ouspress

Typewritten Text

oregon geology

oregon geology

6th Edition

elizabeth l. and William n. orr

oregon State University PressCorvallis

Front cover:

Colorful layered volcanics are exposed on the east

bank of Klamath lake (Photo by William n. orr)

the paper in this book meets the guidelines for

permanence and durability of the Committee on

Production guidelines for book longevity of the

Council on library resources and the minimum

requirements of the american national Standard

for Permanence of Paper for Printed library

materials z39.48-1984.

library of Congress Cataloging-in-Publication Data

orr, elizabeth l.

oregon geology / elizabeth l. and William n. orr.

p. cm.

includes bibliographical references and index.

iSbn 978-0-87071-681-2 (alk. paper) --

iSbn 978-0-87071-682-9 (e-book)

1. geology--oregon.  i. orr, William n., 1939- ii.

title.

Qe155.o775 2012

557.95--dc23

                                                           2012015116

© 2012 elizabeth l. and William n. orr

all rights reserved. First published in 2012 by

oregon State University Press

Printed in the United States of america

oregon State University Press

121 the Valley library

Corvallis or 97331-4501

541-737-3166 • fax 541-737-3170

www.osupress.oregonstate.edu

Dedicated to: the Vulgar boaters

Contents

Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

introduction: life on the edge . . . . . . . . . . . . . . . . 9

blue mountains . . . . . . . . . . . . . . . . . . . . . . . . 18

Klamath mountains . . . . . . . . . . . . . . . . . . . . . . 48

basin and range . . . . . . . . . . . . . . . . . . . . . . . . 76

owyhee Plateau . . . . . . . . . . . . . . . . . . . . . . . . 96

high lava Plains . . . . . . . . . . . . . . . . . . . . . . . 110

Deschutes-Umatilla Plateau . . . . . . . . . . . . . . . . . 130

Cascade mountains . . . . . . . . . . . . . . . . . . . . . 154

Willamette Valley . . . . . . . . . . . . . . . . . . . . . . 186

Coast range & Continental margin . . . . . . . . . . . . . 212

references . . . . . . . . . . . . . . . . . . . . . . . . . . 247

index . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289

Shaded relief map from Loy, et al., eds., 2001

7

Prefacein our periodic revisions of Oregon Geology, we are

invariably challenged by the need to address new

ideas and trends in research. Since the last edition

in 2000, many revolutionary models and theories

have been put forward, leaving us to select those

which might have lasting merit and those which

should be replaced.

the overall shift in thinking has been away from

general geology and economics and toward tec-

tonics. among the tectonic concepts, hot spots or

mantle plumes have emerged as an elegant expla-

nation for much of the volcanic activity east of the

Cascades. our understanding of events surrounding

the accretion of terranes has been further refined,

and the unexpected discovery of an enormous

caldera in central oregon has provided answers to

many of the unsolved tertiary volcanic issues there.

on a more practical level, we noted an increased

emphasis on geologic hazards such as earthquakes

and tsunamis as well as an awareness of alterations

to the environment that relate to geology. in the

area of technology, the use of liDar as a geologic

tool has been astonishingly effective for recognizing,

mapping, and evaluating landslides across oregon.

because of our reliance on the labors of oth-

ers, we felt such efforts should be recognized, so,

with some trepidation, we added short biographi-

cal sketches and photographs of just a few of the

noteworthy individuals.

8

Acknowledgmentsthanks to the many colleagues who reviewed all or

portions of the text and diagrams, thus helping us

to avoid errors:

Cal barnes, texas tech University, lubbock, texas

John beaulieu, oregon Department of geology

and mineral industries

howard brooks, oregon Department of geology

and mineral industries

William burns, oregon Department of geology

and mineral industries

Victor Camp, San Diego State University

Julie Donnelly-nolan, U.S. geological Survey

rebecca Dorsey, University of oregon

mark Ferns, eastern oregon State College

Peter hooper, Washington State University

harvey Kelsey, humboldt State University

Paul Komar, oregon State University

Vern Kulm, oregon State University

todd lamaskin, University of oregon

Jason mcClaughry, oregon Department of

geology and mineral industries

alan niem, oregon State University

Wendy niem, oregon State University

Jim o’Connor, U.S. geological Survey

Silvio Pezzopane, University of oregon

len ramp, oregon Department of geology and

mineral industries

bob reynolds, Central oregon Community

College

Josh rohring, University of oregon

gary Smith, University of new mexico

martin Streck, Portland State University

ed taylor, oregon State University

terry tolan, gSi Water Solutions, Kennewick,

Washington

tracy Vallier, U.S. geological Survey

beverly Vogt, oregon Department of geology and

mineral industries

bob yeats, oregon State University

We utilized the science libraries at the University of

oregon and oregon State University along with re-

sources from the archives at oregon State University

and the State archives in Salem. libraries and local

historical societies are always valuable sources for

information long forgotten. indexer Jean mooney’s

attention to detail repaired overlooked errors.

elizabeth orr – William orr

eugene, oregon, 2012

9

Life on the Edgegeology is the story of how the earth has evolved

through time. Some processes such as volcanism,

landslides, or earthquakes are sudden, highly vis-

ible, and catastrophic while erosion, deposition, or

changing climates and sea levels are more subtle

and lengthy. because of oregon’s position on the

leading edge of a moving crustal plate, a striking

diversity of geologic events have gone into molding

its topography. before this complex picture could be

deciphered, over a century of field work collecting

data on stratigraphic relationships, faulting pat-

terns, volcanic episodes, environments, and dates

of rocks had to be compiled. only then could there

be an understanding of the tectonic overprint that

drives most of the state’s geologic episodes.

as the details of oregon’s past emerged, it be-

came apparent that the underlying geology was

not completely in concert with the physiographic

boundaries. landforms are more obvious and can

readily be drawn, in contrast to the outlines for geo-

logic phenomena, which tend to overlap, be buried,

or obscured. in spite of this, the geologic content has

been adapted to the individual geographic provinces,

defined in 1950 by University of oregon geographer

Samuel Dicken. he imposed them on a base map of

the state drawn by erwin raisz.

Geologists such as Thomas Condon, Joseph Diller, Israel Russell, and Howel Williams took the first steps at interpreting Oregon’s geologic terrain. (In this unusual 1898 photo, Diller is sitting beneath a large schist outcrop of Otter Point Formation near Winston, Oregon; courtesy Douglas County Museum, Roseburg)

10 OregOngeOlOgy

Drifting tectonic platesthe premise of moving continents or plate tecton-

ics is central to all aspects of oregon’s geology. the

notion that continents move was first published in

1915 by its chief advocate alfred Wegener when he

reconstructed the supercontinent Pangaea by match-

ing the shapes of continental margins. Continental

drift as a workable theory soon came up short in

light of what was known at the time about the struc-

ture of the earth’s crust. the theory stalled for almost

50 years until marine geologists recognized evidence

from ocean floors to support the hypothesis that

deep-seated plates, with continents imbedded on

their surfaces, are in motion. the new idea of global

plate tectonics emerged after studies of rock magnet-

ics and the realization that the plates are not drifting

but are spreading along mid-ocean ridges. the adop-

tion of this idea ushered in an entirely new way of

looking at the prehistory of the earth as well as at the

beginnings of the Pacific northwest.

Interaction of platesthe advent of plate tectonics was a milestone in

geologic thinking. moving slabs of crust and upper

mantle may separate, collide, or grind past one an-

other. Where plates rift and divide, new crust forms.

Currently, lengthy continuous chains of undersea

volcanic mountains can be found at rifting zones

lifeOntheedge 11

along the floors of every major ocean. Subduction

takes place when two plates collide, and one descends

beneath another. once ocean crust ages and cools,

its density increases, and the older, heavier crust is

thrust below or subducted by the overriding slab.

Where plates slide past each other, transform faults of

epic size and length develop at the boundary between

the two, accompanied by destructive earthquakes.

among the most visible by-products of plate

collision and subduction are the build-up of an

accretionary wedge, the emplacement of volcanic

archipelagos (arcs), and the formation of sedimenta-

ry basins. During the subduction process, sediments

atop the descending slab are peeled off to accumulate

as a jumbled prism or mélange at the outer margin

of the upper plate. associated with this, magma,

rising from the lower descending plate, penetrates

the upper slab to emerge at the surface as a volcanic

chain. between the accretionary prism and the vol-

canic archipelago, a forearc basin or depression may

develop with a similar backarc basin between the

arc and the larger continental mass (craton). over

time, erosion of the volcanic highlands sheds copi-

ous amounts of sediment into both basins.

Arrival of terranesalmost a half billion years in the past, the oldest

rocks that would make up oregon were being

Going back 400 million years, Oregon has had a fascinating history of piecemeal construction, volcanism, and sedimentation even as it was populated by an array of plants and animals.

12 OregOngeOlOgy

The configuration of the Pacific Northwest adapts easily to global models that address the interaction between tectonic plates. Composed of multiple strips, the continental margin and outer high of the Coast Range, the Willamette Valley forearc low, the Cascade volcanic arc, and the high desert backarc basin fit together to make the parcel that is Oregon.

The geographic distance between the subduction trench and volcanic archipelago is a function of the relative age of the crust being subducted and the rate of plate movement. Young, warm crust is buoyant and assumes a low angle of subduction with considerable distance between the arc and trench. Older cooler crust is more dense and droops at a pronounced angle upon subduction, bringing the arc close to the trench.

lifeOntheedge 13

deposited elsewhere in the Pacific basin or even in

distant asia. atop subducting plates, assemblages of

rocks or terranes, imbedded within the crust, are

borne along to be annexed to a larger landmass.

the terranes might be volcanic island chains or

larger pieces of crust. Defined as recognizable suites

of rocks that have a similar geologic origin, terranes

are bordered by faults, share a history of sedimenta-

tion and displacement, and are distinct from the sur-

rounding strata. after attachment (accretion) to the

continent, the terranes are altered and deformed by

the heat and pressure of metamorphism as they are

being rotated into position. arriving one after the

other, the displaced terranes gradually converged to

construct the Pacific northwest.

Constructing Oregonbecause the foundation bedrock of the state has

been assembled piece-by-piece, it is a collage of dis-

placed terranes which originated elsewhere around

the Pacific basin. on opposite sides of oregon, ter-

rane rocks of the blue mountains and the Klamath

mountains are the oldest and most accessible, offer-

ing the best areas to decipher the state’s accretionary

history. During the mesozoic era, successive waves of

volcanic island chains traveled eastward and merged

with western north america to construct these two

provinces. originating in tropical settings, the crustal

pieces brought with them a striking array of fossil

fish, large marine reptiles, and fern-like terrestrial

plants in association with limestones and reefs.

by the end of Cretaceous time, 65 million years

ago, the last of the older terranes had arrived and

been accreted. only the Coast range block (Siletzia)

remained to be emplaced during the early eocene.

With the acquisition of Siletzia, the contours of or-

egon were beginning to appear.

Volcanoes, extension, and tectonics Volcanism and sedimentation, the predominant

geologic processes throughout oregon‘s Cenozoic

interval, are direct by-products of plate tectonic ac-

tivity. eocene to oligocene volcanism coincided with

collision of the Farallon and north american plates.

While the Farallon slab was being subducted, partial

melting at depths up to 75 miles produced low den-

sity magma that rose through the overriding north

american plate to erupt thick layers of ash and lava

over the area that is now the Western Cascades.

Well into the miocene epoch, the landscape

was reshaped by the construction of vast basalt

plateaus in northeast and southeast oregon and

by the spread of incandescent, fast-moving ash

flows in the central region. episodes of volcanism

rarely matched worldwide began with immense

outpourings of Columbia river flood basalts from

a shield volcano in the vicinity of Steens mountain.

the basalt platform would ultimately cover half of

When tectonic plates collide, seamounts, crustal fragments, and island archipelagos are scraped off and accreted to the larger overriding continental block. Following accretion of particularly large tracts, a new subduction zone develops on the outboard side of the oceanic slab.

14 OregOngeOlOgy

oregon and large portions of Washington and ida-

ho. because they were so voluminous and rapid,

tongues of the flows raced across the landscape to

the Pacific ocean where they penetrated the soft

coastal sediments.

the basalt eruptions were triggered by move-

ment of the north american plate over a hot spot

or mantle plume that is located today beneath

yellowstone, Wyoming. if an area of concentrated

heat in the mantle rises, the plume melts the over-

lying crust and emerges as a volcanic hot spot. as

the continent passed over the stationary plume,

the balloon-like head flattened and spread out

west and northwestward, sending lavas to the blue

mountains and across the high lava Plains and

basin and range.

on the owyhee plateau, miocene volcanic cen-

ters were concurrent with eruptive phases of the

Columbia river basalts. explosive activity in the

mcDermitt and owyhee fields some 17 million years

ago was generated by crustal stretching and the

proximity of the yellowstone hot spot. the violent

episodes and subsequent collapse of the vents cre-

ated immense calderas, that are several times larger

than those at Crater lake and newberry Caldera.

the geologic signature of the basin and range

and high lava Plains is the consequence of crustal

thinning and volcanism imposed by the interaction

between the north american continental and the

offshore Pacific plates. as the crust stretched, it

eventually broke into a landscape of north-south

faulted hills and valleys, characterizing the region

today. Volcanism, initiated 10 million years ago,

continued into the recent. the eruptive surges

were both age progressive and bimodal. that is,

they became younger in age from east to west,

beginning at harney basin and ending near new-

berry Crater. in conjunction with the age progres-

sive phenomenon, the bimodal composition varied

from older rhyolitic to younger basaltic lavas.

With waning cycles of the Columbia river ba-

salts, eruptions in the Cascades had shifted as in

Around 50,000 years ago, what is now the Portland-Vancouver metropolitan area saw extensive volcanic activity from the Boring lava field. Looking eastward across Portland toward Mount Hood, just a few of the 80 small volcanoes and cones that compose the Boring field can be seen. (Photo courtesy Oregon State Highway Department)

lifeOntheedge 15

a wave eastward to construct the high Cascade

shield and stratocones during the late miocene

and into the Quaternary Period. Composed of both

basalt and andesitic lavas, the high Cascade peaks

stand in sharp contrast to those of the eroded older

Western range. While most of the high Cascade

eruptions in oregon had diminished or ceased by

30,000 years ago, there have been a number of

episodes since that time. mount mazama’s spec-

tacular explosion, dated at 7,700 years, is the most

notable, but mount hood and numerous domes in

the central chain have been active historically. the

1980 eruption of mount St. helens in Washington

was the most visible and largest in recent times.

Marine and terrestrial basinsthick sedimentary layers that cover large areas

of oregon are critical to interpreting the state’s

geologic past. Changing marine and terrestrial

environments are reflected in the stratigraphy

and fossils, which have been especially useful

for interpreting depositional settings and climate

variations.

as part of a worldwide trend during the late me-

sozoic, rising seas covered much of oregon. Some

60 million years ago, only the blue and Klamath

mountains projected above the surrounding

oceans, with a shoreline that ran diagonally from

the Klamath mountains into eastern Washington.

Following repositioning of the Farallon, Kula,

and north america plates, a lengthy forearc basin

connected these two provinces with the great Val-

ley of California. a thick covering of Cretaceous

sediments, which spread across the basins in the

ochoco and Klamath mountains, entombs some

of the state’s first autochthonous (home-grown)

rocks and fossils. this was the high water mark

before regional uplift forced the waters to retreat.

the early tertiary saw the arrival and rotation

of the large Coast range block of Siletzia, the final

terrane to be annexed. Situated along the edge

of north america and west of the emerging Cas-

cade volcanic arc, Siletzia subsided into a narrow

trough even as it was being accreted. throughout

the eocene epoch, erosion from both the interior

of the continent and the Klamath mountains shed

copious quantities of debris into the basin, which

today underlies the continental shelf and Coast

range, Willamette Valley, and Western Cascades.

elevation of the coastal margin and depression

of the Willamette Valley brought a shallowing of

ocean waters and a reduction of sedimentation

during the latest oligocene.

the subduction of Siletzia beneath the Cascades

and eastward toward idaho generated the Clarno

and Challis volcanic eruptions. lava and ash of

the Clarno Formation blanketed large portions of

eastern oregon, overwhelming lakes and streams.

Clarno sediments and mudflows, along with those

of the successively younger John Day, mascall,

and rattlesnake formations, preserve remarkable

fossil plant and animal remains, which provide a

continuous environmental picture from the eo-

cene through the miocene.

Climate change oregon’s geologic record reveals extraordinary

shifts in climate, from the tropical humid condi-

tions of the Paleocene and eocene to glaciation

during the Pliocene and Pleistocene. many of these

were global trends and not restricted to the Pacific

northwest.

often regional climates are a consequence of

tectonic activity. moving from one latitude to an-

other, crustal plates experience profoundly diver-

gent conditions enroute. ash from explosive volca-

nism, triggered by plate collision, can obscure the

sunlight and cause a rapid drop in temperatures.

alternately, the same episodes may foster a rise in

temperatures with the release of greenhouse gas-

ses. because of its proximity to the Pacific ocean

and the direction of prevailing winds, much of

western oregon’s climate is additionally governed

by variations in the marine offshore realm.

Worldwide, the eocene to oligocene bound-

ary marks a global transition from tropical and

semi-tropical climates to those of a more temperate

nature. Cooling ocean water and falling air tempera-

tures generated clear floral and faunal modifications,

sometimes even leading to extinctions. in western

oregon, changes in the subtropical terrestrial plants

and marine invertebrates in the Keasey, Cowlitz,

and eugene formations are particularly notable. in

eastern oregon, the tropical humid environment

was transformed with the steady elevation of the

Cascade volcanic barrier. by cutting off the moist air

16 OregOngeOlOgy

masses from the Pacific, it dramatically altered con-

ditions by the late oligocene and into the miocene,

resulting in the high desert of today.

beginning a little less than 2 million years ago,

the ice ages or Pleistocene epoch was time of cold

temperatures, heavy rainfall, and the rapid build-

up of continental ice masses. Worldwide, lower

temperatures fostered polar ice caps and lowered

sea levels. throughout this interval, ocean waters

rose and fell during cycles of cooler and warmer

periods, and glacial erosion deeply etched the land.

these trends peaked around 18,000 years ago, af-

ter which the earth entered its present-day warm

interglacial phase.

While no continental glaciers reached oregon,

thick ice caps covered the mountain ridges, and

increased precipitation filled pluvial lakes in the

broad fault-bounded depressions of the basin and

range. these ephemeral lakes, some of which cov-

ered hundreds of square miles, provided habitats

for herds of mammals, migratory birds, and variet-

ies of fish. today all of these shallow basins have

diminished or dried up completely.

The geologic future of Oregonthe geology perspective means examining the past

as well as anticipating the future. to do so, it is nec-

essary to take the long view of modifications to the

earth’s surface and atmosphere, which are extreme-

ly complicated and invariably cyclic. Certainly, this

applies to the current public focus on global warm-

ing. glaciologists calculate that, at present, the earth

is approaching the end of a 10,000-year interglacial

period and should be entering a glacial phase within

the next 23,000 years. During these larger episodes,

average global temperatures fluctuate frequently,

and the last 10,000 years (holocene) has been any-

thing but stable. if, in the future, glacial conditions

prevail and vast ice sheets take up and store ocean

water, the oregon coast will see a substantial drop

An indirect effect of the cold Pleistocene was cataclysmic flooding as continental ice masses advanced into Washington from Canada. Ice dams, which impounded glacial Lake Missoula, failed periodically, releasing as many as 100 huge floods that scoured eastern Washington and the Columbia River channel on the way to the Pacific Ocean. The volumes of water backed up as temporary Lake Allison in the Willamette Valley, leaving thick layers of silt across the floor. (In the photo, the individual shorelines of Lake Missoula in Montana are visible on the hillsides; courtesy U.S. Geological Survey)

lifeOntheedge 17

in sea level. but, on the other hand, with warmer

conditions and melting ice, the oceans will rise to

invade the land. these are long-term developments

that come about over thousands of years.

Caught between converging crustal plates, the

Pacific northwest faces a future of massive earth-

quakes and tsunamis. only in the last 20 years has

the public become aware of the potential for high

magnitude quakes associated with the Cascadia

subduction zone. Since then, there has been an

ongoing push to compile and analyze data on seis-

micity. efforts to explain the current low incidence

of Cascadian subduction activity include a number

of theories, but to date they fail to explain all pos-

sibilities satisfactorily.

289

Indexillustrations are indicated by italics.

Aabert rim, 78, 82, 82, 83, 84, 88, 92abiqua Creek, 199abyssal plain, 215, 215, 229–230,

229, 230, 231–233, 231, 232accretion, terrane, 11–13, 12, 13accretionary wedge, 11, 12, 13adams, John, 227, 234addicott, Warren, 224, 227adel earthquake, 82, 88adrian, 106age progression

basin and range, 14, 84–86, 84, 85

blue mountains, 22, 23, 29, 34–36, 34

Cascade mountains, 14–15, 159–163, 159, 160–161, 166, 167–168, 167

Coast range, 215, 227–229, 228high lava Plains, 11, 14, 113–117,

114, 117, 118Klamath mountains, 50–52, 51,

52, 55, 59–60, 60overview, 14–15owyhee plateau, 100Willamette Valley, 193, 194

agency (mcKay) basin, 132, 139, 140–141, 140

agness, 58alaska earthquake of 1964, 66, 235alaskan Wrangellia, 26, 26albany earthquake, 202, 203albany Quadrangle, 193–194alder grove terrace, 229aldrich group, 25, 28, 30aldrich mountains, 20alkali Canyon Formation, 140, 141,

141allan, Jonathan, 236allen, Charlotte, 60allen, John e., 20, 177, 178, 195allen, maxwell, 64allison, ira, 79, 188, 193–194, 196,

197almeda mine, 68alsea bay, 229, 231, 234

alsea Formation, 189, 222, 223alsea river, 213, 241alsea Spit, 236aluminum, 208alvin Canyon fault, 231, 232alvord basin, 78, 89, 90, 91, 94alvord Creek, 84, 86alvord Creek Formation, 83, 85alvord desert, 81, 83, 92, 93, 120alvord hot Springs, 90, 92alvord lake, 86, 87, 91, 92, 94amity hills, 191, 202ammonites, 28, 28, 30, 31, 32, 57, 224amphibolites, 52, 53, 56ana river, 78, 82, 94ankeny hills, 187antelope Creek, 97antelope reservoir, 107antelope Valley graben, 100, 102applegate group, 10, 49, 52, 52, 53, 69, 72

applegate river, 49, 67, 71applegate-Waldo-gold hill mining area, 67, 68, 69, 69, 70

aquifers. See water resourcesarago Peak terrace, 229arch Cape, 226arch rock Point, 75arches. See sea stacks and archesarizona inn landslide, 65arlington (Umatilla) basin, 132, 139, 140–141, 140, 141, 144–145, 149

armentrout, John, 224army Corps of engineers, 173, 175, 180, 207, 207, 224, 237, 237

arnold, ralph, 213arnold lava Cave system, 127, 128arthropods, 87, 189, 219, 221, 224ash flows. See ignimbritesashland, 53, 53, 64, 66, 67, 71ashland pluton, 53, 59, 60, 67, 69astoria

interseismic elastic strain, 218landslides, 238, 240offshore topography, 225, 229,

230, 230, 231, 231, 232astoria basin, 214, 220, 222, 223,

231astoria Canyon, 229, 230, 230, 231

astoria fan, 229, 230, 230, 231, 231, 232

astoria Formation, 222, 224–225, 224, 225, 238, 239, 240, 240, 242, 244

atwater, brian, 234atwater, tanya, 213auburn ditch, 40aurora mine, 105austin hot Springs, 176, 176ayers lake, 241

Bbackarc basins, 11, 12bacon, Charles, 163–164, 164, 177badger, thomas, 88badlands lava beds, 118, 118, 128baker, C.D., 64baker, Victor, 195baker graben, 31, 101baker terrane, 11, 21, 22, 23, 24–26,

24, 25, 27, 28, 29, 30, 31–32, 40, 134

baker Valley aquifer, 42balanced rocks, 151, 151bald mountain batholith, 22, 31baldwin, ewart, 50, 64, 189, 213, 219, 224

balster, Clifford, 193, 194, 196bandon, 224, 228, 241barnes, Calvin, 49, 60barnes butte, 35, 36barren Valley, 105barrett Spur, 168basin and range, 78–94

geologic processes and features, 79–88basement rocks, 79–80extension, 11, 14, 59, 78, 80–82, 84, 90, 98, 100, 101, 120, 136, 217

fault patterns, 78, 80, 81–83, 88, 115, 119, 120, 120, 166

mantle plume, 14, 78–79, 84, 84, 100, 101, 136

pluvial lakes, 16, 79, 79, 82, 82, 83, 86–88

stratigraphy chart, 85volcanism, 14, 36–37, 78–79, 80, 84–86, 98, 99, 114, 115, 135

290 index

basin and range (continued)hazards, 82, 88–89highlights, 92–94landscape, 78natural resources, 89–92overview, 14, 16, 78past and present work on, 78–79physiographic map, 76–77

basins, formation of, 11, 12, 15bastasch, rick, 147bastendorff beach, 221bastendorff Formation, 189, 221, 222bateman Formation, 220, 221, 222batholiths, 21, 22, 27, 31, 49, 52, 59, 69, 137, 158

battle ground lake, 192battle mountain, 100battle rock, 74bauxite, 208bayocean, 237, 237bC Creek member, 28beacon rock, 178, 178, 179–180bear Creek Valley, 64, 66beatys butte volcanics, 85, 86, 114beaulieu, John, 145, 200, 207beaver Creek fault, 203beavers, 103–104, 104beeson, marvin, 132, 143, 177, 191, 225–226

begg Formation, 25, 30belemnites, 58belknap Crater, 160–161, 161, 162, 166, 184, 185

bellspring peneplain, 63bend

hazards, 122–123, 145natural resources, 147–148, 147Sisters fault zone, 118, 120volcanism, 113, 117, 118, 118, 122–123, 132, 141–142

benham Falls, 144bennett Flat landslide, 89benton mine, 68bentonites, 42, 106berg, J.W., 64bernard Formation, 25, 32berthiaume, Sheridan, 23beverly beach, 235, 238bezore, Stephen, 61big basin member, 32, 34big Craggies botanical area, 58big hole, 118, 122big indian gorge, 83big lake, 185big mud Flat, 105big nick, the, 93big obsidian Flow, 117, 125big Sand gap, 87big Sheep Creek, 27bimodal volcanism, 14–15, 35–36, 84, 86, 98, 99, 113, 117, 117

bingen anticline, 136–137, 138birch Creek tuff, 99birds, 16, 79, 87, 121

bishop, ellen, 151bison, 199bivalves. See mollusksblachly landslide, 241black butte, 120, 140, 148–149, 167,

184, 208black Crater, 185black hills, 216, 219black sands, 242–243blackwell, David, 176blake, m.C., 49, 56, 57, 58blakely, richard, 202, 203, 204blanco fracture zone, 157, 229, 231blome, Charles, 24, 25, 51blossom bar shear zone, 57blue lake, 183, 185blue ledge mine, 70blue mountains, 20–47

geologic processes and features, 10, 11, 13, 14, 21–38, 52, 59, 102, 104, 113, 120, 120, 138, 139, 141, 145

glaciation, 11, 23, 27, 37–38, 38, 43, 43, 47

hazards, 38–39highlights, 43–47landscape, 20natural resources, 40–43, 112, 131

overview, 13, 15, 21–23past and present work on, 20–21physiographic map, 18–19stratigraphy charts, 25, 32

blue mountains anticline, 30, 33, 138, 145

blue river dam, 207blue river mining district, 175, 175blue river ramp, 167bluejoint lake, 94boardman State Park and natural bridge, 75

bohemia mining district, 174–175, 175

bonanza Quicksilver mine, 208bonneville Dam, 138, 172, 173, 178,

188bonneville flood, 38, 39, 47, 99, 105bonneville landslide, 172, 173, 180borax lake, 89, 89, 90borax mining, 89, 89boring lavas, 10, 14, 143, 159, 167, 173, 178, 179–180, 190, 191, 192, 192, 193, 198, 205, 222

bott, Jacqueline, 64, 202bouger gravity field, 80boundary Springs, 49bourne subterrane, 22, 25–26boxcar rapids, 145brachiopods, 24, 27, 30, 224braunmiller, Jochen, 145breitenbush hot Springs, 159, 176bretz, J. harlen, 194bretz mine, 105bridge Creek flora, 46

bridge of the gods, 172, 173, 178briggs Creek gold mine, 70briggs Creek subterrane, 51, 52, 54,

55, 56, 61brisbois member, 25brogan, Phil, 112, 112broken top, 159, 160–161, 161, 162,

163, 168, 169, 181, 182brontotheres, 33, 33brookings, 49, 51, 61, 64, 65, 66, 74, 75

brooks, howard, 21, 23, 25, 30, 40, 67

brothers fault zone, 36, 81, 81, 82, 101, 115, 116, 118, 120, 120, 166, 202

brownlee fault, 38bruer, Wes, 241–242bryan, Kirk, 97bryozoa, 27, 224buckskin Peak pluton, 59, 60buddenhagen, harold, 166buell limestone, 189, 222, 222bull run lake, 209bull run syncline. See mosier-bull run syncline

bully Creek floods, 105bully Creek tuff, 99burlingame Canyon, 195–196burns, marjorie, 195burns, Scott, 173, 177, 195, 204, 205, 205

burns, William, 205burns butte, 114, 120burnt river, 40burnt river Canyon, 25, 26burnt river Schist, 24, 25, 25burt, Walter, 209butte Creek, 199butte Creek Volcanic Sandstone, 99, 103, 104

butter Creek, 131, 141byerly, Perry, 64

CCache Creek belt, 52Calapooia fan, 194Calapooia fault, 202, 203Calapooia river, 187, 209Calapooya mountains, 155calderas

See also Crater lake; newberry Crater

blue mountains, 11, 34–36, 34, 35, 47, 47, 98

high lava Plains, 115, 116owyhee plateau, 14, 98–102, 100,

101, 102, 104, 105, 109Caldwell, rodney, 209Callaghan, eugene, 166Camas landslides, 172camels, 37, 104Cameron, Kenneth, 174

index 291

Camp, Victor, 86, 97–98, 99, 100, 103, 115, 132, 135, 137

Campbell lake, 94Canby-molalla lineament, 202, 203Cannon beach, 226, 235, 235, 240Canyon Creek, 40Canyon mountain complex, 24–25,

25Canyonville fault zone, 53, 58, 61,

220Canyonville landslide, 65–66Cape arago, 221, 228, 229, 232, 242Cape blanco

ancestral shoreline, changes in, 218, 218, 220, 225, 227

earthquakes, 64faults, 64, 230, 233fossils, 224, 227geologic highlights, 74, 213, 227, 243

gold mining, 242offshore topography, 230, 230Sixes river terrane, 51, 58, 61terraces, 227–229, 228

Cape Falcon, 226Cape Ferrelo, 74Cape Foulweather, 226Cape horn, 178, 180Cape lookout, 226, 226Cape meares, 226, 237, 237, 238Cape Perpetua, 223Cape Sebastian (continental slope), 230, 230

Cape Sebastian Formation, 52, 56, 58, 63, 74, 75

Caps Creek Formation, 25Carlson, richard, 135Carson, robert, 142Carter, Deron, 87Cascade bench, 230, 230Cascade head, 219, 222–223, 230,

230, 238Cascade locks, 172, 172, 178Cascade mountains, 155–185

geologic processes and features, 151, 190Cenozoic history, 157–169Coast range overlap, 188, 214,

215, 216, 220, 221, 222, 223crustal extension, 80, 81, 82,

162, 165, 166–168, 166, 167eastside depositional basins, 139, 140, 167–168

eruptive styles, variations in, 159, 161, 162, 165–166, 165

faults, 81, 81, 82, 120, 166–168, 166, 167, 203

high Cascade graben, 80, 132, 138, 139, 156, 159, 159, 166–168, 167

high Cascade volcanism, 159–168

Klamath overlap, 52, 64

migration of volcanic arc, 158, 159, 160, 165–166, 165

newberry Crater, 117overview, 10, 11, 12, 13, 14–16, 156–157

redirection of river channels, 143, 144

stratigraphy chart, 159Western Cascade volcanism, 158–159

Willamette Valley overlap, 188, 189, 191, 193–194, 194, 198, 210–211, 214, 215, 216

hazards, 157, 169, 170–174, 200, 203

highlights, 177–185landscape, 155natural resources, 49, 71, 148, 168, 174–177, 187, 208–209

overview, 156–157past and present work on, 155–156, 177, 178, 180, 188

physiographic maps, 154rainshadow, 11, 15–16, 37, 155, 177

Cascadia channel, 229, 230, 234Cascadia subduction zone, 12, 214,

218, 229, 231, 231, 232See also subduction earthquakes

Cashman, Katharine, 180Castle Peak caldera, 100, 102Cathedral rock, 45Catlow fault, 81, 82, 83Catlow Valley, 78, 81, 83, 93Cave Creek fault, 26caves and tubes, 44, 44, 72, 72, 107, 108, 108, 118, 122, 124, 126, 127–128, 127, 221, 223, 244

Cenozoic Geology of the Blue Mountains (Walker), 21

central metamorphic terrane, 51, 59Century Drive eruption, 142cephalopods, 28, 31, 58

See also ammonitesChalk basin, 103Chalk butte Formation, 99, 104Challis volcanic eruption, 15, 32–33Champion mine, 174–175, 175channeled scablands, 195, 195Chehalem mountains, 187, 193, 209Chetco complex, 55, 56, 59, 60, 61Chetco Peak glaciers, 50Chetco river, 49, 58, 64, 67, 69–70, 71

Chetco-illinois mining district, 67, 68, 69–70

Chetco-illinois plutonics, 52, 56, 59, 60

Chewaucan basin earthquakes, 88Chewaucan lake, 79, 82, 86, 87, 94Chewaucan marshes, 87, 94Chewaucan river, 78Chief Joseph dike swarm, 36, 36,

134, 135, 135, 138

China hat, 114, 116, 118, 120Chitwood, lawrence, 113, 118, 125Christmas lake Valley, 113, 118, 120, 148

chromite, 61, 67, 70–71, 71, 242chromium, 61cinder cones, 165–166cinnabar. See mercurycirques, 38, 83, 85, 163, 168Clackamas river, 155, 171, 187, 192, 209

Clackamas river fault belt, 166, 167, 167, 202

clams, 27, 28, 30, 32, 57, 128, 221, 224, 229

Clark Fork river, 132, 142, 195, 195Clarks butte, 107Clarno Formation, 11, 15, 32–33, 32,

33, 34, 34, 35, 35, 39, 41, 44, 44, 46, 133, 147, 148, 167

Clatskanie landslides, 241Clatsop Plains, 245Clear lake (Cascades), 183, 185, 185Clear lake (Florence), 245Clear lake (roseburg), 245Clearwater embayment, 135Cleawox lake, 244Cleetwood Cove, 164Clement, William, 87climate change, 15–17, 16

See also glaciation; global warming; tropical environments

Cline buttes basalts, 139, 140, 141Cloud Cap lavas, 160, 161Cloudcap bay, 160, 164Clover Creek greenstone, 25, 26, 27, 27

coal, 50, 241, 242Coaledo Formation, 220, 221, 221,

222, 241, 242Coast range, 213–246

geologic processes and features Cascade overlap, 188, 214, 215,

216, 220, 221, 222, 223Cenozoic history, 215–229Columbia river basalts, 139,

219, 222, 225–226, 225, 226, 243, 244, 245–246

faulting, 203, 215, 216, 217–218, 217, 229

Klamath overlap, 15, 51, 61, 62–64, 189, 214, 216, 218, 219, 220, 221

ophiolites, 54, 54, 55, 56, 57, 63, 70

overview, 10, 12, 13, 14, 15, 214–215, 215

stratigraphy chart, 222Willamette Valley overlap, 15, 188–189, 189, 193, 194, 214, 215, 222

Willamette Valley subsidence, 188, 191, 193, 218

hazards, 203, 233–241

292 index

Coast range (continued)highlights, 243–246landscape, 213natural resources, 241–243overview, 214–215past and present work on, 132, 213, 214, 236

physiographic map, 212Coast range anticline, 222coastal bogs and marshes, 10, 215, 221, 223, 234

coastal erosion hazards, 215, 235–238, 236, 237, 238, 244

coastal terraces, 213, 214, 215, 222, 227–229, 228, 236, 238, 239, 240, 242, 243

Coburg hills, 167, 206, 210coccoliths, 219, 221Coe glacier, 168Coffee Creek Formation, 11, 23, 24,

25Coffeepot Crater, 107, 107Coglar butte, 82Cohen, andrew, 87Colebrooke schist, 52, 55, 56, 57–58,

63Coleman, robert, 57–58Coleman hills volcanics, 84, 85Colestin Formation, 52, 64, 158, 159,

189, 220Collier Cone, 160–161, 163, 166, 185Collier glacier, 169Columbia arc, 30Columbia embayment, 30Columbia hills, 133, 137, 138, 142Columbia plateau, 79, 79, 84, 99, 100, 115, 131, 132, 139, 142, 143, 148

Columbia riverancestral pathways, 142–143, 143, 167, 188, 191, 209, 226

Cascades, 155, 167, 167, 168, 172–173, 174, 177

Coast range and continental margin, 213, 225, 226, 230, 230, 231, 234

Deschutes-Umatilla plateau, 131, 132, 133, 138, 139, 140, 142–143, 142, 143, 144

Fossil lake drainage, 121hazards, 144, 146, 170, 172–173,

172, 173, 174missoula floods, 16, 142, 178, 180, 180, 194–198

Portland hills silt, 193scenic highlights, 177–180, 178,

179, 180water resources, 20, 147, 155, 168, 177

Columbia river basalt groupbasin and range, 81, 86blue mountains, 23, 27, 32, 36,

36, 37, 42, 45

Cascade mountains, 158, 159, 159, 167, 172, 173, 174, 178, 179

Coast range, 139, 219, 222, 225–226, 225, 226, 243, 244, 245–246

Deschutes-Umatilla plateau, 131–132, 131, 132, 133–139, 140, 141, 142–143, 143, 145, 147

landslides, 145, 172, 173, 174, 205

mantle plume, 14, 99, 100, 101, 132, 134, 136, 137

overview, 13–15owyhee basalts, 103Steens mountains, 11, 13–14, 86, 99, 101, 134, 135, 135, 137, 138

stratigraphy charts, 136, 141, 159Willamette Valley, 139, 188, 190, 191–192, 193, 198, 202, 205, 208, 209, 209, 210–211, 226

Columbia river gorge, 177–180, 178, 179, 180, 188, 194, 195–196, 195, 198

Columbia river highway, 177, 178Columbia trans-arc lowland, 137,

138, 139, 143, 166columnar basalts, 133–135, 134, 210composite vs. shield volcanoes, 161, 162, 162, 165–166

Condon, thomas, 187, 196, 224Condrey mountain terrane, 51, 52, 53–54, 53, 61

Coney, Peter, 51Connor Creek fault, 30, 31Connor Creek mine, 40conodonts, 24, 24, 52Conrad, timothy, 224Conrey, richard, 139, 156, 162, 166, 167–168, 180

continental drift. See plate tectonicscontinental margin, 12, 15, 64, 188, 213, 214, 215, 215, 218, 229–233, 235, 242

continental shelf, 12, 15, 214, 215, 221, 223, 224, 229–230, 229, 230, 231, 232

continental slope, 12, 215, 215, 223, 229, 230, 232

Cooks Chasm, 244Coon hollow Formation, 25, 28Cooper Spur, 168Coos bay, 50, 88, 241Coos bay basin, 214, 220, 221, 223–224, 225, 231, 232

Coos bay terraces, 50, 64Coos Conglomerate, 222, 224Coos river, 213copper, 20, 40, 41, 61, 67, 68, 69, 70, 71, 175

Copper butte, 70Coquille bank, 230, 230, 232Coquille Formation, 222, 227Coquille Point, 227, 228Coquille river, 213, 217, 242

Coquille river fault zone, 61, 217corals, 11, 24, 25, 28, 28, 59, 223, 224

Corderzo mine, 105Cornucopia mines, 40Corvallis fault, 200, 203, 217coseismic strain release, 233, 233, 234

Cottage grove, 174, 189, 207, 208Cougar fault, 167Cove hot springs, 42Cove Palisades State Park, 141, 144, 145, 147, 149–151, 149, 150

Cow Creek, 104, 105–106, 107Cowlitz Formation, 15, 222, 223, 242

Coyote butte Formation, 23, 24, 25Coyote lake, 86, 87crabs, 189, 224Crack-in-the-ground, 112, 118, 119Crandell, Dwight, 161Crane, 121Crane Creek fault zone, 31Crater lake, 10, 81, 87, 155, 159,

160–161, 161, 163–165, 164, 177, 181, 182, 183

See also mount mazamaCrater rock, 161, 162, 162, 168, 168Crescent Formation, 216, 218, 219Crescent lake, 183Crestview terrace, 229crinoids, 27, 28, 223crocodiles, 11, 31, 33Crook Point, 64, 74, 75Crooked Creek, 87Crooked river

basalt flows, 34, 39, 132, 144, 144Cove Palisades State Park, 144, 149–151, 150

landscape, 131Smith rock, 47, 47

Crooked river caldera, 11, 34–36, 34, 35, 47, 47, 98

Crooked river gorge, 132, 149, 150, 152, 152

Crown Point, 143, 178, 178Crump geyser, 90, 91Crump lake, 94crustal earthquakes, 200–204, 201,

202, 203, 204crustal thinning. See extensional tectonics

Cuddy mountain, idaho, 30, 31, 38Cummings, michael, 91, 97–98, 102, 104

DDaisy bank fault, 231, 232Dall, William, 224Dalles, the

Columbia river gorge, 177, 178hazards, 144, 145, 146, 172, 173missoula floods, 132, 142, 195, 196, 198

index 293

natural resources, 148, 208yakima fold belt, 138

Dalles basin, the, 132, 139, 140, 140, 141

Dalles Formation, the, 32, 133, 140, 141, 145, 159, 167, 167

Dalles-Umatilla syncline, 138dam construction, 148, 151, 173,

188, 207, 207See also reservoirs

Danforth Formation, 116Darienzo, mark, 234Davidson, elijah, 72Days Creek Formation, 52, 57Dayton, 196debris flows, 238, 240–241Dee Wright observatory, 184, 185deep-sea fans, 10, 12, 32, 63, 63, 214, 219, 221, 222

Deer butte Formation, 99, 103, 104, 109

Delamar mining district, 105–106Delta Park flood, 206–207Denning Spring, 32Depoe bay, 243, 244Derrick Cave, 127Deschutes basin, 139, 139, 140, 141, 145, 147, 148–149, 151

Deschutes Formation, 32, 39, 139, 140, 141, 145, 148, 149, 151, 151, 159, 167, 167

Deschutes river, 124, 131, 142, 145–146, 147, 148–151, 155, 174

Deschutes river Canyon, 34, 39, 47, 132, 139, 141, 144, 144, 145

Deschutes river channel, 117, 123, 125, 132, 142, 144, 144, 146, 174, 195

Deschutes valley earthquakes, 145, 200

Deschutes-Umatilla plateau, 131–152geologic processes and features, 35, 133–144, 133

hazards, 144–146highlights, 149–152landscape, 131natural resources, 146–149overview, 132–133past and present work on, 131–132, 139

physiographic maps, 130Desert Spring tuff, 141detachment faulting, 82Devils backbone, 75Devils Churn, 244Devils elbow, 244Devils garden lava beds, 118, 118, 121

Devils gate fault zone, 100, 102Devils lake, 245Devils Punchbowl, 244Devine Canyon tuff, 32, 85, 99, 103,

114, 115–116, 115, 120

dextral shear, 80, 120, 216, 217Diamond Craters, 112, 118, 119, 120,

120Diamond hill member, 190, 194Diamond lake, 183, 183Diamond Peak, 159diatomite, 42, 91, 146–147, 224diatoms, 32, 37, 42, 144, 165, 185, 192

Dicken, Samuel, 9Dickinson, William, 20, 23, 28, 213dikes

blue mountains, 25, 35, 36, 36, 37Cascade mountains, 163, 182Coast range, 219, 225–226, 237, 242, 245

Deschutes-Umatilla plateau, 132, 133, 134, 135, 135, 138

high lava Plains, 116, 122Klamath mountains, 56, 57, 59, 61, 61

owyhee plateau, 99–100, 101Willamette Valley, 210

Diller, Joseph, 9, 49, 63, 64, 163, 213, 224

Diller glacier, 169Dillman Cave, 126Dinner Creek tuff, 99, 100, 102, 102,

114dinosaurs, 58, 75Dodge bridge flood, 66Dodson landslide, 172, 173, 173Dogami (oregon State Department of geology and mineral industries), 20, 67, 68, 70, 90, 155, 176–177, 188, 200, 206, 208, 213, 235

Dokka, roy, 80Donato, mary, 49, 53Donnelly-nolan, Julie, 117, 120Donner and blitzen river, 83, 92, 112

Dooley rhyolite, 32, 37Dorena lake, 175Dorsey, rebecca, 30, 32Dothan Formation, 51, 52, 55, 56, 58,

61, 63, 66, 68, 70, 74, 75, 220, 232Dott, robert, 49, 50, 58, 213Doyle Creek Formation, 25, 27, 28dredges, gold, 40–41, 40, 41, 69, 70Drewsey Formation, 32, 37, 42Drift Creek, 199, 241Dry butte (high lava Plains), 116Dry butte subterrane, 51, 52, 54, 55, 56, 56, 59, 61, 63

Dry Creek butte fault zone, 100, 102Dry Creek rhyodacite, 99Dry mountain, 36–37Duck Creek butte lavas, 100, 114,

114, 115duckbill dinosaurs, 58Dundee, 191Durkee, 25Dutton, Clarence, 173

Eeagle Cap Wilderness, 38eagle Creek, 158, 180eagle Creek fault, 30, 31eagle Creek Formation, 159, 172, 174

eagle Creek member, 28eagle mountains. See Wallowa mountains

earthflows, 238, 240earthquakes, 11, 17

basin and range, 82, 88, 88blue mountains, 38Cascade mountains, 170, 174, 200, 203

Coast range, 214, 215, 233–235, 233, 235

Deschutes-Umatilla plateau, 144–145

Klamath mountains, 64, 66, 66owyhee plateau, 105Willamette Valley, 188, 200–204

east albany fault, 202, 203east bank fault, 201, 202east butte, 114, 120east lake, 117, 124east lava field, 118, 118East of the Cascades (brogan), 112eastern California shear zone, 80, 88, 145, 166

eastern hayfork terrane, 53eastern Klamath terrane, 51, 52, 59echo flood, 146ecola State Park, 235, 240eden ridge coal field, 241ediacara, 52edson butte, 58el Dorado ditch, 40elephant mountain member, 136, 140

elephant rock, 225elephants, 103elgin ridge, 114eliot glacier, 168elk mountain, 114elk outlier, 56–57elk river, 56–57, 65elk river Formation, 222, 227elk subterrane, 51, 52, 54, 56–57, 61elkhorn mountains, 20, 31, 40elkhorn ridge argillite, 24, 25–26,

25elkton Formation, 220, 221, 222elkton syncline, 217, 218ella butte, 148ellensburg Formation, 141elowah Falls, 178empire Formation, 222, 224, 227empire mining operations, 242Environmental, Groundwater, and

Engineering Geology (burns), 204eola hills, 187, 191, 202, 209erratics, 10, 79, 93, 120, 142, 196–198, 197

294 index

estacada, 171, 191, 192esterly mine, 68eugene, 88, 167, 175, 187, 189–190,

189, 196, 197, 206, 207, 209, 210, 210

eugene Formation, 15, 158, 159, 167, 189–190, 189, 190, 194, 203, 206, 210, 222, 223, 242

eugene-Denio fault zone, 81–82, 81, 120, 166

evans, James, 97–98evarts, russell, 193explorer Plate, 157extensional tectonics, 10–11, 12, 14,

31, 33, 78, 80–82, 80, 81, 166extinctions, 10, 15, 190, 223

FFall Creek mining district, 175, 175Farallon plate, 13, 15, 62, 80, 84, 156, 157, 188, 189, 215, 216, 223, 225

Fecht, Karl, 143Fern ridge terrace, 229Ferns, mark, 25, 34, 97, 98, 102, 105–106

Fiddler mountain olistostrome, 56Fields Creek Formation, 25Fire and Ice (harris), 180fish, 13, 16, 24, 37, 52, 87, 103, 104, 121, 128, 223, 224

Fish Creek, 83, 171Fish lake, 92, 183, 185Fisher, richard, 34Fisher Formation, 158, 159, 167, 189, 203, 206, 208, 220, 222

Flagstaff lake, 94Flat mountain, 246Flint, richard, 194flooding (modern)

See also tsunamisCascade mountains, 170–171, 170Coast range, 241Deschutes-Umatilla plateau, 145–146, 146

Klamath mountains, 66, 66owyhee plateau, 105Pleistocene, 16Willamette Valley, 188, 205, 206–207, 207

Floras lake Sandstone, 222, 224Florence, 238, 245Flournoy (White tail ridge) Formation, 63, 63, 64, 167, 219, 221, 222

foraminifera, 61, 189, 219, 221forearc basins, 11, 12, 15Forked butte event, 161Forks of Salmon plutons, 59Fort Jones terrane, 53Fort rock basin, 113, 118, 119, 120–121, 121, 122, 123, 148

Fort rock lake, 79, 86, 120–121, 122Fossil, 46

Fossil lake, 79, 86, 121Fossil Point, 224fossils

basin and range, 16, 79, 86–88blue mountains, 11, 13, 15, 23, 24, 24, 25, 26, 27, 28, 28, 30, 31, 32, 33–34, 33, 34, 37, 44, 46

Cascade mountains, 158–159, 165Coast range, 188, 219–221, 222, 223, 224–225, 224, 226–227, 229, 234

Deschutes-Umatilla plateau, 132, 139, 140, 141, 144

eastern oregon, 11extinctions, 10, 15, 190, 223high lava Plains, 113, 121, 128Klamath mountains, 13, 15, 51, 52, 53, 54, 56, 57, 58, 59, 61, 62, 63

owyhee plateau, 98, 103–104, 104

Willamette Valley, 188, 189, 190, 191, 192, 199, 210

Foster Creek landslide, 89Fountain landslide, 172, 173, 174Four Craters lava beds, 118, 118, 119Four-in-one cone, 160–161, 166, 185Fowler, Jerry, 224Franciscan unit, 51, 55, 57Frederick butte, 114, 116, 118, 120Fremont, John C., 78Fremont national Forest, 89Frenchman Springs member, 136, 141, 143, 143

From Greenhouse to Icehouse (Prothero), 190

Frontal (Sandy river) fault, 202, 202fuller’s earth. See bentonitesFulmar fault, 216, 229, 231, 232fusulinids, 24, 25

Ggable Creek Formation, 25, 32gales Creek fault zone, 202, 203, 217galice Formation, 52, 54, 55, 56, 58, 59, 63, 68, 69, 70, 220, 242

galice-Silver Peak mining district, 67, 68–69, 68

game lake, 57gannett, marshall, 92, 209garcia, michael, 58gardner, Cynthia, 163garnets, 52, 56, 242garrison lake, 74gas and oil resources, 133, 208, 213, 241–242

gateway, 139, 140, 141gearhart mountain volcanics, 36–37, 85, 86

gemstones, 79, 90gentile, John, 240geodes, 41–42, 41, 109Geologic Map of Oregon (Walker and macleod), 21, 113

Geological reconnaissance of the northern Coast Ranges and Klamath Mountains, California (irwin), 50

Geology of Oregon (baldwin), 50Geology of the Southwest Coast (Dott),

50geothermal resources

basin and range, 80, 89, 89, 90–91, 90, 92

blue mountains, 42Cascade mountains, 176–177, 176Deschutes-Umatilla plateau, 147high lava Plains, 123Klamath mountains, 69owyhee plateau, 98, 106Willamette Valley, 176

giaramita, mario, 56gilbert, g.K., 78, 79, 173gillespie butte, 210gilluly, James, 20glacial moraines, 37, 43, 43, 183, 184glaciation, 10

See also missoula floodsbasin and range, 79, 79, 83, 85, 87, 87, 92, 93

blue mountains, 11, 23, 27, 37–38, 38, 43, 43, 47

Cascade mountains, 156–157, 160, 162, 163, 168, 168, 169, 171, 171, 178, 179, 181–182, 182, 183, 183, 184

cirques, 38, 83, 85, 163, 168Coast range, 215, 226Deschutes-Umatilla plateau, 142future episodes, 16–17high lava Plains, 113, 120Klamath mountains, 50, 64owyhee plateau, 98, 105Steens mountains, 11, 85, 87, 92,

93, 105Willamette Valley, 193, 194–198, 206

glacier lake, 38gladstone, 206glass buttes, 114, 116, 120glenbrook fault, 217glenn, Jerry, 193, 196glenns Ferry Formation, 99, 104global warming (modern), 16, 209–210, 218

goat island, 75goble volcanics, 219, 222gold

blue mountains, 20, 21, 40–41, 40, 41

Cascade mountains, 174–175, 175Coast range, 242–243Klamath mountains, 50, 58, 61, 67–70, 68

owyhee plateau, 98, 105–106Gold and Silver in Oregon (brooks and ramp), 67

gold beach, 49, 62, 64, 65, 66, 75

index 295

gold beach terrane, 32, 51, 52, 55, 56, 57, 58, 61, 63

Gold Belt of the Blue Mountains, The (lindgren), 20

gold hill floods, 66gold hill pluton, 59, 60, 67gold hill-applegate-Waldo mining area, 67, 68, 69, 69, 70

gold ray dam, 72goldfinger, Chris, 234goose lake, 81, 82, 86gorda plate, 64, 157, 229, 231, 231, 233

grabens. See extensional tectonicsgrand Canyon of the Snake river.

See hells Canyongrande ronde basalt, 27, 32, 36, 86, 100, 101, 134, 135–136, 135, 136, 137, 137, 141, 178, 190

grande ronde river, 20, 42grande ronde Valley, 31, 39, 42, 225–226

granite mountains. See Wallowa mountains

grants Pass, 49, 64, 66, 70, 71, 71, 72

grants Pass pluton, 53, 59–60, 60, 67, 69

grassy mountain, 106, 106grassy mountain basalt, 99grave Creek, 32, 68, 69graveyard Point cliffs, 74gravity anomalies, 80, 176gray butte, 35, 35, 36grayback pluton, 53, 59, 60graylock Formation, 25grays harbor, Washington, 225–226,

231great Valley of California, 15, 32,

32, 62green mountain basalts, 118, 119green Peak, 246green ridge escarpment, 139, 166,

167, 168green ridge fault, 118, 166, 167greenback member, 196greenback mining district, 67, 69greenhorn mountains, 11, 20, 40greenhorn subterrane, 22, 25–26greenleaf Peak, 172, 172gregory Point, 221, 221greis ranch Sands, 189griffin, henry, 40griggs, allan, 227grindstone terrane, 22, 23–24, 24, 25grivetti, rex, 213grizzly mountain butte, 35, 36groh, ed, 112, 151groundwater. See water resourcesgrouse Creek, 27grunder, anita, 113guano lake, 86, 94guano Valley, 81guffanti, marianne, 165

Hhadrosaurs, 58hager mountain, 114hale butte, 210hamlet Formation, 222, 223hammond, Paul, 155, 166hampton butte, 116, 118, 120hampton tuff, 85, 114, 115, 116, 120hannibal, harold, 213hardscrabble butte, 210harney basin, 14, 93, 112, 113, 114, 115–116, 115, 118, 120, 120, 124

harney lake, 86, 120, 121, 123harper, greg, 54, 57harris, Stephen, 180hart, William, 135hart lake, 94hart mountain, 78, 82, 92, 93harwood, David, 49hat Point, 38, 46hatton, raymond, 113, 180, 241hayden glacier, 169haystack rock, 226, 235haystack Valley member, 32, 34heads, the, 74heap-leaching, 68, 175heceta bank, 230, 230heceta fault, 231heceta head, 223helena mine, 174–175heliote (sunstones), 79, 90hells Canyon, 21, 31, 38, 43, 46–47,

200heppner flood, 146, 146hermiston, 145, 149hickman, Carole, 190high Cascades, 12, 15, 80, 81, 82, 132, 139, 143, 151, 159–169, 179, 180–183, 185, 193

See also Cascade mountainshigh lava Plains, 112–129

geologic processes and features, 11, 14, 79, 81, 84, 86, 101, 113–122, 132, 166

hazards, 122–123highlights, 124–129landscape, 112natural resources, 123–124overview, 113past and present work on, 112–113, 165

physiographic map, 110–111stratigraphy chart, 114

highlands landslide, 205hillsboro Formation, 192hines (hot springs), 123hines, gustavus, 173h.J. andrews experimental Forest, 170

hodge, edwin t., 155, 162, 174, 178, 188, 192, 194

hofmeister, Jon, 205hogback mountain, 78holden, e.S., 64

hole-in-the-ground, 109, 118, 121, 122

hole-in-the-Wall landslide, 38–39hood, Samuel, 181hood river, 171, 172, 174, 180, 191hood river fault, 138, 167, 167hood river lavas, 160, 161hood river valley, 167, 174hooper, Peter, 33, 132, 135hooskenaden Creek, 65hornbrook Formation, 32, 32, 52, 62, 62, 64

horse Creek fault, 166, 167horse heaven hills, 142horse heaven hills anticline, 136–137, 138, 141

horse heaven mining district, 21, 41horse mountain, 114horses, 103–104hot lake, 42hot spots (mantle plumes)

basin and range, 14, 78–79, 84, 84, 100, 101, 136

Columbia river basalts, 14, 99, 100, 101, 132, 134, 136, 137

high lava Plains, 14, 115, 132overview, 14, 84, 84owyhee plateau, 14, 99, 100, 101, 103

Steens mountains, 78–79, 84, 84, 99, 101, 134, 137

yakima fold belt, 137hot springs

basin and range, 80, 88, 89, 90, 91–92

blue mountains, 42Cascade mountains, 159, 176–177, 176

Deschutes-Umatilla plateau, 147high lava Plains, 123owyhee plateau, 106

housen, bernie, 32howell, David, 49hudspeth Formation, 25, 32hughes, ellis, 197human artifacts, 121, 122humbug mountain Conglomerate,

52, 56, 74, 74hunsaker Creek Formation, 25, 27, 41

hunter Creek basalt, 99, 100, 102, 108hunters Cove Formation, 52, 56, 58,

63, 75hunters hot Springs, 91huntington, 30huntington Formation, 25, 30hurwal Formation, 25, 27–28, 27husband mountain, 162hyde Formation, 25hydrate ridge, 230, 242hydrocarbons, 133, 241–242hydrogen sulfide, 231, 233, 242hydrothermal energy. See geothermal resources

296 index

IIchthyosaurs, 11, 31, 58idaho batholith, 22, 137, 220idaho group, 99ignimbrites, 13

blue mountains, 32, 33, 34, 37, 44, 45

Cascade mountains, 164, 174Deschutes-Umatilla plateau, 139, 141–142, 151, 151

high lava Plains, 115, 116, 121illinois river, 49, 67, 69–70, 71illinois river pluton (Chetco river complex), 52, 56, 59, 60

illinois-Chetco mining district, 67, 68, 69–70

illumination ridge, 162, 174imbler, 32imnaha basalt, 27, 32, 36, 36, 46, 86,

101, 135, 135, 136, 137imnaha glacier, 38imnaha river, 20, 27indian Creek terrace, 227, 228industrial rock, 42, 91, 106, 146–147, 146

inflated lava, 118interseismic (elastic) strain, 218, 218, 233–234, 233

intraplate earthquakes, 200, 203–204, 204

intrusions. See dikes; plutons and batholiths; sills

inverted topography, 72, 74, 128, 226, 245

irish bend member, 190, 196iron, 54, 61, 61, 208iron Dyke mine, 41, 70iron mountain, 114, 120, 208ironside mountain inlier, 30irwin, Porter, 49, 50, 51, 53, 59, 60,

63island, the, 144, 150, 151island archipelagos, 10–13, 12, 13izee terrane, 11, 21, 22, 23, 25, 27, 28, 30, 31–32, 134

JJackson hot Springs, 176Jacksonville pluton, 59, 60Janda, richard, 227–228Jefferson, anne, 177Jefferson, thomas, 187Jensen, robert, 113, 120, 128John Day fault zone, 30John Day Formation, 11, 15, 32, 33–36, 34, 35, 39, 42, 44, 44, 45, 46, 47, 47, 133, 139, 141, 145, 148, 167, 187

John Day Fossil beds national monument, 44–46, 45

John Day inlier, 28John Day mining district, 40, 40, 42John Day river, 20, 33, 40, 42, 131, 147, 195

John Day (town), 24, 25, 115John Day Valley, 34, 42, 132Johnson, James, 174Jones, David, 26, 49, 51Jordan, brennan, 113Jordan Craters volcanic field, 99, 105, 107, 107

Jordan Creek, 105–106, 107Joseph, 37Josephine ophiolite, 52, 54, 54, 55, 56–57, 61, 63, 67, 70

Jump Creek rhyolite, 99, 100, 108Jumpoff Joe Creek, 69Jump-off Joe peninsula, 238, 239Juniper butte, 35, 36Juniper ridge, 114, 116Juntura, 37, 102Juntura Formation, 32, 37, 42

KKalmiopsis Wilderness, 49, 58, 70Keasey Formation, 15, 189, 222, 223Kelsey, harvey, 214, 229Kerby, 71Kiger gorge, 83, 92, 93Kimberly, 44Kimberly member, 32, 34Kings Valley fault, 202, 217, 246Kittleman, larry, 97, 98, 108Klamath basin, 87–88, 92Klamath Falls, 80, 88, 88, 91, 200Klamath graben, 88, 166Klamath lake, 49, 78, 81, 86, 88, 92, 94

Klamath mountains, 49–75See also Klamath-blue mountains lineament

geologic processes and features, 50–64accretion of terranes, 50–52, 51,

52, 53, 54, 55Coast range overlap, 15, 51,

61, 62–64, 189, 214, 216, 218, 219, 220, 221

glaciation, 50, 64individual terranes, 51, 52–59ochoco basin overlap, 11, 15, 31–32, 32, 62, 62

offshore topography, 15, 230–231

ophiolites, 10, 49, 52, 53, 54, 54, 55, 56–57, 56, 59, 60–62, 61, 62, 63, 67, 69, 70

overview, 13, 15, 50plutons, 49, 53, 56, 58, 59–60,

60, 61, 67, 68, 70rotation of terranes, 50, 52, 53,

53, 59stratigraphy chart, 52thrust faults, 50–51, 51, 53, 55, 57, 58, 60, 61

hazards, 64–66highlights, 72–75landscape, 49

natural resources, 67–72overview, 50past and present work on, 49–50,

62, 68physiographic map, 48

Klamath river, 49, 61, 72, 78, 87, 91Klamath uplands, 32, 63, 63Klamath-bellspring plateau, 63Klamath-blue mountains lineament,

30, 31, 36, 138, 166Knox butte, 210Koch, John, 49Komar, Paul, 66, 218, 235–236, 236, 237, 238

Koosah Waterfalls, 183, 185Kula plate, 15, 62, 80, 215, 216Kwolh butte, 163

Lla Voy tables, 83lacomb Unit, 190, 193, 194ladd Creek, 42ladd glacier, 168lagrande, 42lake abert, 78, 81, 82, 86, 94lake allison, 16, 188, 195, 196, 196lake alvord, 86, 87, 91, 92, 94lake ayers, 241lake benham, 144lake billy Chinook, 140, 144, 144, 145, 149–151, 150

lake bonneville flood, 38, 39, 47, 99, 105

lake Chewaucan, 79, 82, 86, 87, 94lake Coleman, 87lake Condon, 142, 195, 195lake Coyote, 86, 87lake Creek, 184lake idaho, 103, 104, 109lake labish, 199lake lahontan, 87lake lewis, 142, 195, 195lake malheur, 86, 120, 120, 121, 123lake missoula. See missoula floodslake modoc, 87–88, 94lake oswego, 196, 198, 208lake owyhee volcanic field, 14, 37, 98, 99–100, 100, 101, 102, 104, 105, 109

lake Simtustus, 140, 150, 151Lakes of North America (russell), 79lakeview, 88, 89, 91, 200lamaskin, todd, 30landslides

basin and range, 88–89, 88, 89blue mountains, 38–39, 39Cascade mountains, 170–174Coast range, 235, 238–241, 238,

239, 240Deschutes-Umatilla plateau, 145Klamath mountains, 65–66, 65, 66owyhee plateau, 105Willamette Valley, 188, 204–206,

205, 206, 207

index 297

langell Valley, 94larch mountain, 178lassen Peak, 165last Chance mine, 242last Chance ridge, 116latourell Falls, 178, 178lava butte, 117, 118, 120, 124, 125, 144

lava Cast Forest, 124, 126lava caves. See caves and tubeslava lake, 163, 183, 185lava mountain volcano complex, 118

lava river Cave, 124, 126, 127lava top butte, 118, 118, 128lavacicle Cave, 127–128lawrence, David, 98lawrence, robert, 81laylock Formation, 25lead ores, 175lebanon, 202, 203, 208lebanon fan, 194leffler Unit, 190, 193, 194leland, 69lenon hill, 210leslie gulch tuff, 99, 100, 108, 109,

109lewis and Clark expedition, 187libby mine, 242liDar (light Detection and ranging), 170, 205, 206, 206

lighthouse beach, 221limonite, 208lindgren, Waldemar, 20lindsey, Kevin, 147lineaments, 30, 31, 31, 102, 138, 166, 203

See also olympic-Wallowa lineament (oWl)

linn member, 190, 193–194linton lake, 163listric faulting, 82little blitzen Canyon, 83, 92little butte Formation, 158, 159, 170, 189, 203, 206, 210, 222

little glass butte, 116little indian Canyon, 92little lava lake, 163little mud Flat, 105little nash Crater, 185little owyhee river, 97little Squaw back, 140, 141littlefield rhyolite, 99, 102Living with Earthquakes in the Pacific

Northwest (yeats), 204llano de oro (esterly mine), 68llao bay eruption, 160, 164llao rock, 164lobster Creek, 58locked zone earthquake model, 233logging, 65, 170–171, 240, 241, 245lonesome Formation, 25, 30long tom river, 187, 213long Valley fault system, 31

lookingglass (tenmile) Formation, 63, 63, 64, 136, 219, 220, 221, 222, 232

lookout mountain mines, 40, 40lookout rock, 65loon lake landslide, 241lost Creek lake, 72lost lake, 185lostine glacier, 37–38lower Klamath lake, 86, 92, 94luckiamute river, 187, 194, 213lucky boy mine, 175lucky lake, 163lund, John, 91

Mmaars, 119, 121, 122, 192mabey, matthew, 64mack arch, 75mack reef, 75macleod, norm, 113, 113madin, ian, 64, 170, 205, 206, 211madras, 34, 131, 132, 139, 140, 145, 148

madstone Cabin fault, 61magnesium, 54magnetite, 242Magnificent Gateway, The (allen), 177mahogany mountain, 97, 99, 100, 106, 109

malheur basin, 112, 121malheur Cave, 128malheur gorge basalt, 85, 86, 99, 102malheur lake, 86, 120, 120, 121, 123malheur maar, 119malheur national Wildlife refuge, 123

malheur river, 86, 97, 102, 106–107, 121

malpass member, 196mammoths, 199mankinen, edward, 59mann, gary, 38, 145mantle plumes. See hot spotsmarble, 25, 43, 72marine reptiles, 11, 13, 23, 28, 28, 31, 58, 225

marine terraces, 213, 214, 215, 222, 227–229, 228, 236, 238, 239, 240, 242, 243

marion lake, 162martin bridge Formation, 25, 26, 27–28, 27, 28

marys Peak, 213, 246marys river, 187, 203, 213mascall Formation, 11, 15, 32, 34, 37mason, ralph, 211mastodons, 37, 199matterhorn mountain, 43, 43matthieu lakes fissure, 163maupin, 132, 142, 145may Creek terrane, 10, 51, 52, 53,

61, 63maynard, leroy, 163

mcadoo, brian, 235mcClaughry, Jason, 34mcCloud, norm, 21mcDermitt volcanic field, 14, 37, 98, 99–100, 99, 100, 101, 105, 109

mcDowell, Patricia, 193mchugh, margaret, 65mcinelly, galan, 229mckay, Daniele, 122mcKay agency basin, 132, 139, 140–141, 140

mcKay Creek, 141mcKay Formation, 32, 140, 141, 141mcKee, edwin, 100, 113mcKenzie fan, 194mcKenzie river, 155, 159, 163, 166,

167, 175, 177, 183, 185, 187, 209mcloughlin, John, 183mcloughlin fault zone, 81–82, 81,

120, 166medford, 53, 64, 71, 72medicine lake volcano, 117, 165megaquakes. See subduction earthquakes

megashears. See lineamentsmélanges, 11, 12mendocino fracture zone, 64, 157, 233

mercury (quicksilver), 21, 41, 79, 89, 98, 105, 107, 116, 175, 208

merriam, Charles, 23merriam, John, 34, 131–132merriam Cone, 165metcalf, rodney, 62metcalf terrace, 227, 228, 229metchosin volcanics, 218, 219, 219metolius river, 131, 132, 148–149,

150, 151, 155, 167metolius Springs, 148–149meyer, Charles, 38, 145mickey Springs, 90microfossils

basin and range, 87blue mountains, 24, 24, 25, 28,

28, 32, 37, 42Cascade mountains, 158, 165, 185Coast range, 219–221, 222, 223, 225, 234

Deschutes-Umatilla plateau, 144Klamath mountains, 51, 52, 53, 54, 61

owyhee plateau, 103Willamette Valley, 189, 192

middle Sister, 160–161, 161, 162–163, 169

mill Creek (turner) gap, 194, 198miller, m. meghan, 49millican, 128milton-Freewater, 145, 200minam glacier, 38mineral resources

basin and range, 79, 89–92, 89blue mountains, 20, 21, 40–42,

40, 41

298 index

mineral resources (continued)Cascade mountains, 174–175, 175Coast range, 213, 242–243Deschutes-Umatilla plateau, 146–147, 146

Klamath mountains, 50, 54, 58, 58, 61, 61, 67–72, 67

owyhee plateau, 98, 105–106, 107

Willamette Valley, 188, 208mineral springs. See geothermal resources

mining. See mineral resourcesmissoula floods

Cascade mountains, 177, 178, 180, 180

Columbia river channel, 16, 142, 178, 180, 180, 194–198

Deschutes-Umatilla plateau, 132, 133, 141, 142

Willamette Valley, 10, 16, 188, 190, 194–198, 206, 209

mist gas field, 208, 241–242mitchell, 46, 115mitchell butte, 109mitchell inlier, 32mitchell Point, 180modoc Point, 88modoc rim, 78, 92molalla, 158, 191, 203molalla Formation, 159, 190, 191,

222molalla river, 155, 187, 209molalla-Canby lineament, 202, 203mollusks, 23, 27, 28, 28, 56, 58,

128, 158, 189, 219–221, 222, 223, 224–225, 227

monger, James, 51monroe, 192monument dike swarm, 36, 36, 135,

138moore, ellen, 223, 224morcom Crater, 104morgan, lisa, 136mosier, 148mosier-bull run syncline, 137, 138, 143

mount adams, 158, 165mount angel fault, 202, 203mount ashland, 49, 59, 71mount bachelor, 131, 160–161, 161, 163, 163, 169, 181, 182

mount bailey, 159mount baker, 161mount hood, 14, 157, 181, 198

ancestral Columbia river, 143, 143

Cascade arc migration, 158, 159, 160, 165, 166

Cascade arc rift, 167climbers, 180–181eruptive history, 160–161, 161–162, 169, 174

eruptive style, 161, 165, 166

geothermal resources, 176–177hazards, 169, 170, 171, 171, 172, 174

overview, 15surface features, 162, 168, 168

mount Jefferson, 139, 158, 159, 160–161, 161, 162, 165, 165, 166, 167, 181

mount lassen, 161, 165mount mazama, 15, 38, 87, 117,

117, 160–161, 164, 182, 183, 234See also Crater lake

mount mcloughlin, 81–82, 81, 120, 159, 160–161, 161, 163, 181, 183

mount Pleasant, 178mount rainier, 158, 165, 166mount Scott, 160, 164, 182, 192mount Shasta, 165mount St. helens, 15, 157, 158, 161,

165mount Sylvania, 192mount tabor, 192mount thielsen, 159, 160–161, 161, 163, 181, 182, 183, 183

mount Washington, 158, 159, 160–161, 161, 167, 181, 182, 185

mount zion, 178, 180mountain lakes Wilderness, 88mowich group, 25, 30mud lake, 121, 123muhs, Daniel, 229mule Creek canyon, 57mule Creek mining district, 67, 70mule mountain volcanics, 52, 57multnomah Falls, 172, 178, 178, 179murray, ian, 206musick mine, 175mutton mountains, 139, 140myrtle Creek Formation, 57

Nnabelek, John, 214narrows, the, 123nash Crater, 160–161, 166, 183, 185,

185neahkahnie mountain, 226, 240negrini, robert, 87nehalem arch, 217, 218nehalem bank, 230, 230nehalem basin, 223, 224nehalem river, 213nehalem-Willapa hills folds, 217–218, 217

nellies Point cliffs, 74nestell, merlynd, 24nestucca Formation, 220, 222, 222, 238, 240

netarts bay, 226, 234, 240nevada rift. See oregon-nevada riftnevadan orogeny, 54, 55, 56, 59, 60newberry, John, 125, 151newberry Crater

eruptive history, 10, 11, 114, 117, 117, 122–123, 125, 125, 132, 144, 146, 151

fault systems, 120, 120, 122geologic highlights, 121, 124, 124, 125, 125, 126, 127, 152

glaciation, 120natural resources, 123, 148past and present work on, 112, 113, 120

stratigraphy chart, 141surface features, 112, 117, 117, 124, 124, 125, 125

westward age-progressive cycle, 14, 113, 114, 117, 117

newberry Volcano national monument, 123, 124, 126

newell Creek Canyon slide, 204, 205newport, 214, 218, 218, 221, 222,

222, 223, 225, 226, 231, 232, 238, 239, 242

newport basin, 220, 224, 231, 232newport embayment, 225newport terrace, 229newport-beaver hill coal field, 241,

242newton Clark glacier, 168nicely Formation, 25nickel, 61, 67, 70, 70nickel mountain, 70niem, alan, 64, 128, 214, 218, 219, 223, 224

niem, Wendy, 64, 214, 218, 219, 223, 224

nilsen, tor, 62nitinat fan, 229, 231, 231nixon, earl K., 68noonday mine, 175norbisrath, hans, 213north american plate, 12, 13, 14, 15north Fork terrane, 53north Junction, 145north Pole mine, 69north Santiam mining district, 175,

175north Santiam river, 158, 175, 187,

194, 198, 203, 207, 209north Sister, 160–161, 161, 162, 163,

169, 182north Squaw tips, 163Northwest Coast, The (Komar), 236nye beach, 239nye Formation, 222, 223, 225, 238,

239, 240

Ooatfield fault, 201, 202obsidian, 113, 116, 117, 125, 125ochoco basin, 11, 15, 22, 29, 31–32,

32, 62, 62ochoco mountains, 15, 20, 31–32,

32, 34, 34, 35, 37, 62, 131, 139, 144ochoco reservoir, 35, 36, 39

index 299

o’Connor, Jim, 105, 173, 177, 193, 194

odell lake, 183officer’s Cave, 44, 44ogden, Peter, 152ohanapecosh Formation, 159, 172,

216oil and gas resources, 133, 208, 213, 241–242

okanogan lobe, 195old maid event, 161, 162, 162, 174olds Ferry terrane, 11, 21, 22, 23, 24,

25, 27, 29, 30, 31olistoliths, 23olistostrome, 56olson mountain, 72olympic-Wallowa lineament (oWl),

30, 31, 38, 81, 81, 120, 138, 145oneonta Falls, 178, 179onion Camp complex, 56opal Springs, 148, 149opalite mining district, 105opals, 79, 90ophiolites

blue mountains, 11, 24–25, 25Coast range, 54, 54, 55, 56, 57,

63, 70Klamath mountains, 10, 49, 52, 53, 54, 54, 55, 56–57, 56, 59, 60–62, 61, 63, 67, 69, 70

overview, 12, 60–62sequences, 61–62, 61suprasubduction model, 62

ophir, 49, 64ordnance, 148, 149oregon bureau of mines and geology, 123–124, 124

oregon Caves national monument, 72, 72

oregon City, 187, 192, 196, 198, 204, 205

oregon Dunes national recreation area, 245

oregon islands national Wildlife refuge, 75

oregon State Department of geology and mineral industries (Dogami), 20, 67, 68, 70, 90, 155, 176–177, 188, 200, 206, 208, 213, 235

oregon-idaho graben, 11, 37, 81, 98, 99, 100, 100, 101, 102, 102, 103

oregon-nevada rift, 80, 81, 98, 100, 101, 102, 134

Oregon’s Sisters County (hatton), 180Oreodons, 33, 46orleans fault, 51, 61ortley anticline, 136–137ostracods, 87, 219, 221oswald West mudstone, 223, 227oswald West State Park, 240otter Point Formation, 9, 52, 55, 56, 58, 63, 74, 74, 75, 227

outhouse flood, 145

oWl (olympic-Wallowa lineament), 30, 31, 38, 81, 81, 120, 138, 145

owl Creek fault, 203owyhee basalts, 99, 99, 102, 103,

106, 109owyhee plateau, 97–109

geologic processes and features, 14, 80, 98–105, 114, 135

hazards, 105highlights, 107–109landscape, 97natural resources, 105–107overview, 14, 98past and present work on, 97–98physiographic map, 96stratigraphy chart, 99

owyhee reservoir, 97, 103, 105, 106, 107, 108, 109

owyhee ridge, 109owyhee river, 87, 97, 100, 103, 105, 107, 108, 109

owyhee river canyon, 99, 104, 106, 108–109, 109

owyhee volcanic field. See lake owyhee volcanic field

oysters, 30

PPacific plate, 12, 14, 80, 157, 217,

229, 233pahoehoe lava, 104, 107, 107, 119, 127, 133

Painted hills, 44, 46Paisley, 88Palmer, Joel, 180Palmer, leonard, 211Palomino butte, 114, 116, 128Palouse sediments, 193Pangaea, 10, 23Pardee, Joseph, 195, 213Parks, henry m., 124Parsons, roger, 193, 194, 196Pasco basin, 135, 137, 138, 142, 195Patton, horace, 163Paulina lake, 117, 124Paulina mountains, 118Paulina Peak, 112, 117, 124, 127Paulina Valley, 116Payne Cliffs Formation, 52, 62, 64,

73, 158, 159, 189Pearsoll Peak pluton, 58, 70Peck, Dallas, 49, 62, 155, 159Pedro mountain mines, 40pelecypods, 30Pelican butte, 159Pelton Dam, 148, 151Pendleton, 144, 149Peninsula, the, 145, 150, 151Pepper mountain, 178peridotites, 25, 58, 61, 70Perpetua bank, 230, 230Pessagno, emile, 51, 54Pete, French, 123

Peter Skene ogden State Park, 152, 152

Peterson, Curt, 234Peterson, norman, 112, 151Peterson butte, 210petrified wood, 158–159, 194petroleum. See gas and oil resourcesPezzopane, Silvio, 82, 88, 119Phantom Cone, 160, 164Phoca rock, 179, 180Phoenix quakes, 64Pickett Peak terrane, 51, 52, 55, 56, 57–58, 61, 63

Picture gorge, 34, 44, 45Picture gorge basalt, 32, 34, 36, 36,

101, 135, 136Pierce, Kenneth, 136Pigeon Point, 224Pike Creek Formation, 83, 85Pillar rock, 226Pillars of hercules, 180Pillars of rome, 109pillow lavas, 25, 57, 58, 59, 61, 61,

134, 219, 243, 245Pilot butte, 35, 36, 118, 125Pine Creek graben, 31Pine Creek Valley, 38Pine mountain, 118, 120Pioneer terrace, 227, 228, 229, 242Piper, arthur, 112Pistol river, 64Pittock, henry, 181Pittsburg bluff Formation, 189, 222, 223

Pittsburg landing, 39plate tectonics, 10–13, 12, 13, 14, 15platinum, 61, 242, 243Plesiosaurs, 11, 31plugs. See volcanic plugsPlush diamonds, 90plutons and batholiths

basin and range, 79–80blue mountains, 21, 22, 23, 24,

27, 29, 31, 40, 42Cascade mountains, 158Deschutes-Umatilla plateau, 137Klamath mountains, 49, 52, 53, 56, 58, 59–60, 60, 61, 67, 68, 69, 70

pluvial lakes, 11, 16, 16, 79, 82–83, 85, 86–88, 94, 99, 105, 113, 120–121, 122

Poison Creek Fault, 28Poker Jim ridge, 82, 93Polallie Creek avalanche, 171Polallie event, 87, 161, 162, 162pollen, 103, 158, 165, 192Pomona member, 136, 143, 216Popenoe, William, 49“pop-up” faults, 202, 231Port orford, 49, 51, 58, 61, 62, 64, 65, 65, 74, 74

Port orford Formation, 222, 227

300 index

Portlandgeologic processes and features,

14, 166, 167, 189, 190, 191–192, 191, 192, 193, 195, 196, 197, 217

hazards, 146, 172, 200, 201, 201, 202, 202, 205, 205, 206–207, 211

highlights, 177, 178, 179, 211landscape, 187past and present work on, 132, 192, 211

water resources, 187, 209–210Portland basin, 190, 191–192, 201,

202Portland hills anticline, 202, 217Portland hills fault, 166, 201, 201, 202, 202, 217

Portland hills silt, 190, 193, 205, 205post-western Klamath granodiorite intrusions, 59–60, 60

Potholes lava field, 118, 118Poverty ridge terrace, 227, 228Powder mountains. See Wallowa mountains

Powder river, 20, 39, 40, 42Powell butte (Portland), 192Powell buttes (blue mountains), 30,

35, 36, 118, 140Powers, 241Prater Creek tuff, 32, 85, 114, 115–116, 115, 120

Precambrian belt series, 191precious metals. See mineral resources

Priest, george, 88, 156, 161, 165, 176Priest rapids basalts, 136, 140, 143,

143, 178Princeton, 121Prineville, 35, 39, 43–44, 115Prineville basalt, 135, 136Pringle, Patrick, 174Proposal rock, 223Prothero, Donald, 189–190Pterosaurs, 31Pudding river, 187, 199Pueblo mountains, 79–80, 84Puget lobe, 195Pullman, Washington, 135pumice, 109, 116, 117, 141–142, 146, 146, 147

Pumpkin ridge landslide, 39Punchbowl landslide, 89Purcell lobe, 195, 195Pyramid rock, 226

QQuartz basin, 103–104Quartz mountain, 106, 114, 116,

118, 120Quartzberg mining district, 40Quartzville mining district, 175, 175Queen Charlotte fault, 157Queen of bronze mine, 70quicksilver. See mercuryQuincy basin, 195

Rrabbit hills volcanics, 84, 85radiolaria, 24, 24, 25, 28, 28, 51, 53, 54, 61

rail Cabin argillite, 25raisz, erwin, 9ramp, len, 57, 60, 61, 64, 66, 67, 68rams butte, 114randolph, 242rattlesnake Creek terrane, 51, 52, 53, 53, 54, 55, 59, 60, 61, 67, 69

rattlesnake Formation, 11, 15, 32, 34, 37, 37

rattlesnake tuff, 85, 114, 115, 116, 120

reckendorf, Frank, 206red basin, 103–104red bluffs, 172red butte, 105–106red hills, 191redcloud Cliff dome, 164redmond, 139, 140, 141, 147reedsport, 155reefs, 13, 28, 28, 30, 50, 74, 75, 221,

221reid, harry F., 161reid glacier, 168reidel, Steve, 132, 133, 137reith anticline, 141rensberger, John, 34reptiles, 11, 31, 58

See also marine reptilesreservoirs, 39, 42–43, 72, 97, 105, 106, 106, 107, 108, 109, 175, 207, 207

retallack, greg, 34, 190reverse (inverted) topography, 72, 74, 128, 226, 245

rhinoceroses, 33, 37, 103–104rhododendron Formation, 159, 167, 171

rickreall limestone, 189, 222, 222riddle Formation, 52, 57riddle mining operations, 70, 70ridgeway butte fault, 203rifting. See extensional tectonicsriver bend member, 190, 196road building, 65, 170–171, 237,

240, 241roads end, 240roaring river, 171roberton Formation, 25, 30roberts, michael, 192rock Creek, 34rock hill, 210rock mesa, 161, 174rocky butte, 107, 179, 192rocky Point Formation, 52, 56rodents, 37, 103, 104roering, Joshua, 241rogue Canyon, 230, 230rogue Formation, 52, 55, 56, 63, 68,

220

rogue river, 49, 57, 57, 66, 67, 68–69, 71–72, 73, 230, 230

rogue Valley, 54, 66rogue Valley subterrane, 51, 52, 54,

55, 56, 56, 60, 61rogue-Chetco volcanic arc, 54, 55, 56, 59

rome, 103, 104, 109rome beds, 99, 103, 109rooster rock, 178, 178, 179, 180roseburg, 58–59, 155, 158, 189, 245roseburg Formation, 50, 64, 216, 218, 219, 220, 232

ross, Clyde, 20, 115ross, marty, 132, 137round butte basalt, 139, 140, 141,

141round butte Dam, 145, 148, 150, 151

round-top butte, 114, 116rowland Formation, 190, 194, 194roxy Formation, 159royse landslide, 173, 173ruckel Creek landslide, 173, 174ruggiero, Peter, 236rush Creek landslide, 38russell, israel, 79, 97, 112, 131ruth vein, 175rye Valley ditch, 40rytuba, James, 97–98, 100ryu, in-Chang, 64, 219

SSacajawea Peak, 43Saddle butte caldera, 100, 100Saddle butte caves, 108, 108Saddle butte volcanic field, 108Saddle mountain, 213, 245–246, 245Saddle mountains basalt, 135, 135, 136, 136, 137, 140, 143, 143, 216

Saddle rock, 75Sahalie Waterfalls, 183, 185Salem, 143, 187, 188, 189, 189, 198,

200, 202, 207, 209, 210Salem hills, 191, 202, 209Salmon river Canyon, 27Sand Canyon, 168sand dunes, 243, 244, 245Sand gap, 123Sand mountain-nash Crater, 160–

161, 166, 183, 185, 185sand spit erosion, 236, 237, 237Sandstone of Floras lake, 222, 224Sandy glacier, 168Sandy river, 168, 172, 174, 192Sandy river (Frontal) fault, 202, 202Sandy river mudstone, 190, 191–192, 205, 222

Sanger mine, 40Santiam Pass, 166, 185Santiam river, 155, 158, 175, 187,

194, 198, 203, 207, 209Sardine Formation, 158, 159, 159, 170

index 301

Savage rapids dam, 72Sawtooth Crater volcano, 36–37Scappoose Formation, 223Scappoose mining operations, 208Scarberry, Kaleb, 80, 82Schlicker, herb, 192, 200Scotch Creek member, 28Scott, William, 156, 161, 163, 174Scotts mills earthquake, 200, 202–203

Scotts mills Formation, 158, 159, 189, 190, 191, 202, 222

Scottsburg landslide, 241Sea lion Caves, 223, 244sea stacks and arches, 50, 74–75, 75, 221, 221, 225, 226, 235

sea urchins, 223Seal rock, 225–226, 225seals, 223, 224seamount subduction, 230, 234Seaside, 235, 245–246sedimentary basins, formation of, 11, 12, 15

Selma landslide, 65serpentine, 24–25, 26, 54, 56, 61–62, 65

Seven Devils mountains, 20, 26, 27, 27, 43

Seven Devils terrace, 227, 228, 229, 242

Seven Devils Volcanic group, 25, 26–27, 27

shark teeth, 223, 225sharks, 189Sharps Creek, 174Shasta bolly intrusive, 60Sheep mountain, 114Sheep rock, 34, 44, 45Sheepshead mountains, 81, 100Shepperds Dell, 178Sheridan erratic, 197Sheridan mountain, 163Sherrod, David, 156, 165Shervais, John, 49, 62Sherwood trough, 138, 139, 166Shevlin Park eruption, 142shield vs. composite volcanoes, 161, 162, 162, 165–166

Ship, the, 149, 150, 151Shitike Formation, 167Sierra nevada mountains, 32, 52,

52, 54, 59, 60Silberling, norm, 23, 49Siletz bay, 235Siletz river, 213Siletz river Valley, 234Siletz river Volcanics, 167, 189, 203,

216, 218–219, 219, 221, 222, 232Siletz Spit, 236Siletzia, 10, 13, 15, 62, 188, 189, 214, 215, 215, 216, 218–219, 219, 230, 231, 233–234

sills, 59, 210, 210, 219, 222, 225–226, 225, 246

Siltcoos lake, 244, 245silver, 40, 41, 50, 61, 67, 69, 106, 175, 175

Silver butte terrace, 227, 228Silver Creek, 112, 199Silver Falls, 210–211Silver lake, 81, 121Silver Peak-galice mining district,

67, 68–69, 68Silver Point, 240Silverton, 191, 210–211Silvies river, 112, 128–129Simpson reef, 221, 221Sims butte, 185Simtustus Formation, 32, 139, 139, 140, 141, 159, 167, 167

Siskiyou mountains, 49, 70Siskiyou Pass, 158Siskiyou Suite, 60Siskiyou Summit fault, 158Sisters fault zone, 36, 118, 120, 120,

166Sisters mountains. See three SistersSisters rocks, 58, 74, 75Sitkum lake, 241Siuslaw river, 213, 230Sixes river, 58, 61, 65, 70, 234Sixes river mining district, 67, 70Sixes river terrane, 51, 52, 57, 58–59, 61

Six-Soldier slide, 65Skamania, Washington, 172, 179–180

Skinner butte, 210Skull Springs, 103–104slickenslides, 80Slide mountain-Winter ridge, 82,

82, 88sloths, 87, 199Smartville ophiolite, 54, 54Smith, gary, 139, 151Smith, george, 132Smith, James, 156, 165Smith, John, 47Smith, Warren D., 20, 97, 178, 188, 208

Smith river subterrane, 51, 52, 54, 55, 56, 56, 60, 61, 63, 69–70

Smith rock, 36, 47, 47, 149Smuggler Cove Formation, 189, 222, 223

snails, 121, 128, 224Snake river, 20, 21, 27, 31, 41, 43, 46–47, 46, 87, 97, 104, 109, 121, 195

Snake river Canyon, 26, 27, 27, 28, 38, 39, 40, 46, 105

See also hells CanyonSnake river fault zone, 30, 30Snake river graben, 81, 100, 104,

134Snake river Plain, 31, 79, 84, 84, 99,

100, 101, 102, 105, 115, 134, 145

Snavely, Parke, 213, 214, 216, 224, 225

Snoke, arthur, 49Snoqualmie Pass, 158Snow Camp terrane, 51, 52, 55, 56, 57, 58, 61, 63, 70

Snowshoe Formation, 25, 30Sourdough Flat, 70South Fork mountains, 57, 58South mountain, idaho, 97South Santiam river, 187, 194, 203,

207South Sister, 160–161, 161, 162–163, 174, 182

South Slough, 224, 234South Squaw tips, 163Sparta, 38–39Speare Canyon, 146Spencer butte, 210Spencer Formation, 167, 189, 192,

194, 222, 242spits, erosion of, 236, 237, 237Spokane floods. See missoula floodsSpotted ridge Formation, 11, 23, 24, 25

Sprague river, 78Spring Creek tuff, 99, 100Spring lake, 163Squaw back ridge basalt, 140, 141,

141Squaw butte, 114, 116, 120Squaw Creek fault zone, 100, 102Squaw mountain, 59, 60, 114, 118Squaw tips, 163Stadter forest, 174Stage gulch, 148Stanfield, 149Stanley, george, 26, 28Stanley, William, 176Star mountain rhyolite, 99Stayton basin, 191–192, 198Stayton fan, 194Steel bay dome, 164Steel Cliff, 162, 168Steen, enoch, 43Steens mountains

basaltsbasin and range, 78–79, 82, 83, 84–86, 84, 85, 92–93, 93, 100

Columbia river basalt group, 11, 13–14, 86, 99, 101, 134, 135, 135, 137, 138

high lava Plains, 114, 115, 116mantle plume, 78–79, 84, 84, 99, 101, 134, 137

owyhee plateau, 98–99, 99, 100, 101

escarpment, 83, 89, 120fault, 81, 82, 83, 90, 91, 92–93, 92, 115, 120, 120, 202

glaciation, 11, 85, 87, 92, 93, 105natural resources, 89, 90, 91–92, 112

overview, 13–15

302 index

Steere, margaret, 156Steins Pillar, 35, 43–44, 44Stembridge, Jim, 236Sterling Creek mine, 67, 69stitching plutons, 59, 61Stockade mountain rhyolite, 99Stone Corral lake, 94Stonewall bank, 230, 230Stovall, James, 244stratigraphy charts

basin and range, 85blue mountains, 25, 32Cascade mountains, 159Coast range, 222Columbia river basalt group,

136, 141, 159Deschutes-Umatilla plateau, 136,

141high lava Plains, 114Klamath mountains, 52owyhee plateau, 99Willamette Valley, 190

stratovolcanoes vs. shield volcanoes, 161, 162, 165–166

Strawberry mountain, 20, 32, 36–37Streck, martin, 113Strobel, michael, 209–210subduction earthquakes, 17, 64, 66, 174, 200, 203–204, 204, 205, 215, 233–234, 233

subduction processes, 11, 12, 13, 13, 15

subduction-zone ophiolites, 62submarine canyons, 12, 229, 230,

230, 231, 231submarine fans, 10, 12, 32, 63, 63, 214, 219, 221, 222

Succor Creek, 97, 98, 108–109, 108Sucker Creek Formation, 42, 99, 103, 106, 108–109, 108

Sugarloaf mountain, 213Summer lake, 81, 82, 86Summer lake basin, 78, 82, 87, 88,

89, 94Summerville, 39Summit Point member, 28Summit rock, 183Sumpter, 25–26, 41Sunset bay, 221Sunset Valley, 128–129sunstones, 79, 90Suplee Formation, 25, 30suprasubduction-zone ophiolites, 62Susanville, 41Suttle lake, 184, 185Swanson, Fred, 170Swim (warm springs), 176

Ttable mountain, 122, 172, 172table rock, 72–74, 73, 118, 122, 211tahkenitch lake, 245takilma, 69tamolitch Falls, 166

tanner rock landslide, 172tarheel Formation, 222, 224taylor, David, 58taylor, edward, 155, 156, 165–166, 167, 180

taylor, george, 241tectonics. See plate tectonicsTectonics of the Willamette Valley (yeats), 204

telescoping, 55, 61, 231tenmile (lookingglass) Formation, 63, 63, 64, 136, 219, 220, 221, 222, 232

tenmile lake, 245terraces, coastal, 213, 214, 215, 222, 227–229, 228, 236, 238, 239, 240, 242, 243

terrane accretion, 11–13, 12, 13terranes, definition of, 13, 51terrebonne, 146–147tethrow butte basalt, 139, 140, 141,

141, 151thayer, tom, 23thermal springs. See geothermal resources

thomas Creek, 78thompson ridge fault, 231thompson ridge pluton, 59, 60three arch rocks, 226three Fingers caldera, 100, 100three mile hill, 107three Sisters

Cascade arc migration, 159Cascade arc rift, 166, 167eruptive history, 139, 160–161, 161, 162–163, 174

eruptive style, 161, 165geothermal energy, 176hazards, 157, 161, 174surface features, 169, 181–183,

181, 182three-Fingered Jack, 159, 160–161, 161, 167, 181, 182

thundereggs (geodes), 41–42, 41, 109

tichnor rock, 74tillamook, 218, 218, 229, 231tillamook basin, 224tillamook bay, 225, 230, 230, 237,

237tillamook head, 226, 230, 235tillamook highlands, 217, 218tillamook Spit, 237, 237tillamook volcanics, 216, 219, 222,

222, 240timber harvesting, 65, 170–171, 240, 241, 245

timberline event, 161, 162, 174tims Peak basalt, 99, 102tolan, terry, 132, 143, 147, 177, 191tooth rock landslide, 172, 173, 180touchet beds, 195–196tower mountain caldera, 11, 34, 35,

35

townley, Sidney, 64trace fossils, 223trask mountain, 213travis, Christopher, 80tréhu, anne, 214, 234, 242triangle lake landslide, 241trimble, Donald, 192, 193trinity limestone, 51trinity river, 53tropical environments

blue mountains, 24, 32, 33, 33, 46

Cascade mountains, 158–159Coast range, 221, 222, 223extinctions, 10, 15, 190, 223overview, 15–16Willamette Valley, 189, 189, 190

trout Creek mountains, 79–80trout Creek rapids, 145troutdale Formation, 132, 143, 159, 167, 173, 190, 191–192, 191, 198, 205, 209, 222, 226

troutdale smelter, 208trowbridge Formation, 25, 30tsunamis, 66, 214, 215, 233, 234, 235, 235

tualatin basin, 187, 190, 192, 193, 201, 202, 205

tualatin mountains, 191, 193, 201tualatin river, 187, 213tualatin Valley, 191, 192, 193, 200, 209

tubes. See caves and tubestucker hill volcanics, 85tuff rings, 113, 121, 122tule lake, 92, 94tumalo fault, 120tumalo highland, 141–142tumalo tuff, 141, 142tumalt Creek landslide, 173tumulus, 118tunnel Point Formation, 221, 222turner (mill Creek) gap, 194, 198turner-albright mining district, 54,

67, 69, 70turtle Cove member, 32, 34, 45turtles, 225twin Falls, idaho, 104Two Islands, The (Condon), 187tyee basin, 32, 62–63, 63, 217, 218,

220, 232tyee Formation, 63, 63, 189, 203,

216, 219, 220, 221, 222, 222, 223, 232, 241, 246

tygh basin, 139, 140, 140, 141tygh Valley Formation, 167

UUkiah, 35Umatilla (arlington) basin, 132, 139, 140–141, 140, 141, 144–145, 149

Umatilla earthquakes, 144–145, 200Umatilla river, 131, 141, 146, 147Umpqua Formation, 64

index 303

Umpqua group, 64Umpqua river, 155, 213, 230, 241Union hot springs, 42Unity mining district, 40Unity reservoir, 37Upper Klamath lake, 49, 78, 86, 88, 92, 94

uranium, 79, 89, 98, 105urban geology, 211U.S. army Corps of engineers, 173, 175, 180, 207, 207, 224, 237, 237

VVale, 105, 106Vale fault zone, 30, 31, 81, 100, 102, 105, 138

Valen lake, 66Valen lake fault, 51, 58, 60Valentine Spring Formation, 57–58Vallier, tracy, 21, 23, 26–27, 31, 38, 46

Van tassel, Jay, 37Vancouver, Washington, 14, 167, 191–192, 191, 192, 193, 201, 205

Vancouver island, 157, 158, 216, 218, 219, 231

Vanport flood, 206–207Vester Formation, 25, 28, 30Vigrass, laurence, 20, 28Vineyard mountain, 203Virtue mine, 40, 40Vista house, 178Vogt, beverly, 143, 156, 176, 177,

191Vokes, harold, 213volcanic activity (modern), 105, 122–123, 157, 161, 169, 174, 185

volcanic age progression. See age progression

volcanic hot spots. See hot spotsvolcanic island archipelagos, 10–13,

12, 13volcanic plugs, 41, 163, 178, 179–180, 182, 183, 210

volcanic tuff rings, 113, 121, 122Vulcan Peak, 61

WWagontire mountain, 114, 120Wahkeena Falls, 178Waitt, richard, 195Wakonda terrace, 229Waldo hills, 187, 191, 202, 203Waldo lake, 183Waldo-gold hill-applegate mining area, 67, 68, 69, 69, 70

Waldport, 229Walker, george, 21, 81, 112, 113,

113Walker lane shear zone, 80, 145,

166Walker rim fault zone, 118, 120,

120, 166Wall rock ridge fault zone, 100, 102

Walla Walla, Washington, 26, 195–196

Wallowa batholith, 27, 31Wallowa lake, 27, 37, 43, 43Wallowa mountains, 20, 22, 23, 26, 27, 27, 31, 31, 36, 37–38, 38, 40, 40, 43, 43

Wallowa terrane, 11, 21, 22, 23, 24, 25, 26–28, 27, 29, 31, 40, 134

Wallula fault zone, 27, 30, 31, 145Wallula gap, 131, 142, 195, 195, 196walruses, 224Wanapum basalt, 32, 36, 135, 135, 136, 136, 137, 141, 143, 143, 178, 190

Wang, yumei, 173Wapinitia rapids, 145War eagle mountain, idaho, 97Wardlaw, bruce, 24Warm Springs reservation, 147Warm Springs river, 155Warm Springs valley, 123Warner lakes, 82, 86, 87Warner Peak, 78Warner range, 101Warner rim faults, 82, 91Warner Valley, 78, 81, 82, 82, 88, 91, 93, 94

Warren, W.C., 213Warrendale landslide, 173Washburne, Chester, 213Washougal slides, 172Watchman, the, 164, 164water resources

See also geothermal resourcesbasin and range, 78, 79, 79, 88,

89, 91–92, 91, 92, 94, 94blue mountains, 20, 42–43, 46–47, 46, 131

Cascade mountains, 155, 163, 163, 168, 170, 177, 187

Coast range, 155, 213, 214, 243, 245

critical groundwater areas, 148, 209

Deschutes-Umatilla plateau, 131, 132–133, 147–149, 147, 148

high lava Plains, 112, 123–124, 124, 127, 128

Klamath mountains, 49, 71–72, 71

owyhee plateau, 97, 98, 105, 106–107, 106

Willamette Valley, 187, 188, 208–210, 209, 213

waterfalls, 124, 166, 172, 178–179, 179, 210–211

Waters, aaron, 21, 131, 132, 172Waters Creek, 71Waters of Oregon (bastasch), 147Watters, robert, 88Watts, Phil, 235Weatherby Formation, 25, 30Weaver, Craig, 165

Wecoma fault, 231, 232Wegener, alfred, 10Weldon, ray, 82, 119Wells, Francis, 49Wells, ray, 217West hills (Portland), 205West Point hill, 210Western Cascades, 12, 13, 15, 167–168, 189, 220, 221, 222, 223

See also Cascade mountainswestern hayfork terrane, 51, 52, 53,

53, 59, 60, 61, 63western Klamath plutonic suite, 59,

60western Klamath terrane, 51, 52, 53, 54–57, 58

western Paleozoic and triassic belt, 10, 51, 51, 52, 53, 55, 59, 63

Whale head fault, 61whales, 223, 224, 224Whiskey run terrace, 227, 228, 229, 242

White river, 155, 162, 162, 168, 171, 171, 174

White river glacier, 168White rock pluton, 59, 60White Salmon river, 174White tail ridge (Flournoy) Formation, 63, 63, 64, 167, 219, 221, 222

Whitehorse landslide, 145Whitsett limestones, 52, 59Wicks, Charles, 174Wild rogue Wilderness, 57Wild Sheep Creek Formation, 25, 27, 28

Wildcat mountain caldera, 11, 34, 34, 35, 35

Wildcat mountain tuff, 99Wilkes, John, 245Wilkins, David, 87Wilkinson, William, 188Willamette Formation (Silt), 10, 16,

190, 193, 194, 196, 198, 201, 209, 222

Willamette meteorite, 197Willamette river, 146, 155, 167, 175, 187, 193–194, 194, 198, 199, 201, 202, 203, 207, 209

Willamette Valley, 187–211geologic processes and features

ancestral Columbia river, 143, 167, 188, 191, 209, 226

Cascade overlap, 188, 189, 191, 193–194, 194, 198, 210–211, 214, 215, 216

Cenozoic history, 188–199Coast range overlap, 15, 188–189, 189, 193, 194, 214, 215, 222

coastal uplift, 188, 190, 191, 193, 218

304 index

Willamette Valley (continued)geologic processes and features

(continued)Columbia river basalts, 139, 188, 190, 191–192, 193, 198, 202, 205, 208, 209, 209, 210–211, 226

missoula floods, 10, 16, 188, 190, 194–198, 206, 209

overview, 10, 12, 15, 188stratigraphy chart, 222

hazards, 200–207highlights, 210–211landscape, 187natural resources, 208–210, 213overview, 188past and present work on, 132, 187, 188, 193, 200, 204

physiographic map, 186Willapa basin, 231Willapa Canyon fault, 231, 231Willapa hills, 219Willapa hills-Crescent Formation,

216Willapa hills-nehalem folds, 217–218, 217

Williams, howel, 112, 155, 155, 162, 163

Williams, ira, 177Williamson river, 78Willow Creek, 131, 141, 146, 147, 149Wilson, Doyle, 192Wilson Point fault, 53Wilson river, 213Wilson river highway landslides, 240

Wilsonville water treatment plant, 209

Wimer pluton, 59, 60Wind mountain landslide, 172Windy ridge Formation, 25, 27Winston, 9Winter ridge-Slide mountain, 82,

82, 88Winter rim, 78, 82, 92Wise, William, 161Wishram, Washington, 142Witter, robert, 236Wizard island, 161, 164, 165Woahink lake, 244, 245Womens Forum State Park, 143, 178, 178

Wong, ivan, 64, 202Wood river, 78Wood river Valley, 177Woodburn, 199, 203Woodward, Dennis, 209Wooley Creek suite, 55, 59, 60Wrangellia superterrane, 26, 26, 52Wright, James, 49Wrights Point, 120, 128–129Wyatt member, 196Wyoming, 84, 99, 101

Yyachats, 240yachats basalt, 216, 219, 220, 222–223, 222, 244

yachats terrace, 229yakima, Washington, 133, 138

yakima basalt, 132, 135, 136yakima fold belt, 101, 136–137, 138yakima river, 131yamhill fault, 217yamhill Formation, 189, 203, 222,

222, 242yamhill river, 187, 213yamsay mountain volcanics, 85, 86, 114

yapoah basalts, 160–161, 166, 184, 185yapoah Cone, 185yaquina bay, 230, 231yaquina Formation, 222, 223, 242yaquina head, 226, 226, 229yaquina river, 213yeats, bob, 204, 204yellow butte intrusive, 60yellow rock, 75yellowstone hot spot. See hot spotsyoakam Point, 221, 221yolla bolly terrane, 51, 52, 55, 56, 57, 58, 61, 63

yonna Formation, 85, 87–88yonna Valley, 94yreka subterrane, 52yule, J. Douglas, 56

Zzeolites, 42, 106, 242zigzag event, 162zigzag glacier, 168, 174zigzag river, 168, 174zinc, 40, 61, 175zircons, 242