcanic rocks and by the 

offshore marine siltstone up into which the sandstone grades. 

Although there are local occurrences of basaltic sandstones containing clasts of unit B basalt, most unit B sandstones contain little or no detritus obviously derived from local sources. The sandstone mineralogy suggests derivation from plutonic and 

metamorphic source rocks similar to the pre-Tertiary crystalline 

rocks of north-central and northeastern Washington. The abundant glass shards in the siltstones imply contemporaneous explosive volcanism, probably either within the depositional basin or 

just east of it in the area now underlain by the Cascade Range of 

Oregon and southern Washington. 

Except for the thick massive sandstone, which was mapped in 

the Grays River valley and which may be a shallow-water transgressive unit deposited as the subaerial volcanic mass was submerged, unit B sandstones are scattered among offshore marine 

siltstone and volcanic rocks, and apparently were deposited in 

deep water. The predominant sedimentary structures, parallel 

lamination with some small-scale crossbedding and load structures, are similar to structures in the upper parts of turbidites 

(Bouma, 1962, p. 49), and because they occur with Foraminifera 

typical of offshore open-sea conditions, they suggest that the 

sandstones may represent the distal parts of turbidity current deposits (Walker, 1967). 

INTRUSIVE ROCKS 

Basaltic intrusives are abundant throughout the quadrangle. 

However, all intrusive rocks in the southern two-thirds of the 

quadrangle, as well as the large mass at the west edge (sees. 14 

and 23, T. 11 N., R. 9 W.), are related in origin to the flows exposed along the Columbia River, and are described in the section 

"Basalt Flows and Intrusive Rocks" in this report. The intrusive 

rocks, described here, in the remainder of the quadrangle range 

from basalt dikes a few feet wide to relatively large gabbro intrusives. 

LITHOLOGY 

Many of the small intrusives in the northern third of the quadrangle are porphyritic basalt that closely resembles the porphyritic basalt flows of unit B, and they are undoubtedly shallow 

intrusives related in origin to the unit B volcanic rocks. 
30 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

The larger instrusives are diabases to medium-grained augite 

gabbros that range in texture from intersertal to subophitic; 

some are porphyritic. In a typical gabbro, twinned and zoned plagioclase, which ranges from labradorite to sodic bytownite 

(An r.o-•:J, occurs as phenocrysts and as subophitic intergrowths 

with augite (NY approximately 1.70; 2V typically 46°-49°). Olivine is generally completely altered to clay minerals; however, a 

small amount is preserved in places (Foso in one occurrence). 

Scattered subhedral to skeletal crystals of magnetite or ilmenite occur, and patches of chloritic or montmorillonitic clay minerals fill some interstices. 

Some of the intrusive rocks have been albitized. In a typical example (table 7, column 49), plagioclase has been altered to 

oligoclase and thomsonite, a calcic zeolite. A few unaltered cores 

in large plagioclase crystals are of labradoritic composition. 

Columns 45 to 48 of table 7 represent unalbitized rocks or 

rocks in which only incipient alteration has occurred (columns 46 

and 4 7 table 20) . They contain small amounts of normative 

quartz and orthoclase, and the normative plagioclase is An 56-63· 

Such rocks approximate N ockolds' average tholeiitic basalt 

(N ockolds, 1954, table 7), and they fall close to the Crescentunit B basalt trend in figure 12. 

Columns 49 and 50 (table 7) are analyses of albitized rocks 

probably modified by addition of soda. Their original composition 

may have been similar to that of the rocks of columns 45 to 48. 

Because of their usually high soda contents, they fall well above 

the Crescent-unit B basalt trend shown in figure 12. 

AGE AND GEOLOGIC RELATIONS 

A late Eocene age is inferred for the intrusive rocks because 

( 1) the smaller intrusives are petrographically similar to the 

flows of unit B; (2) the intrusive rocks and the volcanic rocks of 

unit B are closely associated geographically; (3) intrusive rocks 

extensively intrude the Crescent Formation and units A and B, 

but are not known to intrude strata younger than unit B; ( 4) the 

unaltered intrusive rocks lie close to the Crescent-unit B basalt 

trend (fig. 12). 

EOCENE(?) TO MIOCENE SERIES 

LINCOLN CREEK FORMATION 

Marine tuffaceous siltstone, with subordinate basaltic and glauconitic sandstone, overlies unit B and is referred to the Lincoln 

Creek Formation (Beikman and others, 1967). The formation 
EOCENE ( ?) TO MIOCENE SERIES 31 

TABLE 7 .-Chemical analyses and normative compositions, in weight percent, of 

Eocene intrusi11e rocks 

[Analyses recalculated to water-free basis. Analytical methods described by Shapiro and Brannock (1~62), 

supplemented by X-ray fluorescence. Analysts: P. L. D. Elmore, S.D. Botts, G. W. Chloe, Lowell Artis, Hezekiah Smith. Location of samples shown in fig. 4] 

Si02---- ___________ _ AbO a_ _____________ _ 

F~OL ____________ _ FeO _______________ _ MgO ______________ _ CaO ______________ _ 

Na20 ______________ _ 

K20 __________ - ----- Ti02 ______________ _ 

P20 5- ______ -------- MnO _______ -------- C02-- _____________ _ H20- _____________ _ 

H20+---- --- _ ------

45 

49.9 

16.0 

3.0 

8.9 

4.6 

10.7 

2.9 

.61 

3.1 

.39 

.16 

.68 

.91 

Q__________________ 2.9 

Or_________________ 3.6 Ab_________________ 24.1 An_________________ 29. 0 

Wo __ -------------- 9.0 En_________________ 11.4 Fs_________________ 9.1 Fo ________________ _ Fa ________________ _ 

Mt_._______________ 4.3 IL _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 5. 8 

Ap_________________ .9 Cc ________________ _ 

Normative plagioclase________ An 55 

46 47 

Chemical analyses 

46.2 47.1 

15.1 15.1 6.1 6.1 8.2 8.1 6.1 6.0 10.4 9.8 2.6 2.6 .57 .56 4.0 3.9 .50 .53 .18 .17 

.10 .05 1.8 1.9 2.2 1.5 

Norms 

1.7 3.4 3.4 3.3 22.1 22.0 27.9 27.8 8.3 7.1 15.1 15.0 3.9 3.8 

8.8 8.9 7.5 7.3 1.2 1.3 .2 .1 

An5s An5s 

48 

49.1 

16.8 

5.3 

5. 7 4. 7 12.1 

2.4 

.17 

3.1 

.40 

.13 

.08 

3.0 

1.0 

7.2 

1.0 

20.3 

34.5 

9.3 

11.7 

1.2 

7. 7 5.9 

.9 

.2 

An6a 

49 

48.7 

16.1 

3.3 

8.9 

5.3 

9.0 

3.9 

.91 

3.1 

.46 

.17 

.16 

.59 

3.7 

5.4 

32.7 

23.9 

7.0 

6.4 

4.2 

4.8 

3.5 

4.8 

6.0 

1.1 

.4 

An42 

50 

48.0 

14.0 

3.4 

10.6 

5.8 

9.5 

3.1 

.67 

4.0 

.57 

.21 

.08 

.79 

1.9 

3.9 

26.0 

22.5 

8.5 

14.4 

10.5 .1 

.1 

4.9 

7.6 

1.4 

.2 

An4s 

45. Porphyritic basalt dike in NW,Y.4NW>4 sec. 35, T. 12 N., R. 8 W. Field No. WGR-63-415; USGS Lab. No. 162227. 46. Porphyritic basalt with partially altered plagioclase, SW%NW~;j' sec. 3, T. 11 N., R. 7 W. Field No. WoGR64-592; USGS Lab. No. 164290. 47. Gabbro (from same intrusive as no. 46), SE~-4NW% sec. 3, T. 11 N., R. 7 W. Field No. WoGR64- 593; USGS Lab. No. 164291. 48. Diabase intrusive from SE%SE~i sec. 8, T. 11 N., R. 8 W. Field No. WoGR64-494; USGS Lab. No. 164285. 49. Porphyritic basalt with plagioclase altered to oligoclase and thomsonite, NE,Y.4NE% sec. 2, T. 11 N., 

R. 9 W. Field No. WoGR64-476; USGS Lab. No. 164282. . 50. Basalt with partially albitized plagioclase, NW~iNW~4 sec. 33, T. 12 N., R. 7 W. Field No. WoGR64- 714; USGS Lab. No. 164295. 

crops out extensively in the southeastern part of the Grays River 

quadrangle but has not been recognized elsewhere in the quadrangle. However, unit B and Lincoln Creek siltstones are lithologically similar, and unit B in this area may include some strata 

equivalent to the Lincoln Creek Formation. 

No obvious angular discordance is recognized between the Lincoln Creek Formation and the older rocks in the central part of 

the quadrangle, but an unconformity separates the Lincoln Creek 

from unit Beast of the Grays River valley. 

Sparsity of structural data due to poor exposures precludes a 

precise determination of the formation's thickness, which un-
32 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

doubtedly varies because of the unconformity between the Lincoln 

Creek and the overlying Astoria Formation. The Atlantic Richfield Co.-Weyerhaeuser 1 well, near the mouth of Deep River, 

penetrated approximately 3,500 feet of strata that correlate with 

the Lincoln Creek Formation on the basis of Foraminifera. 

LITHOLOGY 

The Lincoln Creek Formation consists of two units of tuffaceous siltstone, each with a basal zone of basaltic and glauconitic 

sandstone. A discontinuous line drawn from sec. 24, T. 10 N., R. 

8 W., to sec. 2, T. 9 N., R. 7 W., indicates the lowest occurrence 

known of glauconite or sandstone in the upper part of the formation. Relatively well sorted very fine-grained sandstone interlaminated with tuffaceous siltstone near the east edge of the quadrangle (fig. 4) may be a local facies of the lower part of the 

formation or possibly a pre-Lincoln Creek unit in fault or unconformable contact with the Lincoln Creek. 

SILTSTONE 

Lincoln Creek siltstone is commonly massive or indistinctly 

bedded, although it is distinctly bedded locally. In general, bedding is less well developed than in unit B siltstones. The rock is 

well indurated in the lower part of the formation but becomes 

less well indurated upward. Concretions are common. In fresh 

outcrop surfaces the siltstone is gray, but in most exposures it is 

weathered to soft yellow clay. The siltstone contains scattered 

clasts of quartz and feldspar, basaltic fragments partly altered to 

glauconite, and glass shards altered to heulandite in a matrix of 

montmorillonitic clay (fig. 13). Foraminifera are locally abundant. 

LOWER BASAL TIC AND GLAUCONITIC SANDSTONE 

Basaltic sandstone occurs in the lower part of the Lincoln 

Creek Formation, and the contact with unit B is at its base. It is 

thickest, about 800 feet, in the east-central part of the quadrangle 

near Fossil and Klints Creeks, where it contains interbedded siltstone. The sandstone is medium light gray to olive gray or dark 

greenish gray, massive, and very fine to fine grained. In the easternmost outcrops, where large clasts are coarsest and most abundant, it contains rounded grains of basalt and glauconite up to 

half a centimeter in diameter. Carbonized wood fragments occur 

locally. Molluscan fossils are abundant, and subspherical concretions up to several inches in diameter commonly contain crab re-
EOCENE(?) TO MIOCENE SERIES 33 

FIGURE 13.-Photomicrograph of Lincoln Creek tuffaceous siltstone. Quartz, 

feldspar, glass shards, and lithic fragments in montmorillonitic matrix. 

Black spots are iron sulfide nodules and carbonaceous fragments. Planepolarized light. 

mains. West of the Grays River valley, the sandstone is much 

thinner, the sandstone-siltstone ratio is lower, and the largest 

grains are much smaller. 

The average composition of the lower basaltic and glauconitic 

sandstone of the Lincoln Creek Formation is shown below. The 

data are based on seven thin-section point counts supplemented 

by counts on stained grain mounts. 

Volume 

percent (avg) 

Monocrystalline quartz ------------------------------------------ 9 

Polycrystalline quartz -------------------------------------------- 2 

Potassium feldspar ---------------------------------------------- 4 

Plagioclase ----------------------------------------------------- 12 

Mica and chlorite ----------------------------------------------- 4 

Volcanic rocks -------------------------------------------------- 14 

Volcanic(?) rocks ----------------------------------------------- 9 

Matrix -------------------------------------------------------- 37 

Glauconite ------------------------------------------------------ 7 

Other ---------------------------------------------------------- 2 

100 
34 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

The lower sandstone is volcanic wacke consisting predominantly 

of grains of quartz, feldspar, basalt, and glauconite in a matrix 

of clay minerals, silt, and some calcite (fig. 14). The clasts are 

mainly angular silt to fine-sand size grains, but rounded volcanic 

fragments and glauconite grains through the sand and granule 

sizes occur in places. As a group, the lower sandstones are richer 

in plagioclase relative to quartz and potassium feldspar than the 

other Lincoln Creek sandstone units in the map area (fig. 15). 

Basalt fragments, many with trachytic and porphyritic textures 

similar to those of unit B volcanic rocks, are commonly altered in 

varying degrees to glauconite. Although some glauconite formed 

from nonvolcanic detritus such as biotite or from unidentifiable 

fine-grained source materials, much of the glauconite is an alteration product of volcanic detritus. Accordingly, rocks with much 

glauconite have few volcanic and probable volcanic clasts. Typically, volcanic fragments, probable volcanic fragments, and glauconite together make up about 30 percent of lower Lincoln Creek 

sandstone. Matrix material, from about 30 to 45 percent of the 

sandstone, is detrital silt and clay, calcite, and clay minerals derived from unstable clasts whose boundaries are now unrecognizable. 

FIGURE 14.- Photomicrograph of lower basaltic sandstone of the Lincoln 

Creek Formation. Predominantly quartz, feldspar, basaltic fragments, and 

glauconite in a calcareous matrix. Plane-polarized light. 
EOCENE ( ?) TO MIOCENE SERIES 35 

Quartz 

0 

0 

0 

EXPLANATION 

0 

Upper basaltic and glauconitic 

sandstone 

Lower basaltic and glauconitic 

sandstone; hornblende plus 

epidote z 40 percent 

~ Lower basaltic and glauconitic 

sandstone; hornblende plus 

epidote ::;; 4 percent 

0 

lnterlaminated sandstone 

and siltstone 

FIGURE 15.-Relative proportions of quartz, potassium feldspar, and plagioclase in Lincoln Creek Formation sandstones. 

Heavy minerals from 11 samples from the Grays River quadrangle and from the Skamokawa quadrangle in the headwaters of 

Fossil Creek were examined. The lower Lincoln Creek sandstones, 

like the unit B sandstones, can be separated into two distinct 

groups on the basis of heavy minerals. Heavy minerals from 

three rocks, two of them from the westernmost outcrops west of 

Hull Creek, contain 0 to 4 percent hornblende plus epidote and 

consist mainly of garnet, zircon, sphene, and apatite with small 

amounts of rutile and tourmaline. The remaining samples, all 

from east of Hull Creek, contain from 40 to 83 percent amphibole 

plus epidote. Amphibole is predominantly green or blue-green 

hornblende with subordinate brown hornblende and, in a few 

samples, a small amount of a distinctive red oxyhornblende. Zircon, garnet, sphene, and apatite are common in the hornblendeepidote-rich rocks, and tourmaline, rutile, staurolite, and clinopyroxene occur in small quantities. Data are insufficient to show 

any clear relation between variation in light- and heavy-mineral 

compositions (fig. 15). 
36 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

UPPER BASALTIC AND GLAUCONITIC SANDSTONE 

In the upper part of the formation, glauconitic, basaltic, and 

tuffaceous sandstone is abundant, although subordinate to siltstone. Light-colored tuff beds occur locally. Glauconitic beds are 

common, some being more than 10 feet thick and in many places 

consisting of more than 50 percent glauconite. 

The upper sandstones are intensively weathered and consist 

largely of an oxidized paste. Angular quartz and feldspar of silt 

to very fine sand size constitute about 20 to 25 percent of the rock, 

and the few other identifiable grains include glauconite, volcanic 

clasts, and mica. Grain-mount counts of three specimens suggest 

that the upper basaltic sandstones contain less plagioclase relative 

to quartz and potassium feldspar than do the lower Lincoln Creek 

basaltic sandstones (fig. 15). 

Green or blue-green amphibole and epidote together constitute 

32 to 74 percent of nonopaque heavy minerals counted in seven 

samples. Zircon, ranging from 1 to 52 percent, is predominant 

among the remaining heavy minerals. Garnet, sphene, tourmaline, 

apatite, staurolite, and rutile each generally constitute less than 

10 percent of any sample, and monazite, a red oxyhornblende, and 

clinopyroxene are extremely rare. 

East of Jim Crow Creek in the SWl!t. sec. 3, T. 9 N., R. 7 W., 

the small knoll which is nearly enclosed by the 600-foot topographic contour line on the topographic map is underlain by very 

fine to fine-grained volcanic wacke with a small amount of lapilli 

tuff. The tuff consists of granules of amygdaloidal vitrophyre and 

microporphyritic basalt in a sandstone matrix. About 3,000 feet 

to the east on the small hill in the SEl!t. SE1j1 sec. 3, T. 9 N., R. 7 

W., a breccia dike intrudes tuffaceous sandy siltstone overlain by 

at least 10 feet of glauconitic sandstone. The dike, which cannot 

be traced to the top of the outcrop, consists of granules of the 

same amygdaloidal vitrophyre and microporphyritic basalt as 

occur in the tuff in a detrital groundmass of very fine to finegrained sandstone. The vitrophyre granules are angular; plagioclase crystals and sharp projections of volcanic glass extend unbroken from the granules into the enclosing sandstone matrix. 

INTERLAMINATED SANDSTONE AND SILTSTONE 

Siltstone with some interlaminated sandstone is exposed in the 

headwaters of Klints Creek and in roadcuts at the east edge of 

the quadrangle (fig. 4). The same sequence is also exposed in the 

valley of Eggman Creek just east of the quadrangle. 

The siltstone, which is tuffaceous and montmorillonitic, is rela-
EOCENE(?) TO MIOCENE SERIES 37 

tively soft and contains some mica and abundant finely comminuted carbonaceous debris. The sandstone is relatively well sorted 

and very fine to fine grained with well-developed lamination and 

small-scale crossbedding. Mica and carbonaceous debris are 

abundant on sandstone bedding surfaces, and a few thin coaly 

laminae occur locally. Round limestone cobbles that may be reworked concretions occur in a 2- to 3-foot-thick lens of sandy conglomerate in Klints Creek. The conglomerate contains poorly preserved mollusks (M-15, table 9); mud pecten shells occur locally 

on sandstone bedding surfaces. 

Modal analyses of two sandstone samples (shown below) from 

interlaminated sandstone and siltstone indicate that they contain 

less volcanic detritus than other Lincoln Creek sandstones and 

less plagioclase relative to quartz and potash feldspar than the 

nearby lower Lincoln Creek basaltic sandstone (fig. 15). The matrix is clay minerals and calcite. 

Monocrystalline quartz ---------------------------

Polycrystalline quartz ----------------------------

Potassium feldspar -------------------------------

Plagioclase --------------------------------------

Mica and chlorite ---------------------------------

Metamorphic rocks -------------------------------

Volcanic rocks -----------------------------------

Indeterminate fine-grained clasts ------------------

Matrix ------------------------------------------

Other -------------------------------------------

Volume 

percent 

17 

4.5 

7 

14 

7 

1 

3.5 

6 

40 

0 

100 

Volume 

percent 

13.5 

7.5 

11.5 

15.5 

2.5 

1.5 

10.5 

6 

31 

.5 

100 

Predominant nonopaque heavy minerals in the sandstone are 

zircon, garnet, sphene, and apatite. Minor constituents include 

tourmaline, staurolite, rutile, epidote, and rare hornblende. 

Poor exposure obscures the relations of the interlaminated 

sandstone and siltstone to the lower part' of the Lincoln Creek 

Formation, which crops out nearby. The interlaminated sandstone 

and siltstone differ from the nearby Lincoln Creek strata in both 

mineralogy and fabric but resemble the very fine-grained sandstone and interlaminated siltstone in unit B. In figure 4 the unit 

is shown as a local facies of the lower part of the Lincoln Creek. 

Alternatively, it may be part of unit B, either in fault contact 

with, or unconformably overlain by, the Lincoln Creek. 
38 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

AGE AND CORRELATION 

Foraminifera (table 8) from the lower basaltic sandstone of 

the Lincoln Creek Formation (F-31 to F-36) represent the Sigmmnorphina schencki zone of Snavely and others (1958) and 

Cass·idulina galvinensis zone of Rau ( 1966) of latest Eocene ( ?) 

and Oligocene age (Refugian Stage of Schenck and Kleinpell, 

1936). Foraminifera from the remainder of the formation (F -37 

to F-47) represent the Pseudoglandulina aff. P. 1:njlatn zone 

(Rau, 1958) of Oligocene age (Zemorrian Stage of Kleinpell, 

1938). Foraminifera (see fig. 4) suggest that the uppermost part 

of unit B (of early Refugian Age) in the Grays River area may 

TABLE 8.-Foraminijera from Lincoln Creek 

[Identifications by W. W. Rau, Fossil localities shown in fig. 4, except 

Fossil localities __________________________________________________________________ F-31 F-32 

Washington Div. Mines and Geology Lab. No _______________________________________ S-410 S-408 

Allomorphina macrostoma Karrer___________________________________________________ C AnomaUna californiensis Cushman and Hobson _____________________________________ _ Bolivina sp _____________________________________________________________________ _ 

margz:nata adelaidana Cushman and Kleinpell ___________________________________ _ 

Buccella mansfieldi oregonensis (Cushman, R. E. and Stewart, K. C.)_ _________________ _ Bulimina alligata Cushman and Laiming ___________________________________________ _ pupoides d'Orbigny _____________________________________________ ------------- Buliminella subfuszjormis Cushman _______________________________________________ _ Cassidulina crassipunctata Cushman and Hobson ___________________________________ _ galvinensis Cushman and FrizzelL ____________________________________________ _ Cassidulinoides sp _______________________________________________________________ _ Cibicides elmaensis Rau_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ F aff. C. perlucida NuttalL ____________________________________________________ _ Cornuspira byramensis Cushman __________________________________________________ _ Dentalina spp _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ R 

sp. C of Rau, 1948----------------------------------------------------------- quadrulata Cushman and Laiming _____________________________________________ _ 

Ellipsonodosaria cf. E. cocoaensis (Cushman) _______________________________________ _ Elphidium cf. E. minutum Cushman ______________________________________________ _ Entosolenia sp. _________________________________________________________________ _ 

Eponides yeguaensis Weinzierl and Applin __________________________________________ _ Gaudryina alazanensis Cushman __________________________________________________ _ GlobigPrina spp _____________________________________________ ·- ___________________ _ Guttulina sp ____________________________________________________________________ _ 

hantkeni Cushman and Ozawa ________________________________________________ _ 

Gyroidina orbicularis planata Cushman_____________________________________________ F Karreriella washingtonensis Rau __________________________________________________ _ Lagena semistriata Williamson ____________________________________________________ _ Nodosaria cf. N. arundinea Schwager ______________________________________________ _ 

cf. N. grand is Reuss _________________________________________________________ _ Non ion cf. N. incisum (Cushman) _____ ----------------- __________________________ _ pompilloides (Fichtel and Moll) _______________________________________________ _ 

Plectofrondicularia packardi multilineata Cushman and Simonson_______________________ R 

~f~P~ ~~~~~iC'u!~~n~n_d_ ~~~~~~~·- ~·- ~~~= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = Pseudoglandulina injlata (Bornemann) _____________________________________________ _ Pyrgo lupheri Rau ______________________________________________________________ _ Quinqueloculina sp ______________________________________________________________ _ imperialis Hanna and Hanna _________________________________________________ _ weaveri Rau ____________________________________________________ --- ___ - __ ---- Robulu.~ spp ____________________________________________________________________ _ 

cf. R. limbosus hockleyensis (Cushman and Applin) ______________________________ _ 

Sigmomorphina schencki Cushman and Ozawa_______________________________________ R Siphonodosaria jrizzelli Rau ______________________________________________________ _ Spiroloculina texana Cushman and Ellisor __________________________________________ _ Uvigerina garzaensis Cushman and Siegfus _________________________________________ _ Valvulineria willapaensis Rau ____________________________________________________ _ Virgulina sp ___________________________________________________________________ _ 

t SW,!,:[NE7,l, sec. 1, T. 9 N., R. 7 W., Skamokawa quad.; Refugian Stage. 

F 

c 

F 

R 

c 

R 

R 

c 

R 
EOCENE ( ?) TO MIOCENE SERIES 39 

represent strata which are included in the Lincoln Creek Formation in other areas of southwest Washington. 

Mollusks (table 9) from the lower basaltic sandstone are referable to the Oligocene "Lincoln Stage" of Weaver and others 

(1944). Faunal groups corresponding to the Molopophorus gabbi 

(M-3 to M-8) and Twrritella porterens1:s (M-9 to M-14) zones 

of Durham (1944) are recognized. The same strata contain Foraminifera of Refugian Age. 

Megafossils occurring just below the base of the upper basaltic 

and glauconitic sandstone and within the upper part of the Lincoln Creek Formation are referable to the Echinophoria rex 

Formation, Grays River area, Washington 

as noted. C, common; F, few; R, rare; ?, identification questionable] 

F-33 F-34t F-35 F-36 F-37 F-38 F-39 F-40 F-41 F-42 F-43 F-44 F-45 F-46 F-47 

4185 4260 S-407 4187 3901 3899 3897 3903 3898 3906 3905 4206 3904 4203 4350 

F 

R 

R 

R 

R 

R 

F 

c 

c 

F 

F 

R 

F 

F 

R 

F 

F 

F 

R 

c 

F 

R 

R 

R 

c 

R 

c 

F 

F 

R 

R 

F 

? 

R 

R 

F 

c 

R 

F 

c 

c 

c F R F 

R 

F 

F 

R 

R 

R F 

R 

R 

F 

R 

R 

R F 

R ? 

F 

R 

F 

c 

? 

R 

ia' 

F 

c 

c 

R 

F 

R 

R 

R 

R R R 

R F 

R 

F F 

R 

c R F 

c 

R 

F 

F 

F 

F 

F 

R 

F 
40 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 9.-M egafossils from Lincoln Creek 

[Identifications by W. 0. Addicott. Fossil localities shown in fig. 4, except as noted. X, present as for definite identification; aff, comparable but apparently different form; sp, species not determinable; ? 

Fossil localities____________________________________ M-3 M-4 M-5 M-6 M-7 M-81 

U.S.G.S. Cenozoic locality __________________________ M2506 M2499 M2507 M2508 M2518 M2590 

M2564 

Gastropods: Acteon sp ___________ ------------------- ______ _ X 

Aforia campbelli Durham ______________________ _ 

cf. A. clallamensis wardi (Tegland) __________ _ Ampullina? sp ________________________________ _ 

Ancistrolepis clarki forma teglandae Durham ______ _ Bathybembix washingtoniana (Dall) ______________ _ 

Bruclarkia columbiana (Anderson and Martin) ____ _ X Calyptraea sp _________________________________ _ 

::Chrl!sodom1~s',', packardi Weaver ________________ _ Echmophona ______________________________ _ 

Ex ilia lincolnensis Weaver_ ____________________ _ Liracassis apta (Tegland) ______________________ _ 

rex (Tegland) ___ -------------------------- Naticid ______________________________________ _ X Nevcrita sp ___________________________ ---------

Perse lincolnensis (Van Winkle) _________________ _ 

olympicensis quimperensis Durham __________ _ cf cf X cf 

Polinices cf. P. washingtonensis forma lincolnensis (Weaver) __________________________________ _ '?sp Priscofusus chehalisensis (Weaver) ______________ _ cf. P. stewarti (Tegland) ___________________ _ Propebrla? sp _________________________________ _ 

Scaphander cf. S. gordoni Tegland _______________ _ Sip/wnalia washingtonensis (Weaver) ____________ _ '?sp X 

Turricula washingtonensis (Weaver) _____________ _ Turritella diversilineata Merriam ________________ _ '?sp aff. T. hamiltonensis Clark _________________ _ 

Pelecypods: Acila (Truncacila) shu mardi (Dall) ______________ _ X sp sp cf (Acila) gettysburgensis (Reagan) ____________ _ 

cf. A. nehalemensis Hanna _________________ _ X Cardid ______________________________________ _ 

Cochlodesma bainbridgensis Clark _______________ _ Crenella porterensis Weaver? ___________________ _ 

Delectopecten aff. D. peckhami (Gabb) Arnold _____ _ X 

Katherinella arnoldi (Weaver) __________________ _ 

Lucina (Callucina?) dalli (Dickerson) ____________ _ Lucinid ______________________________________ _ X 

X Lucinoma cf. L. hannibali (Clark) _______________ _ Macoma lorenzoensis arnoldi Tegland ____________ _ '?sp twinensis Clark ___________________________ _ 

M acrocallista pittsburgensis (Dall) _______________ _ X 

Mytilid ______________________________ ------ -- _ 

N emocardium lorenzanum (Arnold) ______________ _ '?sp N uculana sp _________________________________ _ 

(Saccella) u•ashingtonensis (Weaver) _________ _ sp cf X 

Periploma bainbridgensis (Clark) ________________ _ 

Pilar dalli (Weaver)_-------------------------- Plagiocardium? lincolnensis (Weaver) ____________ _ sp X X X 

Portlandia chehalisensis (Arnold) ________________ _ 

Solemya (Archarax) cf. S. (A.) dalli Clark ________ _ Solen conradi Dall ____________________________ _ 

cf. S. lincolnensis Weaver __________________ _ X 

Spisula pittsburgensis Clark ____________________ _ Tellina kamakawaensis Clark ___________________ _ cf ?sp X ?sp 

X 

lincolnensis Weaver _______________________ _ X ? aff. "T. obruta Conrad" of authors ________ _ X 

townsendensis Clark _______________________ _ X cf Tellinid ______________________________________ _ X 

Thracia condoni Da!L _________________________ _ schenki Tegland __________________________ _ 

Thyasira cf. T. disjuncta (Gabb) ________________ _ 

Yoldia cf. Y. chehalisensis (Arnold) _____________ _ Cephalopod ______________________________________ _ 

Aturia angustata (Conrad) _____________________ _ Scaphopod _______________________________________ _ 

Dentalium porterensis Weaver __________________ _ Decapod crustacean _______________________________ _ ?sp 

Zanthopsis vulgaris Rathbun____________________ X Barnacle _________________________________________ _ X Fish scales _______________________________________ _ 

1 SE}iSW;i sec. 7, T. 10 N., R. 6 W., Skamokawa quad. 
EOCENE(?) TO MIOCENE SERIES 41 

Formation, Grays River area, Washington 

identified; ?, doubtful identification; cf, similar form, specimen(s) incomplete or too poorly preserved sp, genus questionably identified] 

M-9 M-10 M-11 M-12 M-13 M-14 M-15 M-16 M-17 M-18 M-19 M-20 M-21 

M2561 M2501 M2500 M2505 M2565 M2504 M2566 M2502 M2503 M2786 M2784 M2589 M2782 

X 

X 

X ? 

:X cf ?sp 

X ? 

X 

X 

X X 

X X 

X X X X X X X 

X 

X X cf cf cf X 

X sp X X cf X X 

X sp X 

X 

X 

X X 

X X 

sp cf X sp sp sp 

X X 

X 

X 

X 

X cf X X X sp 

?sp sp X sp X cf sp 

?sp cf X 

X X sp sp X 

X X cf cf cf 

X sp X sp sp sp cf X ? cf cf cf sp X X sp sp X X- X cf ?sp 

X sp sp X sp sp 

X X X 

X 

X sp cf cf cf cf X 

X sp cf 

X 

X sp sp X sp sp sp X 

X 

X X 

X 
42 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

(M-16 to M-17) and Echinophoria apta (M-18 to M-21) zones 

(Durham, 1944) of the "Blakeley Stage" of late Oligocene and 

early Miocene age (Weaver and others, 1944). Foraminifera from 

this part of the formation represent the Zemorrian Pseudoglandulina aff. P. infiata zone, which Rau regards as Oligocene. 

Stratigraphic relations and age of the interlaminated sandstone 

and siltstone at the east edge of the quadrangle are not clear. No 

diagnostic Foraminifera were found. Poorly preserved megafossils (M-15) suggest an age no younger than Oligocene. 

PALEOGEOLOGIC SETTING 

The Lincoln Creek Formation was deposited in a north-southtrending geosyncline open on the west to the Pacific Ocean and 

bounded on the east by largely volcanic continental deposits 

which accumulated in the area of the Cascade Range. Islands and 

peninsulas of pre-Oligocene rock disrupted the continuity of the 

marine basin (Snavely and Wagner, 1963, fig. 13; Wagner and 

Snavely, 1966, p. 42). 

Foraminiferal and molluscan paleoecologic data suggest an 

open-sea, offshore, sublittoral to bathyal environment of deposition. Foraminifera indicate water depths of 300 to 1,000 feet for 

deposition of the lower part of the formation and 1,000 to 3,000 

feet for deposition of the upper part (W. W. Rau, written commun., 1966). Mollusks from the lower sandstone suggest a sublittoral environment with water depths of less than 600 feet, 

whereas mollusks from the upper part of the formation suggest a 

somewhat deeper outermost sublittoral or possible upper bathyal 

environment (W. 0. Addicott, written commun., 1965). 

The presence of a subaerial mass of pre-Oligocene rock near 

the east edge of the quadrangle during the earliest stages of Lincoln Creek deposition is indicated by the angular unconformity at 

the base of the Lincoln Creek Formation near the east edge of 

the quadrangle and by the abundance in the lower sandstone of 

volcanic detritus apparently derived from erosion of unit B subaerial volcanic rocks. Absence of a recognizable microfauna} 

break, the rapid westward thinning of the lower sandstone, and 

the apparent conformity between the Lincoln Creek Formation 

and unit B west of Grays River indicate that deposition of unit B 

and Lincoln Creek strata may have continued uninterrupted a 

short distance west of the pre-Oligocene subaerial high. The upward change from basaltic sandstone to siltstone implies submergence of the local s·ource of basaltic detritus. 

The upper basaltic and glauconitic sandstone may include detri-
EOCENE(?) TO MIOCENE SERIES 43 

tus either eroded from older volcanic rocks within the basin or 

derived from volcanic debris deposited east of the geosyncline. 

However, the presence of the breccia dike east of Jim Crow 

Creek and the nearby outcrops of volcanic wacke and lapilli tuff 

of similar composition (p. 36) suggests that local submarine 

volcanism may also have contributed detritus to the upper basaltic and glauconitic sandstone. 

In addition to the preponderant volcanic detritus, the basaltic 

sandstones of the Lincoln Creek Formation contain heavy minerals derived from crystalline rocks; amphibolites or hornblende 

gneisses probably supplied the abundant green and blue-green 

hornblende. Such rocks are common in the pre-Tertiary orogenic 

belt exposed in the northern Cascade Range and in the Klamath 

Mountains. The abundance of glass shards throughout the formation and the presence of tuff beds in the upper part of the formation record the nearly continuous pyroclastic volcanism that characterized the eastern margin of the geosyncline (Snavely and 

VVagner, 1963,p. 16). 

MIOCENE SERIES 

ASTORIA FORMATION 

Siltstone and sandstone unconformably overlying the Lincoln 

Creek Formation are referred to the Astoria Formation. The 

name "Astoria shales" was originally applied by Condon (Cope, 

1880) to fossiliferous sedimentary rocks that were exposed in the 

vicinity of Astoria, Oreg., but that have since been concealed by 

urban development. Other geologists working in southwestern 

VVashington (for instance, Pease and Hoover, 1957; Snavely and 

others, 1958; VVagner, 1967a, b) have used the name Astoria(?) 

Formation for Miocene strata underlying or interfingering with 

basalt of Miocene age. The name is used here in a similar sense, 

with the exception that the Astoria Formation is not known to 

interfinger with basalt in the Grays River area. 

In this report the Astoria Formation is subdivided into three 

units on the basis of mineral composition and, in part, megascopic differences recognized in the field. Designated I, II, and III 

in figure 4, the units together are equivalent to the previously 

mapped Astoria ( ?) Formation. Unit III coincides with the unnamed unit mapped along the Columbia River bank near Rocky 

Point and on the ridge between Sisson and Salmon Creeks in the 

southwestern part of the quadrangle (VVolfe and McKee, 1968). 

The maximum thickness of the Astoria Formation is unknown. 

The Atlantic Richfield Co.-VV eyerhaeuser 1 well, near the mouth 
44 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

of Deep River, was drilled through about 2,600 feet of strata 

considered to be the Astoria Formation on the basis of Foraminifera. This 2,600-foot thickness, plus approximately 800 feet of 

Unit I strata exposed southwest of the well, plus 1,000 feet or 

more of Unit III, total approximately 4,500 feet for the thickness 

of the Astoria Formation in the southwest part of the Grays 

River quadrangle. The available data suggest that the Astoria 

Formation is unusually thick in the central part of the quadrangle, but the probability of undetected structural repetition precludes determination of the actual thickness. In the southeastern 

part of the quadrangle the thickness ranges from less than 500 

feet near the eastern edge of the map area to approximately 

2,000 feet in the exposures north of Dahlia. 

LITHOLOGY 

UNIT I, ASTORIA FoRMATioN 

Unit I, extensively exposed in the valleys of Grays and Deep 

Rivers, is mainly soft dark-gray argillaceous siltstone to very 

fine-grained sandstone. Fine-and medium-grained sandstones are 

rare. In contrast to most of the pre-Astoria sedimentary rocks, 

unit I contains abundant mica and finely comminuted carbonaceous debris. Glauconite occurs commonly as scattered grains or, 

rarely, is concentrated in beds. Calcareous concretions and massive siltstone similar in appearance to Lincoln Creek siltstone 

occur locally. Unit I is sparsely fossiliferous. 

Much of unit I shows little or no bedding; excavation of relatively unweathered outcrops reveals that nearly all depositional 

structure has been destroyed, presumably by burrowing organisms. Discontinuous wispy layers exposed locally by digging are 

interpreted as remnants of original bedding, and many of the 

strikes and dips of unit I were measured on them. 

Thin sections show that unit I siltstone-sandstone consists of angular to subangular clasts ranging in size from coarse silt to fine 

sand in a matrix that is approximately 30 to 55 percent of the 

rock. The matrix contains detrital silt and clay, as well as unstable clasts so altered that original grain boundaries are indistinguishable. Point counts supplemented by stained grain counts 

give an average composition (table 10) of nearly equal amounts 

of quartz and feldspar and abundant volcanic detritus. Unit I 

tends to be less rich that unit II and more rich than unit III in 

plagioclase relative to quartz plus potash feldspar (fig. 16). In 

contrast to unit III, unit I generally contains more plagioclase 

than potash feldspar. 
MIOCENE SERIES 45 

TABLE 10.-Average compositions, in volume percent, of Astoria Formation sandstones 

Monocrystalline quartz ______________ _ Polycrystalline quartz _______________ _ Potassium feldspar __________________ _ Plagioclase _________________________ _ 

Mica and chlorite ___________________ _ Metamorphic rocks _________________ _ Volcanic rocks _____________________ _ 

Volcanic(?) rocks! __________________ _ Matrix ___________________________ -- Other _____________________________ _ 

Unit I Unit II 

(9 samples) North of 

15 

4 

7 

10 

2 

1 

5 

7 

46 

4 

Altoona Ridge Eden Valley 

(6 samples) (4 samples) 

19 

4 

9 

18 

8 

1 

7 

7 

20 

5 

14 

4 

6 

14 

5 

4 

11 

40 

2 

Unit III 

(9 samples) 

20 

10 

16 

10 

6 

2 

8 

5 

22 

2 

l Volcanic(?) rocks are fine-grained rocks that are probably largely glassy volcanic fragments. 

Quarrz 

. 

0 

EXPLANATION 

0 

North of 

Eden Valley 

Unit 1. 

-. 

South of 

Eden Valley 

Hornblende plus epidote 

:;:2 percent 

Unit II 

Unit Ill 

. -. 

FIGURE 16.-Relative proportions of quartz, potassium feldspar, and plagioclase in the Astoria Formation. 

The heavy minerals of unit I consist predominantly of zircon 

and garnet, with lesser amounts of sphene, tourmaline, apatite, 

and staurolite, and minor monazite, rutile, and kyanite (table 

11). In contrast to unit II, unit I contains little hornblende and 

epidote (fig. 4). 

UNIT II, AsTORIA FoRMATION 

Unit II, in part a lateral equivalent of unit I, forms a band 

along the east edge of unit I and includes all of the Astoria For-
46 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 11.-Heavy-mineral composition of the Astoria Formation, in percent 

Unit II 

Altoona Ridge Unit I ---------- North of Unit II Unit III (20 samples) Low horn- High horn- Eden Valley Average (10 samples) 

blende-epidote blende-epidote (6 samples) (39 samples) 

( <10 percent) ( >10 percent) 

(9 samples) (24 samples) 

Hornblende_ 1 35 8 23 Epidote ____ 1 1 20 29 17 Zircon ______ 30 26 10 9 13 20 Garnet_ ____ 31 21 13 20 16 38 Sphene _____ 11 17 9 15 12 6 Tourmaline_ 8 10 4 7 5 9 Apatite _____ 6 12 6 10 8 11 Monazite ___ 3 2 1 3 Rutile ______ 3 2 1 1 1 2 Staurolite ___ 6 6 2 2 3 7 Kyanite ____ 1 1 1 Other ______ 1 0 2 

mation on Altoona Ridge, immediately north of the Columbia 

River, in the eastern two-thirds of the quadrangle (fig. 4). West 

of the north-south fault that separates the Astoria and Lincoln 

Creek Formations, units I and II are megascopically much alike 

and, at least in the area north of Eden Valley, were first distinguished on the basis of mineralogy. Unit II, however, is sandier, 

slightly coarser (siltstone to fine-grained sandstone), more distinctly bedded, and more fossiliferous than unit I. West of the 

fault, near the mouth of Eden Valley, unit II overlies unit I, but 

farther north unit II is apparently a lateral equivalent of unit I. 

Relatively clean sandstone in beds as thick as 160 feet is interbedded with typical argillaceous Astoria strata on the ridge 

north of the Columbia River in the eastern half of the quadrangle, where the Astoria rests unconformably on the Lincoln Creek 

Formation. The clean sandstone is best exposed in outcrops north 

of Brookfield and on the ridge above Fink Creek. It is generally 

very fine to fine grained and is cross-bedded on a large scale. 

Similar sandstone underlies the unit called basalt of Altoona (see 

p. 57) between Altoona and Dahlia along the bank of the 

Columbia River and occurs in a few thin beds south of Eden Valley, on the western part of Altoona Ridge. 

Unit II rocks are similar to unit I rocks in containing subequal 

amounts of quartz and feldspar and abundant volcanic and probable volcanic detritus in a matrix of detrital silt and clay and the 

decomposition products of altered unstable clasts (table 10). The 

lower average matrix content (20 percent) of the rocks on the 

ridge north of the Columbia River reflects the low matrix content 

(as low as 4 percent) of the well-sorted sandstones interbedded 

with typically argillaceous Astoria siltstone and sandstone. 
MIOCENE SERIES 47 

On the average, unit II is richer in plagioclase than unit I, and 

hence total feldspar exceeds quartz (table 10, fig. 16). With the 

exception of two Altoona Ridge samples of relatively well-sorted 

sandstone with unusually high quartz values (55 and 68 percent), 

unit II is typically richer in plagioclase relative to quartz and 

potash :feldspar than units I and III. Feldspar is generally more 

abundant than quartz in unit II and less abundant than quartz in 

unit I. 

Unit II heavy minerals as a group are distinguished by the 

abundance of green and blue-green hornblende and epidote (fig. 4, 

table 11). Apart from hornblende and epidote, unit II heavy minerals are similar in kind and quantity to those of unit I. They 

consist mainly of zircon, garnet, sphene, and apatite, with minor 

tourmaline, staurolite, monazite, rutile, and kyanite. Hornblende 

and epidote are absent to scarce in 9 of 33 samples collected from 

Altoona Ridge. No systematic relationship between hornblendeepidote abundance and texture, composition, or stratigraphic or 

geographic position within unit II was discovered. 

UNIT III, ASTORIA FORMATION 

Unit III overlies unit I near the west edge of the quadrangle, 

west of Deep River. The unit consists of more than 1,000 feet of 

bedded siltstone with interbeds of very fine to very coarse grained 

friable sandstone from half an inch to at least 40 feet thick. The 

sandstone forms abundant clastic dikes that intrude the surrounding sedimentary rocks. Light-colored tuffaceous beds ranging in thickness from about a sixteenth of an inch to 1 foot occur 

locally. The unit as a whole is characterized by parallel stratification; crossbedding is rare. Parallel lamination and thin bedding 

result from alternation of tuff and siltstone beds, or from concentration of carbonaceous detritus in layers within or at the tops of 

massive sandstone beds. Locally, the sandstone also contains beds 

of tabular pebbles and cobbles derived from the associated siltstone. 

On the ridge south of Salmon Creek, about half a mile west of 

the quadrangle boundary, a conglomerate of pebbles and cobbles 

of basalt is exposed in a single outcrop. Sedimentary rocks above 

and below the conglomerate are similar, except that the overlying 

siltstone may be more tuffaceous than the underlying siltstone 

and contains abundant pumiceous granules and pebbles as well as 

oxidized leaf fragments. 

Except for an isolated concentration of mud pectens, no mega-
48 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

fossils were found in unit III. Foraminifera are present in the siltstone. 

Unit III sandstones contain angular grains through the range 

of sand sizes and hence are coarser than the grains of units I and 

II. Unit III sandstones, like those of unit I, typically contain 

slightly more quartz than feldspar and also contain fairly abundant fragments of volcanic and probable volcanic origin (table 

10) . Polycrystalline quartz comprises a larger part of the total 

quartz than in units I and II, probably because of the coarser 

grain size of unit III. Matrix is less abundant ( 8 to 25 percent) 

than unit I matrix and contains no obvious detrital fines. Volcanic clasts grade into the matrix, which may be entirely decomposition products of unstable fragments. Unit III is distinctive 

because of its low plagioclase content relative to quartz and potash feldspar and its higher ratio of potash feldspar to plagioclase 

(usually > 1) (fig. 16). 

Nonopaque nonmicaceous heavy minerals from the silt to very 

fine sand fractions are similar to those of unit I. Garnet and zircon predominate; tourmaline, sphene, apatite, and staurolite are 

present in moderate amounts; monazite, rutile, and kyanite are 

minor constituents; epidote and hornblende are rare (table 11; 

fig. 4). 

AGE AND CORRELATION 

Foraminifera collected from surface exposures and shallow 

auger holes in units I and II, and in unit III in its more southern 

outcrop, are referable to the Saucesian Stage (early Miocene) of 

Kleinpell (1938). No foraminiferal zonation has been recognized 

in these rocks. However, Foraminifera collected from two localities less than 2 miles west of the Grays River quadrangle, on the 

ridge between Salmon and Sisson Creeks, suggest that at least 

part of unit III, in its ridge outcrops, .may be younger than the 

rest of the Astoria in the Grays River area. Foraminifera from 

just below the basalt sill near the west end of the ridge (F --49, 

table 12) are referred to the Baggina washingtonensis zone, 

which Rau (1967, p. 24, 25) suggests may represent the late 

Saucesian, Relizian, and early Luisian Stages (early to middle 

Miocene) of Kleinpell (1938). Although the evidence is not as 

conclusive, Foraminifera from siltstone above the same sill just 

west of the quadrangle (F -60, table 12) may also belong to the 

Baggina washingtonensiB zone. On the basis of Foraminifera, 

most of the Astoria Formation of the Grays River area is correlative with the Nye Mudstone and Astoria Formation of the New-
MIOCENE SERIES 49 

port Embayment, Oregon {Snavely and others, 1964), with at 

least a lower part of the Clallam Formation of the northern 

Olympic Peninsula (Rau, 1964), and with a lower part of the Astoria of the Grays Harbor basin. 

Molluscan assemblages from the Astoria Formation of the 

Grays River area (table 13) correlate with the fauna of the Astoria Formation of Oregon ( lVloore, 1963) , which is assigned to the 

middle Miocene "Temblor Stage" on the basis of faunal correlation with Califonia rocks. In the Newport Embayment of Oregon 

the Astoria fauna extends down into the upper part of the Nye 

Mudstone. Hence, the Astoria of the Grays River area is broadly 

correlative with the upper part of the Nye Mudstone, as well as 

with the Astoria Formation of the Newport Embayment (W.O. 

Addicott, written commun., 1966). 

PALEOGEOLOGIC SETTING 

Previously published su:mmaries of the geologic history of 

western Washington indicate that by the latter part of early Miocene time the eastern shoreline of the marine basin had shifted 

westward to the approximate position of the present coastline. 

Local structural downwarps, however, indented the Miocene 

coastline. Marine sedimentary rocks of the Astoria Formation of 

the Grays River area were deposited in such a downwarp, near 

the mouth of the present Columbia River. Detritus was probably 

derived largely from northeastern Washington and carried westward by an ancestral Columbia River (Snavely and Wagner, 

1963; Wagner and Snavely, 1966). 

Foraminifera from unit I suggest an offshore, open-sea environment with water 100 to 500 feet deep. A slightly shallower 

depth, perhaps 50 to 500 f4~et, is suggested by unit II Foraminifera (W. W. Rau, written commun., 1966). Molluscan evidence 

(W. 0. Addicott, written eommun., 1965) suggests a middle to 

outer shelf environment for the western part of unit I. Unit II 

megafossil genera having species currently living in the northeastern Pacific Ocean suggest a sublittoral environment with water 

depths of about 100 to 300 :feet. In addition, the molluscan assemblage of unit II suggests that a warmer climate, similar to the 

modern shallow-water clhnate on the Pacific Coast of northern 

Baja California, Mexico, existed in coastal Washington in early to 

middle Miocene time. 

Unit I is interpreted as a relatively deep-water offshore facies 

of the Astoria, and unit II with its sandier character, more distinct bedding, and rich molluscan fauna as a nearshore, shallow-
50 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 12.-Foraminijera from Astoria 

[Identifications by W. W. Rau. Fossil localities F-51 to F-57 shown 

Fossil localities ____________________________________________________ --_-- ____ -----------------

Washington Div. Mines and Geology Lab. No _________________________ ---- __ --------------------

~~Yfv~~~ ~f~s~~ng~~:!~sgu~~;_~_-_- ~ ~ = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = == = == = = = = = = = = = = = = = = = = = = = = = astoriensis Cushman, R. E. and Stewart, K. c ______________________________________________ _ cf. B. brevior Cushman ______________________ ----------- _________________________________ _ marginata adelaidana Cushman and Kleinpel! ____________________________________________ ~---

Buccella rnansfieldi oregonensis (Cushman, R. E. and Stewart, K. C.) ______________________________ _ Bulimina alligata Cushman and Laiming _______________________________________________________ _ ovata d'Orbigny _________________________________________________________________________ _ 

Buliminella subjusijorm is Cushman ___________________________________________________________ _ 

Cassidulina crassipunctata Cushman and Hobson _______________________________________________ _ cf. C. quadrata Cushman and Hughes ______________________________________________________ _ Cibicides atf. C. perlucida NuttalL ____________________________________________________________ _ Dentalina spp ______________________________________________________________________________ _ 

Ellipsonodosaria cf. E. cocoaensis (Cushman) ___________________________________________________ _ 

Elph£dium cf. E. minutum Cushman ___________________________________ ---------------------- __ Epistominella pacifica (Cushman) _____________________________________________________________ _ 

parva (Cushman and Laiming) ___________________________________________________________ _ Gaudryina alazanensis Cushman ______________________________________________________________ _ Globigerina spp _____________________________________________________________________________ _ 

Guttulina problema d'Orbigny ______________________________________________ ~- _________________ _ Gyroidina orbicularis planata Cushman ________________________________________________________ _ Listerella communis (d'Orbigny) _____________________ ---------- _______________________________ _ Marginulina subbullata Hantken ______________________________________________________________ _ Non ion costijerum (Cushman) ________________________________________________________________ _ Nonionella miocenica Cushman _______________________________________________________________ _ 

Planularia astorienesis Cushman, R. E. and Stewart, K. C _______________________________________ _ Plectojrondicularia billmani Rau ______________________________________________________________ _ 

calijornica Cushman and Stewart_ _______________________________ -- _______ -- _______ -- _____ _ 

packardi multilineata Cushman and Simonson ___________________________ --------_--_--_--- __ Pseudoglandulina inftata (Bornemann) __________________________________ - ______ --- ______ ------ __ Quinqueloculina imperial is Hanna and Hanna __________________________________ - _______________ _ 

weaveri Rau ______________________________________ ----------- __ -------------------------- Robulus spp ________________________________________________________________________________ _ 

S iphogenerina kleinpelli Cushman _____________________________________________________________ _ Sphaeroid ina variabilis Reuss _________________________________________________________________ _ 

Uvigerina garzaensis Cushman and Siegfus _____________________________ - ________ ------ _----- _- _- Uvigerinella calijornica ornata Cushman ________________________________________________________ _ cf. U. calijornica ornata Cushman _________________________________________ - __________ -- ___ - obesa impolita Cushman and Laiming ______________________________________________________ _ Valvulineria araucana (d'Orbigny) ____________________________________________________________ _ menloensis Rau _________________________________________________________________________ _ V irgul ina sp _______________________________________________________________________________ _ 

Knappton quadrangle; Saucesian or Relizian Age: 1 NWJ,:J:NW.\4 sec. 11, T. 10 N., R. 9 W. 2 NE>:!SW.\4 Sec. 10, T. 10 N., R. 9 W. a SW_liSW>:! sec. 11, T. 10 N., R. 9 W. 

water facies partly contemporaneous with unit I. As the basin 

filled, the nearshore facies, represented by unit II in the Eden 

Valley area, moved westward over the offshore facies (unit I). 

Farther north, parallelism of unit II with the fault that bounds 

the Astoria on the east suggests that the basin deepened westvvard along a north-south hinge parallel to the fault. Nearshore 

sediments of unit II, locally winnowed by waves or currents, were 

deposited in the shallower eastern part of the basin and are represented by eastward-thinning sandstone and siltstone on Altoona 

Ridge in the eastern half of the quadrangle. 

At approximately the same time that the nearshore facies (unit 

II) was being deposited in the eastern part of the map area, the 

mud and sand of unit III were being deposited near the west edge 
MIOCENE SERIES 51 

Formation, Grays River area, Washington 

in fig. 4. C, common; F, few; R, rare; ?, identification questionable) 

F-481 F-492 F-50 3 F-51 F-52 F-153 F-54 F-55 F-56 F-57 F-584 F-595 F-606 

4261 4267 4208 3914A 3915 4349 3895 4207 4259A 4032 4262 4266 4265 

F 

R 

F 

F 

F 

c 

c 

F 

F 

c 

Knappton quadrangle; Saucesian or Relizian Age: 4 NEii'SW~ sec. 2, T. 9 N., R. 9 W. 5 NW~NW% sec. 15, T. 10 N., R. 9 W. 6 SEJ,4SE7:i sec. 14, T. 10 N., R. 9 W. 

F 

R 

c 

F 

? 

F 

R 

c 

F 

R 

R 

? 

F 

of the quadrangle, possibly in a deep-water, offshore setting. Foraminifera from the southern outcrop area of unit III just west of 

the qu2.drangle (including locality F-58, table 12) suggest an 

open-sea environment with water depths of 500 to 2,000 feet (W. 

W. Rau, written commun., 1966). The only megafossils found in 

unit III were mud pectens at a single locality (M-37, table 13); 

occurring alone, these fossils suggest deposition at bathyal depths 

(W. 0. Addicott, oral commun., 1966). Foraminifera from Rocky 

Point (F-57, table 12) and from the upper part of unit III on 

the ridge south of Salmon Creek (F-59, 60, table 12) indicate 

shallower water depths, 100 to 500 feet and 50 to 300 feet, respectively. Unit III sandstones may have been deposited in relatively deep water, perhaps by turbidity currents. This conclusion 

is supported as follows: Faunal evidence of bathyal depth (at least 
52 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 13.-M egafossils from Astoria 

[Identifications by W. 0. Addicott. Fossil localities shown in fig. 4, except as noted. X, present 

preserved for definite identification; aff, comparable but different form; sp, species not determinable; ? 

Fossil localities _________________________________________________________ M-22 M-23 M-24 

U.S.G.S. Cenozoic locality _______________________________________________ M2780 M2509 M2788 

Echinoid: Periaster? sp_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ X 

Gastropods: ActPon boulderanus Etherington ______________________________________ _ Bruclarkia orPgonensis (Conrad) _____________________________________ _ 

oregonPnsis forma yaquinana (Anderson and Martin) _______________ _ Calyptraea sp ______________________________________________________ _ 

Cancellaria cf. C. oregonensis (Conrad) ________________________________ _ Comitas? n. sp. aff. C. spencerensis Moore _____________________________ _ CrPpidula rostral is (Conrad) _________________________________________ _ Cryptonatica orcgonensis (Conrad) ____________________________________ _ Cylichna sp _______________________________________________________ _ 

Cylichnina petrosa (Conrad) _________________________________________ _ Ficus modPsta Conrad ______________________________________________ _ 

Haminoea articensis Addicott_ _______________________________________ _ H anetia? n. sp _____________________________________________________ _ 

Lidcassis petrosa (Conrad)_ _________________________________________ _ sp Molopophorus? sp __________________________________________________ _ 

N assarius lincolnensis (Anderson and Martin) _________________________ _ Natica cf. N. vokesi Addicott_ _______________________________________ _ Naticid ___________________________________________________________ _ 

"Neptunea" diminuta Etherington ___________________________________ _ Odostomia sp ______________________________________________________ _ Oenopota? s p ______________________________________________________ _ 

Ophiodermella temblorensis (Anderson and Martin) _____________________ _ 

n. sp _________ -- _ --------- --- -------- --- --- -------------- ------ PolinicPs canalis Moore _____________________________________________ _ 

cf. P. galianoi Dall---------------------------------------------- Priscofusus geniculus (Conrad) ______________________________________ _ X 

Psephaea (Miopleiona) indurata (Conrad) _____________________________ _ Scaphander? sp ____________________________________________________ _ Searlesia? sp ______________________________________________________ _ 

Spirotropis washingtonensis Etherington ______________________________ _ Trochita n. sp _____________________________________________________ _ Trophon sp _______________________________________________________ _ Turrid ___________________________________________________________ _ 

Turritella oregonensis (Conrad) ______________________________________ _ 

Pelecypods: Acila (Acila) gettysburgensis (Reagan)_________________________________ X (Truncacila) conradi (Meek)_____________________________________ sp Anadara cf. A. devincta (Conrad) ____________________________________ _ Chione? sp ________________________________________________________ _ 

Crenella cf. C. porterensis Weaver ____________________________________ _ Cyclocardia cf. C. subtPnta (Conrad) __________________________________ _ Delectopecten peckhami (Gab b) Arnold ________________________________ _ Dosinia cf. D. whitneyi (Gabb) ______________________________________ _ Glycymeris sp _____________________________________________________ _ 

Katherinella angustifrons (Conrad)_ __________________________________ _ Lucinoma acutilineata (Conrad) _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ X 

Macoma albaria (Conrad) ______________ ------------__________________ X arctata (Conrad) _______________________________________________ _ 

astori Da!L _____________ --- ____ ---- _--- _-------------- --------- twinrmsis Clark ________________________________________________ _ 

Nucula n. sp. Moore (1963)------------------------------------------

sp- - - - --- ------ ----------------------- ------------------------ Nuculana (Litorhadia) astoriana (Henderson) __________________________ _ (Saccella) calkinsi Moore _______________________________________ _ 

(Sacella) ochsneri elmana Etherington ____________________________ _ Nuculanid ________________________________________________________ _ Panope abrupta (Conrad) ___________________________________________ _ 

Patinowcten propatulus (Conrad) ____________________________________ _ Securella cf. S. ensifera (Dall) _______________________________________ _ Solemya (Archarax) ventricosa Conrad ________________________________ _ Solen con-radi Da!L ________________________________________________ _ Spisula alba ria (Conrad) ____________________________________________ _ Tell ina emacerata Conrad ___________________________________________ _ 

Tellinid ____________________ -------------- ______ -- ____ ------------- Thracia trapezoides Conrad __________________________________________ _ Thyasira bisecta (Conrad) ___________________________________________ _ 

Venerid ________________________________ -------------------- ______ _ Vertipecten fucanus (Dall) ___________________________________________ _ Yold.ia sp _________________________________________________________ _ 

Scaphopods: Dentalium cf. D. pseudonyma Pilsbry and Sharp________________________ sp schencki Moore ________________________________________________ _ 

1 SE~NW!i sec. 12, T. 9 N., R. 7 W., Skamokawa quad. 2 SE:J,iNE~ sec. 35, T. 10N., R. 9W., Knappton quad. 

X 

X 

X 

X 

cf 

?sp 

X 

X 

sp 

X 

X 

X 

X 

X 

X 

X 

sp 

X 

X 

54 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

in part), the extensive development of parallelism in lamination 

and bedding, and the general absence of shallow-water features 

such as large-scale crossbedding and rich molluscan faunas. 

The contrast in composition between the offshore (units I and 

III) and nearshore (unit II) facies suggests that more than one 

route of sand transport to the Grays River area may have existed. The heavy minerals of units I and III and the relatively 

abundant potassium feldspar of unit III could have been derived 

from granitic and high-grade metamorphic rocks, such as those 

exposed north of the Columbia Plateau in northeastern Washington and nearby British Columbia. Unit II undoubtedly includes 

similar source rocks, but the high hornblende-epidote content of 

its heavy minerals and its higher plagioclase content indicate that 

amphibolites and hornblende gneisses such as those of the northern Cascade Range were also significant source rocks. 

MIOCENE TO PLIOCENE(?) SERIES 

BASALT FLOWS AND INTRUSIVE ROCKS 

Basalt flows approximately 500 feet thick overlie the Astoria 

Formation in the southern part of the quadrangle. The flows are 

divided into two units, basalt of Three Tree Point and basalt of 

Altoona, on the basis of lithology, chemistry, and fabric. Intrusive rocks in the southern two-thirds of the quadrangle include 

the two petrochemical types recognized in the flows, as well as a 

third petrochemical type informally designated Pack Sack type 

because of its similarity to the basalt at Pack Sack lookout (Wagner, 1967a). 

LITHOLOGY 

EXTRUSIVE AND INTRUSIVE BASALT OF THREE TREE POINT TYPE 

Basalt of Three Tree Point is exposed along the Columbia 

River in the southeastern part of the quadrangle at Three Tree 

Point and eastward. It consists largely of massive to hackly basalt but also contains some flow breccia and pillow lava. Some intrusive rock may have been mapped with the extrusive unit in its 

westernmost exposures. The basalt is black and aphanitic in the 

flows and in the smaller related intrusives. Larger related intrusives such as the mass on the Columbia River bank immediately 

east of Brookfield or the sill at Elk Mountain have a fine-grained 

sugary texture. 

The basalt of Three Tree Point and the related small intrusives 

are hyalo-ophitic rocks (fig. 17) in which volcanic glass with 
MIOCENE TO PLIOCENE ( ?) SERIES 55 

FIGURE 17.-Photomicrograph of basalt of Three Tree Point. Hyalo-ophitic 

basalt consisting mainly of magnetite- or ilmenite-rich glass, plagioclase, 

and augite. Plane-polarized light. 

abundant magnetite or ilmenite commonly is 40 to 50 percent of 

the total volume. Plagioclase (approximately An4 5 _ 55 ) is about 30 

to 35 percent, and augite (Ny=l.70 to 1.71; 2V=32° to 54°) 20 

to 25 percent of the total volume. Pigeonite is present in some 

rocks, and less than 2 percent of calcite occurs locally in the 

rocks. Absence of olivine distinguishes basalt of Three Tree Point 

type from basalts of Altoona and Pack Sack types. The large intrusive masses are holocrystalline and contain interstitial alkali 

feldspar. 

Chemical analyses of basalt of Three Tree Point type are given 

in table 14 (columns 15 to 25) and in figure 18. The Three Tree 

Point type is characterized by high silica and alkali content. Normative quartz and orthoclase values are high, averaging 10 and 9 

percent, respectively. Normative plagioclase is calcic. andesine, averaging An.r2 in composition. The Three Tree Point type most 

nearly approaches the average andesite or tholeiitic andesite in 

the grouping of Nockolds (1954, table 6). Fused glass beads made 

from basalt of Three Tree Point type have an index of refraction 

from 1.576 to 1.585, significantly lower than that of glass beads 

made from basalts of Altoona and Pack Sack types (McKee, 

1968). 
56 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

TABLE 14.-Chemical analyses and normative compositions in weight percent of basalt 

of Three Tree Point type from the Grays River area and of similar basalt from other 

areas 

[Analyses recalculated to water-free basis; 15-24 by methods described by Shapiro and Brannock (1962), 

supplemented by X -ray fluorescence. Analysts: P. L. D. Elmore, S.D. Botts, G. W. Chloe, Lowell Artis, Hezekiah Smith. Location of 15-21 shown in fig. 4] 

15 16 17 18 19 20 21 22 23 24 25 26 27 

Chemical analyses 

Si02---- -- - -- - 55.6 56.0 55.4 56.6 55 . 2 56.0 56.0 56.2 55.9 56.8 56.0 55.9 54.5 AbOJ- ________ 14 .2 14.6 13.7 14 .0 13.4 13.9 14.0 13.1 13 . 9 14 .5 13.9 14 . 1 14.1 Fe203 ___ ____ _ 1.0 1.1 4.3 2.7 2. 7 3.9 3.1 3. 7 2.4 1.5 2.6 2.2 2.6 Feo ___ _______ 9.6 10.0 8.2 9.3 10 .2 8 .6 9.5 9 . 1 9.6 9.9 9.4 9.9 9.4 MgO _____ ____ 4.0 3.8 4.0 3.2 4.1 3.2 3.4 3.8 3.8 3.6 3.7 3.6 4.2 CaO __ _ ____ __ 7.3 7.0 6.9 7.0 6. 7 6. 7 6.8 6.6 6.9 6.5 6.8 7.1 8.0 Na20 _________ 3 . 3 3.3 3.2 3.0 2.9 3.0 2.7 3.1 3.1 3.4 3.1 3.3 3.0 K20 _____ _____ 1.3 1.3 1.4 1.6 1. 8 1.6 1.7 1.6 1.5 1.5 1.5 1.3 1.5 

Ti02--- -- ---- 1. 8 1.8 2.3 1.9 2 .3 2.0 2.0 2.0 2.1 1.8 2.0 2.0 2.0 P205 ___ ______ .39 .36 .49 .39 .49 .37 .46 .44 .49 .35 .42 .36 .4 Mno __ ____ ___ .20 .20 .16 .20 .17 .71 .20 .11 .19 . 19 .23 .21 .2 

C02---- --- --- 1.2 .53 . 11 .29 .05 .22 H20- ___ ___ __ .32 .34 .86 .57 .41 . 54 .38 .53 .66 .53 -----} 1.2 H20+---- --- - 1.0 1.0 1.1 . 78 . 79 .82 1.0 .67 .94 1.0 

Norms 

Q ______ _____ _ 8.9 8.8 11.3 11 .1 8.9 11.6 11.8 11.7 10.2 8.8 10 .3 8.8 6.9 Or _____ ____ __ 7.8 7.8 8 .5 9.6 10. 8 9.6 10.2 9.6 9.0 9.0 9.2 7. 7 9.0 Ab ______ __ ___ 28.3 27.5 26.8 25.7 24.8 25.7 23.1 26 .6 25.8 28.4 26.3 28.0 25.7 An __ ______ ___ 19.8 21.4 18.9 19.7 17 .9 19.4 20.8 16 .8 19.8 20.1 19.4 19.8 20.3 Wo __ __ ______ 2.6 3.2 4.6 5.2 5.0 4. 7 4.1 4. 7 4.6 4.1 4.3 5.5 7 .0 En _____ ____ __ 9.8 9.3 9.9 8.1 10.1 8.1 8.6 9.3 9.4 8.9 9.2 9.0 10.3 Fs _____ ______ 14.2 14.9 8.1 12.1 13.0 10.6 11.9 10.6 12.4 14 .2 12.2 13.5 12 . 2 

Mt_ --- ----- - 1.5 1.6 6.2 4 . 0 4.0 5.6 4.6 5.3 3.5 2.2 3.9 3.2 3.8 IL ___ ______ __ 3.5 3 .5 4.3 3. 7 4.4 3.8 3.8 3.8 4.1 3.5 3.8 . 3.8 3.8 Ap ___ ____ ____ . 9 .8 1.2 .9 1.2 .9 1.1 1.0 1.2 .8 1.0 . 9 1.0 Cc ____ ___ __ __ 2.8 1.2 .3 . 7 .1 .5 Normative plagioclase __ An41 An44 An41 An43 An42 An43 An41 An39 An43 An4I An12 An41 An44 

15. Basalt of Three Tree Point, Three Tree Point, NW}i sec. 14, T. 9 N., R. 7 W. Field No. WoGR65- 919; USGS Lab. No. 165978. 16. Basalt intrusive, NE}i sec. 18, T . 9 N., R. 7 W., Field No. WoGR65- 1035; USGS Lab. No. 165979. 17. Basalt intrusive, SW}iNW}i sec. 15, T. 9 N., R. 7 W. Field No. WoGR64- 442; USGS Lab. No. 164281. 18. Basalt sill, NW}iNE}i sec. 31, T. llN., R. 7 W. Field No. WGR63-199, USGS Lab. No. 162217. 19. Basalt sill, Elk Mountain, SE}iSE}i sec. 21, T. 10 N., R. 7 W. Field No. WoGR64-523; USGS Lab. No. 164287. 20. Basalt intrusive, NE}iSE}i sec. 22, T. 10 N., R. 8 W. Field No. WGR63- 343; USGS Lab. No. 162218. 21. Basalt dike, NWUSWU sec. 3, T. 10 N., R. 7 W. Field No. WGR63- 71; USGS Lab. No. 162215. 22. Basalt intrusive at Portugese Point ,NEUSE ~ sec. 10, T. 9 N., R. 9 W., Knappton 772' quadrangle, 

Washington. Field No. WoR64- 13; USGS Lab. No. 164299. 23. Basalt sill at Lane Creek, NW}iNW~ sec. 3, T. 10 N., R. 9 W ., Oman Ranch 772' quadrangle, Washington. Field No. WoR64- 9; USGS Lab. No. 164296. 24. Basalt sill, Bear River Ridge, SE}iSE~ sec. 10, T. 10 N., R. 10 W., Chinook 772' quadrangle, 

Washington. Field No. McKFC65- 238; USGS Lab. No. 165982. 25. Average of columns 1 to 10. 26. Tholeiitic basalt, lowest unit of Miocene volcanic rocks, central part of Oregon Coast Range, average of 8 analyses (Snavely and others, 1965, table 1). 27. Yakima Basalt exclusive of late Yakima petrographic type, Columbia Plateau , average of 8 analyses from Waters (1961, table 5). 

Figure 18 shows the very close similarity between the Three 

Tree Point type and the average composition of basalt in the 

lower unit of Miocene volcanic rocks in the Oregon Coast Range 

(Snavely and others, 1965, table 1). Average water-free values 
MIOCENE TO PLIOCENE ( ?) SERIES 57 

for Yakima Basalt of the Columbia River Group exclusive of the 

late Yakima petrographic type (Waters, 1961, table 5) are 

also plotted in figure 18 for comparison. Except for its slightly 

lower silica content, the Yakima Basalt shows striking chemical 

similarity to basalt of Three Tree Point type as well as to the 

lower unit of Miocene volcanic rocks in the Oregon Coast Range, 

as noted previously (Snavely and others, 1965, p. 114). 

EXTRUSIVE AND INTRUSIVE BASALT OF ALTOONA TYPE 

Basalt of Altoona type is exposed along the Columbia River between Altoona and Jim Crow Point. In contrast to the basalt of 

Three Tree Point, it is predominantly flow breccia with small 

amounts of pillow lava and massive basalt. Some of the basaltic 

breccia mapped as basalt of Altoona type may be shallow intrusive rock closely associated with the flows. The basalt is fresh, 

black, and aphanitic. Sparse plagioclase phenocrysts as large as 

half an inch in diameter occur in the flows and in the small intrusive bodies of basalt of Altoona type. 

Basalt of Altoona type is hyalo-ophitic (fig. 19). Glass with 

abundant fine opaque minerals commonly makes up 50 to 60 percent and locally as much as 70 percent (analysis 28, table 15) of 

the total volume. Typically, plagioclase (approximately An6o) 

makes up about 22 to 28 percent, augite (Ny=approximately 

1.71; 2V=48° to 55°) about 9 to 14 percent, and olivine, largely 

altered to mineraloids and clay minerals, about 3 to 6 percent. 

The high ratio of plagioclase to pyroxene, the presence of olivine, 

and the occurrence \>f scattered large plagioclase phenocrysts are 

distinguishing features of basalt of Altoona type. 

The basalt contains small amounts of normative quartz and orthoclase, and the average normative plagioclase composition is 

An-!6 (table 15). Average chemical composition is close to N ockolds' average tholeiitic andesite (1954, table 6). Figure 18 demonstrates the chemical uniformity of basalt of Altoona type. It is 

clearly distinct from basalt of Three Tree Point type because of 

its lower silica content. Basalt of Altoona type contains more 

iron, alkalis, titanium, and phosphate, and less aluminum, magnesium, and calcium than basalt of Pack Sack type. Fused glass 

beads of basalt of Altoona type range in index of refraction from 

1.595 to 1.603, significantly higher indices of refraction than 

beads made from basalt of Three Tree Point type, but their refractive indices coincide in part with those of beads made from 

basalt of Pack Sack type (McKee, 1968) . 
58 GEOLOGY, GRAYS RIVER QUADRANGLE, WASH INGTON 

16 I I 

I A/203 D. 

15 1- X D. D. -

0 0 0 0 •o 14 1- ~ t --&- 0 °BB 0 

w 0 0 13 0 r-- -

• 12 I I I I I 

16 I I I I 1

Fe2 0 3 -f- FeO - 14 r-- 0~ o•~ 

0 0 D o _J3o 12 r-- ~ 0 -

x .. D. IS 0 D D 10 1- 0 

r-- -

8 I I I 1 I 

:~~ : 0:;~ : Q : ~ : DD D~oM::~ I I I I 

11 ~ X& D. CaO--

- D. 

1- g : oj> L:>. -

z ~-W 0 ~ w - u 

a: oo o o o- w I I I [l_ 

3.5 L 0 0 0 0 

oo% ~ 0 rn o D z 3.0 ~ 0 

~ 0 0 z 2.5 0 

u Na 20 w 2.0 

0 2.0 I 

x 0 

0 1.5 Jjo 

~ ~ D o0 • Do-m 

1.0 0 --&- 0 -

oo_. 'if L:>. 

- 0.5 X D. K20 0 I I I I I 

4.0 I I I I 

• Ti02 3.5 1- -

r--ot 000 -eo 0 

3 .0 -

2.5 1- 0 -

D O 

2.0 ~ -&o D. D o 0 0 

1.5 x• D. - D. 

1.0 I 1 I I I I 

0 .9 r-- I I p2 05 0 .7 0~ ·~ 0 cf$Jo -

0.5 1- L:>. 

~ DO 000 D. D-Bf3 Do= 0.3 r-- x• D. 

0.1 I I I 

50 5 1 52 53 54 55 56 57 

Si02 CON TEN T, IN PERCENT 

FIGURE 18.- Silica variation diagrams-basalt flows 

and intrusive rocks. (Analyses recalculated to waterfree basis.) 
MIOCENE TO PLIOCENE ( ?) SERIES 59 

EXPLANATION 

A 

Pack Sack type basalt 

Pomona Basalt of Schmincke (1967), NWV4 

SElf4 sec. 19, T. 11 N., R. 23 E., 10.4 miles 

north of Sunnyside, Wash., from Schmincke (1967., table 4) 

X 

Basalt at Pack Sack lookout, sec. 1, T. 14 N., 

R. 7 W., Raymond quadrangle, Wash. , 

from H. C. Wagner (written com m un., 

1967) 

0 

Altoona-type basalt, Grays River quadrangle 

and vicinity, Washington 

-&-

Tholeiitic basalt, upper unit of Miocene volcanic rocks, central part of Oregon Coast 

Range, average of 11 analyses, from 

Snavely, Wagner, and Macleod (1965, 

table 1) 

Late Yakima petrographic type, Columbia 

Plateau, average of 4 analyses, from 

Waters (1961, table 5) 

• 

Elephant Mountain Basalt of Schmincke 

(1967), SWlj4SWlj4 sec. 33, T. 10 N., 

R. 20 E., central Washington, from 

Schmincke (1967, table 4) 

0 

Three Tree Point type basalt from Grays 

River quadrangle and vicinity, Washington 

Tholeiitic basalt, lower unit of Miocene 

volcanic rocks, central part of Oregon 

Coast Range, average of 8 analyses, from 

Snavely, Wagner, and Macleod, (1965, 

table 1) 

Yakima Basalt exclusive of late Yakima 

petrographic type, Columbia Plateau, average of 8 analyses, from Waters (1961, 

table 5). 

FIGURE 18.-Continued. 

As shown in figure 18, basalt from the upper unit of Miocene 

volcanic rocks in the central part of the Oregon Coast Range 

(Snavely and others, 1965, table 1) is virtually identical chemically with basalt of Altoona type. Snavely, Wagner, and MacLeod 

(1965, p. 114) have pointed out the similarity between their 

upper unit and the late Yakima type of the Columbia River 

Group. In figure 18 an average of four analyses of the late Yakima petrographic type of the Columbia River Group (Waters, 

1961, table 5), as well as an analysis of an upper Yakima flow in 

south-central Washington, the Elephant Mountain Basalt of 

Schmincke (1967, table 4), show marked similarity to basalt of 

Altoona type. 

PACK SAcK TYPE INTRUSIVE RocKs 

Basalt of Pack Sack type, so-called because of its chemical similarity to the basalt at Pack Sack lookout (H. C. Wagner, written 

commun., 1967), is represented by a 200- to 300-foot-thick sill be-
60 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

FIGURE 19.-Photomicrograph of basalt of Altoona type. Glassy basalt with 

microlites of plagioclase, augite, and minor olivine. Plane-polarized light. 

tween Salmon and Sisson Creeks in the southwestern part of the 

Grays River quadrangle and by an intrusive approximately 6 

miles to the north in sees. 14 and 23, T. 11 N., R. 9 W., which is 

part of a much thicker sill extensively exposed west of the map 

area. 

The intrusive between Salmon and Sisson Creeks is a black microporphyritic basalt with aphanitic groundmass. The basalt is 

brecciated in places, and the fractures are filled with carbonate 

minerals. Apophyses of thoroughly decomposed basalt in the siltstone immediately above the upper contact suggest that the mass 

is intrusive. 

Basalt from the southern sill is intersertal to hyalo-ophitic, microporphyritic, and in part slightly trachytic (fig. 20). Subparallel plagioclase phenocrysts (approximately An65 ) are scattered in 

a groundmass containing small randomly oriented to subparallel 

plagioclase laths (approximately An45 ), granules of clinopyroxene 

(Ny= 1.70; 2V approximately 54° ) and olivine (estimated 2V on 

phenocryst suggests composition of approximately Fos5 ), and 
MIOCENE TO PLIOCENE ( ?) SERIES 61 

abundant opaque-dusted glass. An average of two point counts 

on basalt from the southern sill gives the following composition: 

Volume 

percent 

Plagioclase phenocrysts ----------------------------------------- 3.0 

Plagioclase microlites ---- - -------------------------------- - - --- 23.0 

Clinopyroxene granules ----------------------------------------- 19.2 

Olivine phenocrysts ------- ---- --------------------------------- .7 

Olivine granules ___________________ -- --------- --- -------------- 1.8 

Glass and opaque minerals ------ -------------------------------- 51.9 

Carbonate ------------------------------ -------------- --------- .4 

100.0 

TABLE 15.-Chemical analyses and normative com positions, in weight percent, of basalt of Altoona type from the Grays River area and of similar basalt from other areas 

[Analyses recalculated to water-free basis; analyses 28-34 were d one by methods described by Shapiro and Brannock (1962), su pplemented by X-ray fluorescence. Analysts: P. L. D. Elmore, S. D. Botts, G. W . Chloe, Lowell Artis, Hezekiah Smith. Location of 28-32 shown in fig. 4] 

28 29 30 31 32 33 34 35 36 37 38 

Chemical analyses 

SiOL--- --- - -------------- 53.4 51.4 51.5 50.3 51.9 51.3 51.8 51.7 51.8 50. 4 51.6 AhOs_ ___ ___ ______ __ _____ _ 14.6 13.4 13.5 14 .4 13.3 13 .4 14.4 13.9 13.9 13.6 12.6 Fe20a ______ -- __ ---------- 1.7 1.0 2.4 4.8 1.9 2.6 1.5 2 .3 3.5 1.9 2.1 

FeO ____ - --- - -- - --- -- ---- - 8.3 12.3 11 . 7 10 .3 12.5 11.8 11.7 11.2 11.0 12.6 12.6 MgO __________ -- - _------- 3.3 3.9 3.9 4.3 4.6 4.5 4. 7 4 .2 3.9 4.4 4.1 CaO __ ___ __ ______________ 8.2 8.4 R.6 8.3 8.1 8 . 3 8.1 8 .3 7.9 R.4 8.6 Na20 ___ ________ __ __ ______ 3.3 3.3 2.9 2. 7 2.9 2.9 3.0 3.0 3 .1 2.9 2 . 4 

K20 __ __ -- - -------------- - 1.0 .87 . 79 1.1 . 77 1.2 .71 .92 1.0 1.4 1.8 Ti02 __ ___ -- -------------- 3 .2 3.0 2.9 3.0 2.9 3.1 2.6 3.0 3.0 3.2 3.7 P205 ______ - ----------- - -- .67 .60 . 61 .64 .67 .59 .59 .62 .69 . 7 . 72 Mno _____ ___ __ _____ - ____ _ .14 .23 .22 .22 .19 .21 .22 . 20 .23 . 25 .19 

c 02- - -- - -- --- - -- - - ---- --- 2.3 1.7 1.1 . 19 .10 . 73 .87 .09 H20 - _____ - - - __ - - - - - - - - - - .90 .31 . 64 1.6 .11 .46 .41 -----} .9 { .35 

H20+ ------- -- ----------- 1.8 1.5 1.5 1.4 1.3 .64 1.4 .52 

Norms 

Q_-- - -------------------- 12.0 5.4 7. 7 6.0 5.3 4.0 5.4 6.5 6.3 1.7 8 .9 c ___ --------------------- .1 Or _____________________ __ 6.1 5.1 4.6 6. 7 4.6 7.2 4.2 5.5 5.9 8.3 7~ 8- Ab ____ ________ ___ ___ _____ 27.9 27.7 24.2 22.7 24.9 24.9 25.0 25.3 26.2 24.8 20 .6 An __ ______ ___ _____ _______ 21.7 19 .3 21.7 23.8 20.8 19.7 23.8 21.5 21.1 19.9 19.9 Wo __ --- - -- ----- -- ------- 3.1 4.1 5.4 5.8 7.1 3.4 4.1 5 . 7 6. 9 7.8 En _______ ________________ 8.2 9. 7 9 . 7 10.8 11.4 11.1 11.7 10.4 9. 7 11.1 6. 9 Fs _________ ______ ________ 8.8 17.2 15.2 10.5 16.8 14.6 16.5 14.2 12.8 16.7 15.1 

Mt_--- ------------------ 2.4 1.5 3.4 6.9 2.8 3. 8 2.2 3 . 3 5.1 2.R 4.2 IL _________ _________ __ ___ 6.1 5.6 5.4 5. 7 5 .6 6.0 4.R 5.6 5. 7 6. 1 7.0 Ap ___ - - -- -- ----------- --- 1.6 1.4 1.5 1.5 1.6 1.4 1.4 1.5 1.6 1.7 1. 7 Cc ________ ______________ _ 5.2 4.0 2.6 .4 .2 1. 7 2.0 .2 Normative plagioclase _____ _ An44 An41 An47 An 51 An46 An44 An44 An46 An45 An45 An49 

28. Basalt of Altoona, breccia, SE~ SE )4 sec. 18, T. 9 N., R. 7 W. Field No. WoGR65-732A; USGS Lab. No. 165379. 

29. Basalt of Altoona, massive, SE)4SE)4 sec. 18, T. 9 N., R. 7 W. Field No. WoGR65-732; USGS Lab. No. 165378. 

30. Basalt of Altoona, breccia, NW)4NE)4 sec. 16, T. 9 N ., R. 8 W. Field No. WGR63-391; USGS Lab. No. 162224. 

31. Basalt dike, SW>£SE~ sec. 14, T. 10 N., R. 7 W. Field No. WGR63-9; USGS Lab. No. 162214. 32. Basalt intrusive, NE)4SE~ sec. 32, T. 10 N., R. 7 W. Field No. WoGR64- 527; USGS Lab. No. 164288. 

33. Basalt intrusive, SE~SW)4 sec. 7, T. 10 N., R. 6 W., Skamokawa quadrangle, Washington. Field No. WoR64-17; USGS Lab. N o. 164300. 

34. Basalt intrusive, NW>£SW>£ sec. 2, T. 9 N ., R. 4 W., Knappton 7 ,!1 ' quadrangle, Washington. Field No. WoFC65- 61; USGS Lab. No. 165980. 35. Average of columns 1 to 7. 

36. Tholeiitic basalt, upper unit of Miocene volcanic rocks, central part of Oregon Coast Range, average of 11 analyses (Snavely and others, 1965, table 1). 37. Late Yakima petrographic type, Columbia Plateau, average of 4 analyses, from Waters, (1961, table 5). 

38. Elephant Mountain Basalt of Schmincke (1967), SW~SW~ sec. 33, T. 10 N., R. 20 E ., central Washington, from Schmincke (1967, table 4). 
62 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

Basalt from the thicker northern sill is black and finely porphyritic with a fine-grained groundmass. Weathering produces a 

thick brown rind of altered basalt on outcrop surfaces. The basalt 

is holocrystalline, intergranular to subophitic; its composition by 

point count is as follows: 

Volume 

percent 

Plagioclase - --------------------------------------------------- 45.1 

Clinopyroxene ------------------------------------------------- 46.8 

Olivine -------------------------------------------------------- 1.5 

Opaque minerals - - ------------------------------------------- 3.0 

Clay and mineraloid -------------------------------------------- 3.5 

Carbonate ----------------------------------------------------- .1 

100.0 

FIGURE 20.-Photomicrograph of basalt of Pack Sack type from sill south of 

Salmon Creek. Glass-rich microporphyritic basalt with plagioclase, clinopyroxene, and minor olivine. Plane-polarized light. 
MIOCENE TO PLIOCENE ( ?) SERIES 63 

TABLE 16.-Chemical analyses and normative compositions, in weight percent, of basalt 

of Pack Sack type from the Grays River area and of similar basalt from other areas 

[Analyses recalculated to water-free basis; 39-41, 43 by methods described by Shapiro and Brannock (1962), supplemented by X-ray fluorescence. Analysts: P. L. D. Elmore, S. D. Botts, G. W. Chloe, Lowell Artis, Hezekiah Smith. Location of 39-41 shown in fig. 4] 

Si02----- ______________________ _ AbO a ____________________ --- ___ _ 

Fe20a ____ ---------------------- FeO ______ - --------------------- MgO ________________ ----------- CaO __________________________ _ N a20 __________________________ _ K20 ___________________________ _ 

Ti02 ________________ -----------

P20s MnO ____ ----------------------- __________________________ _ 

C02-- __ ---- __ ------------------ H20- _________________________ _ H20+ _________________________ _ 

39 40 

Chemical analyses 

52.1 

14.7 

1.0 

9.5 

6. 7 9.4 

2.6 

.61 

1.6 

.49 

.14 

1.1 

.20 

1.4 

51.8 

14.9 

1.6 

9.0 

6.5 

10.8 

2.3 

.61 

1.8 

.37 

.16 

.12 

.29 

.91 

Norms 

Q______________________________ 4.8 3.5 Or_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 . 6 3 . 6 

Ab_____________________________ 21.6 19.7 An_____________________________ 26.9 28.4 Wo____________________________ 4.0 9.3 En_____________________________ 16.6 16.1 Fs_____________________________ 14.2 12.5 M t_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1. 5 2. 3 IL _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 3 . 1 3 . 5 

Ap_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 1. 2 . 9 

Cc_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 2. 6 . 3 

Normative plagioclase____________ Anss Ansg 

41 

52.1 

15.4 

1.0 

9.4 

7.2 

10.2 

2.4 

.52 

1.4 

.23 

.18 

.27 

.63 

1.8 

3.0 

20.5 

29.5 

8.2 

17.9 

14.4 

1.5 

2. 7 

.6 

Ansg 

42 43 44 

52.0 51.4 51.6 15.0 14.7 14.4 1.2 2.8 1.7 9.3 8.3 9.2 6.8 7.3 7.0 10.1 10.9 10.7 2.4 2.3 2.4 .58 .42 .74 1.6 1.6 1.7 .36 .25 .28 .16 .16 .17 .4 .63 

.33 

3.4 3.2 2.1 3.4 2.5 4.5 20.6 19.4 20.8 28.3 28.5 25.5 7.2 10.0 10.5 16.9 18.2 17.6 13.7 10.6 12.7 1.8 4.1 2.6 3.1 3.0 3.2 

.9 .6 . 7 

1.0 

Ansa Ansg Anss 

39. Basalt sill intruding Astoria Formation in NW%'SW~i sec. 14, T. 10 N., R. 9 W., Knappton 7~' 

quadrangle, Wash. Field No. McKR64-629; USGS Lab. No. 164292. 40. Basalt sill in SW~NE%' sec. 23, T. 11 N., R. 9 W., Oman Ranch 7~' quadrangle, Washington. Field No. WoGR64-492; USGS Lab. No. 164284. 41. Basalt sill in NW%'SE}4 sec. 21, T. 11 N., R. 9 W., Oman Ranch 7~' quadrangle, Wash. Field No. WoFC65-72; USGS Lab. No. 165981. 42. Average of analyses 1 to 3. 43. Basalt at Pack Sack lookout, sec. 1, T. 14 N., R. 7 W., Raymond quadrangle, Wash., from Wagner, 

(written commun., 1967). 44. Pomona Basalt of Schmincke (1967), NW%'SE%' sec. 19, T. 11 N., R. 23 E., 10.4 mile north of Sun- nyside, Wash., from Schmincke (1967, table 4). 

Chemical analyses of basalt of Pack Sack type are listed in 

table 16 (columns 39 to 42) and compared with the basalt at 

Pack Sack lookout (column 43) and Pomona Basalt of Schmincke 

(1967) from south-central Washington (column 44). Basalt of 

Pack Sack type corresponds closely to normal tholeiitic basalt of 

Nockolds (1954, table 7). It contains small amounts of normative 

quartz and orthoclase, and the normative plagioclase averages 

Anss· Chemical data summarized in figure 18 show that Pack Sack 

type basalt in the Grays River area is very similar to both the 

basalt at Pack Sack lookout, Raymond quadrangle, and the Pomona Basalt of Schmincke ( 1967) of the Columbia Plateau. Bas-
64 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

alt of Pack Sack type, like that of Altoona type, clearly differs 

from basalt of Three Tree Point type in its lower silica content. 

Ranges of other oxides exclude or nearly exclude basalt of Altoona type. Pack Sack type is richer than Altoona type in oxides 

of aluminum, magnesium, and calcium, and contains less of all 

other major oxides except silica. Silica variation diagrams for 

basalt of south-central Washington (Schmincke, 1967, fig. 17) 

show the same chemical relationships between Pomona and prePomona b_asalts that exist between Pack Sack and Altoona types 

(fig. 18) . Index of refraction of fused glass beads ranges from 

1.593 to 1.598 and overlaps the range determined for basalt of Altoona type (McKee, 1968). 

AGE AND CORRELATION 

The basalts of Three Tree Point and Altoona rest on the Astoria Formation of early or middle Miocene age. In the central part 

of the Oregon Coast Range the two volcanic units, chemical correlatives of the basalts of Three Tree Point and Altoona, are 

regarded as middle Miocene in age (Snavely and others, 1965, pl. 

1, p. 112). In the Raymond quadrangle, north of the Grays River 

quadrangle, pillow basalt of Three Tree Point type, included in 

the lower part of the Astoria Formation, is interbedded with 

lower Miocene (Saucesian Stage of Kleinpell, 1938) strata (H. C. 

Wagner, written commun., 1967). 

Basalt at Pack Sack lookout in the Raymond quadrangle overlies strata containing mollusks of probable middle to late Miocene 

age; overlying strata contain a molluscan fauna of late Miocene 

or early Pliocene age (H. C. Wagner, written commun., 1967). 

Petrochemically, the basalt flows and intrusive rocks of the 

Grays River area are similar to the Yakima Basalt sequence of 

the Columbia Plateau. Yakima Basalt, including the late Yakima 

petrographic type, is regarded as middle Miocene to early Pliocene in age (Waters, 1961, p. 608); potassium-argon dates, summarized by Swanson (1967, p. 1105), indicate an age of approximately 17 to 12 million years for Yakima and late Yakima type 

flows of the Columbia Plateau. 

An age of early or middle Miocene or younger is inferred for 

the basalt flows and intrusive rocks of the Grays River area. Precise temporal equivalence to noncontiguous basalts of other areas 

is not implied, but approximate temporal equivalence to petrochemically similar basalts of the Columbia Plateau and western 

Oregon seems likely. 
QUATERNARY DEPOSITS 65 

PALEOGEOLOGIC SETTING 

The geologic maps of Oregon (Wells and Peck, 1961) and 

Washington (Huntting and others, 1961) show that the Miocene 

flows and intrusive rocks in the Grays River area are nearly continuous with the Columbia River Group of the Columbia Plateau, 

except in an area covered by younger rocks near Portland. However, the abundance of related intrusives in the Grays River area 

suggests proximity to an eruptive center; thus, the basalts of 

Three Tree Point and Altoona may never have been physically 

connected with basalt flows of the Columbia River Group to the 

east. 

The predominantly massive character of the basalt of Three 

Tree Point indicates that the rock was extruded subaerially. The 

basalt of Altoona, on the other hand, is extensively brecciated and 

locally includes pillow lava; presumably it accumulated below sea 

level in the Grays River area. Complex mixing of sandstone and 

basalt breccia near the lower contact of the basalt of Altoona 

may be the result of splaying of intrusive feeders at very shallow 

depths in wet unconsolidated sand or of disruption of the wet 

sand by an overriding flow. 

The southern sill of basalt of Pack Sack type intrudes the Astoria Formation. Its brecciation and high glass content suggest 

that the intrusion occurred at relatively shallow depths. The 

northern sill, which intrudes unit B, is, however, holocrystalline 

and probably crystallized at significantly greater depths. West of 

the map area, basalts of Three Tree Point and Pack Sack types 

occur as thick, broadly folded, northwest-striking sills. 

QUATERNARY DEPOSITS 

Older alluvium.-Deposits as much as 100 feet thick of sand, 

silt, and gravel derived from the local sedimentary and volcanic 

rocks are mapped as older alluvium (Wolfe and McKee, 1968) 

where they are terrace remnants along the edges of the Grays 

River valley. The broad flat upper surfaces of the terraces are 

easily recognized on aerial photographs. 

Alluvium.-Holocene alluvium consisting of sand, silt, and 

gravel derived from local sources fills the major stream valleys. 

In the valleys of Salmon Creek and the Naselle River, this unit 

also includes some alluvium possibly as old as Pleistocene, as well 

as deposits produced by mass movement on valley walls. 

Landslide debris.-Mass movement, from surface creep to land-
66 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

slides covering areas as wide as half a mile, is ubiquitous. Only 

the largest landslides, easily recognizable on aerial photographs, 

are shown on the map (Wolfe and McKee, 1968). 

REFERENCES CITED 

Beikman, H. M., Rau, W. W., and Wagner, H. C., 1967, The Lincoln Creek 

Formation, Grays Harbor basin, southwestern Washington: U.S. Geol. 

Survey Bull. 1244-I, p. Il-114. 

Bouma, A. H., 1962, Sedimentology of some flysch deposits; a graphic approach to facies interpretation: Amsterdam, Elsevier Publishing Co., 

168 p. 

Clark, B. L., and Vokes, H. E., 1936, Summary of marine Eocene sequence 

of western North America: Geol. Soc. America Bull., v. 47, no. 6, p. 

851-878. 

Cope, E. D., 1880, Corrections of the geological maps of Oregon: Am. N aturalist, v. 14, p. 457-458. 

Durham, J. W., 1944, Megafauna! zones of the Oligocene of northwestern 

Washington: California Univ. Pubs., Dept. Geol. Sci. Bull., v. 27, no 5, 

p. 101-211. 

Gower, H. D., 1960, Geology of the Pysht quadrangle, Washington: U.S. 

Geol. Survey Geol. Quad. Map GQ-129, scale 1 :62,500.' 

Gower, H. D., and Pease, M. H., Jr., 1965, Geology of the Montesano quadrangle, Washington: US. Geol. Survey Geol. Quad. Map GQ-374, scale 

1:62,500 

Henriksen, D. A., 1956, Eocene stratigraphy of the lower Cowlitz River-eastern Willapa Hills area, southwestern Washington: Washington Div. 

Mines and Geology Bull. 43, 122 p. 

Huntting, M. T., Bennett, W. A. G., Livingston, V. E., Jr., and Moen, W. S, 

1961, Geologic map of Washington: Washington Div. Mines and Geology, scale 1:500,000. 

Kleinpell, R. M., 1938, Miocene stratigraphy of California: Tulsa, Okla., Am. 

Assoc. Petroleum Geologists, 450 p. 

Livingston, V. E., Jr., 1966, Geology and mineral resources of the KelsoCathlamet area, Cowlitz and Wahkiakum Counties, Washington: Washington Div. Mines and Geology Bull. 54, 110 p. 

Mallory, V. S., 1959, Lower Tertiary biostratigraphy of the California coast 

ranges: Tulsa, Okla., Am. Assoc. Petroleum Geologists, 416 p. 

McKee, E. H., 1968, Refractive index of glass beads distinguishes Tertiary 

basalts in the Grays River area, southwestern Washington in Geological 

Survey research, 1968: U.S. Geol. Survey Prof. Paper 600-C, p. 

C27-C30. 

Moore, E. J., 1963, Miocene marine mollusks from the Astoria Formation in 

Oregon: U.S. Geol. Survey Prof. Paper 419, 109 p. 

Nockolds, S. R., 1954, Average chemical compositions of some igneous rocks: 

Geol. Soc. America Bull., v. 65, no. 10, p. 1007-1032. 

Pease, H. H., Jr., and Hoover, Linn., 1957, Geology of the Doty-Minot Peak 

area, Washington: U.S. Geol. Survey Oil and Gas Inv. Map OM-188, 

scale 1 :62,500. 
REFERENCES CITED 67 

Rau, W. W., 1958, Stratigraphy and foraminiferal zonation in some of the 

Tertiary rocks of southwestern Washington: U.S. Geol. Survey Oil and 

Gas Inv. Chart OC-57. 

Rau, W. W., 1964, Foraminifera from the northern Olympic Peninsula, 

Washington: U.S. Geol. Survey Prof. Paper 374-G, p. G1-G33. 

---1966, Stratigraphy and Foraminifera of the Satsop River area, southern Olympic Peninsula, Washington: Washington Div. Mines and Geol· 

ogy Bull. 53, 66 p. 

---1967, Geology of the Wynoochee Valley quadrangle, Grays Harbor 

County, Washington: Washington Div. Mines and Geology Bull. 56, 51 

. p. 

Schenck, H. G., and Kleinpell, R. M., 1936, Refugian stage of Pacific Coast 

Tertiary: Am. Assoc. Petroleum Geologists Bull., v. 20, no. 2, p. 

215-225. 

Schmincke, Hans-Ulrich, 1967, Stratigraphy and petrography of four upper 

Yakima basalt flows in south-central Washington: Geol. Soc. America 

Bull., v. 78, no. 11, p. 1385-1422. 

Shapiro, Leonard, and Brannock, W. W., 1962, Rapid analysis of silicate, 

carbonate, and phosphate rocks: U.S. Geol. Survey Bull. 1144-A, p. 

Al-A56. 

Snavely, P. D., Jr., Brown, R. D., Roberts, A. E., and Rau, W. W., 1958, Geology and coal resources of the Centralia-Chehalis district, Washington: U.S. Geol. Survey Bull. 1053, 159 p. 

Snavely, P. D., Jr., MacLeod, N. S., and Wagner, H. C., 1968, Tholeiitic and 

alkalic basalts of the Eocene Siletz River Volcanics, Oregon Coast 

Range: Am. Jour. Sci., v. 266, no. 6, p. 454-481. 

Snavely, P. D., Jr., Rau, W. W., and Wagner, H. C., 1964, Miocene stratigraphy of the Yaquina Bay area, Newport, Oregon: Ore Bin, v. 26, no. 8, 

p. 133-151. 

Snavely, P. D., Jr., and Vokes, H. E., 1949, Geology of the coastal area from 

Cape Kiwanda to Cape Foulweather, Oregon: U.S. Geol. Survey Oil and 

Gas Inv. Prelim. Map 97, scale 1:62,500. 

Snavely, P. D., Jr., and Wagner, H. C., 1963, Tertiary geologic history of 

western Oregon and Washington: Washington Div. Mines and Geology 

Rept. Inv. 22, 25 p. 

Snavely, P. D., Jr., Wagner, H. C., and MacLeod, N. S., 1964, Rhythmic-bedded eugeosynclinal deposits of the Tyee Formation, Oregon Coast 

Range: Kansas Geol. Survey Bull. 169, v. 2, p. 461-480. 

---1965, Preliminary data on compositional variations of Tertiary volcanic rocks in the central part of the Oregon Coast Range: Ore Bin, v. 

27, no. 6, p. 101-117. 

Swanson, D. A., 1967, Yakima Basalt of the Tieton River area, south-central 

Washington: Geol. Soc. America Bull., v. 78, p. 1077-1109. 

Wagner, H. C., 1967a, Preliminary geologic map of the Raymond quadrangle, Pacific County, Washington: U.S. Geol. Survey open-file map, scale 

1:62,500. 

---1967b, Preliminary geologic map of the South Bend quadrangle, Pa-

.cific County, Washington: U.S. Geol. Survey open-file map, scale 

1:62,500. 
68 GEOLOGY, GRAYS RIVER QUADRANGLE, WASHINGTON 

Wagner, H. C., and Snavely, P. D., Jr., 1966, Geology and mineral resources 

-Geology, western Washington, in Mineral and water resources of 

Washington: U.S. 89th Cong., 2d sess., Senate Comm. Interior and Insular Affairs, p. 37-46. 

Walker, R. G., 1967, Turbidite sedimentary structures and their relationship 

to proximal and distal depositional environments: Jour Sed. Petrology, 

v. 37, no. 1, p. 25-43. 

Waters, A. C., 1961, Stratigraphic and lithologic variations in the Columbia 

River basalt: Am. Jour. Sci., v. 259, no. 8, p. 583-611. 

Weaver, C E., 1912, A preliminary report on the Tertiary paleontology of 

western Washington: Washington Geol. Survey Bull. 15, 80 p. 

---1937, Tertiary stratigraphy of western Washington and northwestern 

Oregon: Washington Univ. Pub. Geol., v. 4, 266 p. 

Weaver, C. E., and others, 1944, Correlation of the marine Cenozoic formations of western North America: Geol. Soc. America Bull., v. 55, no. 5, 

p. 569-598. 

Wells, F. G., and Peck, D. L., 1961, Geologic map of Oregon west of the 

121st meridian: U.S. Geol. Survey Misc. Geol. Inv. Map I-325, scale 

1:500,000 

Wilkinson, W. D., Lowry, W. D., and Baldwin, E. M., 1946, Geology of the 

St. Helens quadrangle, Oregon: Oregon Dept. Geology and Mineral Industries, Bull. 31, 39 p. 

Wolfe, E. W., and McKee, E. H., 1968, Geology of the Grays River quadrangle, Wahkiakum and Pacific Counties, Washington: Washington Div. 

Mines and Geology Geol. Map GM-4, scale 1:62,500. 
INDEX 

[Italic page numbers indicate major references] 

A D 

Page Page 

Addicott, W. 0., identification of mollusks_ 3 Diabase 

written commun --------------- 42, 49, 51 

--------------------------------- 29 

Artis, Lowell, analyst _____ 7, 22, 31, 56, 61, 63 

Astoria Formation ----------------------- 43 

age and correlation ------------------ 48 

Foraminifera ------------------------ 49 

fossil zones -------------------------- 48 

glauconite --------------------------- 44 

heavy minerals ------------------- 45, 47 

megafossils -------------------------- 51 

paleogeologic setting ----------------- 49 

petrography ------------------------- 44 

sandstone ---------------------------- 44 

sediment sources ------------------ 49, 54 

siltstone -------------------------- 44, 46 

thickness ---------------------------- 43 

tuff --------------------------------- 47 

unit I. ------------~------------------ 44 

unit II ------------------------------ 45 

unit III ----------------------------- 47 

Atlantic Richfield Weyerhaeuser 1 well __ 19, 

32, 43 

B 

Basalt flows and intrusive rocks ---------- 54 

age and correlation ------------------ 64 

Altoona type petrography ------------ 57 

Chemical analyses ---------- 55, 61, 63, 64 

Pack Sack type petrography --------- 59 

paleogeologic setting ------~---------- 65 

Three Tree Point type petrography __ 54 

"Blakely Stage" ------------------------- 42 

Botts, S. D., analyst 7, 22, 31, 56, 61. 63 

c 

Chloe, G. W., analyst _____ 7, 22, 31, 56, 61, 63 

Clallam Formation ----------------------,.- 49 

Columbia River Group rocks ------------- 65 

Cowlitz Formation ----------------------- 27 

Crescent Formation ---------------------- 4 

age and correlation ------------------ 7 

basalt -------------------------------

chemical analyses ------------------ 6, 23 

Foraminifera ------------------------ 9 

lithology ----------------------------- 4 

paleogeologic setting ----------------- 10 

petrography ------------------------- 5 

Radiolaria --------------------------- 4 

siltstone -----------------------------

tuff ---------------------------------

E 

Elephant Mountain Basalt ------------ 59, 61 

Elmore, P. L. D., analyst __ 7, 22, 31. 56, 61, 63 

Eocene Intrusive rocks ------------------- 29 

age and geologic relations ------------ 30 

alteration ---------------------------- 30 

chemical analyses -------------------- 30 

lithology ----------------------------- 29 

petrography ------------------------- 30 

Eocene Series rocks ---------------------- 4 

Eocene ( ? ) to Miocene Series rocks ------- 30 

F 

Fossil zone, Baggina washingtonensis ----- 48 

Cassidulina galvinensis --------------- 38 

Echinophoria apta ------------------- 42 

rex ------------------------------ 39 

Molopophorus gabbi ------------------ 39 

Pseudoglandulina injtata ---------- 38, 42 

Sigmomorphina schencki ------------- 38 

Turritella porterensis ----------------- 39 

G 

Gabbro ---------------------------------- 29 

H 

Heavy minerals, Astoria Formation ---- 8, 45 

Lincoln Creek Formation ------------ 35 

Unit A sandstone -------------------- 12 

Unit B sandstone -------------------- 17 

L 

Lincoln Creek Formation ---------------- 30 

age and correlation ------------------ 38 

concretions ----------------------- 32, 37 

Foraminifera ------------------------ 38 

fossil zones -------------------------- 38 

glauconite ------------------------ 32, 36 

heavy minerals ---------------------- 35 

interlaminated sandstone and siltstone - 36 

lower basaltic and glauconitic sandstone 32 

megafossils -------------------------- 39 

paleogeologic setting ----------------- 42 

petrography ------------------------- 33 

sandstone ---------------------------- 32 

sediment sources --------------------- 42 

69 
70 INDEX 

Page Page 

Lincoln Creek Formation-Continued s 

siltstone ----------------------------- 32 

thickness ------------------------- 31, 32 Saucesian Stage ---------------------- 48, 64 

tuff --------------------------------- 36 Siletz River Volcanics ------------ 6, 7, 14, 23 

upper basaltic and glauconitic sandstone 36 Smith, Hezekiah, analyst __ 7, 22, 31, 56, 61. 63 

"Lincoln Stage" ------------------------- 39 

Location of report area ------------------ 2 T 

Luisian Stage ------------------------ 48, 49 

"Tejon Stage" --------------------------- 27 

M "Temblor" Stage ------------------------- 49 

Tyee Formation -------------------------- 14 

Mcintosh Formation, correlation with 

Unit A --------------------- 13 U 

Megafossils, Astoria Formation ----------- 51 

Lincoln Creek Formation ------------- 39 Ulatisian (stage) ---------------------- 7, 13 

Unit B ------------------------------ 26 Unit A ---------------------------------- 10 

Miocene Series rocks --------------------- 43 

Miocene to Pliocene ( ?) Series rocks ______ 54 

Miocene volcanic rocks, Oregon 

Coast Range --------- 56, 59, 61 

Modal analysis, Altoona type rocks ------- 57 

Astoria Formation sandstone --------- 45 

Crescent Formation basalt ----------- 5 

Lincoln Creek Formation sandstone_ 33, 37 

Pack Sack type rocks ---------------- 60 

Three Tree Point type rocks --------- 54 

Unit A sandstone -------------------- 11 

Unit B basalt -------------------- 19, 21 

Unit B sandstone -------------------- 17 

N 

Narizian (stage) ---------------------- 7, 13 

Nye Mudstone --------------------------- 49 

p 

Pack Sack Lookout basalt ---------------- 63 

Petrographic techniques ------------------ 4 

Pomona Basalt -------------------------- 63 

Previous investigations, Grays ·River area _ 2 

Q 

Quaternary deposits ---------------------- 65 

R 

Rau, W. W., identification of Forminifera _ 3 

written commun ----- 10, 14, 28, 42, 49, 51 

Raymond quadrangle rocks, correlation 

with Unit A ---------------- 13 

References cited ------------------------- 66 

Refugian Stage -------------------------- 26 

age and correlation ---------------- 8, 13 

Foraminifera ------------------------ 13 

heavy minerals, sandstone ------------ 12 

lithology ----------------------------- 10 

megafossils -------------------------- 18 

modal analyses ----------------------- 11 

paleogeologic setting ----------------- 14 

petrography ------------------------- 11 

sandstone ---------------------------- 10 

siltstone ----------------------------- 10 

Unit B ---------------------------------- 15 

age and correlation ---------------- 8, 26 

basalt ---------------------------- 18, 26 

chemical analyses, basalt ---------- 21, 26 

concretions -------------------------- 15 

Foraminifera ------------------------ 24 

fossil zones -------------------------- 26 

glauconite --------------------------- 16 

heavy minerals (of sandstone) ------- 17 

megafossils ----------------------- 26, 27 

modal analyses, sandstone ------------ 17 

paleogeologic setting ----------------- 28 

petrography ------------------------- 15 

sandstone ---------------------------- 16 

siltstone ----------------------------- 15 

tuff --------------------------------- 18 

volcanic rocks ----------------------- 18 

w 

Wagner, H. C., written commun ------ 59, 64 

y 

Yakima basalt, Columbia River Plateau __ 56, 

57, 59, 61, 64 

z 

Relizian Stage --------------------------- 48 Zemorrian Stage ------------------------- 38 

*U.S. GOVERNMENT PRINTING OFFICE: 1972 0-438-211