U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2005–5019

The Togiak-Tikchik Complex of Southwestern Alaska, 

a Replacement for the Gemuk Group: Stratigraphic 

Nomenclature That Has Outlived Its Time
The Togiak-Tikchik Complex of Southwestern Alaska, 

a Replacement for the Gemuk Group: Stratigraphic 

Nomenclature That Has Outlived Its Time

By F.H. Wilson and W.L. Coonrad

Scientific Investigations Report 2005–5019

U.S. Department of the Interior

U.S. Geological Survey 
U.S. Department of the Interior

Gale A. Norton, Secretary

U.S. Geological Survey

Charles G. Groat, Director

Version 1.0, 2005

This publication is available only online at:

http://pubs.usgs.gov/sir/2005/5019/

Manuscript approved for publication, February 3, 2005

Text edited by George A. Havach

Production and design by Stephen L. Scott

Any use of trade, product, or firm names in this publication

is for descriptive purposes only and does not imply 

endorsement by the U.S. Government 
Contents

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

Introduction -------------------------------------------------------------------------------------------------- 1

History: Definition and Use --------------------------------------------------------------------------------- 1

Implicit Abandonment -------------------------------------------------------------------------------------- 4

The Togiat-Tikchik Complex—Modern Usage ----------------------------------------------------------- 5

Conclusion --------------------------------------------------------------------------------------------------- 8

Acknowledgments ------------------------------------------------------------------------------------------ 8

References Cited ------------------------------------------------------------------------------------------- 8

Figures

1. Geologic map of the Taylor Mountains 1:250,000-scale quadrangle, southwestern 

 Alaska, showing location of type area of the Gemuk Group as originally 

 designated by Cady and others (1955) -------------------------------------------------------------- 2

2. Satellite thematic mapper image of the Tucson Basin showing the geomorphic 

 expression of the late Pliocene to early Pleistocene Cienega Creek alluvial fan -------------- 3

3. Map of simplified residual gravity anomalies in the Tucson Basin ------------------------------- 6

III
1

The Togiak-Tikchik Complex of Southwestern Alaska, 

a Replacement for the Gemuk Group: Stratigraphic 

Nomenclature That Has Outlived Its Time

By F.H. Wilson and W.L. Coonrad

Abstract

During early exploratory reconnaissance of southwestern 

Alaska in the 1940s and 1950s, the term “Gemuk Group” 

was used to name a varied assemblage of sedimentary and 

volcanic rocks in southwestern Alaska. Throughout the 1950s 

and early 1960s, the name was broadly applied in the region; 

yet by the end of the 1960s, it was no longer in use, and 

later maps assigned the rocks originally in this unit to various informal units and, later, to various terranes. The name 

“Gemuk Group” is herein abandoned, and the rocks previously assigned to the Gemuk Group, a diverse and structurally complex assemblage, are renamed the “Togiak-Tikchik 

Complex.”

Introduction

In the mid-1950s, Cady and others (1955) coined the 

stratigraphic term “Gemuk Group” to name a varied assemblage of sedimentary and volcanic rocks in southwestern 

Alaska. They designated the type locality as rocks exposed 

north of the middle “course” of the Gemuk River (Gemuk 

is a Yupik word for “small hill”) in the Taylor Mountains 

1:250,000-scale quadrangle and described other exposures of 

the Gemuk Group to the northeast in the Sleetmute quadrangle and to the northwest in the Russian Mission quadrangle 

(fig. 1). The Gemuk was defined during the waning stage of 

a wide-ranging exploratory-mapping effort conducted by 

the U.S. Geological Survey (USGS) starting in the 1890s to 

establish the framework geology of Alaska. The geologic 

maps produced by these exploratory surveys were primarily 

based on long crosscountry foot or boat traverses on which 

there was little opportunity to examine exposures off the path 

of travel or to revisit exposures. Many formal stratigraphic 

names were assigned to the geologic units described as a 

result of these expeditions, and some of these names remain 

in current use.

Recent efforts at compiling the geology of Alaska, 

particularly of southwestern Alaska, show that the name 

“Gemuk Group” is no longer widely used. The first of these 

recent compilations (Wilson and others, 1998) continued use 

of the term, but subsequent, more focused regional compilations have yielded additional information on the history and 

use of the name “Gemuk Group” as a stratigraphic and geologic unit. As a result, our premise here is that the name has 

outlived its usefulness and should be abandoned. Instead, the 

rocks traditionally assigned to the Gemuk Group represent a 

tectonic assemblage or collage and as a whole should therefore be referred to as a complex. Given the long use of the 

term “Gemuk Group,” we further suggest that a new name be 

applied to reflect this revised status.

History: Definition and Use

As summarized in the USGS’ Lexicon of Geologic Names

(Keroher and others, 1966, p. 1488), the Gemuk Group was 

named after the Gemuk River. The type locality was designated 

as favorable exposures north of the lower middle course of the 

Gemuk River, southwest of the Kuskokwim River in the Taylor 

Mountains quadrangle in southwestern Alaska. The exposures 

extend northward about 15 mi (25 km) from the northwest 

side of the Gemuk River valley into the drainage basins of 

Atsaksovluk and Chikululnuk Creeks, and northeastward about 

15 mi (25 km) into the headwaters area of the main fork of 

the Holokuk River in the Sleetmute quadrangle. The unit as 

defined consists of dense, dark, massive siltstone with interbeds 

of chert, volcanic rocks, limestone, graywacke, and breccia. 

According to Cady and others (1955), the volcanic rocks are 

chiefly andesitic in composition, although altered volcanic 

rocks mapped in the unit north of the Kuskokwim River were 

thought to have been originally basalt. The Gemuk Group was 

estimated to have an exposed thickness of 15,000 to 25,000 ft 

(4,600–7,600 m), and the massive siltstone was estimated to 

be 10,000 to 15,000 ft (3,100–4,600 m) thick in the vicinity of 

Cinnabar Creek. Nowhere is the base of the unit exposed, but 

the Gemuk Group was thought to conformably underlie sedimentary rocks of the Cretaceous Kuskokwim Group. Fossils of 

Late Triassic and Early Cretaceous age were collected from the 

unit, and Cady and others (1955) indicated that the rocks below 

the Cinnabar Creek section differ lithologically and may be 

older than Late Triassic. They suggested an age range of Carboniferous(?), Permian(?), Triassic, and Early Cretaceous for 

the Gemuk Group, based in part on tentative correlations with 

rocks mapped by Mertie (1938) to the south.

In their original publication, Cady and others (1955, p. 27) 

also suggested that the Gemuk Group extends southward to 
2 The Togiak-Tikchik Complex of Southwestern Alaska, a Replacement for the Gemuk Group

61°15’

159°00’ 158°45’ 158°30’ 158°15’

61°00’

61°45’

Figure 1. Geologic map of part of the Taylor Mountains 1:250,000-scale quadrangle, southwestern Alaska (see fig. 

2), showing location of type area of the Gemuk Group as originally designated by Cady and others (1955). Area of 

inferred rocks of the Gemuk Group north of the Aniak River is not shown. Map units: Kk, Kuskokwim Group; K^PCg, 

Gemuk Group; Qfp, flood-plain deposits; Qg, glacial deposits; Qs, silt deposits; QTg, gravel deposits; Tba, basalt 

dikes; Th, Holokuk Basalt; Tqd, quartz diorite dikes; Tr, Tr(?), albite rhyolite dikes; Tw, Tw(?), Waterboot Basalt.
3

Chikuminuk Lake and probably farther southward. Sainsbury 

and MacKevett (1965), in their study of mercury deposits in 

southwestern Alaska, reported additional Triassic fossil collections in the Cinnabar Creek area. They also noted that part of 

the Cinnabar Creek section of the Gemuk Group probably is 

overturned and that, in general, the structure at Cinnabar Creek 

is significantly more complex than Cady and others (1955) had 

indicated.

Maps published subsequent to Cady and others (1955) for 

the Bethel, Russian Mission, Goodnews Bay, and Hagemeister Island quadrangles (Hoare and Coonrad, 1959a, b, 1961a, 

b) and compilations for the Taylor Mountains and Dillingham 

156o

162o

62o

59o

61o

60o

159o

0

0

10 20 30 40 50 60 KILOMETERS

10 20 30 MILES

Yukon River

Kuskokwim River

Kuskokwim

Bay

Togiak

Bay

Tikchik Lakes

TAYLOR MOUNTAINS

SLEETMUTE

RUSSIAN MISSION

BETHEL

DILLINGHAM

GOODNEWS

BAY

HAGEMEISTER ISLAND

Figure 1

Figure 2. Southwestern Alaska, showing location of area over which previously (before 1969) the Gemuk Group was believed to extend. 

Rec-tangles, 1:250,000-scale geologic quadrangles.

History: Definition and Use
4 The Togiak-Tikchik Complex of Southwestern Alaska, a Replacement for the Gemuk Group

quadrangles by J.N. Platt and E.H. Mueller (unpub. data, 

1957) extended the known area of the Gemuk Group and 

provided additional information on the lithology and age of 

the unit. The unit had been subdivided on these maps into as 

many as three informal formations (for example, Hoare and 

Coonrad, 1959a). As a result, the Gemuk Group was given 

a vast areal distribution, extending more than 350 km across 

southwestern Alaska (fig. 2). Two important facts noted were 

that “* * * rocks of the Gemuk Group have yielded sparse 

fossils ranging in age from Carboniferous to Early Cretaceous. The rocks are complexly folded and faulted.” (Hoare 

and Coonrad, 1961b) Goldfarb and others (1990) stated a 

revised age for the Gemuk Group of Triassic and Lower 

Cretaceous, for which they provided no explanation or justification. Additional fossil collections in the 1950s and 1970s 

(Hoare and Coonrad, 1961a, b; 1978; Hoare and Jones, 1981) 

showed that Cady and others’ (1955) original suggestion that 

some of the rocks assigned to the Gemuk Group are at least 

as old as Carboniferous proved to be true; in fact, Hoare and 

Jones (1981) reported early Paleozoic radiolarians.

Implicit Abandonment

Yet, given the wide distribution of the unit as mapped, 

by 1969 and 1970 the term “Gemuk Group” was no longer 

in use. Field notes of 1969 and 1970 by W.H. Condon and 

J.M. Hoare no longer refer to the Gemuk Group, whereas 

Hoare’s notes of 1953 do. Hoare was one of the coauthors of 

the report by Cady and others (1955), as well as responsible 

for mapping much of the area where the Gemuk Group was 

known. In their revision of the original maps of the Goodnews Bay and Hagemeister Islands and parts of the Bethel, 

Dillingham, and Taylor Mountains quadrangles, Hoare and 

Coonrad (1978) no longer used the name “Gemuk Group.” 

Rocks shown on Hoare and Coonrad’s (1959a) geologic map 

of the Bethel quadrangle as part of the subdivided Gemuk 

Group were assigned to two new informal map units (KJvs, 

MzPz) on Hoare and Coonrad’s (1978) revised map. Rocks 

in the Goodnews Bay and Hagemeister Island quadrangles 

originally included in the Gemuk Group were assigned to 

these two new map units and other units varying widely in 

lithology; none of the unit descriptions mentions the Gemuk 

Group. However, the descriptions for all of these map units 

clearly include rocks that would have reasonably been 

assigned to the Gemuk Group in the past. Map unit Kts, 

consisting of tuff and sedimentary rocks, has yielded fossils 

of Early Cretaceous age (Hoare and Coonrad, 1978) from 

limy beds containing Buchia and tuffaceous chert containing 

radiolarians. The widespread map unit KJvs, which consists 

of volcanic rocks, including basalt and more abundant andesite, interbedded with thick sections of tuffaceous siltstone, 

tuffaceous chert, and massive or thin-bedded argillite, ranges 

in age from Middle Jurassic to Early Cretaceous but possibly 

includes Triassic and Permian rocks. Map unit Jk, informally 

referred to as the “Weary graywacke” (Hoare and others, 

1975) and later as the “graywacke of Kulukak Bay” (Hoare 

and Coonrad, 1978), consists of quartz- and plagioclaserich graywacke to quartz-poor volcanic wacke described as 

turbidites by Box (1985). Map unit MzPz, more closely associated with the previously mapped Gemuk Group, is lithologically similar to the Gemuk Group as originally defined 

but also includes conglomerate and limestone. Although each 

of these rock packages was assigned to the Gemuk Group 

as originally defined, subsequent mapping and understanding of the regional geology has led to their redefinition as 

distinct map units. The implicit message is that the Gemuk 

Group and its subdivisions no longer proved useful in mapping, a not uncommon occurrence for units defined during 

the exploratory phase of geologic mapping in Alaska. Similar 

terms subsequently abandoned after wide use include the 

Birch Creek Schist of interior Alaska and the Shaktolik Group 

of west-central Alaska. The name “Holitna Group,” also 

originally defined by Cady and others (1955), has also been 

suggested for abandonment as a better understanding of those 

rocks has developed (see Adrain and others, 1995; Blodgett 

and Wilson, 2001).

During the course of studies in southwestern Alaska, 

Box and others (1993) published a revised map of the Bethel 

quadrangle and the southern part of the Russian Mission 

quadrangle. Their map is strongly terrane based; however, 

the critical point here is that they assigned rocks previously 

mapped as part of the Gemuk Group to multiple distinct terranes. They did not use the name “Gemuk Group” for a geologic unit, another implicit message suggesting that the unit 

is no longer useful for mapping purposes. On Box and others’ 

(1993) map, the rocks assigned to map units KJvs and MzPz 

of Hoare and Coonrad (1978) are reassigned to multiple 

informal geologic units in two terranes: (1) melange (unit 

TrPzm), marine sandstone, shale, limestone, and conglomerate (unit TrDs), and massive volcanic and volcaniclastic rocks 

(unit MDv) of the Tikchik terrane; and (2) phyllite and chert 

(unit JTrp), pillow basalt and minor interbedded chert (unit 

Trb), marine volcaniclastic sandstone, conglomerate, shale, 

and interbedded tuff (unit Kvs), argillite and tuffaceous chert 

(unit KJc), marine volcaniclastic sandstone, conglomerate, 

and argillite (unit Jvs), and marine arkosic sandstone and 

argillite (unit Ja) of the Togiak terrane. Few stratigraphic ties 

have been established between these units, and so we have no 

justification for assigning them to a single stratigraphic unit 

(the Gemuk Group). The rocks assigned to the Gemuk Group 

in the Russian Mission quadrangle by Cady and others (1955) 

and Hoare and Coonrad (1959b) were assigned to a unit of 

andesitic and basaltic lava flows and marine epiclastic rocks 

of the Nyac terrane by Box and others (1993) and included in 

the enigmatic Portage sequence by Decker and others (1994), 

who also no longer referred any rocks to the Gemuk Group. 

The only explicit mention of the Gemuk is to rocks in their 

“Portage sequence” as having been originally mapped as 

“part of the undivided Gemuk Group” (Decker and others, 

1994, p. 298). Here again, the implicit message is that the 

term “Gemuk Group” has fallen out of use.
5

The Togiak-Tikchik Complex—Modern 

Usage

As mentioned above, recent efforts at compiling the 

geology of Alaska have brought renewed attention to the 

Gemuk Group. Wilson and others (1998) used the term without close examination of its past usage or broader definition. 

Subsequent, more focused work in southwestern Alaska has 

yielded additional information on the history and use of the 

term “Gemuk Group” as a stratigraphic and geologic unit 

name. Miller and others (2004) have suggested that the name 

be restricted in its use to the type area and a limited extent 

northward, significantly less than as originally suggested by 

Cady and others (1955) or as mapped by Hoare and Coonrad 

(1959a, b, 1961a, b). New field data and fossil collections by 

Miller and others (2004) in the Sleetmute quadrangle do suggest that a distinctive geologic unit is present. However, these 

new data do not extend the unit southward to include the full 

type area of the Gemuk Group, and the suggestion that these 

“contiguous rocks” represent a stratigraphic unit is premature, 

particularly given the structural complexities reported by 

Sainsbury and MacKevett (1965) and indicated for the rest of 

the rocks traditionally mapped as part of the unit (Hoare and 

Coonrad, 1978; Box, 1985; Box and others, 1993; Decker and 

others, 1994). Sainsbury and MacKevett (1965), in contrast 

to Cady and others (1955), suggested that the stratigraphic 

column section of the Gemuk Group in the Cinnabar Creek 

area (within the type area) is a structurally complex rather than 

homoclinal section exposing 10,000 to 15,000 ft (3,000–4,600 

m) of sequence. They recognized a major fold repeating a unit 

of fossiliferous limestone, a general southeastward convergence of beds, and infaulting of a unit of graywacke, siltstone, 

and volcanic rocks. They also showed the Gemuk Group 

as continuing southward, into an area mapped by Cady and 

others (1955) as the Kuskokwim Group. This revision results 

in a better match with Hoare and Coonrad’s (1959b) map of 

the Bethel quadrangle.

On the basis of information presented by Sainsbury and 

MacKevett (1965), the Gemuk Group in the type area does 

not appear to be a coherent stratigraphic unit. Box (1985) and 

Box and others (1993) assigned rocks traditionally part of 

the Gemuk Group to multiple tectonostratigraphic terranes. A 

current compilation for the Taylor Mountains and Dillingham 

quadrangles, using the maps of J.N. Platt and E.H. Mueller 

(unpub. data, 1957), the field notes of J.M. Hoare and W.H. 

Condon (unpub. data, 1969, 1970), and more recent data, 

provides ample evidence that a wide variety of rocks have 

been included in the Gemuk Group as originally defined. 

Rock types ranging from siltstone and sandstone to abundant 

chert of many varieties, volcanic rocks, and limestone of various ages have all been assigned to the Gemuk Group. Fossils 

ranging in age from early Paleozoic to Early Cretaceous have 

been collected from these rocks. Faulting and folding characterize many parts of the unit, some of which clearly represent melange. As a result, we propose that the term “Gemuk 

Group” does not represent a coherent stratigraphic unit, has 

outlived its usefulness in fostering understanding the geology 

of southwestern Alaska, and should therefore be abandoned. 

However, in contrast to the suggestion by Box and others 

(1993) or Decker and others (1994) that the various parts of 

the Gemuk Group represent distinctive terranes, we do not 

believe that mapping to date is sufficient to clearly distinguish 

terranes (fig. 3). The terrane definitions, names, and boundaries used by Box and others (1993) and Decker and others 

(1994) vary significantly, and although Box (1985) provided 

some information regarding linkages between subterranes in 

southwestern Alaska, much uncertainty remains regarding 

which rocks belong to which terrane.

On their maps, Hoare and Coonrad (1959b) and Box and 

others (1993) show major throughgoing faults cutting the 

region, including the Togiak-Tikchik Fault cutting through 

map unit KJvs of Hoare and Coonrad (1978) or separating 

the Togiak and Tikchik terranes of Box and others (1993), or, 

alternatively, cutting through the Hagemeister subterrane of 

the Togiak terrane (Decker and others, 1994). This fault, long 

thought to be an extension of the Denali Fault system of southcentral Alaska, has little demonstrated offset in southwestern 

Alaska, certainly nothing approaching the hundreds of kilometers of offset recognized on the Denali Fault in south-central 

Alaska.

As defined here, the Togiak-Tikchik Complex generally 

includes rocks mapped as part of the Gemuk Group by Cady 

and others (1955), J.N. Platt and E.H. Mueller (unpub. data, 

1957), Hoare and Coonrad (1959a, b, 1961a, b), and Sainsbury 

and MacKevett (1965). The name “Togiak-Tikchik complex” 

is derived from two geographic features that fall within the 

outcrop area of the unit. The extent and lithologic diversity 

of the unit are such that no single geographic locality can 

encompass a representative section, and so we have hyphenated names derived from two localities: Togiak Bay on the 

southwest and the Tikchik Lakes near the northeastern limit 

of the outcrop area. Definition of a type area or locality for the 

Togiak-Tikchik Complex is difficult, owing to limited mapping within the outcrop area. However, a representative group 

of localities would reasonably include the original type area 

of the Gemuk Group along the lower Gemuk River, including 

the Cinnabar Creek area, as well as the Tikchik Lakes area 

in the southwestern part of the Taylor Mountains quadrangle. 

Although some locally distinct lithologic packages can be 

mapped and identified within the unit, overall, stratigraphic 

ties between the various lithologic packages have yet to be 

established. The name “Togiak-Tikchik Complex” is mainly 

proposed because the Gemuk Group, as originally defined, 

was a stratigraphic unit, whereas the Togiak-Tikchik Complex 

is a structural collection of diverse lithologic packages that 

probably do not have a coherent stratigraphy and include a 

melange facies.

The maps by J.N. Platt and E.H. Mueller (unpub. data, 

1957), and Hoare and Coonrad (1959a, b, 1961a, b) subdivided the originally undivided Gemuk Group into lithologic 

packages; however, subsequent mapping has not continued use 

The Togiak-Tikchik Complex—Modern Usage
6 The Togiak-Tikchik Complex of Southwestern Alaska, a Replacement for the Gemuk Group

of those subdivisions. Rocks included in the Togiak-Tikchik 

Complex, as defined here, range in age from confirmed early 

Paleozoic through Carboniferous, Permian, Triassic, Jurassic, 

and Early Cretaceous. Permian fossils are widely distributed, 

as are Early Cretaceous fossils. Certainly, some of the rocks 

included in the complex will ultimately be found to correlate 

with well-defined units elsewhere. Some rocks originally 

included in the Gemuk Group have been shown to more properly belong to the Kuskokwim Group (see Hoare and Coonrad, 

1978), and some rocks assigned to the Kuskokwim Group 

should have been assigned to the Gemuk Group (Sainsbury 

and MacKevett, 1965). Precise definition of the boundary or 

0 25 50 75 100 KILOMETERS

Figure 3. Tectonostratigraphic-terrane map of southwestern Alaska, showing terranes to which rocks of the Gemuk Group were previously 

(before 1969) assigned. Rectangles, 1:250,000-scale geologic quadrangles. Modified from Decker and others (1994).
7

areal extent of the Togiak-Tikchik Complex is impossible, 

owing to the inadequacy of geologic mapping in the region. 

Nonetheless, a reasonable approximation of its extent is shown 

in figure 2 as the limits of the Gemuk Group as mapped by 

Hoare and Coonrad (1959a, 1961a, b) in all but the Russian Mission quadrangle. Within a more modern context, the 

Togiak-Tikchik Complex includes the Togiak terrane and the 

Nukluk and Tikchik subterranes of the Goodnews terrane of 

Decker and others (1994) and may also properly include the 

Portage sequence of Decker and others (1994), rocks of which 

were included in the original Gemuk Group by Cady and 

others (1955). W.W. Patton (written commun., 2004) has suggested that the Portage sequence of Decker and others (1994) 

should be assigned to the combined Angayucham-Tozitna terrane of west-central Alaska.

Conclusion

The name “Gemuk Group” is herein abandoned, and the 

rocks previously assigned to the Gemuk Group, a relatively 

contiguous, early Paleozoic to Early Cretaceous, lithologically diverse and structurally complex assemblage of rocks 

in the Sleetmute, Taylor Mountains, Bethel, Russian Mission, 

Goodnews Bay, and Dillingham quadrangles, are renamed 

the “Togiak-Tikchik Complex” to better reflect the outcrop 

area and the nature of the unit as a structural juxtaposition of 

diverse stratigraphic units. Although separation of these rocks 

into tectonostratigraphic terranes has been attempted numerous times, uncertainties have yielded a varying assemblage of 

terranes (Jones and others, 1981; Box, 1985; Box and others, 

1993; Decker and others, 1994). Each of these efforts has 

Conclusion
8 The Togiak-Tikchik Complex of Southwestern Alaska, a Replacement for the Gemuk Group

resulted in some lithologic packages (Paleozoic chert, Permian 

limestone) being divided among terranes. Until better mapping, chemistry, and age control exist, we suggest the name 

“Togiak-Tikchik Complex,” and its possible future subdivisions, as the best way to refer to these rocks. Although the 

Togiak-Tikchik Complex remains an enigmatic unit in southwestern Alaska, its recognition as a structural collage rather 

than a distinct stratigraphic entity is important in developing 

an understanding of these rocks and the geology of southwestern Alaska.

Acknowledgments

This manuscript would not have been written without the 

encouragement and support of my coauthor, Warren Coonrad, 

over the years. An introduction to southwestern Alaska under 

his tutelage in the mid-1970s sparked an interest in southwestern Alaska that has never gone away. Discussions with several colleagues and reviews of the manuscript by William W. 

Patton, Jr., and Rocky Reifenstuhl helped significantly clarify 

the writing. Geologic-names review by Scott W. Starratt is 

gratefully acknowledged.

References Cited

Adrain, J.M., Chatterton, B.D.E., and Blodgett, R.B., 1995, 

Silurian trilobites from southwestern Alaska: Journal of Paleontology, v. 69, no. 4, p. 723–736.

Blodgett, R.B., and Wilson, F.H., 2001, Reconnaissance geology north of the Hoholitna River, Taylor Mountains D–1 

1:63,360-scale quadrangle, southwestern Alaska, in Gough, 

L.P., and Wilson, F.H., eds., Geologic studies in Alaska by the 

U.S. Geological Survey: U.S. Geological Survey Professional 

Paper 1633, p. 73–82.

Box, S.E., 1985, Mesozoic tectonic evolution of the northern 

Bristol Bay region, southwestern Alaska: Santa Cruz, University of California, Ph.D. thesis, 163 p.

Box, S.E., Moll-Stalcup, E.J., Frost, T.P., and Murphy, J.M., 1993, 

Preliminary geologic map of the Bethel and southern Russian 

Mission quadrangles, southwestern Alaska: U.S. Geological 

Survey Miscellaneous Field Studies Map MF–2226–A, scale 

1:250,000.

Cady, W.M., Wallace, R.E., Hoare, J.M., and Webber, E.J., 1955, 

The central Kuskokwim region, Alaska: U.S. Geological 

Survey Professional Paper 268, 132 p.

Decker, John, Bergman, S.C., Blodgett, R.B., Box, S.E., Bundtzen, T.K., Clough, J.G., Coonrad, W.L., Gilbert, W.G., Miller, 

M.L., Murphy, J.M., Robinson, M.S., and Wallace, W.K., 

1994, Geology of southwestern Alaska, in Plafker, George, 

and Berg, H.C., eds. The geology of Alaska, v. G–1 of The 

geology of North America: Boulder, Colo., Geological Society 

of America, p. 285–310.

Goldfarb, R.J., Gray, J.E., Pickthorn, W.J., Gent, C.A., and 

Cieutat, B.A., 1990, Stable isotope systematics of epithermal 

mercury-antimony mineralization, southwestern Alaska, in

Goldfarb, R.J., Nash, J.T., and Stoeser, J.W., eds., Geochemical 

studies in Alaska by the U.S. Geological Survey, 1989: U.S. 

Geological Survey Bulletin 1950, p. E1–E9.

Hoare, J.M., and Coonrad, W.L., 1959a, Geology of the Bethel 

quadrangle, Alaska: U.S. Geological Survey Miscellaneous 

Geologic Investigations Map I–285, scale 1:250,000.

Hoare, J.M., and Coonrad, W.L., 1959b, Geology of the Russian Mission quadrangle, Alaska: U.S. Geological Survey 

Miscellaneous Geologic Investigations Series Map I–292, 

scale 1:250,000.

Hoare, J.M., and Coonrad, W.L., 1961a, Geologic map of the 

Goodnews quadrangle, Alaska: U.S. Geological Survey 

Miscellaneous Geologic Investigations Map I–339, scale 

1:250,000.

Hoare, J.M., and Coonrad, W.L., 1961b, Geologic map of the 

Hagemeister Island quadrangle, Alaska: U.S. Geological 

Survey Miscellaneous Geologic Investigations Map I–321, 

scale 1:250,000.

Hoare, J.M., and Coonrad, W.L, 1978, Geologic map of the 

Goodnews Bay and Hagemeister Island quadrangles region, 

southwestern Alaska: U.S. Geological Survey Open-File 

Report 78–9–B, scale 1:250,000, 2 sheets.

Hoare, J.M., Coonrad, W.L., Detterman, R.L., and Jones, D.L., 

1975, Preliminary geologic map of the Goodnews Bay A–3 and 

parts of the A–2 and B–2 quadrangles, Alaska: U.S. Geological 

Survey Open-File Report 75–308, scale 1:63,360.

Hoare, J.M., and Jones, D.L., 1981, Lower Paleozoic radiolarian chert and associated rocks in the Tikchik Lakes area, 

southwestern Alaska, in Albert, N.R.D., and Hudson, Travis, 

eds., The U.S. Geological Survey in Alaska; accomplishments during 1979: U.S. Geological Survey Circular 823–B, 

p. 44–45.

Jones, D.L., Silberling, N.J., Berg, H.C., and Plafker, George, 

1981, Map showing tectonostratigraphic terranes of Alaska, 

columnar sections, and summary description of terranes: 

U.S. Geological Survey Open-File Report 81–792, scale 

1:2,500,000.

Keroher, G.C., and others, 1966, Lexicon of geologic names of 

the United States for 1936–1960: U.S. Geological Survey Bulletin 1200, 4,341 p. [URL http://ngmsvr.wr.usgs.gov/Geolex/

geolex_home.html]

Mertie, J.B., Jr., 1938, The Nushagak district, Alaska: U.S. Geological Survey Bulletin 903, 96 p.

Miller, M.L., Bradley, D.C., Bundtzen, T.K., Pessagno, E.A., 

Jr., Blodgett, R.B., Tucker, Robert, and Wooden, Joe, 2004, 

Reevaluating the Triassic to Cretaceous “Gemuk Group”—evidence from the Sleetmute quadrangle, southwest Alaska [abs.]: 

The Geologic Diversity of Alaska; Alaska Geological Society 

Technical Conference, 2004, p. 17.

Sainsbury, C.L., and MacKevett, E.M., Jr., 1965, Quicksilver 

deposits of southwestern Alaska: U.S. Geological Survey 

Bulletin 1187, 89 p.

Wilson, F.H., Dover, J.H., Bradley, D.C., Weber, F.R., Bundtzen, 

T.K., and Haeussler, P.J., 1998, Geologic map of Central 

(Interior) Alaska: U.S. Geological Survey Open-File Report 

98–133, 63 p., scale 1:500,000, 3 sheets.