Haydite Raw Material 

in the Kings River, 

Sutton, and Lawing 

Areas, Alaska

GEOLOGICAL SURVEY BULLETIN 1039-C

Haydite Raw Material 

in the Kings River, 

Sutton, and Lawing 

Areas, Alaska

By RICHARD A. ECKHART and GEORGE PLAFKER

INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA 

GEOLOGICAL SURVEY BULLETIN 1039-C

A geologic study of three areas that contain raw material for haydite, a lightweight vesicular construction material

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1959
UNITED STATES DEPARTMENT OF THE INTERIOR 

FRED A. SEATON, Secretary

GEOLOGICAL SURVEY 

Thomas B. Nolan, Director

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

Washington 25, D.C.
CONTENTS

Page

Abstract_________________________________________ 33

General introduction. _____ _________________________________________ 33

Haydite raw material (black shale) in the Kings River and Button areas of

the Matanuska Valley, Alaska, by Richard A. Eckhart_______________ 35

Introduction...______________________ _________________________ 35

Location of area_________________________________________ 35

Previous investigation____________________________________ 35

Present investigation_____________________________________ 37

Geography___ __ __ _____________________________________ 37

Geology______________________________________ 38

Matanuska formation______________________________________ 38

Kings River area______________________________________ 40

Button area___________________________________________ 43

Surficial deposits.._______________________________________ 45

Factors affecting development_______________________________ 45

Properties of lightweight aggregate.-. _______________________ 45

Bloating tests_____________________________________________ 46

Discussion of bloating____________________________________ 49

Properties desired of haydite raw material ____________________ 52

Other economic factors____________________ _________________ 53

Reserves,________________________________________________ 54

Mining claims___________________________________________ 55

Other potential sources of haydite raw materials_________________ 55

Conclusions_________________________________________________ 56

Haydite raw material (bloating argillite) near Lawing, Alaska, by George

Plafker________________________________________ 57

Introduction__________________________________________________ 57

Geology-_______________________________ ______________________ 57

General description______________________________________ 57

Lawing argillite deposit__________-______________-__________ 58

Bloating characteristics_______________________________________ 60

Reserves _____________________________________________________ 63

References cited_____-_________.,_-__-____-__________-__---_-_--___- 63

Index____________________________________________________________ 65

m
IV CONTENTS

ILLUSTRATIONS

Pas*

PLATE '7. Geologic map and section of haydite raw-material (blackshale) area along Kings River______________ ___ _ In pocket

8. Geologic map and section of haydite raw-material (blackshale) area near Sutton___________ __ ___ In pocket

9. A, Cliff overlooking Kings River; B, Black shale of unit F at

Sutton area______________________ Facing 44

10. A, Haydite made from a shale sample from Kings River area;

B, Changes in argiilite samples within bloating range. Facing 45 

FIGURE 9. Index map of south-central Alaska showing locations of

deposits of haydite raw material____ ________________ 36

10. Geologic map showing distribution of the Matanuska formation in the Matanuska Valley______________________ 39

11. Geologic map of argiilite deposit near Lawing._____________ 59

12. Average water absorption and weight of six argiilite samples

from Lawing area________ __ _______ ______ 61

TABLES

Page 

TABLE 1. Results of stationary-kiln bloating tests on samples from

Kings River area_______________________-___--_-_-__--__ 47

2. Results of stationary-kiln bloating tests on shale samples from

Sutton area_________________________________________ 47

3. Specifications of raw material and product in rotary-kiln test

of shale from Kings River area___________________________ 48

4. Kiln-operation conditions for rotary-kiln test of shale from

Kings River area___________-_-_-____---__-_--__--__-__. 48

5. Chemical analysis of shale sample from Kings River area.____ 51

6. Water absorption and weight of six argiilite samples__________ 60
INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

HAYDITE RAW MATERIAL IN THE KINGS RIVER, 

SUTTON, AND LAWING AREAS, ALASKA

By RICHARD A. ECKHART and GEORGE PLAFKER

ABSTRACT

Argillaceous rocks and associated graywacke of the Matanuska formation, of 

Late Cretaceous age, are exposed in much of the Mataauska Valley. At the 

confluence of the Matanuska and Kings Rivers, and on the Matanuska River 

about 3 miles west of Sutton, there are deposits of arenaceous shale of the 

Matanuska formation that are possible sources of raw material for haydite. 

Clays and shales that are a suitable raw material for haydite must bloat when 

heated, produce a glassy phase viscous enough to trap a gas, and contain a 

material that will evolve a gas at or slightly above the temperature at which 

the glassy phase is produced. Bloating tests of the argillaceous material from 

the Kings River and Sutton areas indicate that the shahs meets these qualifications and is a good source of raw material for haydifcj. Large reserves are 

available, and both localities are close to transportation, fuel, and a market

North of Lawing, along The Alaska Railroad and the Siward-Anchorage highway, interfingering argillite, slate, and graywacke of probable Mesozoic age 

crop out. Bloating tests of the argillite indicate that it is a suitable source 

for haydite raw material.

GENERAL INTRODUCTION

The present large demand for construction materials and their high 

cost have emphasized the need for local supplies of lightweight aggregates in Alaska. The high cost of transportation precludes shipping 

such low-cost bulky products into the State; likewise the development 

of suitable deposits of raw materials in Alaska that are not easily 

accessible to rail or highway transportation probably would be 

uneconomical.

Several raw or processed materials, including haydite, pumice, 

perlite, and diatomite, may be used as lightweight aggregates. 

"Haydite" is the commercial term applied to a vesicular, lightweight, 

expanded product, similar to coal cinders, that results from the con33
34 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

trolled heating of suitable clays or argillaceous rocks in a rotary kiln 

to temperatures generally between 1,000° and 1,300°C. The term is 

synonymous with the terms "expanded shale" and "expanded clay."

From 1946 to 1949 pumice was mined on Augustine Island and 

shipped to Anchorage for the manufacture of lightweight building 

blocks. This material is at present (1952) being mined at Geographic 

Harbor in Katmai National Monument and shipped to Anchorage for 

the same purpose. As far as is known no other lightweight aggregates are being produced in Alaska.

Haydite produced in Alaska could be used to make lightweight 

concrete blocks. It might also be used as a high-strength lightweight aggregate in structural concretes; the use of such concretes 

in some structures in the United States has resulted in considerable 

savings in more expensive materials, particularly structural steel. 

Haydite has greater compressive strength, lower water absorption, 

and better particle shape than pumice. For these reasons it would 

generally be a more favorable concrete aggregate. Most concretes 

using pumice, however, have better insulation value than those using 

haydite (U. S. Housing and Home Finance Agency, 1949, p. 21, 25). 

The choice of aggregate, therefore, would depend largely on the 

specifications of the concrete required.

Two reports are combined here to describe three areas in which 

haydite raw materials have been found. The report on the Kings 

River and Sutton areas is the result of a special investigation made 

by the U. S. Geological Survey to study the argillaceous rocks in these 

areas and to determine their suitability for the manufacture of haydite. The report on the Lawing area is based on a brief examination 

and sampling undertaken after U. S. Bureau of Mines tests of & 

sample from the area showed promising results.
HAYDITE RAW MATERIAL (BLACK SHALE) IN THE KINGS RIVER 

AND SUTTON AREAS OF THE MATANUSKA VALLEY, ALASKA

By RICHARD A. EOKHAKT

INTRODUCTION

LOCATION OF AREA

Both the Kings River and Sutton areas are in the valley of the 

Matamiska River, which flows into Knik Arm, in south-central Alaska 

(fig. 9). One area is near the mouth of Kings River, about 67 miles 

northeast of Anchorage via the Glenn Highway. The other is between Sutton and Moose Creek, near mile 16 (measured from Matanuska) on the Sutton Subdivision of The Alaska Railroad.

PBEVIOTTS INVESTIGATIONS

The areas here described are near the coal deposits in the Matanuska 

Valley. Considerable work has been done by the Geological Survey 

in this region, primarily in connection with coal investigations. 

Mendenhall (1900, p. 265-300) gave the first general geologic and 

geographic description of the valley after making a traverse from 

Cook Inlet to the Tanana River in 1898. In 1905, Martin (1906) made 

a reconnaissance study of the coal in part of the valley. Since that 

time, the area of coal deposition and adjacent regions has been studied 

by numerous workers (see Capps, 1940, p. 68-86).

The haydite potentiality of the shale in the Kings River area was 

first recognized by the Anchorage Sand and Gravel Co. Early in 

1950, this company sent samples of the rock to Mr. W. G. Bauer, consulting engineer, Seattle, Wash., for testing. Mr. Bauer reported that 

the samples were suitable haydite raw material, and a company called 

Basic Building Products, Inc., was then formed in Anchorage to 

undertake the development of the deposit.

In July 1950, G. O. Gates of the U. S. Geological Survey briefly 

investigated the geology of the areas here described. He recognized 

the similarity of the shale in the Sutton area to that in the Kings River 

area, and recommended that the former be sampled and tested to determine its suitability for the manufacture of haydite. Later in the 

summer of 1950 the Bureau of Mines sampled the shale in the Kings

35
36 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

150" 148° 

FIGUBB 9. Index map of south-central Alaska showing locations of deposits 

of haydite raw material.
HAYDITE RAW MATERIAL, KINGS RIVER, BUTTON, LAWING 37

River and Sutton areas and subsequently ran tests on these samples 

(Rutledge, F. A., 1953). Results of the tests are included in this 

report.

PRESENT INVESTIGATION

During August 1951 a party of the U.S. Geological Survey examined 

the Kings River and Sutton areas to determine the distribution, 

structure, lithologic characteristics, and accessibility of the argillaceous rocks in each locality. A detailed topographic and geologic 

map (pi. 7) of the Kings River area was made by planetable and 

alidade methods. The geology in the Sutton area was plotted on a 

base map compiled by the Topographic Division, U.S. Geological 

Survey (pi. 8).

GEOGRAPHY

The valley of the Matanuska River is about 5 miles wide and lies 

between roughly parallel eastward-trending mountain fronts. The 

valley is bordered by the Talkeetna Mountains to the north and the 

Chugach Mountains to the south. Within the valley are rounded hills, 

some of which attain altitudes of 3,500 feet above the level of the 

gravel flats in the floor of the valley. The Mantanuska River is about 

85 miles long and has a drainage basin of about 1,000 square miles 

(Martin and Katz, 1912, p. 10).

The Glenn Highway, extending from Anchorage to the Richardson 

Highway near Glennallen, follows the north side of the valley. Most 

of the south side of the valley is inaccessible except on foot. A spur 

line of The Alaska Railroad, called the Sutton Subdivision, extends 

from the main line at Matanuska to Moose Creek and Jonesville, 

serving the valley's coal-mining industry.

The Kings River area as referred to in this report includes about 

one-fourth of a square mile at the confluence of the Matanuska and 

Kings Rivers. The latter, which heads in the Talkeetna Mountains, 

borders the area on the north, whereas the Matanuska River forms 

the south and west boundaries. To the east the area is bordered by 

low hills forming the divide between the two rivers. The principal 

topographic feature of the area is a small, northeastward-trending 

ridge, about three-fourths of a mile long and half a mile wide, which 

attains an altitude of about 1,060 feet. The remainder of the area 

consists of a thin strip of gravel flats between the ridge and the rivers. 

The Glenn Highway parallels the Matanuska River in this locality 

and crosses the west and south margins of the area.

The Sutton area as referred to in this report includes an area of 

about six-tenths of a square mile, situated on a conspicuous bend in 

the Matanuska River about 3 miles west of Sutton. The river lies

401351 59 2
38 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

along the south and most of the east boundary of the area which consists of a depression-marked bench with steep cliffs, up to 225 feet 

high, facing the river, A low gravel bench locally 700 feet wide lies 

between the cliff and the river on the south side of the area. The 

Glenn Highway crosses the northern part of the area, and The Alaska 

Railroad (Sutton Subdivision) crosses the area at the base of the cliffs.

Vegetation in both the Kings River and Sutton areas includes 

grasses, devilsclub, alder, cottonwood, birch, and a small amount of 

spruce.

Although the summers are mild and the winters are moderate, as 

compared with most of Alaska, year-round quarrying operations in 

the Kings River and Sutton areas would be affected by the climate. 

Snowfall during the winter is not heavy, but the many drifts and 

low temperatures would probably hamper operations.

GEOLOGY

Folded and faulted sedimentary rocks of Mesozoic and Tertiary 

age comprise the major part of the bedrock in the Matanuska Valley. 

The sedimentary units are cut by numerous small bodies of intrusive 

rocks of acidic and basic composition. On the north the sedimentary 

units are bordered by granitic rocks of the western Talkeetna Mountains, sedimentary rocks of Mesozoic age, and volcanic rocks of the 

eastern Talkeetna Mountains. On the south they are bordered by 

Jthe metamorphic and granitic rocks of the Chugach Mountains. 

General structural trends within the valley are oriented in a northeasterly or easterly direction. Most geologic boundaries of the valley 

are marked by zones of faulting.

MATANTJSKA FORMATION

The argillaceous rocks and 'associated graywacke in the Sutton and 

Kings River areas are part of the Matanuska formation. This formation has a wide distribution in the Matanuska Valley (fig. 10), 

cropping out in irregular areas and belts extending from a few miles 

below the mouth of Moose Creek eastward to the headwaters of Caribou Creek (Capps, 1940, p. 77). As described by Martin and Katz 

(1912, p. 34-36), the Matanuska formation consists essentially of dark 

shale and greenish-gray graywacke with a subordinate amount of 

conglomerate. On Granite Creek, where the most complete section 

known is exposed, the formation has a thickness of at least 4,000 feet 

of which the lower half is almost all shale and the upper half consists 

of alternating graywacke and shale, the graywacke predominating 

(Martin and Katz, 1912, p. 34-35).
Magnetic declination varies from 27* to 28* East

149"

Base torn U. S. Geological Survey 

ousdrangle. 1951

FIQUBE 10. Geologic map showing distribution of the Matanusk
40 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN

The base of the formation has not been observed, but it probably 

rests unconformably upon an erosion surface that truncates rocks 

ranging in age from Early Jurassic to Early Cretaceous. The 

Matanuska formation is unconformably overlain by coal-bearing rocks 

of Tertiary age. Inoceramus and other fossils have been collected 

from the shale and graywacke of the Matanuska formation. On the 

basis of these, the formation is definitely assigned to the Upper 

Cretaceous (Capps, 1927, p. 37-40).

KINGS RIVER AREA

The Matanuska formation is believed to underlie the ridge and 

gravel flats comprising the Kings River area. Although exposures 

are not plentiful, outcrops examined indicate that the ridge may be 

divided into two major units on the basis of lithologic characteristics. 

One unit underlies the northern third of the ridge and consists largely 

of shale. The other underlies the remaining portion of the ridge and 

consists of interbedded graywacke and shale (pi. 7).

The shale is almost continuously exposed from the road cut about 

1,000 feet south of the Kings Eiver bridge, northeast along the Kings 

River. Along the south side of the river it is exposed in a steep cliff 

(pi. 9J.), but at the northeast end of the map area and beyond, it is 

concealed by river gravel. A few small exposures suggest that the 

shale underlies the vegetation and soil at higher elevations in the 

northern part of the ridge.

The shale is black, rather hard, and massive; jointing is common. 

Locally the shale contains a few thin beds and lenses of graywacke 

that are rarely more than a few feet thick. No graywacke, however, 

was observed in the shale exposed between the road cut and point Z 

(pi. 7) on the Kings Eiver. Owing to the lack of bedding in this 

exposure the thickness of the grit-free portion of the unit is unknown. 

The thickness of the entire shale unit likewise could not be determined 

because of the lack of bedding, the large amount of shearing and 

faulting, and the generally indefinite location of its contact with 

the graywacke to the south. The stratigraphy of the Matanuska 

formation, described by Martin and Katz (1912, p. 34-35), suggests 

that the shale unit in the Kings River area is near the base of the 

formation, but no direct evidence of the sequence in this area was 

noted.

The petrographic character of the shale was-studied in some detail, 

as this material is of primary interest as a source of haydite. Thin 

sections prepared from specimens collected at the north end of the 

road cut show that the rock consists of clay and very fine subangular 

mineral fragments. The clay is probably illite. This identification
HAYDITE RAW MATERIAL, KINGS RIVER, BUTTON, LAWING 41

is based on a comparison of stain-test reactions of the clay with known 

clay and the results of differential thermal analyses. The mineral 

fragments are largely quartz and feldspar, with subordinate amounts 

of muscovite, biotite, chlorite, epidote, pyrite and (or) mareasite, 

amphibole and (or) pyroxene, and possibly opal. The presence of 

organic matter in the shale was determined by differential thermal 

analyses and the loss of color due to heating during the analyses. 

The feldspar includes plagioclase and probably orthoclase. Calcite 

was identified in only one thin section. Its presence may be due either 

to calcite stringers that locally cut the shale or to small limy nodules. 

Such nodules occur in the rock at the northeast corner of the map 

area.

The southern two-thirds of the ridge is underlain by interbedded 

graywacke and shale with graywacke predominating. Two distinct 

gray wacke zones containing very little interbedded shale are exposed 

south of the main shale units. In the road cut a thin band of shale 

separates these zones, and their contacts are marked by vertical or 

nearly vertical faults. Several exposures of graywacke near the 

highest elevation on the ridge suggest that these zones may be continuous across the ridge. The outcrop on the south end of the ridge 

(pi. 7) consists of intimately interbedded shale and graywacke in 

about equal proportions.

The graywacke is dark greenish gray, fine grained, and well cemented. A thin section of a specimen collected at the road cut shows 

that the rock is composed of poorly sorted and sized angular to subangular fragments. These fragments consist largely of quartz and 

feldspar with subordinate amounts of muscovite, calcite, chlorite, rock 

fragments, biotite, epidote, zoisite, clinozoisite and apatite, in order 

of decreasing abundance. The feldspar includes plagioclase (largely 

oligoclase), orthoclase, microcline, and perthite, with the first two 

minerals being most abundant. Much of the orthoclase-shows alteration to sericite and clay, whereas the oligoclase is very fresh. Quartz 

fragments are fractured and strained. Eock fragments appear to 

represent andesite and (or) basalt lava flows or dike rocks. Most 

of the calcite occurs as irregular masses filling the interstices between 

allogenic grains, but some of it may be detrital. A cement of sericite, 

.clay, and chlorite is probably the principal bond between the constituent fragments of the graywacke, although some of the calcite contributes to the cementation.

Locally the graywacke contains small lenses of conglomerate. The 

conglomerate consists of well-rounded quartz, granite, chert, greenstone, and quartzite cobbles, up to 4 inches across, in a graywacke 

matrix. The matrix is shaly in some places. In the easternmost out-
42 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

crop mapped along the highway, the conglomerate contains limestone 

fragments set in a calcareous graywacke matrix.

Individual beds of gray wacke average between 2y2 to 3 feet in thickness, and the thickest is about 5 feet. In most exposures, shale layers 

in the graywacke zones are several feet or less in thickness. This 

shale is black, rather soft, and thinly laminated. Joints are generally 

lacking. Mineralogically the shale is similar to that described above.

The section along line A-A' in plate 7 shows the structure in the 

western part of the Kings River area where exposures are abundant 

enough to warrant an interpretation. The attitudes of the strata 

south of the main shale unit suggest an anticlinal structure whose 

axis trends roughly northeastward. Although this structure is not 

well exposed, it is believed to be faulted along or near its axis. This 

is suggested by the fact that what may be the westward extension of 

the same fold appears in the graywacke and shale that form the cliff 

on the west bank of the Matanuska River. As observed from the 

Glenn Highway, the anticline exposed in the west bank appears to 

be faulted and sheared along its axis. No data were obtained concerning movement along the fault. The strata on the north flank of 

this structure dip moderately northward. The attitude of the shalft 

along section A-A* is unknown as no bedding was observed. Farther 

east, along the Kings River (point Z in pi. 7), several graywacke 

layers in the shale dip steeply southward, but the westward projection 

of this attitude would be subject to question.

A great amount of shearing and faulting has taken place in the 

graywacke and shale. Not all the fault and shear zones are shown 

in plate 7, and, also, for the sake of simplicity shear zones are shown 

as faults. Slickensides and grooves are abundant along the faults^ 

and their surfaces are locally coated with calcite. Movement along 

the zones is believed to be largely horizontal, although at some places 

a vertical displacement of 2 or 3 feet was observed.

Slickensides and grooves on the vertical fault between the shale 

and graywacke in the road cut indicate that movement has been horizontal, but no evidence was found as to the direction and amount of 

displacement. The eastward extension of this fault was not found.

A well-defined joint system, striking northeastward and dipping 

40°-70° N., was observed in the shale between the road cut and point 

Z (pi. 7) along the Kings River. In shale exposures farther up the 

river, Martin and Katz (1912, p. 36) found that the jointing is perpendicular to the bedding and to a minor set of joints. They believe 

that the minor joints are also perpendicular to the bedding.
HAYDITE RAW MATERIAL, KINGS RIVER, SUTTON, LAWING 43 

SUTTON AREA

The Matanuska formation probably forms the bedrock of the Sutton area, although exposures are found only in the cliffs along the 

railroad. The formation there consists of interbedded black shale 

and graywacke, with individual beds ranging from less than a foot 

to about 4 feet in thickness. Both the shale and graywacke are about 

the same in lithologic character as that in the Kings River area. 

There are, however, zones in the formation in the Sutton area in 

which either shale or graywacke predominate. Because of the possible economic value of the shale it seemed desirable to map these zones 

as distinct units. The stratigraphic section in the Sutton area is, 

therefore, divided on the basis of lithologic characteristics into 10 

units, arbitrarily designated as units A through J in descending order 

(pi. 8).

Units A through F represent a normal stratigraphic sequence. 

Units G through J may include part of the overlying units, but the 

lack of marker beds and the presence of several faults with unknown 

displacements precludes such a correlation. Quaternary deposits unconf ormably overlie all the units.

Unit A crops out at the north end of the cliff along the railroad. 

Its northern extent is concealed by unconsolidated Quaternary deposits. The unit is largely black shale with an estimated 10 percent 

interbedded graywacke. A few thin layers of dark siltstone and 

gritty shale, less than 2 feet thick, also occur in the unit. The shale 

is finely laminated for the most part, and rather soft. It is cut by 

numerous thin calcite stringers and locally contains subrounded calcareous nodules up to about 4 inches in diameter which give the shale 

a conglomeratic appearance from a distance. The unit is cut by two 

sets of joints that occur in the black shale of unit A. These strike 

about N. 15° E. and dip about 75° NW. and 40° SE. The top of the 

unit is not exposed. It has a thickness of more than 490 feet, and is 

conformably underlain on the south by unit B.

Unit B is estimated to consist of about 50 percent black shale and 

50 percent graywacke, the 2 rock types being interbedded in layers 

averaging between 2 to 3 feet in thickness. The shale has the same 

appearance as that in unit A; the graywacke contains numerous black 

shale fragments and streaks up to about 2 inches long. The unit has 

a thickness of 230 feet and is conformably underlain by unit C.

Unit C consists of graywacke with an estimated 10 percent interbedded black shale. Both rock types are similar to those in units A 

and B. The unit has a thickness of 700 feet and is conformably 

underlain by unit D.
44 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

Unit D is similar to unit A, as it consists of black shale with an 

estimated 10 percent interbedded graywacke and siltstone. Some of 

the clastic material occurs in small irregular masses within the shale. 

The thickness of this unit is 230 feet. It is conformably underlain by 

unitE.

Unit E is similar to unit C, as it consists of graywacke with an 

estimated 10 percent interbedded black shale. This unit has a thickness of 160 feet and is conformably underlain by unit F.

Unit F consists of black shale free of any interbedded graywacke 

or siltstone (pi. 9#). The unit, however, contains numerous thin 

impure limestone layers, less than a foot thick, which form resistant 

layers in the shale.

The calcareous beds are estimated to compose less than 10 percent 

of the unit. The limestone is fine grained and blue black and weathers to a dark brown. Impurities include small angular fragments 

of quartz, chert, feldspar, mica, chlorite, clinozoisite, and apatite. A 

thin section shows forms having circular cross sections that may be 

radiolaria. Unit F has a thickness of more than 360 feet. The base 

of the unit is not exposed.

Unit G consists of interbedded black shale and graywacke, in about 

equal amounts. Layers of each rock type average 3 to 4 feet in thickness. The stratigraphic position and thickness of the unit are unknown, as neither the base nor the top of the unit is exposed. Its 

lateral extent is believed to be limited on the east and west by faulting.

Unit H consists of graywacke and appears to be free of black shale. 

The graywacke is similar to that in the units described above. 

Neither the base nor the top of the unit is exposed. The lateral extent of the unit is limited by faulting.

Unit I is similar to units A and D, as it consists of black shale with 

an estimated 10 percent interbedded graywacke. The eastern extent 

of the unit is limited by a fault which according to F. F. Barnes 

(oral communication) has displaced this unit and unit J southward. 

Unit I may be the stratigraphic equivalent of unit D. Unit I has a 

thickness of more than 240 feet, and is conformably underlain by 

unit J. The top of the unit is not exposed.

Unit J consists of graywacke with an estimated 10 percent black 

shale. This unit is similar lithologically to units C and E, and it 

may be that the sequence formed by units I and J is the stratigraphic 

equivalent of the sequence formed by units D and E. Unit J has a 

thickness of more than 240 feet. The base of the unit was not 

observed.

The section along line A-A' in plate 8 shows that the Sutton area 

is underlain by a homoclinal succession of steeply northward-dipping 

strata. Beds in this structure strike N. 80°-85° E. and dip 78°-88°
GEOLOGICAL SURVEY BULLETIN 1039 PLATE 9

A. CLIFF OVERLOOKING KINGS RIVER

t * « i I f » I

B. BLACK SHALE OF UNIT F AT SUTTON AREA
GEOLOGICAL SURVEY BULLETIN 1039 PLATE 10

HAYDITE MADE FROM A. SHALE SAMPLE FROM KINGS RIVER AREA 

Bloating temperature was 1.052°C

21006 F 220(^ F 2300° F 24Q0* F

B. CHANGES IN ARGILLITE SAMPLES WITHIM BLOATING RANGE
HAYDITE RAW MATERIAL, KINGS RIVER, STJTTON, LAWING 45

N. Bedding is very distinct, although locally it is slightly contorted. 

The homoclinal structure is cut by numerous faults and shear zones. 

Most of the surfaces along which movement has taken place are 

coated with calcite. Not all the faults and shears observed are shown 

in plate 8. The most noticeable fault is a small thrust which is exposed in the cliff along the east side of the area. It strikes roughly 

west, dips about 10° S., and has a horizontal displacement of about 6 

feet.

STTRITCIAL DEPOSITS

Gravel of the Matanuska River and Kings River makes up the 

Quaternary surficial deposits of the Kings River area. The gravel, 

which rests unconformably upon the Matanuska formation includes 

silt, sand, cobbles, and boulders from most of the various rock types 

found in the Matanuska Valley.

Quaternary deposits consisting mostly of river gravel and loess 

unconformably overlie the Matanuska formation in the Sutton area. 

Locally, the loess is up to 10 feet thick. At several places the alluvium may be of glacial origin.

FACTORS AFFECTING DEVELOPMENT

PROPERTIES OP LIGHTWEIGHT AGGREGATE

Standard specifications for lightweight aggregates for concrete, including haydite, have been adopted by the American Society for Testing Materials (1950, p. 720-722). Both chemical and physical tests 

are necessary to determine the suitability of a particular material. 

In the absence of such tests, some of the generally desirable properties 

of lightweight aggregates (Conley and others, 1948, p. 7-8) are described below. This list may serve as a guide to evaluate the shale in 

the Sutton and Kings River areas. The following properties pertain 

to a lightweight aggregate to be used in concrete, but most of them 

also would apply to aggregate used in building blocks:

Lightweight. The aggregate should not weigh more than half as 

much as the standard aggregate it replaces. Because rock or gravel 

aggregates have a bulk density of approximately 100 pounds per 

cubic foot, the ideal light aggregate should have a bulk density of less 

than 50 pounds per cubic foot.

High strength. The individual particles of the aggregate should 

be as strong as possible. Concrete with a strong aggregate will require less cement than one with a weaker aggregate, thus resulting in 

savings of cost and weight.

491351 59 3
46 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

Well-rounded particles. The ideal aggregate should have wellrounded, preferably spherical, surfaces. This quality promotes good 

workability.

Low water absorption. The individual particles should have closed 

pores; otherwise, water from the concrete mix will fill the pores, thus 

dehydrating the concrete and giving a poor set. High absorption may 

be compensated to some extent by presoaking the aggregate.

Uniform particle-size gradation. The aggregate must be composed of a range of sizes, including a sufficient quantity of fine-grained 

particles. This size gradation promotes workability.

Chemical inertness. The aggregate should not contain compounds 

that would tend to react with the cement and affect its setting.

Loio production cost. The production cost of the lightweight aggregate is the ultimate factor that determines its acceptability, for the 

aggregate must compete with other lightweight aggregates and heavy 

aggregates such as sand and gravel. This means that the raw material 

must be easily mined, located near markets and a source of fuel, and 

processed with a minimum of technological difficulty. Although their 

production costs are higher, lightweight aggregates may favorably 

compete with heavy aggregates if the initial extra production costs are 

offset by one of the following factors: a saving in weight that permits 

elimination of some reinforcing steel, use of lighter weight forms which 

results in reduction of labor costs, or the attainment of better thermal 

and sound insulation qualities.

BLOATING TESTS

The conditions and results of tests made by the U. S. Bureau of 

Mines on samples of argillaceous material collected by the bureau from 

the Kings River and Sutton areas are shown in tables 1, 2, 3 and 4. 

The tests were run at the Bureau of Mines' Electrotechnical Laboratory, Norris, Tenn. (Rutledge, 1953).

For the stationary-kiln tests, the samples were crushed to pass an 

8-mesh sieve, and small briquets, approximately one-half inch by 1 

inch by 2 inches, were formed by hand-tamping dampened particles 

into a mold. The briquets were artificially dried for about 12 hours at 

100°C, or air-dried for several days before firing.

A laboratory kiln was heated to 1,150°C and a series of samples inserted on a silicon carbide slab. Sufficient time was allowed for the 

kiln to come to equilibrium after loading, and the samples were held 

at the maximum temperature for 15 minutes before removing for visual 

inspection. The kiln temperature for other heats was then adjusted 

upward or downward, in steps of 50 °C, as indicated by the condition of
HAYDITE RAW MATERIAL, KINGS RIVER, SUTTON, LAWING 47

the specimens. A sufficient number of heats were run to indicate the 

bloating range and optimum bloating temperature of the material.

TABLE 1. Results of stationary-kiln bloating tests on samples from 

Kings River area

Sample

3

4 

5 

6

7 

8 

9

Temperature (°C)

1, 100 

1, 150 

1,200 

1, 100 

1,150 

1,200 

1, 100 

1, 150 

1,200 

1, 100 

1,150 

1,200 

1, 100 

1, 150 

1,200 

1, 100 

1, 150 

1,200 

1, 100 

1, 150 

1,200

Bloating results

Poor

X 

X 

X 

X 

X 

X 

X

Fair

X

X 

X

X 

X

X 

X

X

X

X

Good

X

X

X

X

Remarks '

Temperature too low.

Temperature too high. 

Temperature too low.

Temperature too high. 

Temperature too low.

Temperature too high. 

Temperature too low.

Temperature too high.

1 See pi. 7 for locations of samples 3-8. Location of sample 9 is described on p. 54. 

TABLE 2. Results of stationary-kiln bloating tests on shale samples from Sutton area

Sample

53 

54

Temperature (°C)

1, 100 

1, 150 

1,200

1, 100 

1, 150 

1,200

Bloating results

Poor

X

X 

X

X

Fair Good

X

X

Remarks

Bloated 2 _ _

Bloated 2 __

Locations of samples *

Sample length 80 ft. Cut 

normal to strike and dip 

of beds adjacent to 

railroad. 

Sample length 50 ft. Cut 

approximately normal 

to strike and dip of beds 

near upper contact adjacent to railroad.

1 Channel samples spaced 400 feet apart along strike of beds in unit F (see pi. 8).

2 Large cellular structural bubbles J-6 to J4 inch in diameter.

The product of the rotary-kiln test of shale from the Kings River 

area had fine uniformly spaced pores, indicating excellent vesicular 

structure. It showed an expansion of 100 percent and tended to clinker 

and form logs in the kiln. The temperature of the kiln, which was 

difficult to control or read closer than 50° C, was slightly high for best 

results.
48 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

TABLE 3. Specifications of raw material and product in rotary-kiln test of shale

from Kings River area

Particle size:

Minimum ______meshMaximum ________in.

Weight of feed:

Cu ft __________Ib. 

Total __________lb.

Weight of product:

Cu ft «% in diameter) __________lb_ 

Total __________Ib.

Bulk specific gravity:

Fine ____________________

280

Bulk specific gravity, saturated 

surface, dry basis:

Fine ______________ 1.29 

Coarse _________ 1.12

Apparent specific gravity:

Fine _______________ 1. 66 

Coarse _________ 1.16

Absorption:

Fine ________percent__ 33.2 

Coarse _______percent 44. 5

43

215

0.89 

Coarse ___________ 0.84

TABLE 4. Kiln-operation conditions for rotary-kiln test of shale from Kings

River area

Time

(a.m.)

10:10

10:40

10:45

11:20

Temperature (°C)

1, 190

1,200

Remarks

Start fire.

Off to load.

Loaded and fired.

Off.

Mesh

 2 +4.

 4 +6.

 6 +8.

Percent 

_ 19.0 

_ 15.5 

_ 11.1

Screen analysis of the product after crushing to minus %-inch size 

is shown by the following tabulation:

Mesh Percent

 18 +30______________ 5.0

 30 4-70_______________ 9.0

 70 +100______________ 3.0 

-8+18_______________ 23.4 100_________________ 14.0

Mr. A. F. Waldron, president, Basic Building Products, Inc., has 

kindly made available to the author a report of tests on Kings River 

shale samples by W. G. Bauer (written communication, Oct. 23,1951). 

After preliminary tests on the samples, Mr. Bauer made five followup 

firings on one of the samples to determine optimum heating rates, 

temperatures, kiln atmospheric conditions, bloating range, glaze coating, heat spalling, and sticking tendencies. All firings were made in 

a gas-fired rotary kiln. Firing schedules were held to those employed 

in commercial-size kilns using similar raw material. The kiln was 

correlated to a large rotary kiln used in a commercial plant that 

treated similar raw material and, therefore, Mr. Bauer believes the test 

results can be duplicated on a commercial scale.

The tests showed that the maximum temperature required for bloating is 1,980°F (about 1,080°C). The weight of the product was 

judged to be about 42 pounds per cubic foot when the full range of
HAYDITE RAW MATERIAL, KINGS RIVER, SUTTON, LAWING 49

required sizes is obtained. It was necessary to crush the kiln product 

in order to obtain the required fines. 

Summarizing the results of his tests, Mr. Bauer states,

the shale forms a good ceramic glaze or coating which is harder than steel at 

a temperature of 1,870°F and which takes place just prior to bloating. The 

bloating range is not wide, although the pores become too large if the material 

is held at the maximum temperature too long. Some sticking occurs in the kiln, 

especially when particle size range of the feed is large and much fine material is 

present. There are operational and equipment-design techniques, however, to 

overcome this to a large extent.

Mr. Bauer concludes that the shale sample produces

a haydite-equivalent product and there are no special processing difficulties. 

There are definite indications that considerable further improvement in uniformity, strength, and absorption can be achieved in a correctly designed commercial installation.

DISCUSSION OP BLOATING

Grim and Bradley (1940); Austin, Nunes, and Sullivan (1942); 

Conley and others (1948); Riley (1951); and other investigators have 

done valuable work on the bloating properties of clay and shale. The 

following discussion is based largely on the works cited above.

The mechanisms by which some clay and shale bloat when heated 

are not fully understood. There appears to be no direct correlation 

between chemical composition and bloating properties. Probably the 

mineralogic composition governing the chemical combinations in the 

raw material is of basic importance. It is known, however, that the 

following conditions must be fulfilled to produce a bloat (Conley and 

others 1948, p. 10): (1), The material, when heated sufficiently, must 

produce a pyroplastic or glassy phase which is developed by fluxes to 

the point of incipient fusion. The viscosity of the phase must be 

great enough to trap a gas. (2), Some constituent or constituents 

of the material must evolve a gas at or slightly above the temperature 

at which the pyroplastic phase is produced. The gas is then trapped 

by the viscous melt and produces a cellular structure. The gas must 

not be readily soluble in the melt.

By plotting a large number of chemical analyses of bloating and 

nonbloating clay, Riley (1951) was able to define the limits of bloating 

on a composition diagram. He states,

The "area of bloating" on this diagram showed desirable compositions of clays 

which satisfy the first necessary condition for bloating. As a test of the area 

of bloating, silica and alumina were added to nonbloating clays to give them 

compositions conforming to points within this area. When fired these mixtures 

bloated.

It should be emphasized that the bloating would not have taken place 

if the second condition for bloating was not satisfied; that is, if gasproducing constituents were not present.
50 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

The impurities of some clay and shale are potential sources of gas 

for bloating. Some of these are carbonaceous matter, iron compounds, 

carbonates, and sulfates. Conley and others (1948, p. 98) state that, 

"these need be present only in small proportions (1-2 percent) to 

effect extensive bloating." Riley (1951, p. 121), in a study of a shale 

from Minnesota, demonstrated that hematite, pyrite, and dolomite 

are the only accessory minerals that dissociated and produced gas at 

the proper temperature.

Conley and others (1948, p. 30) concluded from their studies that 

if the combined impurities of clay or shale are less than 5 percent, 

the rock is almost certainly a nonbloating type. However, Grim and 

Bradley (1940) bloated purified samples of illite and montmorillonite 

clay. Riley (1951, p. 124) also bloated a purified sample of illite.

Many samples of nonbloating clay and shale may be made to bloat 

by using admixtures such as sulfur, carbon, hydrocarbons, and sulfates; some clay and shale that is nonbloating at normal temperatures will bloat at temperatures higher than those now employed 

commercially (1,000°-1,300°C). The use of admixtures or higher 

kiln temperatures, however, increases production costs.

Table 5 shows the chemical composition of a shale sample collected 

at the north end of the road cut at the Kings River area. It is interesting to note that this composition falls within the "area of 

bloating" on Riley's composition diagram. The analysis shows no 

sulfur in the sample, but pyrite and (or) marcasite (both are iron 

sulfides) were observed in a thin section of the same sample and 

identified by microchemical tests, suggesting that they are sparsely 

disseminated in the shale but were not present in the portion of the 

sample anaylzed.

Precise quantitative mineralogic analyses of the Kings River and 

Suttoii haydite raw materials are not available, but the chemical 

analysis, thin-section studies, and stain tests indicate that the shale 

from the Kings River area has the following mineral composition: 

50-60 percent quartz and feldspar, 10-15 percent illite, 15-20 percent 

mica, 5-10 percent calcite, opal, chlorite, epidote and other ferromagnesian minerals, 1 percent or less pyrite and (or) marcasite and 

organic matter. The shale of unit F at the Sutton area is believed 

to have roughly the same chemical and mineral composition.

The bloated shale from the Kings River area has a cellular structure with a sealed outer surface (pi. 10J.). A thin section shows 

that the cell walls consist of glass with many embedded fragments of 

unaltered quartz and feldspar. Within the cells are a few small 

fragments of quartz, feldspar, and an unidentified mineral that occurs 

in isotropic and anisotropic grains and has a negative relief. Refractive indices of this mineral are unknown, as specimens of the bloated
HAYDITE RAW MATERIAL, KINGS RIVER, BUTTON, LAWING 51

shale are not available. It is possibly a glass, but it is unlike the 

glass of the cell walls.

From the thin-section study it appears that quartz and feldspar are 

the only minerals in the shale that survive the bloating process, and 

that glass and an unidentified mineral, which may also be glass or an 

artificial mineral, are the only new substances formed in the kiln.

TABLE 5. Chemical analysis of shale sample from Kings River area 

[Analysis by H. M. Hyman, U. S. Geological Survey]

Chemical constituent

Si02 _-___-_-___-____-_____

A12 O8 _____________________

Fe_Oa~--~ -_---

FeO-__

MgO_-_-___________-____-

CaO_ -_______ ______

NaaO_--__._____. _________

K2 0_____-_-_______-______

H2 0-____________________

Percent

60. 17

16.02

1.29

5. 14

3. 17

2.33

9 99

2.72

0. 64

Chemical constituent

H2 0 + _ _ 

TiOa

C0a - __-_- _- 

PoOfi

S - ----- ------

MnO_--- __ -- 

Total.- __ ________

Percent

3 78

73

77

29

00

15

1 99. 42

i Sample contains some organic matter.

The quartz and feldspar apparently play no part in the bloating 

process. The other constituents of the shale behave as follows: Some 

melt to a glassy phase; others are dissolved in the glassy phase once 

it has formed, as the temperature increases; still others evolve a gas 

or gases which vesiculate the glass. Which minerals participate in 

each of these functions is unknown, but the physical and chemical 

characteristics of some of the minerals present are at least suggestive.

Purified samples of illite were bloated experimentally by Grim and 

Bradley (1940, p. 8-10). They found that at a temperature of 850°C, 

illite has lost all of its water; from 850° to 1,300°C, spinel forms 

from illite; and at 1,100°C, mullite forms from illite. No attempt 

was made to explain the bloating phenomenon. It is possible, however, that a dissociation of Fe2O3 in the spinel takes place, providing 

oxygen as the gas for bloating. Hydrogen and water vapor could 

not be responsible for the bloating because water is lost at a temperature much lower than that needed to produce the pyroplastic 

phase. The shale from the Kings Kiver area and the shale comprising unit F in the Sutton area are estimated to contain 10-15 percent illite, but no mullite or spinel were observed in the haydite from 

the Kings River area. It is probable that the reaction of illite with 

the other ingredients of this rock does not yield mullite or a spinel 

and, therefore, whether or not the illite could be responsible for the 

bloating gas is not known.
52 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

Biotite when heated to temperatures around 1,200°C yielded leucite, 

Fe2O3, and spinel (Grim and Bradley, 1940, p. 9). As with illite, 

a dissociation of the Fe2O3 and the spinel might produce oxygen. 

The argillaceous rocks in the Kings River and Sutton areas contain 

biotite but, as stated above, the haydite does not contain spinel and 

no leucite was identified. Therefore, it is not known whether or 

not biotite could be responsible for the bloating gas. Biotite also 

contains water, but all of it would probably be driven off by the time 

the bloating temperature is reached.

It has been demonstrated that pyrite will evolve gas, probably 

sulfur dioxide, at a temperature within the bloating range. Marcasite should do the same. The shale in the areas here described 

probably contains less than 1 percent iron sulfide minerals. If gasproducing constituents must be present in the amount of 1-2 percent, it is considered unlikely that iron sulfide minerals are of major 

significance in the production of gas in these rocks during bloating. 

This conclusion is based on the lack of sulfur in the chemical analysis 

shown in table 5. More analyses are needed, however, to support this 

conclusion.

The Sutton and Kings River haydite raw materials contain a small 

amount of calcite. This mineral may be responsible, at least in part, 

for the bloating. It dissociates at temperatures below those at which 

bloating takes place, but Riley (1951, p. 127) believes that calcite may 

react with other ingredients to form compounds that dissociate at 

temperatures high enough for bloating. He suggests cancrinite and 

potassium carbonate as possible intermediate compounds. Part of 

the calcite may also act as a flux in the formation of the glassy phase.

It is possible that no single mineral constituent of the argillaceous 

rocks in the Kings River and Sutton areas is the sole gas-producing 

agent, but, rather, that the pyroplastic phase and bloating gas or gases 

are the result of reactions largely among illite, mica, ferromagnesian 

minerals, and calcite. Intensive laboratory study would be needed to 

explain fully the bloating of the shale. One valuable contribution 

would be quantitative analyses of the gas or gases evolved during 

bloating.

PEOPEETIES DESIRED OP HAYDITE RAW MATERIAL

The following properties are listed by Conley and others (1948, p. 

76, 81-82) as desirable in raw material that will bloat in a rotary 

kiln. These properties have been briefly applied to the shale unit in 

the Kings River area and unit F in the Sutton area. It is assumed 

that all the material in these units bloats under the same conditions 

and with the same results as obtained in bloating tests on samples.
HAYDITE RAW MATERIAL, KINGS RIVER, SUTTON, LAWING 5&

Short bloating time. Fast-bloating material requires less time in 

the kiln and, therefore, the kiln may be operated at a greater capacity,. 

Tests by the U. S. Bureau of Mines (table 4) and Mr. Bauer indicate 

that the Kings River shale possesses this property. Samples of the 

Sutton shale were not tested in the rotary kiln.

Wide range between temperature of bloating and temperature of 

agglomerating. Materials that agglomerate at temperatures near 

those at which they bloat cause serious kiln operating difficulties. 

Not only does this property cause the material to stick to the kiln, 

lining and to form "logs," but it impedes the movement of the feed 

through the kiln and may prevent part of the feed from receiving the 

proper amount of heat. Generally, the finer the particle size of the 

feed, the greater the tendency to agglomerate. There are, however,, 

remedies for this problem. Both the U. S. Bureau of Mines 

(Rutledge, 1953) and Mr. Bauer observed that the shale from the 

Kings River area showed some tendency to agglomerate. They do 

not, however, consider this tendency to be serious. As the shale from 

the Sutton area was not tested in the rotary kiln, it is not known 

whether or not the shale possesses this property.

Low bloating temperature. Because of fuel costs, a material that 

bloats at temperatures greater than about 1,300°C in the rotary kiln 

is generally considered undesirable as a raw material unless there are 

other strong factors in its favor. Tests indicate the shale from the 

Kings River area bloats in the rotary kiln at temperatures less than 

1,200° C and that the shale from the Sutton area also bloats below 

that temperature in a stationary kiln. It is believed that the shale 

from the Sutton area would bloat at 1,200°C or less in a rotary kiln.

Presence of free carbon. A substantial amount of free carbon is 

desirable. The exothermal reaction of its combination with oxygen 

reduces the amount of fuel required for bloating. Differential thermal 

analyses indicate an exothermic reaction in the shale from the Kings 

River area up to about 400°C.

OTHER ECONOMIC FACTORS

Coal from the mine at Jonesville is a potential source of fuel for a 

haydite plant using shale from either the Kings River area or the 

Sutton area.

The part of the shale unit at the Kings River area exposed from the 

road cut to point Z (pi. T) along the Kings River appears free of 

graywacke and, therefore, is considered the best source of haydite 

raw material in the Kings River area. The remainder of the exposed 

part of the unit contains 10 percent or less graywacke. The effect this 

impurity would have on the bloating of the shale is unknown. It
54 INVESTIGATIONS OP CONSTRUCTION MATERIALS IN ALASKA

occurs in beds up to several feet thick and, therefore, much of it might 

be excluded from the raw material in quarrying. If included in the 

feed and passed through the kiln the graywacke would not bloat and 

probably would only add weight to the product.

The interbedded graywacke-and-shale unit in the Kings Eiver area 

is not considered a potential source of haydite material, for samples 

of the shale (7 and 8, table 1) did not bloat satisfactorily in stationaryMln tests. A shale sample (9, table 1) from the easternmost outcrop 

along the highway also did not bloat satisfactorily (Eutledge, 1953). 

The large proportion of graywacke and the fact that none of the shale 

l>eds observed are thick enough for mining are other factors that rule 

out this unit as a source of haydite raw material.

The shale from the Kings River area is easily accessible from the 

Glenn Highway, and enough working room exists for quarrying 

operations (pi. 7). Much of the shale unit is free of overburden, and 

where present the overburden probably does not exceed 3 feet in thickness. Locally considerable brush and timber would have to be stripped 

before quarrying.

Unit F is considered the best potential source of haydite raw 

material in the Sutton area. The limestone that occurs in thin beds 

within the unit is apparently not a contaminating constituent, for it 

undoubtedly made up parts of the samples collected and successfully 

bloated by the Bureau of Mines (see location column in table 2). Unit 

F is easily accessible from the railroad and enough working room is 

available for quarrying operations (pi. 8). Very little soil and brush 

cover the western part of the unit on the side of the bench. At the top 

of the bench, Quaternary material as much as 10 feet thick covers the 

shale, but this is true in only a small area which is not included in the 

reserves.

Units D and I are other possible sources of haydite shale in the 

Sutton area, but lack of room for quarrying between these units and 

the railroad is a disadvantage. Their graywacke content is also an undesirable feature. According to F. A. Eutledge (oral communication) 

a sample of unit A tested by the Bureau of Mines did not bloat 

satisfactorily.

RESERVES

All calculations of reserves are based on the assumption that the 

specific gravity of the black shale is 2.65; that is, 12 cubic feet of ore 

weighs 1 short ton.

Reserves in the Kings River area were calculated only for the main 

shale unit. Calculations were made by constructing five vertical sections across the unit, oriented S. 35° E. An altitude of 560 feet was
HAYDITE RAW MATERIAL, KINGS RIVER, SUTTON, LAWING 55

assumed as the bottom of each section, as this is the approximate altitude of the base of the cliff along the Kings River and, therefore, 

probably the lowest practical working limit in quarrying. The south 

contact of the shale is assumed to be vertical. Graywacke layers in the 

shale are included in the reserves. These layers probably comprise 

less than 10 percent of the unit. The inferred reserves are 34,900,000 

short tons.

Reserves of the graywacke-free shale exposed from the road cut to 

point Z (pi. 7) along the Kings River are estimated to comprise 20 

percent of the total reserves of the unit, or 7,980,000 short tons.

Reserves in the Sutton area were calculated only for unit F. Calculations were made by constructing four vertical sections across the 

unit, oriented N. 40° W. An altitude of 425 feet was assumed as the 

bottom of each section. The part of the unit that underlies Quaternary material at the top of the bench is not included in the reserves. 

The indicated reserves are considered to be 24,900,000 short tons.

MINING CLAIMS

At the time this investigation was made, several mining claims were 

held by A. F. Waldron and Jack Harrison of Anchorage on part of the 

shale unit in the Kings River area. The claim marker shown in 

plate 7 represents the northwest corner of discovery No. 1 claim held 

by these men. No other claims were known to be staked on this unit.

According to the U.S. Bureau of Land Management no mining 

claims had been staked on or near the bedrock exposures in the Sutton 

area as of August 1951.

OTHER POTENTIAL SOURCES OF HAYDITE RAW 

MATERIALS

Other potential sources of haydite shale in the Matanuska formation 

are suggested by extensive exposures along the highway between Kings 

River and Chickaloon and along the highway between Hicks Creek 

and Caribou Creek. The latter locality, however, has the disadvantage 

of being a considerable distance from a market and a source of fuel. 

The former area might compare favorably with the Kings River area. 

A sample of shale collected between Kings River and Chickaloon at 

mile 71.5 yielded a satisfactory bloat in stationary-kiln tests by the 

Bureau of Mines (Rutledge, 1953).

A sample of shale of the Matanuska formation exposed near the 

north abutment of the Matanuska River bridge, near Palmer (see 

fig. 10) was collected and tested in a stationary kiln by the Bureau 

of Mines (Rutledge, 1953). The sample did not bloat satisfactorily.
56 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

CONCLUSIONS

Hie graywacke-free portion of the shale unit in the Kings Kiver 

area and unit F in the Sutton area appear to be the best sources of 

haydite raw material considered in this report. These units have 

relatively large accessible reserves and, if all the shale bloats as 

successfully as tests on samples indicate, a large tonnage of raw 

material is available. Both localities are favorably located with 

respect to year-round rail and truck transportation, source of fuel, 

and market.

In view of the limited exposures at each locality, additional 

methods of exploration, such as trenching^ drilling, or sampling are 

needed to determine the reserves of shale in the Kings River and 

Sutton areas suitable for the manufacture of haydite.
HAYDITE RAW MATERIAL (BLOATING ARGILLITE) NEAR LAWING,

ALASKA

By GEORGE PLAFKER

INTRODUCTION

The argillite described in this report is 2% miles north of Lawing

 along both The Alaska Railroad and the Seward-Anchorage highway (fig. 9). The area is 89 miles by rail from Anchorage and 25^ 

miles from Seward. In 1952 the writer collected a grab sample of the 

argillite exposed in a highway cut at this locality and submitted 

it to the U. S. Bureau of Mines for a bloating test. On the strength 

of promising results from the initial test, the area was revisited in 

1953 for 1 day and the argillite exposed in road cuts for a distance^

 of 1,800 feet north of the outlet of Lower Trail Lake was mapped 

and systematically sampled. 

The U. S. Bureau of Public Roads made available a highway line-

 change map (scale 1:1,200) which was used as a base for this work.

GEOLOGY

GENERAL DESCRIPTION

The argillite sampled near Lawing is part of a thick series of 

slightly metamorphosed clastic sedimentary rocks of probable Mesozoic age that underlies a large part of the Kenai Mountains. Bedrock in the Lawing area consists almost entirely of well-indurated

 dark gray to black thinly bedded argillite and slate interfingering in 

varying proportions with lenticular beds of fine- to medium-grained 

liard massive graywacke. Interstratified with the argillaceous beds 

&nd graywacke, but in very minor amounts, are lenticular bodies of 

conglomerate less than 10 feet thick. In a few places the argillaceous 

beds and graywacke are cut by veinlets and irregular masses of 

quartz.

In general, structures in the area are characterized by closely 

appressed isoclinal folds which strike approximately north, and are, 

in part, overturned to the west. Everywhere, jointing is well developed in the graywacke, and an imperfect cleavage is present in the 

fine-grained rock. Although local deviations are numerous, cleavage 

as a rule is parallel to the bedding.

57
58 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

All low-lying parts of the Kenai Peninsula were glaciated during 

the Pleistocene epoch. Unconsolidated deposits of glacial and postglacial age are found overlying bedrock throughout the area.

LAWING ARGILLITE DEPOSIT

Lithologic characteristics. The argillite mapped on figure 11 is a 

hard black fine-grained rock with a smooth silky sheen on fresh 

surfaces. The rock breaks along bedding planes into thin slabs with 

irregular sharp edges. No mappable beds of sandstone or other impurities were found in the deposit.

In thin sections the rocks are seen to consist of approximately 25-50 

percent silt-sized particles less than 1 mm in diameter, embedded in 

a very fine grained dark-colored matrix. Clear angular fragments of 

quartz and plagioclase feldspar predominate, with subordinate 

amounts of detrital muscovite flakes. The flakes of mica generally 

lie parallel to the bedding and, in combination with chlorite, give the 

rock its characteristic platy parting. Sections cut normal to the 

stratification show an aggregate positive elongation due to parallelism of the mica flakes. A very finely laminated structure is caused 

by streaks and minute lenticles of carbonaceous material and magnetite, which clouds and masks the fine-grained matrix minerals.

The matrix consists largely of clay-sized particles predominantly 

of a colorless flaky mineral with very low birefringence and relatively 

high refractive index (£=1.58). The X-ray diffraction pattern indicates that the clay-sized minerals are predominantly chlorite with 

subordinate amounts of illite. This probably represents incipient 

recrystallization to chlorite of original clay minerals, due to low-grade 

regional metamorphism.

Accessory minerals are abundant magnetite and scant epidote, garnet, tourmaline, carbonate, zircon, and sphene. Iron sulfides are conspicuously absent.

Structure. Both the bedding and cleavage in the argillite deposit 

strike uniformly north to N. 15° E. and dip about 55° E. to southeast. 

The road cuts of the Seward-Anchorage highway are excavated 

essentially along bedding planes in the argillite. A single fault 

trending N. 45° W., and dipping 43° SW. cuts the argillite. It is 

filled with 2-3 inches of quartz. Thin quartz stringers less than 1 

inch thick occur in 1 area (fig. 11) as a swarm of conjugate sets trending N. 60° W. and N. 80° W., and dipping 60° NE. and 33° S., 

respectively.

Unconsolidated deposits. Steep slopes in the vicinity of the deposit 

are mantled by a veneer of loose argillite slide rock. Most of the 

material along The Alaska Railroad is fill derived from outside the 

mapped area.
HATDITE RAW MATEBIAL, KINGS EIVEI^ &U3TONV

EXPLANATION

Loose talus and fill

Argillite 

Darkerpatternindicatestaeatkeredrock

Area covered by vegetation 

Probably underlain by argillite

Contact 

Dotted- where concealed

Fault, showing dip

Strike and dip of beds 

May be overturned

Sampled locality

Zone of closely spaced Intersecting 

quartz stringers less tha'n 1 In. 

thick trending, N.60*W, dipping 

60'NE, and trending N.SO'W, 

dipping 35'S6.

Water-surface elevation 468.4 ft 

(July 1.1950)

100 0 100 200

Contour interval 20 feet 

Datum is mean sea level

300 Feet "i

Geology by George PJa.fker 

July 1953

Base map from U. S. Bureau of Public Roads 

line-change plan, project A-2, B-3. 

Contours sketched from elevations 

on slope stakes

FIGURE 11. Geologic map of argillite deposit near Lawing.
 60 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

BLOATING CHARACTERISTICS

Twelve samples of argillite were taken at the localities shown on 

figure 11. These were paired to give a total of six samples that were 

submitted to the U. S. Bureau of Mines Electrotechnical Laboratory 

at Norris, Tenn., for bloating tests. The absorption and weight for

 each of the paired samples at regular temperature intervals in the 

bloating range are tabulated in table 6; averages of these figures for 

the six samples are shown graphically as figure 12.

The tests were made in a stationary Mln using a fast fire (15-minute 

bloat). Because only small samples were available, the tabulated 

weight figures were obtained by using the water displacement method 

to obtain apparent specific gravity. These weight figures are approximately 15 pounds per cubic foot higher than would be obtained by the 

usual commercial container method described by the American Society 

for Testing Materials (1955, p. 1241-1242). The estimated average 

weights that would be obtained in the bloating range by using the

 container method are also shown graphically in figure 12.

TABLE 6. Water absorption and weight of six argillite samples 

[Symbols: O, coarse (ty-l in); F, fine (4 mesh-^ ln)J

Temperature <°F)

Sample

AB

0 F

IJ

0 F

CH

0 F

FQ

O F

DE

O F

KL

O F

Water absorption (Ibs per en ft of argillite)

2,000 ________ _

^,100..__. ________

2,200___ __________

2,300__,__________

2,400 ___ __ ____

4

7

10

13

14

5

8

12

13

17

3

7

11

18

26

3

7

10

23

27

4

7

17

32

31

3

8

1?,

23

27

3

7

13

26

36

4

6

14

24

45

3

6

9

11

24

4

6

9

11

23

3

6

12

16

19

3

7

11

12

19

Weight of argillite (Ibs per cu ft)

2,000___-_________

2,100 ___ _____

2,200 __ _________

2,300__________.__

2,400 __ ____ _

160

133

56

32

25

160

133

66

37

30

159

125

49

21

21

157

127

51

29

24

159

127

44

25

27

142

119

55

27

28

159

125

59

24

25

158

123

56

25

19

160

133

45

36

28

155

120

44

24

26

158

129

62

25

23

160

129

59

30

27

The six samples tested showed little or 110 differences in bloating 

properties. The change in particle shape through the bloating rang© 

for a typical sample is shown as plate 10. The samples reach the 

60-pound, or floating, stage at a temperature ranging from 2,1T5°F 

to 2,2000F. At 2,000°F the particle surface has a dull light-brown-
140

120

100

80

40

Desirable w

All under

^

eight level

will float

Ssa. -

x

\

^

. 

\W-Measu

-\-Est

\

\

\

.. --

ft

 4 

4

»

red weight ob

mated weigM

V

^

, "

AR

me

me

h in

tain

th

^

1900 2100 2200 

TEMPERATURE, IN DEGREES FAHRENHE

12, Average water absorption and weight of six arg
^62 INVESTIGATIONS OF CONSTRUCTION MATERIALS IN ALASKA

ish-orange glazed surface harder than, steel and a soft dark-gray

interior with a dull luster. Thin sections show that the average

: grain size is smaller than in the natural material, and that there is

 some glass formed in the outer 0.6 mm. Magnetite near the surface 

has been oxidized to blood-red hematite. The interior of the grains 

appears to be essentially unchanged except that the muscovite has been 

destroyed. X-ray diffraction gives a pattern for quartz and plagioclase indicating that the matrix has changed to glass. 

At 2,100°F the particle surface is a glazed light brown. The

4 centers of the particles are hard and dark red, with a faint vitreous

-luster. Slight spreading of the bedding planes is noticeable in the 

; particles, and a few elongate holes are visible. In thin section the 

interior of the particle is seen to be shot through with long narrow 

openings as much as 0.1 mm wide that are parallel to bedding planes. 

The interior is almost entirely glass (refractive index=1.54r) except 

for the silt-sized quartz and plagioclase and a few scattered specks

-of magnetite.

By 2,200°F, the specimens have a moderate-brown outer surface 

with a medium-dark-gray interior. All of the material is now harder 

than steel. Thin sections show a definite cellular structure with dis-

% crete holes slightly elongated parallel to the bedding and as much 

as 3.5 mm in the longer dimension. X-ray diffraction patterns show 

that only quartz remains in a matrix of glass. In thin section the

*quartz grains have irregular margins due to reaction with the glass 

matrix.

By 2,300°F, the particles assume a dusty moderate-brown cellular, 

and a brownish-gray interior. The material is now highly cellular, 

with thin vitreous brownish-gray glass membranes between the 

vesicles. A thin section shows that the glass is 'almost black and is

:still charged with quartz particles. The vesicle walls are now extremely thin, and many of them have been distended to the point of 

rupture, forming large aggregates of vesicles or small connections between the vesicles. At this point the strength of the particles begins 

to drop markedly and the water absorption increases correspondingly. 

The results of the bloating test were summarized by T. A. Kleinfelter (1954, written communication), Chief of the Kaw Materials 

Branch for the U. S. Bureau of Mines at Norris, Tenn., as follows:

With all of them the best all-round bloat occurs at 2,300° F. By 2,400°F, all 

of them had reached the over-bloated stage, and would probably cause trouble 

in the kiln by sticking and thus forming rings and ball-like masses in the kiln. 

On the whole this gives us a bloating or firing range of not over 150° F for good 

operating conditions, which is a bit on the narrow side.

However, with a well-controlled kiln, and especially if the firing procedure 

In the length of time the material is subjected to the top heats is worked out
HATDTTE HAW MATERIAL, KINGS RIVER, SUTTON, LAWESTG 63

properly a good first class product should result The material from 2,200° 

through 2,300° F is quite good, shows no signs of stickiness and has good 

^strength.

RESERVES

The lack of adequate topographic and geologic control uphill from 

the road-cut exposures described in table 1 makes impossible anything but a general statement on the amount of argillite in the area. 

Relatively pure argillite with less than 1 percent quartz as thin 

stringers makes up all of the deposit shown on figure 11. This section represents a stratigraphic interval of 375 feet (assuming a constant 55° dip), and is exposed along the strike for 1,750 feet and for 

«, vertical distance of more than 100 feet. The uniform character 

of the argillite indicates that similar material may also be present 

;uphill from the road cuts. This material could be readily sampled 

from shallow pits dug to bedrock or by means of low-angle core holes 

drilled into the hillside from the highway or from the abandoned 

road above the highway.

REFERENCES CITED

American Society for Testing Materials, Book of ASTM Standards, 1950, pt

3: Philadelphia, Pa. 

American Society for Testing Materials, Book of ASTM Standards, 1955, pt 3:

Philadelphia, Pa. 

Austin, C. R., Nunes, J. L., and Sullivan, J. D., 1942, Basic factors involved in

bloating clays: Am. Inst Mining Metall. Engineers Tech. Pub. 1486. 

<3apps, S. B., 1927, Geology of the upper Matanuska Valley, Alaska: U. S. Geol.

Survey Bull. 791. 

 1940, Geology of The Alaska Railroad region: U. S. Geol. Survey Bull.

907. 

Conley, J. B., Wilson, Hewitt, Klinefelter, T. A., and others, 1948, Production

of lightweight concrete aggregates from clays, shales, slates, and other

materials: U. S. Bur. Mines Bept Inv. 4401. 

Grim, B. E., and Bradley, W. P., 1940, Investigation of the effect of heat on

clay minerals illite and montmorillonite: Illinois State Geol. Survey Rept

Inv. 66. 

Martin, G. C., 1906, A reconnaissance of the Matanuska coal field, Alaska, in

1905: U. S. Geol. Survey Bull. 289. 

Martin, G. C., and Katz., P. J., 1912, Geology and coal fields of the lower

Matanuska Valley, Alaska: U. S. Geol. Survey Bull. 500. 

Mendenhall, W. C., 1900, A reconnaissance from Resurrection Bay to the Tanana

River, Alaska, in 1898: U. S. Geol. Survey 20th Ann. Rept., pt. 7, p. 265-340. 

Riley, C. M., 1951, Relation of chemical properties to the bloating of clays: Am.

Ceramic Soc. Jour., v. 34, no. 4. 

Rutledge, F. A., and others, 1953, Nonmetallie deposits accessible to The Alaska

Railroad as possible sources of raw materials for the construction industry:

U. S. Bur. Mines Rept. Inv. 4932.

U. S. Housing and Home Finance Agency, 1949, Lightweight aggregate concretes : Washington, U. S. Government Printing Office.

INDEX

Page

Aggregate, lightweight, properties desired- 45-46 

Alaska Railroad, The _ _ _ 37,57 

Amphibole___________________ 41 

Andesite.. 41

Apatite-__________________ 41,44 

Argffllte, bloating tests_____.______ 60-63 

deposit near Lawing, lithologic character.. 58 

reserves 63 

water absorption and weight . .. 60 

X-ray diffraction pattern................. fig, 62

Basalt lava.... - . . .. ..... 41

Bauer, W. G., quoted..__ __.__.__ 49

Biotite ______________._ 41,52

Bloating, causes 51^52

conditions 49-50

tests, argillite _.__.___._...... 60-63

operating conditions ..... 48

procedure--... . .... .. 46-49,60

results______......____ 47,49,60,6*

 Caleite. _____..__.__._._ 41,42,43,50,52 

Canerinite _____.__ __.__.__ 52 

Ohert_______________________ 44

 Chlorite-____.____.____-_.. 41,44,50,58 

Climate_______-___-__-_____ 38

 Clinozoteite........._.____._____._ 41,44

 Coal..________________-____. 53

 Conclusions.__._.......... __.__ 56

Dolomite_-_ __ - _ 50

Epidote ____-__-___ 41,50,58

Taulting. .____-_-________ 38,42,45 

Peldspar---_..._...._.-__. .. 41,44,50,58

Garnet_ ____......._..._____ 58

Geography. 35,37-38 

Glaciation, effects. . 45,58

Haydite, denned___.___________ 33-34

raw materials, chemical analysis..--___ 50,51

properties desired 52-53

reserves 54-55,63

screen analysis 48

specifications . 48

use . . . 34

Hematite......______..._..._....._ 50,62

Highways _-__-_.__ 37,57

mite..._._____.____...___ 40,50,51,52 

Inoceramus................................... 40

Page

Introduction.._.. 33-34,57

Investigation, present 37,57

previous 35,37

Joints. . - 42,43,57

Kleinfelter, T. A., quoted__... . 62-63 

I/eueite.._ _.... 52

Magnetite.__ - - 68,62 

Matanuska formation, Hicks Creek-Caribou

Creek 55

Kings River area 40-42

Kings River-Chickaloon 55

structure-._ . 42,44-45

Button area. - 43-45

thickness-_.__ ~ - 38

Matanuska River valley, location... 37

Marcasite-_______-_____-__ 41,50,52

Mica._____________...._._ 41,44,50,58

Microcline_... 41

Mining claims_... - 55

Mullite...____________.___ 51

Muscovite._____________-__~ 41,58,62

Opal. ... 

Orthoclase.

41,50

41

Perthite_____________ .. 41 

Plagioclase 41,58,62

Pumice, mining history 34 

Pyrite... ..... .... .... ... ..... 41,50,52

Pyroxene_____-_.... 41

Quartz ......__ 41,44,50,57,58,62,63

Riley, C. M., quoted . . 49

Seriette__... . 41 

Slickensides.._... 42 

Sphene._____... 58 

Spinel. .__ . . - - 51 

Surfieial deposits. See Unconsolidated deTourmaline___.... 58

Unconsolidated deposits. 45,58 

Vegetation______ ________-__- 38

Zircon.. 

Zoislte.

65