______NORTHWEST PETROLEUIVI _ SSOCIATION ..,,

1988. SPRING SYMPOSIUM

OCEAN SHORES TO KALALOCH GUIDEBOOK

MAY 20 AND 21, 1988

...... ,. . \ ' .

WASHINGTON DIVISION OF GEOLOGY AND EARTH RESOURCES Ray Lasmanis, State Geologist

· INTRODUCTION TO THE PETROLEUM GEOLOGY OF THE OLYMPIC COAS T OF WASHINGTON AND ADJACENT PORTIONS OF THE CONTINENTAL SHELF: A ROAD LOG . Compiled by Staff

WASHINGTON DIVISION OF GEOLOGY AND EARTH RESOURCES

This report has not been edited or reviewed for conformity with Division of Geology and Earth Resources standards and nomenclature. This report should not be cited. , . \ •

CONTENTS

Introduction ...... 1

Stratigraphy ...... 2

Tectonics 5

Structure 5

Petroleum Plays ...... 6

References Cited ...... 10 . . Road log ...... -:- ...... 14

Please Note: There is no page 9 in this report ,

IN~ROOUCTION TO THE PETROLEUM GEOLOGY OF -THE OLYMPIC COAST OF WASHINGTON ANO ADJACE NT PARTS OF THE CON TINENTAL SHELF: A ROAD LOG compiled by staff Washington Division of Geology and Earth Resources

INTRODUCTIO N This field trip is designed to introduce geologists to · the structure and stratigraphy of the westernmost Olympic Peninsula between Grays Harbor and Cape Alava (Figure 1). The emphasis of the guide is the petroleum-related aspects of the area but, all of the geology along the route is noted. Structure and stratigraphy observed along this route reflect the complex accretionary tectonics of coastal Washington and Oregon (Figure 2). Much of this geology is poorly understood and little is favorable for petroleum accumulation. However, some of the reservoir and maturation data are surprisingly favorable . Much of this geology can be correlated with structure and stratigraphy on the Washington Outer Continental Shelf [OCS) (McFarland and Rau, 1982; Snavely and others, 1977; Snavely and Kvenvolden, 1988; Snavely, 1988). The road log is adapted, in part, from a 1977 Geological Society of America fie ld guide titled "General Geology of the Southern Olympic Coast" by W. W. Rau . Mos t of the geology contained in this report was gleaned from various inve stigatio ns by Weldon Rau. However, the writers take sole responsibility for any errors in the report. Portions of this field guide are printed with consent of the Geological Society of America. This guide is designed to be used in conjunction with mapping by Walsh and others (1987), by Rau (1975, 1986), and by Tabor and Cady (1978a). Unit symbols in the road log are those given on the maps cited above . The route proceeds northwest from Aberdeen, through Moclips, Tahol ah, Neilton, and Queets to the Kalaloch area in the Olympic Nati onal Park (Figure 1).

l NOTE: Obta in infor mation and appropriate permission , as follows , prior t o starti ng on th is trip : (1) Access to key exposures at Stops 2 , 3, 4, and 7 requires +1.0 feet or lower tides . (2) Particular care should be given to driving as logging trucks present- a hazard on all of these roads. (3) Much of the route i s within the Quinault Nat i on and cannot lega l ly be traversed without a Quinault guide. Geo l ogists may inquire as to the availability of guides at the Quinault Department of Natural Resources in Taholah . (4) Hammers and sampling are not permitted i n the Nationa l Park without a perm i t available at the Park Headquarters i n Port Angeles . (5) The weather is typically awful along this route. Be prepared to be wet . The "outcrops" described in the text are subject to change at any time due to slides and rapid vegetative growth. Plan to search for hidden outcrops. Stra tigraphy The Olympic Peninsula and adjacent portions of the continental shelf contain a thick sequence of middle Eocene to Pliocene, marine and minor paralic, siliciclastic rocks overlying oceanic basement (Figure 3). All of these rocks are overlain by Pliocene and Pleistocene sediments. The sequence is comprised of the fo l lowing units: (A) Crys t all i ne baseme nt exposed southeast of field trip area consists of lower Eocene (Ulatisian) tholeiitic basalt (MORB) with rare intercalations of silicic l astic sed i mentary rocks, all of which are included in the Crescent Formation. Wells drilled in the Raymond-Montesano bas i n and the Shell P-0175 well drilled on the OCS near the mouth of the Columbia River (Rau, 1986; Snavely and Wells, 1984) penetrated Crescent Formation . Although many explorationists regard the Crescent as effective basement , well data indicate that the westernmost exposures are probably involved in thrusting, and as a consequence, Eocene to Pliocene sedimentary strata may under l ie these rocks (Rau, 1986; Snavely and Wagner , 1982). North of Grays Harbo r , within the field trip area, basalts of uncertain origin crop out as exotic blocks within Eocene to Miocene melange sequences; sparse fauna l recover ies suggest that at least some of these rocks are middle Eocene (Ulatisian). These basalts, which form prominent sea stacks along the coast, may be : (1) oceanic crust associated with a microplate that forms the Olympic Core Complex, (2) oceanic

2 crust of the Crescent Format ion [w hich suggests a single, continuous basement terrain everywhere in coastal Washington and British Columbia south of the San Juan fault], (3) flows and sills above basement within sedimentary sequences of Tabor and Cady's Western Olympic Lithic Assemblage (Tabor and Cady 1978 a ) , ·a n d /or ( 4 ) f 1 ow s and s i l l s of Ti l l am o o k / Grays River volcani~J (P. D. Snavely, USGS, oral commun., 1988). (B) The Ozette Melange of middle to late Eocene (Narizian) age (Snavely and Kvenvolden, 1988) and the middle Eocene portions of rocks mapped as Hoh Rock Assemblage by Rau, 1975, 1979) crop out along the northern and southern margins of the field trip area. On the northern margin of the Grays Harbor basin, a few miles north of STOP 1, rocks of probable middle Eocene age mapped as Hoh Rock Assemblage by Rau (1986) are thrust against Crescent basalt. The basalt is, in turn, unconformably overlain by monotonous, deep-water, Eocene siltstones of the Humptulips Formation (Rau, 1987). Upper Eocene rocks are faulted over middle Miocene rocks in the Union Tidelands No. 2 well (Figure 4 after Rau and McFarland, 1982). Snavely and Kvenvolden (1988) interpret a barren, tight, sandstone section between 8,071 and 10,367 feet drilled depth in the Pan American P-0141 well as belonging to the Ozette (Figure 4). The Ozette in the field trip area consists of li thic sandstones (Figure 5) and fine siliciclastic rocks together with altered basalt. Ozette melange will be observed at Stop 2 and as isolated sandstone blocks within younger melange at Stop 3. Oligocene deposition in the area is not well documented. While many faunal assemblages recovered from these rocks are Zemorian to Saucesian, few assemblages unique to the Oligocene are present. (C) The Hoh Rock Assemblage (Rau, 1973), mainly of Saucesian age, was mostly deposited as a turb idite and distal, deep marine sequence . Exposed strata comprise intermediate fan facies (Mutti and Ricci Lucchi facies C - E, 1972). The Hoh rocks will be observed at Stops 3, 5, 6, and T. Figure 6 illustrates the section at Stop 7. The Hoh Rock Assemblage includes both tectonic melange and turbidite sequences. Many exposures of Hoh rocks along the southern portion of the field trip route lie adjacent to faults which a lso cut overlying Mio-Pliocene rocks. The Hoh at Stop 3 is interpreted to be a diap ir (Rau and Grocock, 1974), which appears to displace Pleistocene sediments. Hoh Rock Ass~mblages penetrated in the Shell P-0150 and the P- 0155 OCS wells are also interpreted to be diapirs composed of deep marine fine siliciclastic rocks (F. L. Webster, MMS, or a l . co mm u n . , 1 9 8 8 ) . The Hoh sect i on d r i l 1 e d i n the Pan American P-0141 well appears to be relatively coherent and

3 r

has a high sandstone:fine-clastics ratio. The coarser portions of the Hoh are lithic to lithofeldspathic sandstones (graywackes) consisting mainly of plagioclase, basalt clasts , and mafics with common, very dark gray, angula~ shale clasts ranging from 1/16 to 1/4 inch (Figure 5). Megabreccias-- and conglomerates are common . (D) Upper Mio cene to Pliocene rocks that are exposed along the route of the trip comprise parts of the Montesano and Quinault Formations, some of which were deposited in a high­ energy , shallow marine · environments on the tectonically active accretionary margin (K. A. Campbell, Univ. of WA., written commun ., 1988). The lower part of the Quinault is equivalent to portions of the upper Montesano Formation (Bergen and &ird, 1972) . The lowermost part of the Montesano may be equivalent to part of the Quillayute Formation, which crops out north of the route (Rau, 1979). Offshore, undifferentiated Miocene to Pli ocene si l tstones penetrated in the Shell P-0150, P-0155, and Pan American P-0 141 wells (Snavely and Wagner, 1982; Webster, 1985) are interpreted to be equivalent to the Montesano and overlying Quinault (Figure 4). The Miocene to Pliocene section rests on rocks of various ages owing to a regionally extensive, angular unconformity . The Miocene to Pliocene sections along the route include: (1) The upper Miocene Montesano Formation as descri bed by Rau (1986) and Bigelow (1987) which will be observed at Aberdeen (Stop 1). The Montesano here consists mainly of massive sandstone with interbeds of siltstone, claystone, and coal (Figure 7). These rocks were deposited in at least two Grays Harbor basin deltaic systems (B i gelow, 1987). The sandstones are lithic and lithofeldspathic (Figure 5). (2) The Pl i ocene Quinault Formation crops out west of the Olympic core in a relatively narrow coastal belt essentially between Point Grenvil l e and the Queets River (Rau, 1979). Other l i tho l ogies include l ithic sandstone, siltstone, and minor claystone (Figures 5, 8, 9) . The sections shown on Figure 8 illustrate a sequence interpreted by Rau (1980) to include: (a) an outer continenta l shelf sequence (Duck Creek/Pratt Cliff, north of Stop 3); (b) a bathyal sequence of redeposited sediments, some of which were orginally deposited under neritic conditions (south Taholah); (c) a neritic sequence deposited no deeper than 200 feet at Point Grenvil le (Stop 2) and , (d) a neritic

4 deposit overlain by littoral sandstones and , c o n g l om e r a t e s a t Ca p e El i z a b e t h ( S t o p 3 ) . Ho r n (I-"' ":) · (1969) interpretes the Poin t Grenville sequence ~ ..,;J as a delta but we prefer a proximal fan model / which is als.o consistent with the data. These rocks a·r e ma i n 1 y s i 1 ts tone wi th mi nor 1 i th i c sandstone and claystone. The stratigraphy, foramini1era, and paleoecology of this formation have been studied in detail (Rau, 1970; Horn, 1969).

(E) Younger Pliocene and Pleistocene gravels and other sediments were deposited on various terraces and as alpine glacial sequences. These sediments are thicker than 1900 feet in the Shell P-155 (Webster, 1985, Snavely and Wagner, 1982a). The ~ediments exposed along the route of the trip include: (1) older, deformed, reddish brown weathering, pediment gravels of Pliocene to Pleistocene age; (2) gently deformed Pleistocene gravels (Moore, 1965); (3) beach terrace deposits of Pleistocene age shown on Figure 10 (Rau 1973); and (4) Pleistocene drift and outwash (Moore, 1965). The last are mainly composed of outwash gravels , terminal moraine deposits, and other till from alpine glaciers that flowed down the restricted upper Quinault and Hoh River valleys and spread into wide lobes near the coast . Lake Quinault is partially dammed by one of these moraines.

Tectonics Deformation increases from gentle folding with approximately 150 feet of total uplift of the Pleistocene sequences to intense thrusting and underplating of the Ozette Melange and Hoh Rock Assemblage. Three tectonic events have been recognized : (1) Late Eocene to early Oligocene - Following Ozette deposition , head-on convergence of Paci fic oceanic plates and the older, accreted margin of the North America plate resulted in faulting, uplift, and erosion of pre-early Oligocene rocks. (2) Oligocene - In the Olympic Co re Complex directly east of the field trip area, the Oligocene was primarily a period of uplift and erosion (Tabor and Cady , 1978b). (3) Middle Miocene - A third period of tectonism occurred during the middle Miocene when the Hoh Rock Assemblages and older strata were faulted, folded, and extensively eroded . This event resulted in a widely spread angular unconformity.

5 It is likely that some level of tectonism occurred continuously from the Paleocene to the present and that these three events only represent deformational culminations.

Structure Structure ;~-the field trip area is best des cribed as chaotic. Thrusts (including major underplating}, penetrative folding, broken formations, and melange typical of accretionary margins are exposed along the Olympic beaches (Rau, 1979; Snavely and Kvenvdlden, 1988; Snavely, 1988). Probable shale diapirs such as the Cape Elizabeth structure [Figure 11] (Rau and Grocock, 1974, Orange, 1987) are common on the OCS (Snavely 1981; Snavely and Wells , 1982) . Folding ranges from open to isoclinal with near - vertical to overturned axial planes which may have any orientation. Exposed thrusts generally have east-dipping planes (Rau 1975, 1979, 1987). Snavely and Kvenvolden (1988) infer a possible west­ dipping thrust parallel with the coast. The trace of this thrust is located a few miles offshore except at Ozette Island and the Little Hogsback (directly north of STOP 3) where this thrust may be exposed. While this interpretation may be correct, the contact at little Hogsback could also be the basal contact of a large exotic block in the melange rather than a thrust . North of the field trip area, mainly east-dipping thrusts are interpreted by Rau (1975) to have formed north- trending melange zones. These zones are cut by northeast and northwest-trending strike-slip faults (Rau, 1975, 1979). Higher angle reverse faults and minor normal faults, which have various orientations, are also common. The shale diapirs contain blocks of Hoh Rock Assemblage turb i dites and volcanic rocks . Structure in the Miocene to Pliocene section is general l y less complex. Thrusting apparently commenced during the late Eocene and continued through the early Miocene. Diapirs formed continuously from the Miocene to the Holocene.

Petroleum Plays Despite enticing results of early wildcats, according to the Minerals Management Service (Cooke, 1985), the Wash i ngton OCS [and, by analogy, the Olympic coast] has poor potential to contain significant petroleum accumulations . Cooke estimates the entire Washington/Oregon OCS contains only 40 million barrels and 650 billion cubic feet of risked mean economically recoverable resources. The following summarizes the sparse data available for assessing the petroleum potential of the Olympic coast and adjacent OCS:

6 ) &'

(A) Shows - Numerous wells drilled within and direct ly north of the field trip area had good oil and thermogenic-gas shows including the J. W. Tanner/Sun shine Mining Co . , Medina No. 1 we l l, which recovered 12,000 barrels of 37 to 39 API paraffinic oil [Figure 4] (McFarland, 1983). Several wells near th e town· of Fork s recovered s ma 1 l am o u n ts of s i mi l a r oil. Offshore, the Shell P-150A tested 10 to 26 MCFGPD from Hoh Rock Assemblage (Zieglar and Cassell , 1978). (A) Source Rocks - Despite these shows, no oil-prone and only poorly gas-prone source rocks have been located in Washington and the OCS (Grady, 1985; Snavely and Kvenvolden, 1g88). The rocks are impoverished in organic carbon, and only two hydrogen indices in excess of 250 have been measured . Kvenvolden and others (1988) conclude that oil shows and seeps from Gr·a y s Harbor north to For k s are ro II t JJ a J l :Y correlative . The source of these oils is as-yet unpenetrated intervals within the Ozette melange or older rocks. (B) Maturation - Thermal gradients are a surprisingly high 30 degrees centigrade per kilometer, indicating that the present day oil-generative window lies at depths of 6,000 to 9,000 feet . For this reason, the Washington OCS is considered relatively favorable for oil and gas generation as compared with other accretionary wedges (Snavely, 1988). Tmax and vitrinite reflectance data indi cate in the past, rocks that that have passed through the oil-generative window, may li e at very shallow depths (Grady, 1985; Snavely and Kvenvolden, 1988). (C) Migration - Abundant fine elast ic rocks within every time-stratigraphic unit impede migration. However, thrust faults and diapirs form potential avenues of migration, as evidenced by oil shows in wells which did not penetrate oil­ prone source rocks. The diapir at Cape Elizabeth is petroliferous, and in the past, small, thermogenic gas seeps were active in tidal pools along its southern margin (Rau and Grocock, 1974). (D) Reservoirs - All Hoh and Ozette sandstones observed are lithic to feldspatholithic and contain authigenic-clay, zeolite, and/or calcite cement. Most of these sandstones are texturally immature. Nonetheless, onshore wells near Forks and some outcrop samples have moderately thick, porous and permeable sandstones (Table 1). Reservoir strata onshore may have limited areal extent owing to faults and facies changes. Snavely (1988) suggests that reservoir quality may improve we s t wa r d ; h owe v e r , t h e P- O1 41 we l 1 , t h e o n 1y Wa s h i n g t o n, 0 CS well that did not penetrate a diapir, has little effective porosity.

7 The Miocene to Pliocene section contains remarkable reservoirs. The "Ocean City Sand" of Bergen and Bird (1972) penetrated in the Shell Sampson Johns OCA 2-15 well is 500 feet thick (after correction for mean dip= 40 degrees) and has density-porosity ranging from 24 to 30 percent. The large spontan~ous potentia l , thick mudcake, and moderate invasion profile suggest that this section is continuously porous despitf-a few thin claystone interbeds near the base of the section. A conglomeratic sandstone was penetrated between 454 to 936 feet drilled depth . This zone was not logged with porosity sondes, but qualitative indications of porosity and permeability are present on the dual induction suite . Several other Grays Harbor area wel ls drilled similar Miocene to Pliocene s~ndstone units (Rau and McFarland, 1982). Correlation of these Miocene to Pliocene sandstones with adjacent wells is risky owing to the steep dips and probable rapid facies changes observed elsewhere within the Quinault and Montesano Formations. (E) Structural Plays - Though faulted anticlines are common offshore, public record seismic data are of insufficient quality and quantity to map these folds . Furthermore, reflection quality below the Miocene to Pliocene section is poor. Onshore, exposed folds may be too tight to define using seismic data alone. As noted above, in the section on Tectonics, deformation generally decreases up section . Therefore, folds which developed after the middle Miocene are relatively open and therefore easier to define with reflection data. Acceptable Miocene to Pliocene reservoir strata will be observed in the Montesano (Stop 1), and the Quinault (Stop 2). A porous conglomerate at the base of the Miocene to Pliocene section is an additional reservoir. ~,.. \J ... l,e,( The Shell P-0150 and P-0155 wells both ~d shale diapirs , I ,).tf:. -+ F . L . we I l s , MMS , or a l comm u n . , 1 9 8 8 ) bu t n o we 1 1 s h av e be e n drilled entirely within strata along the margin of these piercement structures. A Miocene to Pliocene sandstone overlying the diapir in the Shell P-0155 ~rorn any petroleum migrating from depth by thick claystone and siltstone sections . A future wildcat dr ill ed along the margin could test all reservoir hor izons sealed by the diapir. The younger the diapir, the greater the number of reservoirs and more porous sandstones that would be evaluated. However, most of these diapirs appear to be roughly circular in plan, so structural closure is probably limited (P. D. Sn-avely, USGS, oral commun. , 1988).

8 TABLE !.--Characteristics of some Olympic Coast and Washington OCS reservoir~-- rocks UNIT POROSITY (%) PERMEABILITY (md) THICKNESS (Reference) ( %) (md) dtt.)

Quinault \ 3 2 1153 ? Olympic coast ,__ (Horn, 1969) [Mean of 9 outcrop samples] . She 11 26 good 500 Sampson Johns 2-15 unknown good 381 [density/sonic*] Hoh/Ozette Browns Point 7 ? 131 (Grady, 1985) --1- ? 59 Belco 1 7 poor 40 Milwaukee Lands-1 [density porosity]

Sunburst State 8-16 1 9 ? 33** (Chamberlain, 1981) 1 7 ? 27 [FOC/CNL porosity] 18 ? 66 18 ? 29 17 ? 15

Western Olympics 13 14 ? (Snavely, 1988) [Mean of 25 outcrop & core samples]

* The Compaction correction for this sandstone is unknown and therefore the reported porosity may be conservative. ** Dips in this well are unknown

10 REFERENCES CITED Addicott, W. 0., 1976, Neogene molluscan stages of Oregon and Washington. In Fritsche, A. E.; Ter Best, Harry, Jr.; Wornardt, W. W., editors, 1976, The Neogene symposium--Se·lected technical papers on paleontology, sedimentology, petrology, tectonics and geologic history of the Pacific coast of North America: Society of Economic Paleontologists and Mineralogists Pacific Section, 51st Annual Meeting, p. 95-115 . Bergen, F. W. ; Bird, K. J., 1972, The biostratigraphy of the Ocean City area, Washington . In The Pacific Coast Miocene Biostratigraphic Symposium, Proceedings: Society of Economic Paleontologists and Mineralogists Pacific Section, p. 173-191. Bigelow, P. K., 1987, The petrology, stratigraphy and basin history of the Montesano Formation, southwestern Washington and southern Olympic Peninsula: Western Washington University Master of Science thesis , 263 p. Cooke, L. W., 1985, Estimates of undiscovered, economically recoverable oil and gas resources for the outer continental shelf as of July 1984: U.S. Minerals Management Service OCS Report MMS 85-0012, 45 p. Florer, L. E., 1972, Quaternary paleoecology and stratigraphy of the sea cliffs, western Olympic Peninsula, Washington : Quaternary Research, v . 2, no. 2, p. 202-216 . Grady, M. T., 1985, Stratigraphy, sedimentology, and hydrocarbon potential of the Hoh turbidite sequence (Miocene}, western Olympic Peninsula, Washington: University of Idaho Master of Science thesis, 192 p. Heusser, C. J., 1972, Palynology and phytogeographical significance of a late-Pleistocene refugium near Kalaloch, Washington: Quaternary Research, v. 2 , no. 2, p. 189-201. Horn, A. D., 1969, The sedimentary history of the Quinault Formation, western Washington: University of Southern California Master of Science thesis, 179 p . Kvenvolden, K. A.; Golan-Bae , Marga ret ; Snavely, P. 0., Jr., 1988a, Preliminary evaluation of the petroleum potential of the Tertiary accretionary terrane, west side of the Olympic Peninsula, Washington--Part 3. Composition of natural gases in seeps, outcrops, and a test well: U.S. Geological Survey Open-File Report 88-75 , p. 50-62.

1 1 Kvenvolden, K. A.; Rapp, J . B.; Hos t ettler, F. D.; Snavely, P. D., Jr., 1988b, Preliminary eva l uation of the petroleum potential of the Tertiary accretionary terrane, west side of the Olympic Peninsula, Washington--Part 2. Comparison of molecular markers in oil and rock extracts: U.S. Geological Survey Open - F"i l e Report 8 8 - 7 5 , p . 2 7 - 49 . McFarland, C. R:~ 1983, Oil and gas exploration in Washington, 1900-1982 : Washington Division of Geology and Earth Resources Information Circular 75, 119 p. Moore , J. L., 1965, Surficial geology of the southwestern Olympic Peninsula: University of Washington Master of Science thesis, 63 p., 1 plate . Mu t t i , E . ; Ri c c·i Lu c c h i , F . , 1 9 7 8 , Tu r b i d i t e s o f t h e n o r t h e r n Apennines--Introduction to facies analysis [trans . by T. H. Nilson]: International Geology Review, v. 20, no. 2, p. 125-166. Orange, D. L., 1987, Hoh melanges in Washington -- Emplacement by diapirism and shear zone deformation [abstract]: Eos (American Geophysical Union Transactions, v. 68, no. 52 , p. 1816. Rau, W. W. , 1970, Foraminifera, stratigraphy, and paleoecology of The Quinault Formation, Point Grenville-Raft River coastal area, Washington: Washington Division of Mines and Geology Bulletin 62, 41 p. Rau, W. W., 1973, Geology of the Washington coast between Point Grenville and the Hoh River: Washington Division of Geology and Earth Resources Bulletin 66, 58 p. Rau, W. W. , 1975, Geologic map of the Destruction Island and Taholah quadrangles, Wash i ngton: Washington Division of Geology and Earth Resources Geologic Map GM-13, 1 sheet, scale 1:63,360. Rau, W. W., 1977, General geology of the southern Olympic Coast . In Brown, E. H.; Ellis, R. C., editors, 1977, Geological excursions in the Pacific Northwest; Geological Society of America annual meeting , 1977: Western Washington University, p . 63-83. Rau , W. W., 1979, Geologic map in the vicinity of the lower Bogachiel and Hoh River valleys, and the Washington coast: Washington Division of Geology and Earth Resources Geologic Map GM-24 , 1 sheet, scale 1 : 62,500. Rau, W. W., 1980, Washington coastal geology between the Hoh and Quillayute Rivers: Washington Division of Geology and Earth Resources Bulletin 72, 57 p . 12 Rau, W. W. , 1986, Geologic map of the Humptulips quadrangle and adjacent areas, Grays Harbor County, Washington: Washington Division of Geology and Earth Resources Geologic Map GM-33, 1 sheet, scale ·1:62,500. Rau , W. W. , 1981-, Mel an g e rocks of \./ash i n gt on ' s Ol y mp i c coast . In Hi l l, M. L., editor, 1987, Cordilleran section of the Geological Society of America: Geological Society of America ONAG Centennial Field Guide 1 , p. 373-376. Rau, W. W.; Grocock, G. R., 1974, Piercement structure outcrops along the Washington coast: Washington Division of Geology and Earth Resources Information Circu lar 51, 7 p. Rau, W. W. ; McFarland, C. R., 1982, Coastal wells of Washington: Washington Division of Geology and Earth Resources Report of Investigations 26, 4 sheets.

Snavely, P. 0., Jr., 1981, Geophysical data collected on the continental margin midway between Washington State and Vancouver Island, B. C., along line 19, USGS R/V S.P. Lee cruise 3-76: U.S. Geological Survey Open-File Report 81-895, 1 sheet, scale 1:250,000. Snavely, P. D. , Jr., 1987, Tertiary geologic framework, neotectonics, and petroleum potential of the Oregon-Washington continental margin. In Scholl, D. W.; Grantz, A.; Vedder, J. G. , editors, 198f':" Geology and resources potential of the continental margin of western North America and adjacent ocean basins-- Beaufort Sea to Baja, California: Circum-Pacific Council for Energy and Mineral Resources, Earth Science Series 6, p. 305- 335. Snavely, P. D., Jr . ; Kvenvolden, K. A. , 1988, Preliminary evaluation of the petroleum potential of the Tertiary accretionary terrane, west side of the Olympic Peninsula, Washington--Part 1 . Geology and hydrocarbon potential: U.S. Geological Survey Open-File Report 88-75, p. 1-26, 1 plate .

Snavely, P. 0., Jr.; Macleod, N. S.; Niem, A. R.; Minasian, D. L., 1986, Geologic map of the Cape Flattery area, northwestern Olympic Peninsula, Washington: U.S. Geological Survey Open-File Report 86-3448, 10 p., 1 plate, scale 1 :48,000 .

13 Snavely, P. D., Jr.; Pearl, J.E.; Lander, 0. L., 1977 , Interim report on petroleum resources potential and geologic hazards in the outer continental shelf--Oregon and Washington Tertiary province; with a section on Resource appraisal estimate, by E. W. Scott: U.S. Geological Survey Open-File Re po r t 7 7 -28 2·, 6 4 p . Snavely, P. o.:·Jr.; Wagner, H. C., 1982a, Geologic cross section across the continental margin of southwestern Washington: U.S . Geological Survey Open -F ile Report 82-459, 10 p., 1 sheet. Snavely, P. D., Jr.; Wagner, H. C., 1982b, Geophysical data collected on the southern Washington continental shelf along line 12, USGS R/V S.P. Lee cruise 3-76: U.S. Geological Survey Open-F~le Report 82-424, 1 sheet.

Sn ave 1y , P . D. , Jr . ; We 1 l s , R. E. , 198 4, Te rt i a r y v o 1 can i c and intrusive rocks on the Oregon and Washington continental shelf : U.S. Geological Survey Open -File Report 84 - 282, 17 p . , 3 plates . Stewart, R. J., 1970, Petrology metamorphism and structural relations of graywackes in the western Olympic Peninsula, Washington : Stanford University Doctor of Philosophy thesis, 123 p., 5 plates. Tabor, R. W.; Cady, W. M. , 1978a, Geologic map of the Olympic Peninsula, Washington: U.S . Geological Survey Miscellaneous Investigations Series Map I-994, 2 sheets, scale 1:125,000 . • Tabor, R. W.; Cady, W. M., 1978b , The structure of the Olympic Mountains, Washington--Analysis of a subduction zone: U. S. Geological Survey Professional Paper 1033, 38 p. Wagner, H. C., 1967, Preliminary geologic map of the Raymond quadrangle, Pacific County, Washington: U.S. Geological Survey Open-File Report 67-265, 1 sheet, scale 1:62,500. Walsh, T. J.; Korosec, M.A.; Phillips, W. M. ; Logan, R. L.; Schasse, H. W., 1987, Geologic map of Washington--Southwest quadrant: Washington Division of Geology and Earth Resources Geologic Map GM-34, 2 sheets, scale 1:250,000, with 28 p. text. Webster, F. L. , 1985, Pacific OCS lease sale, October 1, 1964, Oregon and Washington: U.S . Minerals Management Service Pacific OCS Region report 85-0101, 36 p.

14 Wells, R. E. , 1981, Geologic map of the eastern Willapa Hills, Cowlitz, Lewis, Pacific, and Wahkiakum Counties, Washington: U.S. Geological Survey Open-File Report 81-674, 1 sheet, scale 1:62,500.

Zieglar, D. L. ;· Cassell, J. K. , 1978, A synthesis of OCS well information, offshore central and northern California, Ore­ gon, and Washrngton . In Hill, F.L.; Wilkinson, E.R.; Schnei­ der, R. H., coordinators, 1978, Ene rgy exploration and poli­ ties; pre-prints: California Division of Oil and Gas, 27 p.

15 ROAD LOG

0 . 0 START Field Trip mi l eage at the center of the Wynooche River bridge traveling west on U. S. Highway 12 (Figure 1) . Use Walsh and others (1987) for this portion of the guide . 6.6 Entering Aberdeen . 7 . 0 Directly north of the highway, a road cut exposes Montesano Formation deltaic sandstones (Mm2) and si l tstones. These rocks dip 100 northeast and are on the southern limb of the Cemetery Syncline. 7 . 7 Turn left (south) across Highway 12 onto the Morrison Park access road and immediately turn l eft (east) on the frontage road which heads east to Morrison Park . The turnoff is located 0 . 5 blocks west of the conspicuous log community center building on the south side of the Highway. 8 . 0 STOP 1. Morrison Park. The Montesano is wel l exposed eastward along the railroad tracks and outcrops noted at mileage 7.0 are also accessible from here. This section consists of 371 feet of massive and crossbedded, pebbly sandstone and several fining- and thinning-upwards sequences of abundantly pebb l y sandstone, rare cong l omerate, common muddy si l tstone, and laminated claystone (Bigelow, 1987). Carbonized wood chips, and molluscan fossil fragments are present. Two sequences, near the top of the section (Figure 7) consist of a sharp basal contact, overlain by 33 and 89 feet, respectively, of structureless, coarse-grained sandstone . This coarse sandstone is over l ain by cross-bedded sandstone which f i nes upwards to 1- to 2-inch thick , parallel-laminated, silty claystone . These rocks are interpreted to have been depos i ted near the marine margin of a de l ta issuing from the Olympic mountains (Bigelow, 1987) . RETURN TO U. S . HIGHWAY 12 AND PROCEED WESTWARD . Do not reset odometer . 8.3 Turn left onto Highway 12 and proceed westward and cross the Wishkah River. 9 . 9 Exposures of Montesano are present approximate l y 0.3 mi les north of the route in a series of northwest- trending folds . 16 I '

Three shal l ow wildcats and the 6,725-foot Ohio Oil Co . Robinson Berry No. 1 well were drilled prior to 1933 near the crest of the Reservoir anticline approximately one mile north of this location. The Robinson Berry No. 1 spudded in Astoria Formation (Mm1), penetrated the Lincoln Creek Format i-o n ( 0 Em) at 1 , 4 0 0 fee t , the Hump tu l i p s Format i on (Em1) at 2,320 feet, and the Crescent Formation (Eve) at 5 , 2 5 o f e-e t . 11 .0 Entering Hoquiam 11 . 9 · Junction of Highway 12 (Sumner Ave. here) and 22nd Street . The section exposed on the west side of 22nd Street consists of 300-southwest-dipping massive and paralle l­ laminated siltstone with minor claystone and very fine grained. sandstone with pelecypod fragments and load structures. The rocks are on the southern limb of the Hoquiam anticline . 12.7 JU NCTION WASHINGTON HIGHWAY 109/U.S. HIGHWAY 101. BEAR RIGHT ONTO U. S. HIGHWAY 101 AND PROCEED NORTH. 13.3 Brecciated Grande Ronde basalt exposed on hillside 200 feet to the west. 14.0 Crossing Little Hoqu i am River 14 . 1 Turn out on road to the left (west). Road cuts to the right after the turn (north) contain the north-westernmost outcrops of the Grande Ronde Forma tion of the Columbia River basalts (Mvg) . These basalts were extruded from vents near Walla Walla and flowed down the Columbia River to this location, a distance of 360 miles. Siltstone inclusions at this outcrop contain an excellent Saucesian fauna . Overlying the Grande Ronde are thinly bedded prodelta silts of the Montesano Formation. Eastward, across the river, Montesano beds overlie very poorly exposed Linco l n Creek Formation in the core of the Hoquiam anticline. TURN AROUND ANO HEAD SOUTH ON U.S. HIGHWAY 101. RETURN TO HIGHWAY 109 WEST without resetting odometer . 15.6 JUNCTION U.S. HIGHWAY 101/WASHINGTON HIGHWAY 109. TURN RIGHT and proceed west on Highway 109 (Emerson Street) to~ard Ocean City. 17 . 3 Reddish-brown weathering Pliocene to Pleistocene pediment gravels (QPlc) are exposed in the hil lside 300 feet north of the highway. Grays Harbor is one of few marine estuaries on the entire Pacific Coast.

17 . '

22.5 Mile Post 7 25.8 Bridge across Humptulips River . The Shell Hogan No. 1-8 and Grays Harbor Oil Co . Tulips No. 1 are shallow dryholes d r i l l e d a f e.w mi l e s t o t h e n or t h . 29 . 0 Three wildcats were drilled within a 1-mile radius of this location- between 1960 and 1970. The Shell Ocean City Land and Others, 1-14 is the deepest at 4,268 feet drilled depth. Shell ran three DSTs in this well over the interval 3,527 and 4,265 feet through a 60-mesh slotted liner and recovered up to 85 MCFGPD with an FSIP of 3173 psi and an IFP of 3164 psi . The section tested was mainly grayish brown claystone with a few 2- to 8-foot sandstone beds having density-porosities ranging from 7 to 15 percent. Thorough DSTs of subsequent wells over shorter intervals have shown that these rocks are susceptible to formation damage. 31 . 6 JUNCTION WASHINGTON HIGHWAY 109 ANO WASHINGTON HIGHWAY 115 . BEAR RIGHT ANO PROCEED NORTHWARDS TOWARD MOCLIPS. Sixteen wildcats were drilled within a 1 . 5-mile radius of this junction. These include the Hawksworth State No. 4, the Union State Nos. 1 & 3 , and the Tanner-Sunshine Medina No. 1. All of these wells produced 100 barrels or more of 39 gravity oil from depths of 3,600 to 4,400 feet (McFarland, 1983). This oil appears to have migrated from depth. The Medina No. 1 produced a total of 12,000 barrels of 37-39 API paraffinic oil and was called the "Ocean City Field" prior to abandonment in 1962. Typically the well produced 7 to 10 BOPD. Thermal gradients of 1.570 F per 100 feet (230 C per kilometer) calculated from Medina No . 1, DST No. 3 [3,946 to total depth] indicate that the present-day top of the oil-generative window is deeper than 10,000 feet . Data from Kvenvolden and others, (1988) indicate the Tmax averages 442 for fifteen samples and Ro averages 0.55 for eight samples from various depths in three of these wells. None of the wells showed a significant increase in maturity with depth. TOC values, while low , commonly exceed 0 . 8 percent. The highest Hydrogen Index (HI) value recorded was 255, and most were below 200. These data suggest to us that the rocks were marginally mature prior to deformation and uplift. The tops and lithologi es for two wells in this area are shown on Figure 4. Th e section penetrated in the Medina No. 1 comprises an upper, thick, porous, Miocene to Pliocene sandstone (841 to 1,193 feet dr i lled depth); a thick claystone sequence to 2,309 feet; the Ocean City 18 ' '

sandstone to 2,349 feet; and a massive c l aystone to 3,934 feet. Sandstones from this depth to 3,964 feet and from 4,057 to the 4, 146-foot total depth produced oil . SP development, micro and OIL i nvasion, and mudcake all sugges~ at least some permeability and porosity . 33.5 Turn off_ to Ocean City beaches. Proceed northward on Hi ghway 109. 36.1 Entering Copalis Beach. The town is situated part i ally on alpine g l acial outwash (Qapo). 37 . 0 The sea stacks vi sible through the brush to the west are mapped as Crescent basalt (Eve ) . However, this basalt is thought to be included in the Hoh/Ozette me l ange . 44 . 8 Entering Pacific Beach. 45.8 Entering Moc l ips . During the 1890s, Moclips was a major resort wi th a large hotel which subsequentl y bur ned. Tourists were attracted to Moclips because of i ts name. 47.8 Pass Moc li ps/Olympic Highway and continue northward (straight) toward Taholah on Highway 109. 50 . 1 At this point , Grenville Bay is i n view , with Point Grenvi l le i n the distance . This scenic area was the site of the f irst recorded land i ng by Europeans along the northwest coast. On the morning of July 14 , 1775, the Spanish ship Santiago, commanded by Bruno Heceta , on a voyage of exp l oration, anchored in this bay. Bruno and his crew landed nearby and claimed the land for Spain . He named the bay "rada de Bucare l i" and t he point "Pu nta de los Martires. The bay is now refe r red to as e i ther Santiago or Grenville Bay , the latter g i ve n to it by Capt. Vancouver . At the north end of Grenville Bay the r oad leaves the beach area and ascends onto the prominent flat-topped pi edmont surface of Point Grenville. 5 3. 15 J UN CTION OF PA VED, SOM EWHA T OV ERGROWN ROAD WES T TO THE ABAND ONED PO I NT GRE NVIL LE COAST GUARD STATION AND HI GH WAY 109. ASS UMING YOU ARE PRES ENTLY ACC OM PA NI ED BY A GU ID E FRO M THE QUIN AULT TRIBAL COUNCIL IN TAHOLAH, TURN LEF T (WEST).

53.9 STOP 1. Park at the abandoned Point Grenvil l e Coast Guard Station. This Coast Guard faci l ity was a Loran Station. Walk 100 feet north to a vantage point providing an excellent view northward . Gent l y-dipping Quinau l t Formation can be seen cropping out in the base of all the cliffs , including those at Cape El i zabeth, the headland far 19 •

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to the north. Younger Pleistocene outwash mater i als uncon formably overlie the Quinault Formation and rest on the elevated wave-cut terrace that was carved sometime during the Pleistocene. The relatively flat modern surface of Point Grenville, as well as the tree-covered surface to the north, are part of a young piedmont surface (Fig. 7) that was formed later in the Pleistocene. This surface is comparable to that seen on Destruction Island and other low-lying flat areas to the north . WALK DOWN THE STEEP, SLICK TRAIL NORTHWESTWARD TO THE BFACH. On the beach, volcanic bedrock of Point Grenville and offshore rocks can be seen . Most of the headland you are standing on is underlain by volcanic rocks. Many of them are composed of brecciated materials with much volcani~ glass. Amygdaloidal clasts are common, and veins of secondary calcite and zeolite are seen throughout. Sedimentary rocks, interbedded with the basalt on the south side of this headland have yielded middle Eocene (Ulatisian) foraminifers (Rau, 1973 , 1975) . P. D. Snavely (USGS oral commun., 1988) regards these rocks as Narizian and equivalent to the Grays River, Til lamook, and/or Western Lithic Assemblages. An area of many landslides extends about one-quarter of a mile north of the volcanic headland of Point Grenville . Although largely masked by sand and gravel from overlying Pleistocene deposits, this area is underlain by Narizian rocks, mapped as Hoh Rock Assembla ge but now assigned to the Ozette melange. The bluffs of this area are particularly unstable, as is obvious along the trail to the beach. Near the foot of the trail, late Eocene foraminifers have been collected from melange rocks (Rau, 1975). Some of the forms are: Alabamina cf. A. wilcoxensis californica Mallory Amphimorphina fenkinsi (Church) Asterigerina crassaformis Cushman and Siegfus Bolivina cf. B. incrassata Reuss Bulimina corrugata Cushman a nd Siegfus Bulimina schencki Beck Cibicides mcmastersi Beck Dentalina spp . Globigerina spp. Globocassidulina tlobosa (Hantkin) Gyrodina condoniCushman and Schenck) G. soldanii d'Orbigny Lenticulina spp. Nodogenerina sp. Nodosaria cf. N. longiscata (d'Orbigny)

20 I '

Plectofrondicularia cf. ~- packardi Cushman and Schenck Uv1ger1na ~arzaensis Cushman and Siegfus Va l vuliner1a cf. V. indiscriminata Ma l lory ~- tumeyensis Cushman and Simonson Note th·e landslide block immediately to the north capped with east-dipping Pleistocene materials. Apparently large, exotic o~ulders supporting this block moved seaward as coasta l erosion progressed. This movement has caused the entire block to rotate westward. However, because these boulders are relatively res i stant, the rate of coasta l erosion has been slower here than in the adjacent parts of the cliff. Walk northward to a gap in the small headland to a the major l·andslide area, composed of Ozette me l ange, extending northward to the vertical cliffs of Quinault Formation. Note the sharp contact of the slumped melange area with the Quinault Formation cliffs to the north. Th i s nearly vertical contact is the trace of an west-trending fault.

Continue walking north about 0.75 mi l e. The sheer and somewhat unstable cliffs of sandstone contain varied litho l ogies, textures, and syndepositional sedimentary structures . Both Pliocene foraminifers and megafossils have been identified from this area (Rau, 1970 ; Addicott, 1976). The megafossils constitute one of the reference faunas for the Moclipsian stage (Addicott, 1976). Foraminifers, biva l ves, and gastropods are common is this section. Both the megafossils and foraminifers are mixed shallow­ water and deeper-water forms . The section here displays an overall , fining upwards and deepening upwards related to subsidence (K. A. Campbell, Univ . of WA, written commun., 1988) . Therefore, redeposition of materials s l oughing off a shallow inner-shelf into a deeper environment , possibly outer-shelf or upper - slope depth, took pl ace . Th i s probably occurred within a proximal submarine fan . Horn (1969) interprets this section as a deltaic complex . About 650 feet north of the Ozette/Quinault contact, channel-fi l l sequences of sandstone cobble intraclasts can be seen in the cliffs immediately south of a sma ll waterfall . In most places these channels are filled with coarse, brecciated , fossiliferous material that grades upward into sandstone. A variety of soft-sediment features such as "pull-apart" beds, flame structures, and other contorted bedding can be seen in this area .

21 ..

Note the sharp, well-defined trace of the elevated wave-cut terrace some 100 feet above sea level. The overlying Pleistocene deposits are capped by buff-colored eolian deposits that form a blank et over much of the coastal area. RETURN TO HIGHWAY 109. 54.6 JUNCTION ~OF POINT GRENVILLE GUARD STATION ROAD AND HIGHWAY 109. TURN LEFT ANO PROCEED NORTH IN THE DIRECTION OF TAHOLAH. 56.4 JUNCTION OF HIGHWAY 109 ANO GRAVEL ROAD TO RIGHT. BEAR GENTLY RIGHT AND PROCEED STRAIGHT NORTHWARD ON THE GRAVEL ROAD. This gravel road is the proposed extens ion of Highway 109. 57.2 Cross intersection with paved road and continue north on the gravel road ONLY IF YOU HAVE A QUINAULT GUIDE. 57.3 Crossing the Quinault River. The course of the river is thought to be controlled by an east-northeast-trending lineament interpreted as a fau lt. This probable fault joins the Southern Faul t Zone of Tabor and Cady (1978a). Between Taholah and Lake Quinault , this river is owned and controlled by the Quinault Nat ion. Note the array of fishing equipment . The small grass-covered roadcuts immediately north of the Quinault River at one time exposed melange rocks of the Hoh Rock Assemblage. Lowe r to middle Miocene foraminifers have been collected in this vicinity . North of the Quinault River valley the road traverses another segment of the lower (younger) piedmont surface and continues to Duck Creek. 58.3 The hi l ls to the east (right) are composed largely of, or at least capped with, older Pleistocene outwash gravels. Their upper surface, at about 400 f eet elevation, represents th e older, well-dissected piedmont surface that extended much farther westward during the Pleistocene. Brecciated volcanic rocks similar to those that can be seen at Point Grenville crop out in a rather extensive area near the base of the hill just to the south of Duck Creek. Melange was also exposed along the road immediately south of Duck Creek and under the bridge. 60.1 TURN LEFT AT JUNCTION OF PROPOSED HIGHWAY 109 AND QUINAULT FOREST ROAD 7045 AND PROCEED WEST ON 7045, ANOTHER, SOMEWHAT OVERGROWN GRAVEL ROAD.

22 60.5 TURN LEFT AT "T " JUNCTION. This south-trending, overgrown, gravel road is a portion of the Cape Elizabet h Road built by the Indian Emergency Co nservation Work Corps as a Great Depression-era public wor ks project (Larry Workman, Quinault DNR, oral commun., 1988) . 60 . 6 BEAR RIGHT ANO SLIGHTLY UPHILL . HEAD WEST AND BEAR RIGHT TWICE. -

60.7 STOP 3. ROAD ENDS. BEARS ARE COMMON HERE . FIND A SMALL TRAIL AND HIKE O.~ MILE S WEST-SOUTHWEST TO THE BEACH. The head to the south is Cape Elizabeth, which is directly north of Taholah . The escarpment 2 miles to the north is Pratt Cliff . About 1.5 miles north, Duck Creek and then Camp Cr~ek enter the ocean. The offshore islands, Willoughby Rock to the east and Split Rock to the west, are mapped as Hoh Rock Assemblage basalts that are major resistant blocks within the melange. Along the coast between Pratt Cliff and Cape Elizabeth is a major section of the Quinault Formation. The Quinault in this area is largely a bedded, southeast-dipping, sandy, fossiliferous siltstone displaying evidence of bioturbation and other soft-sediment processes. Deta i led studies of the foraminifers (Rau, 1970) have determined that this part of the formation was deposited during an early part of the Pliocene in cool water at outer-shelf to upper-slope depths. Walk north and investigate this section. The Quinault section is interrupted just south of the beach trail where a northeast-trending, down to the north fault separates the Quinault from chaotically mixed, very dark gray , smell muds , siltstone, feldspatholithic sandstone, and altered-volcanic boulder inclusions . This is the famous Cape Elizabeth structure of Rau and Grocock (1974) [also known as the Duck Creek diapir]. Walk south and have a look. The Cape Elizabeth structure is bounded on the south by a second fault . Slickensides, fractures, and phacoidally shaped exotic blocks are also present. These form a prominent foliation and elongated-clast lineation. The foliation and lineations define a steeply east-plunging syncline shown on Figure 11 (D . L. Orange, Univ. of S. CA., Santa Barbara, written commun. 1988). On rainy days the Cape Elizabeth structure appears to be moving, but Pl eistocene terrace gravels on the top indicate that recent vertical movement is limited .

23 . .

Fossils in the siltstone exotic blocks and from the clay matrix indicate a Saucesian age. The volcanic rocks are andesitic with some chlorite. The clays are composed of illite-montmorillonite, kaolinite, and chlorite. Calcite and pyrite are common. In places, the clays have a strong petroleum odor. Several gas seep~ have been active periodically. These are located along the southern marginal fault in tidal pools. Rau and Grocock (1974) report the following compositional data : C02=0.7%, C1=92.8%, C2=1.4%, C3=0.4%, C4i=O .l , C4n=O.l, C5i =0.08, C5n=0.04, and several heavier hydrocarbon compounds . Some ethylene is also present suggesting that these seeps are very active. 61.2 RETURN TO THE ROAD ANO FROM THERE TO THE INTERSECTION OF ROAD 7045 ANO THE PROPOSED EXTENSION OF HIGHWAY 109. 61 . 4 Duck Creek Bridge. The Quinault Formation underlies road cuts on the north side of Duck Creek . However, it is not apparent as the roadcuts are now grass covered. The largest known onshore outcrop area of the Quinault Formation extends from Duck Creek northward for several miles and, in places, more than a mi l e i.nland. However, much of the area is masked by a relatively thin blanket of younger Pleistocene materials, much of which appears to be beach sand and gravel . 62.5 Camp Creek Bridge . This bridge is built of an old rai l road car with loose planks atop .. . . Travel at your own risk. Additional roadcut Quinault outcrops were once exposed immediately north of Camp Creek . Proceed northward if you choose. 64.4 The road zig zags westward and rejoins a segment of the Cape Elizabeth Road. 65.3 ASK YOUR QUINAULT GUIDE TO LOCATE A VERY OBSCURE WAY-TRAIL TO VISIT THE HOGSBACK AREA DESCRIBED IN RAU (1 987) AS AN OPTIONAL STOP. At this locality, a complex Saucesian melange can be observed. TURN AROUND ANO RETRACE THE ROUTE SOUTHWARD. 72 . 3 INTERSECTION PROPOSED HIGHWAY 109 ANO QUINAULT FOREST ROAD 7700 . TURN RIGHT ANO PROCEED WESTWARD. 72 . 5 "T" JUNCTION, TURN LEFT ANO PROCEED SOUTH ON ROAD 7720. 72.8 TAKE RIGHT LEG OF "Y" ANO PROCEED WEST ON ROAD 7720.3.

24 73.1 STOP 4. STOP CAR AT SMALL ROAD TO SOUTH (LEFT) BELOW PINGO-SCALEO HILL. This 50-foot-high hill is the Garfield gas mound. Proceed up the small road to the south for 75 feet and find an obscure, west-trending path to the top of the mound located 150 feet to the south. Here, two seeps (which were more active in the past) are present:- Kvenvolden and others (1988) report that this gas 7 is 99 . 9% C1 with a trace of C2. The delta 13c is -34.5, and delta deuterium is -177. Although these authors indicate that the data do not present a totally consistent scenario, they conclude the gas is thermogenic. Saucesian foraminifers have been recovered from the seeps. Return to Road 7720.3 and hike 150 feet further west to a point d1rectly north of the summit of the gas mound. In the brush 10 feet to the left of the road, the remains of the Quinault Nos . 1 and 2 wells, drilled by the Indian Oil Company in 1913, are present . With hard work, the casing heads of both wells can be located, and one is bleeding gas with isotopic compositions essentially identical to that of the gas seep [13c is -34.8 and delta deuterium is -196 (Kvenvolden, 1988) . ] The Quinault Nos. 1 and 2 were among the first wells drilled on the coast . These penetrated 100 feet of Pleistocene sediments, 250 feet of probable Quinault conglomerate, and 470 feet of Hoh Rock Assemblage (Rau and McFarland, 1982). RETRACE THE ROUTE BACK TO PROPOSED HIGHWAY 109. 73 . 9 JUNCTION ROAD 7700 AND PROPOSED HIGHWAY 109, TURN RIGHT ANO RETRACE THE ROUTE SOUTH ACROSS THE QUINAULT RIVER BRIDGE. 75.0 JUNCTION WITH PAVED ROAD. TURN RIGHT ANO PROCEED WEST INTO TAHOLAH. 75.3 JUNCTION PAVED ROAD AND HIGHWAY 109, TURN LEFT (SOUTH) AND RETRACE ROUTE TOWARDS MOCLIPS. 79.3 Rock towers at 1 o'clock (to the south-southwest) are Hoh or Ozette blocks which are famed from Quinault legend. The story goes that the tallest sandstone block is a pregnant woman waiting for her lover to come home from the sea. Tough luck.

80 . 6 Crossing small stream, outcrops of Quinault (?) are exposed in the creek bed at 11 o'clock (southeast). LEAVING THE QUINAULT NATION. Services of a guide are not needed beyond this point. 25

·.. ., .... • . ;.· i •

83.3 JUNCTION HIGHWAY 109 AND MOCLIPS/OLYMPIC HIGHWAY . TURN LEFT AND PROCEED EASTWARD IN THE DIRECTION OF NEILTON. The area traversed between Highway 101 and the coast is entirely underlain by alpine drift and till. The road follows- the North Fork of the Moclips River. The channel is mainly filled with alpine outwash (Moore, 1965). --- Note the abundance of lodgepole pine and the generally poor development of the forest in many places. These areas basically mark the presence of till on which impervious layers of marsh and ·1acustrine silt deposits have accumulated since the Pleistocene. Areas with more pervious overlying materials, such as outwash deposits, can support the growth of hemlock and spruce. In approximately 4 mi 1 es- (to trip mi le 8 7 . 3) , the road cuts through an alpine glacial terminal moraine from a large Pleistocene glacier which traveled down the Quinault valley to this locality. Unfortunately, the brush is generally too thick to observe such Pleistocene features. A recessional moraine is passed at approximately mile 89.0. Views northeastward to the Olympic crest occur periodically along this portion of the route. The prominent peaks are Mount Olympus (7,980 feet) and the Queets group. Mt. Olympus is composed of early Tertiary zeolite-facies, metamorphosed slate and phyllite. The Olympic Mountains are comprised of imbricate thrust sheets that dip eastward.

93.2 Passing a small lake which was formerly a gravel pit and an adjacent pit presently in operation (May, 1988) in outwash gravels from the Quinault alpine glacier.

103.8 INTERSECTION OF HOCLIPS/OLYMPIC HIGHWAY AND HIGHWAY 101. TURN LEFT (north) AND PROCEED TOWARDS NIELTON. The base of the hills 0 . 3 miles to the east marks the position of the Southern Fault Zone which is obscured in the timber. This fault is the division between the Grays Harbor (Montesano) basin on the southeast and the Olympic Core Complex on the north. The hills are composed of basalt flows, flow breccias, and pillow basalt of the Crescent Formation. These basalts are crystalline basement associated with the Grays Harbor Basin.

106 . 5 ENTERING NEILTON

110.3 Crossing Quinault River . This river follows the trace of a major northeast-trending lineament interpreted to be a fault which reaches the coast at Point Grenville (see Stop 2). This lineament ties with the Southern Fault Zone 4 miles to the east. The mountains visible to the east (4:00

26 o'clock) are composed of Crescent volcanic rocks on the periphery of the Olympics. Consequently , the Southern Fault Zone is the boundary of major lithologic terrains . 111. 9 The road cli_mbs onto the poor ly exposed recessional alpine morainB that partially dams Lake Quinault. 113 . 6 Crossing- Milbourne Creek. Highway 101 is now trending westward. The hills located 0 . 75 miles to the north are composed of the Western Olympic Lithic Assemblage undifferentiated {Tur) of Tabor and Cady {1978a) . These rocks comprise lithic and feldspath ic sandstone with lesser amounts of argillite, conglomerate, and siltstone . Fossil leaves are present in these rocks. The sandstones have K­ spar ranging from 5 to 10 percent . 116.8 The two small hills located 1 mile south of the road at approximately 9 o'clock, are Lone and Thimble Mountains . These are composed of basaltic rocks lithologically similar to those seen at Point Grenville. Elsewhere these same rocks, which are mapped as part of the Western Olympic Lithic Assemblage (Tabor and Cady, 1978a) contain greenstones and greenschist-facies metamorphic rocks. 12 3 ..3 Crossing Raft River 131. 0 The General· Gas and Electric State No . 1 well was drilled to an unknown depth at a location approximately 1.5 miles north of this spot.

13 5. 6. Mile Post 152. Not far from this location, the Olympic Petroleum Company drilled the C.C. Cook -Quinault Nos. 1 and 2 {Figure 4). These wells drilled approximately 100 feet of drift and then penetrated 1,312 and 2,910 feet respectively, of probable Saucesian Hoh Rock Assemblage. The rocks penetrated were mainly siltstone and claystone, but the No. 2 well logged th ree sandstones with approximately 10 feet of dip-corrected invasion shown on the lateral logs. Quentin R. Query described minor cut and minor gas bleeding from core samples {written commun . in Division of Geology and Earth Resources files) . 135 . 8 Crossing Queets River. 137 . 7 Entering Olympic National Park. 141. 0 Crossing Kalaloch Creek. 141.1 IN TER SECTIO N HIGHWAY 101 AND KALALOCH CREEK DIRT ROAD AT RIGH T. TURN RIGHT AND PROCEED EAST. 14 2 .,1 Intersection with a road from the right. Follow main road 27

.·.·.· straight ahead. 142.4 Siltstone is exposed in deeply weathered outcrops along the road for the next mil e or so. Throughout this distance the road proceeds northerly along the valley floor of Kalaloch Creek. The cours e of the stream is largely structurally controlled in t his area as this valley has been carved in a relatively soft siltstone unit (Thsl of Rau, 1975) and the central or axial area of the isoclinal anticline. 143.3 STOPS. A small quarry; a massive, thick lithic sandstone bed is exposed here and is a basal part of the bedded sandstone unit that overlies the massive siltstone unit of the valley floor. These tight rocks are representive of sandstone outcrops in the area, but wells drilled farther north penetrated a few, moderately thick porous sandstones in equivalent rocks. Continue northerly on main road. 143.6 Intersection. Follow along road to the right marked K-1000 . Continue along road K-1000 where highly weathered siltstone and some sandstone are exposed in a few scattered roadcuts. 144.5 Intersection of K-1000 and K-1200 . Follow to the right (east) on K-1000. Proceed southerly and cross Kalaloch Creek . 144. 7 Intersection. Follow to the right and cross Kalaloch Creek again.

144.9 Intersection . Turn left (east) on main road . From this intersection the road traverses eastward up the east fork of Kalaloch Creek valley and across the east limb of the Kalaloch Creek anticline. The first mappable unit up section from the siltstone of the valley floor is a weathered lithic sandstone unit (Ths of Rau, 1975) as seen in the first few weathered outcrops eastward of this intersection. 145. 1 STOP 6. WALK 0.5 MILES UP THE ROAD ANO OBSERVE HOH TURBIOITES AS DESCRIBED BELOW. The rocks exposed in this outcrop are typical of those mapped as thin-bedded [flysch bedded] sandstone and siltstone (Thss of Rau, 1975). These rocks are essentially vertical and strike northerly. Furthermore, rather subtle, graded bedding and other sedimentary features indicate the tops of these beds are to the east. Note the very sharp base on many sandstone units, whereas the tops of these beds are somewhat more rounded or irregular, a manifestation of graded bedding . As would be expected in turbidite deposition, fossils are particularly rare in all of these rocks, and none have been found here.

28

;: Proceed eastward, on foot, along road. The lithology described above continues in outcrops along the road for not more than a tenth of a mile. Within this distance attitudes change considerably and dips are much less, perhaps as the result of slumping. 145.2 Contact between bedded sandstone and siltstone and a massive~·--lithic sandstone unit (Ths of Rau, 1975). Outcrops of massive sandstone continue for a short distance to a point where the road makes a sharp turn to the left. 145.5 In the vicinity of this sharp bend, the road once again· follows along outcrops of bedded siltstone and sandstone. These outcrops, however, are somewhat masked with colluvium, and the nature of the lithology and structure is not as ~pparent ·as it is in the outcrops at Stop 6. Contact of bedded unit with a thick, very massive, coarse­ grained lithic sandstone unit (Thcs of Rau , 1975). Continue along the road. Although this coarse-grained unit is massive, some bedding indicates that the unit is also nearly vertical and in places slightly overturned . Evidence continues to indicate that the tops of the beds are to the east, thus this unit is also a part of the east limb of the Kalaloch Creek anticline. 146. 1 Top of coarse-grained lithic sandstone unit. Examine the upper part of the coarse-grained unit. In places this unit is poorly indurated, a condition which may be indicative of porosity similar to that observed in well logs of the Hoh. The contact between this major unit and the overlying thick siltstone unit to the east is gradational, as can be seen along the road eastward from this stop for a short dist an c.e. . The thick, coarse-grained unit represents the basal graded interval of a large turbidite sequence; the parallel laminated interval and the current ripple laminated interval are very thin or missing in this sequence; and the upper pelitic interval is represented by the siltstone unit exposed along the road to the east. The trace of the Kalaloch Creek fault has been mapped through this area and is believed to extend northeast through the gap in the ridge. This fault separates the structural block of the isoclinal fold, through which the tour has thus far traversed, from another major structural block in which the strata are folded into a steeply plunging anticline and syncline. Proceed up road into area of siltstone outcrops and pass a small quarry in siltstone. 29 Since crossing a tributary to Kala l och Creek the road has traversed gradually upward and across a strike ridge formed by the thick, bedded sandstone unit. Much of the low - lying area to the north is underlain by siltstone of the axial area of. the Kalaloch Ridge syncline. Typical examp l es of these rocks are exposed in roadcuts immediate l y before this stop. N~te the deformation of thin sandstone beds. These features may be the result of soft sediment deformation . They are at least secondary to the regional structure . Di f ferential erosion is well demonstrated here. At least in the Kalaloch Ridge area, topography mimics the structure . Foraminifers have been collected from several localities in the vic.inity of this stop. They suggest an ear l y to middle Miocene age and depositional environments of co l d water at perhaps no less than upper bathyal depths. RETU RN TO HI GHWAY 101 151 . 1 J UNCTION OF KALALO CH CREEK ROAD AN D U.S. HIG HWA Y 101 . TU RN RIGHT (north ) AND PRO CEED I N THE DIR ECT I ON OF FORK S. 152.1 STOP 7 . PARK AT AN ASPHALTED PUL LO UT ON THE RI GH T HAN D SID E OF THE ROAD JU ST BEY ON D THE GU ARD RAI L. Walk across the road (westward) and proceed down a gully along a way-trail to the beach . From here, the tour continues on foot to one of the more iso l ated beaches about 0.5 mile north, unofficially known as "Hidden Beach". Turf1 right (north) and walk about 0 . 3 miles northward to the first outcrops of Hoh Rock Assemblage. A well-worn, but obscured trail on the cliff to the right (east) is a segment of the original trail used by the early settlers and natives . It was part of the only route along the coast prior to construct i on of Highway 101 . Proceed north along the beach. Along this beach both overturn and steeply dipping Miocene Hoh turbidite sequences and nearly flat-lying Ple i stocene deposits can be viewed. These two units are separated by a wave-cut terrace that formed during the Pleistocene . The trace of this surface can be fo l lowed near the basal part of the bluff along this beach. This surface is at re l atively low elevation in this area , but in other places along the coast, it is more than 100 feet above the present-day sea level owing to recent folding . [Faults which cut Holocene deposits are common along the coast.] Numerous pholad (clam) borings are 30 preserved in many places on this surface giving a honeycomb appearance and clear evidence of uplift . The present strand line was established during the Pleistocene and has remained essentially stable. The maximum eastward extent of marine terrace sediments is only one mile . Pleistocene deposits have been studied in nearby areas by both Heo~ser (1972) and Florer (1972), and they have determined ages for these materials ranging between 16,700 and 47,000 yr B.P . They estimate the lowest of these plant-bearing materials to be some 70,000 years old . Bedrock exposed along the beach comprises more than 2,000 feet of Hoh Rock Assemblage intermediate to distal turbidites on the west limb of the West Fork anticline . This is~clinal fold is faulted near the crest . Its east limb was exposed between Stop 5 and 6. These Hoh turbidites consist of a middle fan association of thick bedded sandstones and laterally continuous thinly bedded fine elastic rocks . These strata are essentially the same rocks that were examined at Stops 5 and 6. Fossils are extremely rare, and only a few early to middle Miocene foraminifers have been found . The largest assemblage came from near the top of the sequence . Load casts, flute casts, ripples, woody fragments, graded bedding, flame structures, channels , and numerous other features are exposed in wave - polished outcrops. Many of these have geopetal features indicating the sequence is overturned . Most of these sandstone beds contain very dark gray siltstone chips, one of the characteristics of turbidite sandstones, and especially of the Hoh Rock Assemblage. Proceed down the beach toward the first headland. Garnet sands (bright red) are usually apparent along this beach. Garnet sands are generally more prevalent on today's beaches beneath areas where the trace of the wave-cut terrace is exposed. Rau (1973) theorized that in the process of carving the terrace during the Pleistocene, a major thickness of older material was removed and, in doing so, the dense garnets were concentrated on this surface . They are now being lowered to the present-day beach where they become reconcentrated. However , the maximum metamorphism recorded on the Olympic Peninsula is at the chlorite-epidote isograd, implying the garnet provenance was distant. The first headland south of the trail (about 1/4 mile) is locally known as "Arch Point" because of a small arch developed on the upland part of the beach at the contact of the Pleistocene deposits with bedrock. The roof of this 31

· ' arch corresponds to the old wave - cut terrace level. The bedrock of this point affords an excellent opportunity to further study sedimentary features. Note the well formed slump structures developed on the outer edge of "Arch Point" near the base of the outcrop. Around the point and immediately to the south of the arch are additional sedimentary features, all indicating overturned beds. A fairly well exposed section of the Pleistocene deposits can be viewed just north of "Arch Point" . Note the lowest deposits of fine gravel overlain by sand that generally grades into finer sand and clays, much of which contains an abundance of carbonized plant material. At low tide, Browns Point, the major promontory extending immediately north, can be negotiated . Beach Trail 3 ascends the cliff directly no rth of Browns Point. One can ascend to Highway 101 or continue along the beach viewing Pleistocene imbricate gravels and the Hoh turbidites of Starfish Point (approximately 0.75 mile to the north) and ascend Beach Trail 5. Beach Trail 5 is the approximate location of the Oklatex Oil & Gas, Oklatex well drilled with cable tools in 1937 to an unknown depth.

156.1 Beach Trail 6 parking area . An excellent view of Destruction Island (weather permitting) is available from this vantage point . The island , which lies about 3 1/2 miles off the coast, is the largest island southward to the Farallon Islands off San Francisco. It was a favorite rendezvous area for the early coastal explorers and fur traders . Two groups of European sailors seeking water near here were massacred by indians who did not like some visitors. It has a bedrock fo undation of steeply dipping Hoh turbidite rocks, largely of thick beds of lithic sandstone, similar to those strata along Hidden Beach. These rocks have been folded into a small syncline, which was subsequently rotated so that its axis is nearly vertical . The beveled end of this syncline is now exposed as the reef and basal part of the island. Still remaining on the ancient terrace in the main body of the island are outwash materials from the latest valley glac i ation . The prominent flat top silhouette represents a remnant of the peidmont surface developed during deposition and is common to much of this coastal area . Proceed to the parking area and thence south on Highway 101.

END OF ROAD LOG

32 C)

STOP

, C) ' . ._>

Ocean Shores-~,>o . Poii,t Brown "\

Wetioort

P-0155 -¢:'!I

! Figure 1. Index map showing the route followed in the road log and the locations of a few important wildcat wells. These wells are: BML, Belco, Milwaukee Land no. 1-1; LS, Leslie Petroleum and others, Sims No. 1; OCQ, Olympic Petroleum, C. C. Cook - Quinault Nos. 1 & 2; IQ, Indian Oil Co ., Quinault Nos . 1 & 2; SCM, Socal Moclips No. 2; US3, Union State No . 3; TSM, Tanner Sunshine Mining, Medina No. 1; SSJ, Sh~ll Sampson Johns No . 2-i5; and UT, Union Tidelands No. 2. The location of Figure 4 is indicated. \ \ \

\ \ '\ \ \ \ \

I ~ I j r-.:.=/I->- s, # ,r/ ~\/ ,,.,,. \ .... I ..... ,...... '~ ~ ~l... I I 4' ~ ~ : 5 l \ I l! I ;1 ~• 0 ' .. It .. I "' /. , / 143 L I 0 I 241 I (') 't \\\ / \ I/ "'> ~ v 2: I \1 ,~ ~\ ,L ~ I I f--- t I ~ I \ \. \ \ 50 100 fCM \ S'-1!• \ ".... \ I 128" Figure 2. A generalized geologic map of the northwestern Pacific coast (as interpreted by Snavely and Kvenvolden, 1988) . . • <

EPOCH-STAGE RELATIONS ON WEST COAST PACIFIC NORTHWEST FORAMINIFERAL SOUTH FLANK MONTESANO-RAYMOND OLYMPIC COAST ZONES OR ASSEMBLAGES Will.APA HILLS BASIN (/) :r BENTHO"IC FORAMINIFERAL w~ STAGES w z HALLIAN g Glacial drih .... UNNAMED Marine and nuvial Quaternary deposits te,race deposits § WHEEl.fRIAN _ • _ • _ • ___ . _ - ?-?-?-' .. ~ -+------1 VENTURIAN UNDIFFERENTIATED ASSEMBLAGES Troutdale Forma1ion Ouinault Fo

DELMONTIAN

MOHNIAN

LUISIAN

RELIZIAN Asloria Formation BAGG/NA WASHINGTONENS/S Astoria Formation Hoh Rock Assemblage t------1w31!apu•..myr -----1 Grande Ronde _ ___. SAUCESIAN SIPHOGENERINA KLEINPELLI and-,'- Basalt ~-+-----i ------iG:ra:oo:.:=e:R:ooo;.~~"jBasalt~0i·«f,~~~[--\)*-klliJ-(8~-1iL...... _-A.-.."""-~~1----~~~~~iSt\¥ ~ -UPPER ZEMORRIAN" ASSEMBLAGE ,__ g ZEMORRlAN ______Lincoln Creek Formation § 'LOWER ZEMORRIAN" ASSEMBLAGE ~--+------+--- Lincoln Creek Formation GALVINENS/S REF saoostone S/GMOMORPHINA SCHENCKl member (Wells. 1981) _ Cow6tz ·.w.' :.,;.·s:::·::::::;;::::::: SUL/MINA SCHENCKJ Formation Grays River (Skookumchuck Volcanics Ozelte Melange Formation PLECTOFRONDICULARIA cl P. JENKINS/ silts~: ~ 1. Humptufipsl~ NARIZIAN 2 2 w z t-----UV-1G_E_R_1N_A_c1._. _u._\'"'._'AZ_OO_E_N_s1_s__ --1~~- -·~ Formation ) McIntosh w u @ McIntosh Formation ~ 1 _ ? _ ? --+===:o:'.),,,F,.°',,..m.,...au,...,·on=,...,.. SUL/MINA cf. S. JACKSONENS/S :•:·:~·:·:•t:::·z·:·:::~•i:::::::\:::.:.~~:::•:::::::·: saoosione of Megler "McIntosh Formation. aoo equivalents lower unir (Wagner, 1967) ULATISlAN VAG/NULINOPSIS VACAVILLENS/S ASSEMBLAGE w z w Crescent Fo

. o· ~ .... _.... ' -·- ~v ;~~};(N{:I MIO/PUo. f':!'Zlti:~~o\ -.. -, --- ,;•,•,•;,• : ,••·, DA TUM: TOP HOH :-.::::-.::~.-:.:/ v.·:····;:·;;:: ~ ~10ZETTE ~ \. 12,000 BO -~·:;_i~~ ... ___ --- ··-· ..-· - ~ ~~:·~:- .....::·:;:\i_-~ -~ ~ -x i:,'.o ;s, HOH \.l~ ~ i:~\}:/n~:~:~ ... -· -,-. ~ ---~rt ~1i!W,:\ ::;.;·,::.::-;·:: \-\0\-\ sc e ,.- :/:::-;:_~_':}.;/,: ...... -· - ... -·-·- ·-· ·.:~:-?:(·;:·:=_: ~ -.--- ~ ---- ~ i -~n-cq -·-,-- •'!.'l•,*,';l;' ::S§ r-:=::i l..::::::J Sillslone and/or lhinly lnlerbedded fine elastics ·:·:,:::.:·~:::~:.:.

~ ~ Clayslone~ ~/ l=,,tJ ;:.::. :·,:· ::: Melange ~ D ~ 0 7-r:,"f\ 'r;, '? E] Sands lone ~

[}] Conglomerale

~

,, \. Figure 4. A stratigraphic cross-section showing some important coastal wildcat wells (after Rau and McFarland, 1982; Zieglar and .Cassell, 1978; Snavely and Wagner, 1982a). QUARTZ

FELDSPAR LITHICS Figure 5. A tertiary QFL plot showing modal compositions of coastal sandstones CDzette, square; Hoh, dots, from Grady, 1985; Montesano, circles, from Bigelow, 1987; Quinault, triangles, from Horn, 1969) . PRELIMINARY SECTION BROWNS POINT - STARFISH POINT

STARFISH NORTH SOUTH POINT BROWNS POINT BROWNS POINT SECTION SECTION SECTION IETWEEH BRO'NNS ANO WESTERNMOST POINT ON WESTERNMOST ,OINT O' ·-·····-, .. , STARFISH POINTS ff SOUTH BROWNS 'OINT ON STAAFJSH flO.INT ....:- ~... ·. :: THIN,IIEOOEO ...... GREEN $AHOSfONE , . - ·...... : SILTSTONE - ···· ...

SILTSTONE IIEOI IRA(GULAA. SANDS10NE aEoS WITH CR0SS.S(00ING IN THINIEDS

• ·~;'.': COVERED .. ~::·· ~ : : :• ._: :· ·:, . COVERED 200 ...... BEOO(O SANDSTONE, 200· - -·· - - -·­ SILTSTONE CH1,s , -...... - .. _ I COMMON ' •.~f.~::' -·:•. dh-' I I •.••. ,.,· • .••• · 200· ~=... =:: I

I I COVEAEO 8£00£0 SAHOSTONE I ANO SI LTSTONE WITH ;;;{J:it DISTURBED BEDDING NEA.R 80TTOM I ::zi,~.I~. I I \·~J}h(t I COVERED I I (NORTH 8ROWN POINT I SECTION 8El0W1HIS I StCTIOHJ I . . ' ; ,' ,O(tl :;.:..;;.-::.. ,,f:~.. SI LTSTONE 1CHl,S - - -.:,.·,; ·. ! , •• I I I TOTAL ESTIMATED StCTION • 1900 FE£T I SECTION$ CON$TAVC1't 0 FROM I •••••...• - UNPVBLISHEO OATA OF RAU STRUC~~~~~ -- ·~::·:~-· MA$$1Vf. SAHOSTONE / ~~t}~~}· WITH CONcAE.HONS ' ----·-··· I {,:~ ,'~ ~~ :~·'.· I I

'"M': ...... _ .. ·(~:.~ · .... ·.

I I I I I I I --·-·, .. .I ..... ;.i··t;:,· , I I I I })}/:; .:{??r / CHIP' CONOLOMERATE-- ·,..,:: :i, ;..:,.-· ?~??}/ R!~H~r*]!i-- r;ttt? IOO' ./·.::_/_ •.,;. 1 COVEREO WITH SANO

COVERE.O

Figure 6. A measured section of t he Hoh Roc k Assemblage turbidites at Browns Point and StarFish Point, Olympic National Park. , ,' . , .. ~ ......

80 .... : . . . . : . : ...... : ~~ uo 40 .... , . - : .. c::::n-, .' . C...... CZ>· ·co·

100

" ~ ~ ~~~- ·.·:~A...... " ...... ·.. ~. . ..:-~:...... • .. • : 60 ----...:·:...... _._ ·. .._._.. 90

" IS

...... ,o

IAS!: !.IOT U10$ED Figure 7. A measured section for the Montesano Formation outcrops at Aberdeen (from Bigelow, 1987) . The base of the section is on the left and the top is at t he right. Patterns are as fol lows: black, claystone; open circles, concretions; sigmas, and fossil f ragments. Thicknesses are in meters...... , .

Cape Elizabeth

North of Duck Creek Point Pratt-Cliff South ?----..S,m~~~~ille ?------of Taholah ··- ·· :}:;:.~:·: / ...... ,,, ,,, -----1. .~. ·1. ?.,"' ···- ·· / -- ··· / / / / / / // / / IOOO' ,, ,, / ,- ?" 500'

[

0

Figure 8. Generalized stratigraphic columns for the Quinault Formation near Taholah (Rau, 1'370) . , • ··I'

R13W

••... • • •••••••••-- ...... : ••••••••• • •• c::,-,..... •• ·:·· . I OI~ ··....···· ----...... -····· ---······· . t.01e ·················---······· · ·······-·········- - - ······ t 0 II 1 Poorly exposed ond slumped -N- 400 010·

1 1000' 500 0 1000'

' 1 300

200'

Sec. 12 03 Sec. 13

~ 100' a n - n T 21 N QI Fault 0 EXPLANATION

Foss iii ferous, carbonaceous, thin­ bedded siltstone, sandy siltstone, a and sandstone.

Massive sandstone with occasional concretion ond sedimentary structure

Outcrop area of Ouinoult Formation Thin-bedded sandstone with occaslonol concretions and thin si It stone beds

~ Channeled surface with introformo­ ~ tionol br eccio

Sedimentary conglomerate in sand­ s tone . Figure 9. A stratigraphic column for the Quinault Formation at Point (3renville (!<:au, 1970) . 11111

FOOTHILLS OF OLYMPIC MOUNTAINS -500'

-400' ------_ _ Ol~dm~,f~ - 300'

DESTRUCTION ISLAND -200· ~er~m~foc_e_ _ -100·

Seo Level- r Seo Level }.. -100·

NO HORIZONTAL SCALE EXPLANATION ~-~;:::~"~-·~WO dopo,;t, ~~ ;-,00 Windblown deposits ~ Older sand and grovel deposits [a LS::J :•,;,;.:··:.;-·:.~:·.·.,· Younger sand ond grovel deposits ~ Bedrock i¥:=3h's\ 1 ~ ·::~·.·:. .. •:::

Figure 10, A schematic cross section showi ng the relations of various Pleistocene terraces and sediments CRau, 1973) •

.. ,\ ' ~ ' • NOTE INCREASE IN LINEATION CLUSTERING TOWARD CONTACTS •

M ~ ~ ~ M >·, ...... ·:, :• ... . ·. ::

CONT ACT HIOOEM BY SLUMP \ / ~ •. .,. > -,,... -'\.... "':c· ..· ... : . o• - ,v-' , ' . _:.::_.:: :::"-~__ .i·-,. : S?~ .-~--- ··- .. -~.,-~ _-...... r, ••. ~ 1.J ·~·~ ... :, .....': 11- •.-;t ,.~-.,. ... ;,}r>"" ~"-, ..::,4,4,.Nc,,t~ ··· - ...... ~.~ ~

' L00KIN0 EAST DUCK CREEK MELANGE ZONE PHOTO-MOSAIC OVERLAY

. ·- MAP VIEW (INSET) LOWER HEMISPHERE PROJECTION ··· ..(.__N \ • · · ~ .... :,."\"-.:' .. ,·...... '\ Follatlon • Clast Long Axis Uneatio n :::.\.. ::::~I" .,·::::::: 4 ' ' • ' • • • • I M 6 :t I f \

-~~~.X?.:f'I \':::.·~. 0 50m ' •• . . ', • . •• I SCAl.E .·,

Figure 11 . The orientations a various s tructures in the Cape Elizabeth structure (Duck Creek melange) from Orange (1987) .

- \ \ J , I ~