<<

THE OF A PART OF THE SOUTHERN

WASATOH MOUNTAINS,

DISSERTATION

Presented in. Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University

By

RAYMOND EARL METTER, B.S., M.S

%***

The Ohio State University 1955

Approved byt

Department of Geology CONTENTS E£g£ INTRODUCTION...... 1 Location and accessibility...... *.1 Physical features. •»...... 5 Climate...... 14 Vegetation...... 16 Previous investigations...... ••...... •.••17 Field work and mapping...... »24 Acknowledgements...... 25

STRATIGRAPHY ...... 27 General statement...... 27 Pre- (?) rocks...... 29 Distribution and nomenclature...... 29 Lithology...... 50 Thickness...... *52 Age and correlation ...... 52 Cambrian system...... 54 Tintic quartzite., ...... *36 Definition and distribution...... 56 Lithology...... 57 Thickness* .... .53 Stratigraphic relations...... Age and correlation...... 59 Ophir formation...... *59 Definition and distribution..59 Lithology...... 41 Thickness...... 42 Stratigraphic relations...... 42 Age and correlation...... 45 Teutonic limestone...... 44 Definition and di stribution...... *>.44 Lithology...... 45 Thickness...... 45 Stratigraphic relations...... 46 Age and correlation...... 46 Dagmar lime stone ...... *50 Definition and distribution...... 5® Lithology ...... *50 Thickness*...... *50 Stratigraphic relations and correlation...... ,51 Herkimer limestone...... 51 Definition and distribution... ..51 Lithology...... *52 Thickness...... 55 Stratigraphic relations ...... 55 Age and correlation...... •..55

ii iii

Bluebird dolomite...... 5^ Definition and distribution...... 5^ Lithology...... »55 Stratigraphic relations...... • • »55 Age and correlation...... ••5'? Oole dolomite...... »5^ Definition and distribution...... 5^ Lithology...... *5^ Thickness...... 57 Stratigraphic relations...... »57 Age and correlation...... *57 Opex dolomite...... 5® Definition and di stribution...... 5® Lithology...... 59 Thickness...... 59 Stratigraphic relations,...... 59 Age and correlation...... 60 Misoissippian system...... 61 Madison limestone...... 65 Definition and distribution...... 65 Lithology...... 65 Thickness...... 68 Stratigraphic relations...... 68 Age and correlation...... 69 Deseret limestone...... 71 Def inition and di stribution, ...... 71 Lithology..... *...... 71 Thickness* .... .72 Stratigraphic relations...... ,...... 75 Age and correlation...... 75 Humbug formation...... 7^ Definition and distribution...... 74 Lithology...... 75 Thickness...... 76 Stratigraphic relations...... 77 Age and correlation...... 77 Great Blue 1 ime stone...... 7® Definition and di stribution...... 78 Lithology...... *78 Thickness...... 80 Stratigraphic relations...... 80 Age and correlation...... 81 and Pennsylvanian systems...... 82 Manning Canyon shale...... 82 Definition and distribution...... 82 Lithology...... 82 Thickness...... 84 Stratigraphic relations...... 84 Age and correlation...... 85 iv

Pennsylvanian and systems...... 86 Oquirrh formation...... *86 Definition and distribution...... 86 Lithology ...... 87 Thickness...... »90 Stratigraphic relations ..... *90 Age and correlation ...... 91 Permian system...... 95 Kirkman limestone...... <95 Definition and distribution...... 95 Lithology...... 96 Thickness...... 97 Stratigraphic relations...... 98 Age and correlation...... 98 Diamond Creek sandstone...... 99 Definition and distribution...... 99 Lithology...... 102 Thickness ...... 102 Stratigraphic relatione...... 102 Age and correlation...... 105 Park City formation...... 105 Definition and distribution...... 105 Lithology...... 104 Thickness...... • .106 Stratigraphic relatione ..107 Age and correlation...... 107 Unconformity between the Permian and systems...108 Triassic system...... 110 Woodside shale...... 110 Thaynes formation ...... 111 Definition and distribution...... Ill Lithology...... Ill Thickness...... 112 Stratigraphic relations...... 115 Age and correlation...... 115 Ankareh formation...... *115 Definition and distribution...... 115 Lithology...... *115 Stratigraphic relations...... 116 Age and correlation...... 116 system...... 117 Nugget sandstone...... 117 Definition and distribution...... 117 Lithology...... 118 Thickness...... 119 Stratigraphic relations ...... 119 Age and correlation...... 120 V

Twin Creek formation...... 120 Definition and distribution...... 120 Lithology...... 121 Thickness ...... 122 Stratigraphic relations...... 122 Age and correlation...... 125 and Tertiary systems...... 127 General Statement ..... 127 ...... 128 Definition and distribution...... 128 Lithology...... • 129 Thickness...... 151 Stratigraphic relations...... 151 Age and correlation...... 151 Flagstaff formation ..... 152 Definition and distribution...... 152 Lithology...... 155 Thickness...... 155 Stratigraphic relations...... 155 Age and correlation, ...... 156 Colton formation,..., ...... 157 Definition and distribution...... 157 Lithology...... 158 Thickness...... 159 Stratigraphic relations...... 159 Age and correlation...... ,140 Crab Creek formation...... 140 Definition and distribution...... ,.l40 Lithology...... l4l Thickness...... 142 Stratigraphic relations...... 142 Age and correlation...... 142 Early Tertiary fan gravel ...... 145 Pyroclastic rocks...... 144 Definition and di stribution....»...... 144 Lithology...... 145 Thickness...... 147 Stratigraphic relations...... 148 Age and correlation...,...... 148 Tertiary (?) and Pleistocene terrace gravels..... 149 Quaternary system...... 154 Le,ke Bonneville and associated deposits...... 154 Glacial deposits...... 155 Distribution...... 155 Age and correlation...... 156 Alluvial fans...... 156 Older fanB...... 156 Younger fans...... 157 vi

Landslides...... 157 Quaternary alluvium...... **159

IGNEOUS ROOKS...... 160 Archean crystalline complex...... 160 Diabase body in the Tintic quartzite...... 161 Dikes...... 165

STRUCTURE...... 165 General featur ...... 165 Folds...... 166 Southern Wasatch Mountain anticline...... 166 Folds in the Crab Creek-Pole Canyon area...... 167 General features...... 167 Pole Canyon syncline...... 168 Shurtz Canyon anticline ...... 168 Minor folding in incompetent beds...... 169 Loafer Canyon anticline ...... 170 Folding in the northern Cedar Hills...... 171 Faults...... 172 Thrust faults...... 172 General statement ...... 172 Santaquin overthrust...... 175 Dry Mountain thrust...... 182 Bear Canyon thrust...... 185 Normal faults...... 185 General statement ...... 185 block at Santaquin Canyon...... 185 Faults north of crystalline complex...... 185 Rock Canyon area...... 186 Thi stl e Canyon fault ...... 187 Faulting near Hyle Hollow...... 187 Northern Cedar Hills...... 188 Wasatch frontal fault...... 189 Transverse faults on Dry Mountain...... 191 Normal faults on Loafer Mountain...... 191 Tear faults...... 191 Crab Creek-Pole Canyon area...... 191 .Faulting near Picayune Canyon...... 192 Chronology of crustal disturbances...... 195

GEOLOGIC HISTORY...... 200

ECONOMIC GEOLOGY...... 207 General statement...... 207 Nonmetallic deposits...... 207 Sand and gravel .... 207 Crushed and broken stone...... 208 vii

Metallic deposits...... 208 Future possibilities...... 210

REFERENCES CITED...... 211

APPENDIX...... 216 Measured sections...... 216 Section 1: Tintic quartzite, proterozoic (?) beds.217 Section 2: Ophir formation...... 218 Section 5 5 Teutonic limestone through Great Slue formation...... 219 Section 4: Part of Oquirrh formation...... 229 Section 5i Part of Oquirrh formation...... 251 Section 6s Part of Oquirrh formation ...... 254- Section 7: Kirkman limestone, uppermost Oquirrh formation...... 256 Section 8: Park City formation...... 257 Section 9 1 Twin Creek formation, ...... 259 Section lQi Flagstaff formation...... 24l Section 11s Flagstaff formation ...... 242 viil ILLUSTRATIONS

Page

FIGURE 1. Index map of central Utah...... *...... •2

2. Location map of southern Wasatch Mountains and environs...... •...... ••....•..••••.•..•>6

5. Cambrian sections of Tintic district, Long Ridge, and Dry Mountain. .... 55

4. Portions of the Paleozoic sections in the central and southern Wasatch Mountains ...... ,62

5. Generalized section of the Oquirrh formation...... 92

6. Triassic correlation chart...... 109

TABLE I. Generalized stratigraphy of Dry Mountain- Loafer Mountain area...... 28

PLATE 1. Panorama of north end of southern Wasatch Mountains.•.10

2, A. Loafer Mountain...... 11 Bo South end of Utah ...... 11

5. A. Topography in upper Payson Canyon...... 12 B. West side of Dry Mountain...... 12

4. A, Southeast limb of Shurtz Canyon anticline...... 15 B. Ridge tops seen from summit of Loafer Mountain....15

5. A. Teutonic limestone in Santaquin Canyon,...... 47 B. Bluebird-type bed in the Cole Canyon dolomite.....47

6. A, Dagmar-type bed in the Cole Canyon dolomite...... 48 B. Alternating light and dark beds of the Cole Canyon dolomite*...... •..48

7. A. Cole Canyon dolomite...... 49 B. Thin-bedded Madison limestone...... 49

8. A. Chert and limestone bed near top of the Madison limestone ...... 65 B. Close view of bedded chert and limestone in upper Madison bed...... 65 ix PLATE !?• A. Typical chert lenses in Madison limestone...... 66 B. Silicified horn corals on bedding surface near top of Deseret limestone...... 66

10. A. Triplophyllites in the upper Madison limestone,...67 B. Kirkman limestone...... 67

11. A. Slope of Diamond Greek sandstone on east side of Loafer Mountain...... 100 B. Outcrop of Diamond Greek sandstone in Grab Greek Canyon.*..... 100

12. A. Permian strata on the east Bide of Loafer Mountain...... 101 B« Hogback of Nugget sandstone and overlying Twin Creek limestone in Thistle. .101

15, A. Even-bedded limestones and shales in the Twin Creek formation ...... 124 B. Gently-dipping Flagstaff limestone At Tinney Flat...... 124

14. A. Flagstaff, Colton, and pyroclasties in angular unconformity over and against Paleozoic rocks at Tinney Flat...... 125 B. Conglomerate in Flagstaff limestone in Frank Young Canyon...... 125

15. A. Flagstaff and North Horn formations in angular unconformity over Nugget sandstone...... ,126 B. Algal ball limestone typical of the Flagstaff formation...... 126

16. A. Scarp formed by basal conglomerate in Colton formation...... •••• 150 B. "Salt Creek formation" on east 3ide of U.S. Route 89 at Birdseye...... 150

17* A. Pyroclastic conglomerates weBt of U.S. Route 89 south of Crab Creek,...... 151 5. Fyroclastics...... 151

18, A. Loop moraine at head of Left Fork of Maple Canyon. • .152 B. Loop moraine at head of Left Fork of Loafer Canyon...... 152

19. A. Moraine at head of Left Fork of Ceab Creek...... 155 B. Terraces north of Birdseye...... ••155 X

PLATE 20. A. Santaquin Oanyon...... 175 B. Contorted beds of Oquirrh formation on south­ west side of Santaquin Oanyon...... 175

21. View east toward Rock Oanyon and the western ridges of Loafer Mountain...... 176

22. View southeast toward western portion of Loafer Mountain. .... *177

25. A. Normal fault parallel to along northwest side of Loafer Mountain...... 178 Bo Front of thrust in Bear Oanyon...... 178

24. A. Normal fault in cut northeast of Dream Mine, south of Salem...... 179 B. Closer view of fault shown above...... *179

25. A. Prominent triangular facets on northern slope of Loafer Mountain..... 180 B. Ridge of Diamond Creek sandstone on north side of fault on east side of Snell Oanyon...... 180

26. A. View down Thistle Creek toward down-faulted beds of pyroclastics, Oolton, and Flagstaff south of Crab Greek...... 181 B. Closer view of downthrown Flagstaff and Colton beds shown above...... *181

27. Geologic map of part of the southern Wasatch Mountains. .in pocket

28. Structure sections. ..in pocket THE GEOLOGY OF A PART OF THE SOUTHERN WASATCH MOUNTAINS, UTAH

INTRODUCTION

This paper is a report of an investigation of the general geol­

ogic features of the northern portion of the southern Wasatch Moun­

tains in central Utah. The investigation was cafried out by the

writer while enrolled as a student at The Ohio State University and

was undertaken as a research project suggested by his advisor.

The study is a contribution to the regional knowledge of central

Utah in that it has resulted in (l) the completion of the initial

geologic mapping of the southern Wasatch Flange, (2) the differenti­

ation and mapping of individual stratigraphic units in an area wherein more generalized separations had been used, (J) the discovery of addi­ tional evidence of thrust faulting in the southern Wasatch Mountains, and (4) the presentation of further evidence as to the sequence of erustal disturbances in this area.

Although the main structural and stratigraphic features are out­ lined, the paper is only an advanced reconnaissance report on some of the area studied.

Location and Accessibility

The area of thiB report lies in the southern part of Utah , about 50 miles south of , and entirely within the region bounded by parallels 59°54* and 40°05' North Latitude, and meridians lll°50l and lll^O* West Longitude. Geological Survey topographic sheets showing parts of this area include the Spanish -2-

Q. Salt Lakey •alt Lake City

Park City*

Heber Stockton Lehi Obhir • £ Mprcur «

5 Fairfield Provo Utah fcSpringville Spanish Fork ial"Pay bo; ial"Pay Spring Lake \ Thistle cka ^ -s' Tint:w X vST Sant® irdseye loldier \Summit Colton

Price Soroni

lelta

Salina

■ichfield

Figure 1. Index map of central Utah including area of this report (shaded). -5-

Fork and Spanish Fork Peak 7§-minute sheets and the Santaquin and

Santaquin Peak l^-minute quadrangles.

More specifically, the area is bounded on the east by Thistle and Spanish Fork Creeks, on the north and west by the approximate boundary of Lake Bonneville sediments along the foot of the Wasatch

Mountains, on the Bouthwest by Santaquin Canyon, and on the south by the southern boundary of Township 10 South. The communities of Birds­ eye, Thistle, Spanish Fork, Salem, Payson, and Santaquin lie within or near the area, in counterclockwise order starting at the southeast

(see fig. 1).

The margin of the area on the east, north, and west is paralleled by excellent highways. U.S. Highway 89 lies just east of Thistle

Creek and Spanish Fork Creek, serving also as U.S. Routes 6 and ^0 from the town of Thistle northward through Spanish Fork Canyon. Routes

89 and 5° co: \tinue northward to Salt Lake City, but Route 6 swings westward to tv? town of Spanish Fork, where it joins U.S. Route 9'L to proceed in a general southweatward direction through the towns of

Salem, Payson, and Santaquin, roughly paralleling the mountain front.

Route 91 continues south and west through Nephi and Cedar City,, Utah, and Las Vegas, Nevada, serving as the main route from southern Cali­ fornia to Salt Lake City, while Route 6 turns westward to Eureka in the Tintic mining district. A good black-topped road extends east and west from near the junotion of Routes 6 and 89 past the Spanish

Fork power house to join Route 91 north of Salem.

The above roads lie iuBt outside the mapped area. Within the -4- area there is one major road— the Nebo Loop road— which runs in a general north-south direction from Payson to Salt Greek Oanyon, east of Nephi. This road is black-topped for 7 miles south of Payson and graded for the rest of its extent, and is open and UBable except during the winter and early spring and during rainy weather. There is a fairly good graded road up Santaquin Oanyon to Tinney Plat, and poorer roads extend part way up Loafer Oanyon and Benny Creek Oanyon.

Several poor roads connect cultivated fields and ranch buildings on the flats east of Loafer Mountain. Foot trails and other secondary roads are shown on the map accompanying this report.

The mainl line of the Denver and Rio Grande Western Railroad enters Thistle from the east and turns northward down Spanish Fork.

The Marysville branch line of that system parallels Thistle Creek southward.

Much of the area is rather rugged and can be visited only on foot or on horseback. Although no point is more than 5 miles by map dis­ tance from a road of some sort, some places require 5 o r 6 hours of - walking time to be reached. The top of Loafer Mountain iB most easily reached by the trail north from the vicinity of the crossroads north of the Payson reservoirs and less readily by the trail up Crab Creek or by the trail up Loafer Canyon. The ridge along Dry Mountain is most accessible on the south where a truck or jeep road extends north from Santaquin Canyon to beyond Santaquin Meadows on the east side of the mountain. Another good route to the top of Dry Mountain lies just east of Santaquin, up the jeep road and along the trail north of the -5- old Syndicate mine.

Physical Features

The area of this report occupies the transition zone wherein sections of the and the Basin and Range provinces are separated by a relatively narrow ridge of the southern Wasatch

MountainB— the westernmost range of the Middle- Rocky Mountain province

(Woolley, plate 1). Two major mountains dominate the area. In the north is Loafer Mountain, a large, round-topped mass with high subor­ dinate ridges extending northward and westward, while to the west is a high, eastward-dipping ridge called Dry Mountain— elongate in a north-south direction and rising southward to a series of minor peaks, terminating at a steep-walled chasm called Santaquin Canyon. Beyond

Santaquin Canyon the continues about 10 miles, termin­ ating just south of the imposing crags of Mount Nebo. (See figure 2.)

The two mountains rise steeply above the southeastern end of Utah

Valley— a broad, north-south trough important agriculturally and occu­ pied by a number of cities, the largedb of which is Provo. (See plate

2.) Leke Bonneville terraces lap against the mountains around the perimeter of Utah Valley, with the highest terraces at elevations between 5,100 and 5*200 feet. Loafer Mountain has twin peaks of

10,685 and 10,687 feet, and the highest peak on Dry Mountain has an elevation of 9,867 feet, A large alluvial fan slants away from the northwestern slope of Loafer Mountain, formed by the coalescence of several smaller fans lying at the foot of the central mass of the mountain, directly down from the summit. Along the southwestern -6-

Utah Lake

XpJ raison ^A|''Tithinq =T 'y 'JAaWb floflies Mipplec £ VSj£

s

s:

Plateau

Scale

Figure 2. Index map of southern Wasatch Mountains and environs, showing features frequently mentioned in this report. -7- flank of Dry Mountain there iB another large fan that has an apex at the mouth of Santaquin Oanyon, at the south end of the mountain. (See plate

A series of lower hills and ridges extends northward from Dry

Mountain, including an unforested knob known as Mollies Nipple (eleva­ tion, 6277 feet), separated from Tithing Mountain (eldvation, 57^1 feet) to the east by the narrow lower course of Payson Oanyon. The hills taper to a single, long sloping ridge, half a mile wide and over

2~|- miles long, once a Lake Bonneville spit, but now underlying part of the town of Payson.

The upper broad heavily-wooded valley of Payson Oanyon separates

Loafer and Dry Mountains and rises southward with hummocky topography to a relatively undissected portion of the section of the Colorado

Plateau province called by Woolley the Moroni Upland, but generally known as the Cedar Hills, which here laps against the eastern flank of Dry Mountain and the southern slopes of Loafer Mountain at eleva­ tions of 7,500 to 8,200 feet. (See plate ) This area is under­ lain by gently-dipping Tertiary rocks lying in angular unconformity over steeply dipping Carboniferous strata. The surface material, in large part, consists of pyroclastic debris.

The tableland terminates on the east at an erosional scarp, a few hundred feet high and approximately in line with the eastern slope of

Loafer Mountain. From the foot of the scarp the surface descends over alluvial fans, pediments, gulches, and terraces to Thistle Creek, which flows in a general northward direction— in this area at eleva­ -8- tions of 5,500 to 5»200 foot. A similar hummocky topography is pres­

ent east of Loafer Mountain, but a series of prominent terraces is also quite notable here.

Immediately to the north and just west of the town of Thistle, a prominent east-dipping hogback of Jurassic sandstone and limestone is overlain in angular unconformity by Tertiary red clays, conglom­ erates and limestones, which dip westward toward the foot of Loafer

Mountain.

Thistle Creek joins the west-flowing Soldier Pork at Thistle to become Spanish Fork, which proceeds through a steep-walled canyon in the Jurassic hogback to flow northwestward for over 2 miles through a broad, red-soiled valley underlain by Triassic rocks to the east aad

Tertiary to the west. Beyond this wider valley Spanish Fork cuts through the Wasatch Range via a narrow, high-walled valley with brush- covered slopes and one major flat-bottomed side Canyon (Pole Canyon) extending toward the summit of Loafer Mountain. It emerges at the southeast corner of Utah Valley in a re-entrant marked by prominent terraces and a large delta of the Pleistocene Lake Bonneville.

Four major perennial streams originate in the area. Crab Creek and Benny Creek flow eastward into Thistle Creek; Crab Creek origi­ nates on the eastern slope of Loafer Mountain, and Benny Creek on the southern slope. Payson and Santaquin Creeks flow northward and north­ westward, respectively, supplied largely by water from the areas over- lain by Tertiary rocke, east of Dry Mountain. The stream in Shurtz

Canyon, two miles northwest of Thistle, also flows most of the time.

Three of the largest and deepest on Loafer Mountain— Maple and Loafer Canyons on the northwest, and Pole Canyon on the north­ east— have only intermittent streams. A spring in Picayune Canyon, at the north end of Dry Mountain, flows with sufficient volume to supply a reservoir tank used by the nearby community of Spring Lake. Panorama of north end of southern Wasatch Mountains, looking south from road in Utah Valley west of Spanish Pork. Loafer Mountain in center,

Dry Mountain at extreme right. Canyons are, from left to right, 1. Spanish Plato 1 Fork, 3. Flat Canyon, 3. Water Canyon, 4. Maple Canyon, 5. Broad Hollow, 6. Loafer Canyon, 7. Bear Canyon, 8. Payson Canyon -11 Plate 2

A* Loafer Mountain, viewed from valley of Diamond Fork, looking southwest.

B. South end of Utah Valley seen from slopes of Loafer Mountain. Looking down Loafer Oanyon a little east of north, toward the central Wasatch Mountains. - 1 2 - Plat© 5

A. Heavily wooded hummocky topography in upper Payson Oanyon, Looking south, with Dry Mountain to right.

B. Relatively arid west side of Dry Mountain, Paleozoic carbonate rocks at top of ridge, pre-Oambrian crystallines at base. Note triangular facets and large alluvial fan which is covered by clumps of sorub oaks. -15- Plate 4

A. Southeast limb of Shurtz Oanyonantic1ine. Beds of Diamond Greek sandstone dip to the left. Pacing southwest. The slopes here are covered by scrub oaks and maples; the valley contains abundant sagebrush.

B. Ridge tops as seen from summit of Loafer Mountain. Looking northeast; Utah Valley to left. -14-

Olimate

Woolley (1946, pp. 50-5 6 ) has summarized the salient features

of the climate of Utah. Briefly reviewed, Utah lies in the temperate

zone and is generally semiarid, with two major sections separated by

the highlands of the Wasatch Mountains and Colorado Plateaus. Vari­

ations in altitude cause wide variations in precipitation and temper­ ature. In southern and eastern Utah, July and August are the wettest months of the year, but in northern and western parts of the state

June, July, and August are the driest months. Winter storms move across the state from southwest to northeast, but most summer precip­ itation originates in the Gulf of Mexico and falls during thunder­

storms, principally of the convective form. Cloudbursts are fairly common, occurring mainly in July and August, generally between noon and early evening.

Records for stations near the area of this report show that the normal annual precipitation is 18.4 inches at the Santaquin power house, 16.54 inches at Payson, 17*55 inches at the Spanish Fork power house, and 12.57 inches at Birdseye, in all cases fairly well distrib­ uted throughout the year, but averaging slightly less in the summer months. Records kept for the six years 1899-1904 showed an annual average of 10.7 inches of precipitation at Thistle (Richardson, p. 15)*

Normal average annual temperatures are 50° at the Santaquin power o house and 52 at the Spanish Fork power house. Temperatures seldom exceed 95°? in "the summer and only rarely fall as low as zero in the winter at these two stations. -15- No record© are available for points high on the mountains in this area, but it can readily be observed that the mountain tops receive much more precipitation than the lowland areaj peaks are often obscur­ ed by heavy showers while the sun shines on the surrounding valleyB.

An example of increase in precipitation with increasing elevation is shown by the records for an area 25 miles to the north, where stations at near Lehi, at the Lower power house, and at Timpanagos Cave receive normal annual precipitation of 12.25,

16*75* anc* 21.45 inches, respectively (Climatological Data, Annual

Summary, 1955)*

Attempts to arrive at definite mathematical relationships between precipitation and altitude in Utah have so far proved unsuccessful

(Woolley, 1946, p. 59)» but Fox and Woolley (l959) empirically der­ ived a method of obtaining an "altitude coefficient" of summer thun­ dershower rainfall for two stations lying at different elevations in the path of a given thunderstorm. The relationship (expressed as

Isss a(l+- 0.2D), where b is the precipitation at the upper station, a the amount at the lower atation, and D the vertical separation of the two in thousands of feet) would imply that a thundershower passing over both the Spanish Fork power house and Loafer Mountain would release over twice as much rainfall on the summit of the mountain as at the power house.

An unusual feature is a strong, cool wind which emanates from

Spanish Fork Oanyon every evening, lasting until well after sunrise.

Trees as much as two miles away from the canyon mouth lean noticeably -16-

to the north, and absence of farm homes in the vicinity of the canyon

is attributed to the unpleasantness of the breeze, Davis (1905,

p. 18) commented upon this phenomenon, stating that "everything mov­

able was drifted away" during the evening he camped in this locality.

Records of snowfall are not complete, but mountain slopes are

reported to be covered with snow during the winter and early spring,

and snow banks usually last until late July in some of the sheltered

areas on the mountain peaks.

Vegetation

Natural vegetation in the area varies considerably, depending

upon differences in rainfall, elevation, and types of soil. Many

places are covered by dense forests, both coniferous and deciduous,

but otherB have typical semiarid aspects, A few areas, particularly

on the northeast flanks of Loafer Mountain, have thick growths of

ferns— some as much as 5 feet high. A few generalizations about the vegetation of the area as a whole are given below.

Lower valleys, terraces, and alluvial fans are characterized by

growths of sagebrush, grasses, and dense clumps of scrub oaks. Cotton­ woods and willows are present in small numbers along the perennial

streams.

Most lower ridges and slopes are covered by thick growths of

scrub oaks or scrub maples— almost impenetrable in ungrazed areas. At

slightly higher elevations junipers and grasses are also present and a few pinon pines grow on some of the ridges southwest of Thistle. A few slopes on the west side of Dry Mountain have small patches of

cactus. Higher ridges and slopes may support juniper, mountain mahogany, and pine, as well as thick entanglements of mountain laurel.

Valley heads and high ridges and flats are in many places covered

by thick growthB of quaking aspen— some choked with underbrush. A

few alpine meadows are present. Fir, pine, and spruce grow in groves

in high valley heads, on the flats, and on top of some of the highest

ridges. High, narrow ridges are generally free of shrubs and trees, and high mountain peeks are bare heaps of angular rock fragments.

(See plate 4,B.)

Previous Investigations

Many of the geological pioneers of the nineteenth century made passing reference to the southern Wasatch Mountains, in most cases merely mentioning Spanish Fork Oanyon or Mount Nebo as geographic ref­ erence points. Only those workers who have described geologic feat­ ures within the area of this report are included in the following list.

Silliman (I8 7 2 ) visited the mining districts near Spanish Fork and Mount Nebo, stating that the chief feature of all deposits of the

Wasatch Range is the occurrence of ores of lead, rich in silver.

Howell (1875, PP» 251-250) suggested that Mount Nebo was the western half of a north-south trending anticline. He also briefly described the rooks in Spanish Fork Oanyon and mentioned the Lake

Bonneville delta at the mouth of the canyon. From north to south in -18- the canyon he identified Carboniferous, Triassic, Jurassic, and

Tertiary beds, pointing out the unconformable relationship of the

Tertiary to the older rocks, and accompanying hie text with a cross- sectional sketch.

Gilbert (I89O.; 1893* P» 396) noted Lake Bonneville deltas at two levels at the mouth of Spanish Pork Canyon and observed a wide zone of faulting cutting through them. He also described details of Lake

Bonneville near-shore features along the western slopes of the Wasatch

Mountains to the south. In a later discussion of the Basin Ranges

Gilbert (1928) presented a sketch map of the entire Wasatch Range frontal scarp, extending it as far south as Mount Nebo.

S.F. Emmons (1693# P« 397) also briefly described the section of rockB through Spanish Fork Oanyon, noting "Upper Carboniferous" strata and beds "presumably of Triassic age." The massive, yellowish-white cross-bedded sandstone which he mentioned as being above the red

Triassic sandstones is evidently the Nugget sandstone, which is ex­ posed in a prominent hogback at Thistle.

Davis (1903# 1905) nia-de the Wasatch Range in the vicinity of

Spanish Pork Canyon noteworthy as the "type area" of triangular fac­ ets on spurs truncated by normal faulting. The facets that first attracted his attention were those immediately north of Spanish Pork, but in his later paper he also described the facets along the moun­ tain front to the west and south. He also noted the presence of fault scarps in alluvial fans along the foot of the range, and described the general attitude of the bedrock wherever it could be readily ascertained in his rather rapid journey along the foot of the moun­

tains* He presented evidence in favor of the fault-block origin of

the Wasatch Mountains, and also commented on the genesis of the deltas

at the mouth of Spanish Fork Oanyon and of the stream terraces in

Diamond Fork.

The first extensive stratigraphic and structural investigation

in the area was by G.F. Loughlin (1915, pp. 447-452; 1919; 1920, pp.

520-555)* who made a reconnaissance study of the Santaquin-Mount Nebo

district during the summer of 1912. He measured sections, collected

, and mapped an area along the Yfesatch Range from Mount Nebo

northward to the north end of Dry Mountain, using the old Manti topo­

graphic sheet as a base. He differentiated, in ascending order,

Archean crystalline rocks, a basal Cambrian quartzite, shale with

Cambrian trilobites (correlative with the Qphir formation), alter­

nating beds of argillaceous limestone and shale (somewhat similar to

the Cambrian Cole Canyon and Bluebell dolomites of the Tintic dis­

trict), Mississippian limestones, and a part of the "intercalated

series". On the east side of Dry Mountain he found Tertiary conglom­

erates and limestones, overlain by andesitic and latitic breccia, and

unoonformably overlying the Paleozoic strata. He noted a similarity

of the Tertiary limestone to the rock being quarried in the Birdseye marble quarry south of Thistle, listed fossils— chiefly of Brazer and Madison age— found on Dry Mountain east of Santaquin, and called attention to the similarity between the lower part of the Santaquin

section and the lower half of the sequence in the Tintic district. -20-

Loughlin also described in detail the petrography of two lampro-

phyre dikes found in the Archean crystalline complex in the area, and

discussed the geology of the major mines then being worked. He

found north-south and east-west normal faulting of the Basin Range

type and he suggested the possibility of thrust faulting in the area.

F.F. Hintze (191J, pp. 97“98) also briefly investigated the area

east of Santaquin in the vicinity of the old Union Chief mine, observ­

ing the basal Cambrian beds and finding a scanty Middle Cambrian

fauna.

The reconnaissance geologic map of Utah which accompanied the

report on ore deposits of the state (Butler, et al., 1920, plate 4)

essentially incorporated Loughlin^ map for the Mount Nebo-Dry Moun­

tain area. Three bands of rock striking northeast across Spanish

Fork Canyon north of Thistle were labeled (from south to north) Jur­

assic, Triassic, and Carboniferous, with a broad embayment of Terti­

ary beds overlapping from the south, paralleling the south side of

Loafer Mountain and the east side of Dry Mountain. The top of Loafer

Mountain was indicated as Triassic and the south side as Jurassic in

age.

Campbell (1922, pp. 22J-251) again described the section through

Spanish Fork Canyon, mentioning Jurassic limestone and sandstone,

Triassic red sandstones and shales, and Carboniferous limestones,

sandstones and shales. He accompanied his account with a geologic map showing the above units extending 5 miles southeast of Spanish

Fork Canyon, as well as Bonneville deposits reaching upstream to the -21-

south and to the west of Thistle.

Buss (1924) made a physiographic study of the Wasatch Range and

adjacent valleys from Provo to Mount Nebo. He especially investi­

gated the scarplets in the Lake Bonneville deposits along the foot of

the range and summarized the evidence for the existence of a Wasatch

frontal fault.

Eardley (1955> 1954) mapped over 2^0 square miles in a rectangu­

lar area including the Wasatch Range from Salt Creek Canyon to a mile

north of Santaquin, the northern portion of Long Ridge, and the south­ west slope of Loafer Mountain. In the Dry Mountain area he recog­ nized essentially the same stratigraphic and structural units as

Loughlin. The mapped outcrop of Tertiary beds was expanded both in detail and in area, and Cambrian and Mississippian beds were shown to be present on the southwestern slope of Loafer Mountain. Additional

evidence of thrusting was presented, especially in the Qphir forma­ tion, where younger beds have been thrust over older. Normal fault­ ing was also indicated on the west slope of Loafer Mountain, Strat­ igraphic unite mapped in the Santaquin-Payson Canyon area included

(from older to younger) the Archean crystalline complex, Algonkian

shales and quartzites, the Tintic quartzite, the Ophir shale, Cambrian limestones and dolomites, the Brazer (?) and Madison formations

(undifferentiated), the "intercalated series11, the "Wasatch conglom­ erate", and volcanic breccia of late Tertiary age.

In a separate paper, Eardley (19J2) discussed the lithologic details and possible origin of the limestone member of the "Wasatch -22-

conglomerate” cropping out both at Tinney Flat in Santaquin Oanyon

and in the Cedar Hills south of Loafer Mountain. He called the lime­

stone "ooidal,” whereas Loughlin had merely referred to it as "con­

cretionary”. In a number of later publications Eardley has referred

to the southern Wasatch Range, and in a paper on Proterozoic (?)

rocks in Utah (Eardley and Hatch, 19^0, PP» 822-825) he again describ­

ed the quartzite and shale sequence of Dry Mountain.

Schneider and Perkes (1957) accurately described a group of sink

holes at the mouth of Pole Oanyon (a western tributary of Spanish

Fork Oanyon), but mistakenly attributed their origin to a meteor

shower.

Schoff (1957; 1951) mapped the geology and drainage of the Cedar

Hills from Benny Oreek south to Moroni. In the northern portion of

the area he distinguished beds of the North Horn, Flagstaff, and Col­

ton formations, lying south of undifferentiated Carboniferous strata

and covered by pyroclastic material.

A.A. Baker (1940; 1947) measured sections in Spanish Fork Canyon

and in recent years has mapped the area east of the canyon. He traced upper Paleozoic and younger formations into the area from regions to

the north and east., and named two Permian unit b — the Kirkman limestone

and the Diamond Creek sandstone'— for areas just north of Spanish Fork.

The upper Paleozoic and Mesozoic formations mapped by the author are mainly continuations of outcrops described by Baker in Spanish Fork

Canyon,

Bissell (1948) described and mapped in detail the various uncon­

solidated deposits of Pleistocene and Recent age in southern Utah -25-

Valley and summarized the geology of the slopes of the Wasatch Range

immediately adjacent to the valley, including some of the formational

contacts and faults. He recognized the Oquirrh formation on the

flanks of Loafer Mountain and in the low hills south of Payson and

described the conglomerates of possible North Horn age which crop out

near the Spanish Fork power house. He mentioned that strata of the

Madison, Deseret, Humbug, Great Blue, and Manning Oanyon formations

are recognizable in the southern Wasatch Range. In other papers

BiBsell (1959> 1950) ^ias demonstrated the value of fusulinids in

zoning the Oquirrh formation in the Wasatch Mountains of this general

region.

During the past five years a number of students from Brigham

Young University have written master’s theses on areas in or near the

southern Wasatch Mountains, and some of the papers have been published

in the Compass. Abbott (1951) made a study of the tabular igneous

body in the lower part of the Tintic quartzite in some places in cen­

tral Utah, examining exposures in the mountains southeast of Provo,

on Long Ridge, on Mount Nebo, and on the west slope of Loafer Moun­

tain in Payson Oanyon. Hodgson (1951) mapped an area at the embay- ment at the mouth of Spanish Fork Canyon in the southeastern corner

of Utah Valley, paying particular attention to the nature of the

Wasatch frontal escarpment, and concluding that the Wasatch frontal

fault exists as a continuous trace here. Brown (1952) mapped an area

in the low ridges and hills south of Payson, using lithologic subdiv­

isions of the Tintic mining district. After studying the section in

1 -24-

Santaquin Canyon and tracing the units northward the writer differed

from Brown in the identification of some of the formations. Peterson

(1952) studied an area surrounding the town of Thistle, from the lower

canyon of Crab Creek northward to Diamond Pork, Harris (195*0 mapped an area north of Birdseye from Bennie Creek to Crab Creek and extend­

ing both east and west from Thistle Creek. The last-mentioned paper

is the most comprehensive of the group and the author agrees with

Harris in most essentials.

Field Work and Mapping

Field work for this report included 9 weeks in the summer of

1952* 15 weeks during the summer and autumn of 1955* an

Mapping of all but the northern portion of the area was done on aerial photographs of approximate scale 1:20,000. Geologic data were transferred from the aerial photographs to a copy of the Nephi Wo, 2 advanced print topographic sheet (enlarged to 1:24,000) and to parts of the Spanish Fork and Spanish Fork Peak quadrangles (1:24,000) by use of a Sketchmaster, The northern portion of the area was mapped directly on the 1:24,000 topographic sheets with the aid of a Paulin altimeter. The final composite map consists of the geologic data men­ tioned above superimposed on a 1:24,000 planimetric base derived from the Spanish Fork, Spanish Fork Peak, Santaquin, and Santaquin Peak quadrangles.

Sections were measured by steel tape and Brunton compass. -25-

The geology of the numerous mines and prospect pits on Dry Moun­

tain was given no more than casual notice. An earlier report has

dealt with the Santaquin mining district, which includes the Dry Moun­

tain area (Loughlin, 1920). Only field identifications were made of

rocks in the Pre-Cambrian crystalline complex of Dry Mountain and of

the fragments in the Tertiary pyroclastic debris. Finally, only the

more salient geomorphological features were noted.

Aoknowledgement s

The writer would like to express his appreciation for the assist­

ance of others who have aided in the field work and the preparation

of this report. The work was undertaken under the guidance of Dr. Ed­

mund M. Spieker of The Ohio State University, and his aid and counsel

and his patience with the writer’s inefficiencies are sincerely apprec­

iated.

Dr. Robert L. Bates and Dr. Charles H. Summerson critically read

the manuscript and gave many helpful suggestions concerning the prep­

aration of the final report.

Fossil identifications were made by several persons. Dr. G.

Arthur Cooper identified the Paleozoic brachiopods, Dr. Christina L.

Balk the trilobites, Dr. Irwin Stumm the corals, Dr. Aurele LaRocque the Flagstaff fauna, and Miss Pauline Smyth the fusulinids.

Mr. Roy Foster of the New Mexico Bureau of Mines and Mineral

Resources spent 5 weeks with the writer in September, 1955i during which time the sections were measured.

Dr. A.A. Baker of the U.S. Geological Survey kindly conducted the - 26 - writer over the section he had measured on the northeast side of

Spanish Fork Oanyon, and Mr. Hal Morris assisted in an examination of the standard Tintic section at Eureka.

Mr. Jim McIntyre and Mr. John Young of the Standard Oil Company of California gave the writer suggestions concerning the Paleozoic section and he accompanied them during a reconnaissance investigation of the Mount Nebo area.

Numerous residents of Utah gave advice and information; the writer is particularly indebted to Mr. Paul Ballard and Mr. Roland Lindsey of Payson, Utah.

Financial aid was given from the Bownocker Fund of The Ohio State

University Department of Oeology during the summer of 1952 and by the

National Science Foundation during the academic year 1952-1955* STRATIGRAPHY

General Statement

Sedimentary rooks ranging in age from pre-Cambrian (?) to Quat­ ernary are present within the mapped area, with beds of ,

Silurian, and possibly age absent. (See Table I.) The old­ est rocks belong to the basal crystalline complex which crops out on the west face of Dry fountain. Rocks generally decrease in age from west to east, with the exception of an outcrop on the western flank of Loafer Mountain where older rocks have been exposed by normal faulting,

Pre-Cambrian (?) and basal units of the Paleozoic rockB are clas­ tic in nature. Cambrian and Mississippian strata are predominantly carbonates, Pennsylvanian and Permian beds are composed of alterna­ tions of arenaceous and carbonate beds. Mesozoic and Cenozoic forma­ tions are primarily clastic, and in the limited area of this report the youngest marine beds are Lower or Middle Jurassic,

Nomenclature used is that of the Tintic district, the south- central Wasatch Mountains, and the Cedar Hills, which lie to the south­ west, northeast, and southeast, respectively, of this area. Correla­ tions are based primarily upon lithologic and sequential similarities with confirmatory paleontologic evidence for a few formations.

-27- - 2 8 -

Table I. Qansralizcd ■•otion of rook* txpoisd in th« northern part of th* iouttaern Wxatoh Mountain*

S y a t o m U n i t Lithology and Thickness

A l l u v i u m

Land siides

Q u a t e r n a r y Younger fane

M o r a i n e

O l d e r f a n e _ __ _ -?__ __ Terraoe gravels Rounded to angular boulders, cobbles; sands, silts.clays Pyroolastica Volcanic conglomerates, breocias; tuffaoeous sands 800' f Undifferentiated Fanglomerates with rounded quart— fanclomeratea zite, limestone fragments 500* a T e r t i a r y Crab Creek; Tufa—like limestone; breccia; f o r m a t i o n algal limestone; conglomerate 500*(?) C o l t o n Conglomerates; sandstones; shales 6oo* ± f o r m a t i o n F l a g s t a f f Fresh—water limestones, largely f o r m a t i o n algal; conglomerates; sandstones; sh a l e s 550* * N o r t h H o r n Conglomerates; sandstones; C r e t a o e o u * (?] f o r m a t i o n deep—red shales 6 0 0 'ze T w i n C r e e k Evenly bedded light—gray f o r m a t i o n limestones and shales 600' J u r a a e i o N u g g e t Red to light—gray eolian s a n d s t o n e sandstones 1 ,400-1,800* A n k a r e h Predominantly red shales, f o r m a t i o n siltatoneSi and sandstones 1,500* T r i a e s i o T h a y n e b Alternating limestones and f o r m a t i o n shales 200' exposed f (l,54o) P a r k C i t y White to pink chertylimestones; f o r m a t i o n middle cherty phosphatio m e m b e r 1, 000-5 , 0 0 0 * P e r m i a n Diamond Creek Buff, pink, or white friable e a n d a t o n e sandstones and quartzites 800* K i r k m a n Laminated fetid black limestone, 1 i m e a t o n e partly breooiated; sandstone 500' ± O q u i r r h Alternating quartzlte, sandstone. f o r m a t i o n and limestone 12, ooo-i5,ooo• Pennsylvanian Manning Canyon Carbonaceous and variegated ehale shales; greenish-brown quartz— ites; limestones G r e a t B l u e Thin—bedded gray to blue—gray l i m e s t o n e l i m e s t o n e s 500- 1200' Miseieaippian Humbug Alternating buff and gray f o r m a t i o n sandstones, limestone, and d o l o m i t e s 660• Deseret limeston > Basal phosphate unit; blue—gray cherty limestones; encrlnites 720* M a d i e o n Blue—gray, fossiliferouB, evenly l i m e s t one bedded, cherty limestones; dolomites 560* Devonian. ( ? ) Op ex Light—gray dolomites; flat— d o l o m i t e pebble conglomerates 550' Cole Canyon Alternating light and dark dolomites; d o l o m i t e Borne like Dogmar 470' B l u e b i r d Dark—gray dolomite with small d o l o m i t e w h i t e n'fcwi|fisy bodies" 190* H e r k i m e r Banded dark—gray limestone and l i m e s t o n e dolomite; shale 500* C a m b r i a n D a g m a r White—weathering laminated 1 ime at one d o l o m i t e 55* T e u t o n i c Banded and oolitio limestone and 1 ime stone d o l o m i t e 450* Ophir formation Shale; phylllte; dark—gray lime­ stone; quartzlte 250* T i n t l o White, buff, pink quartzlte; q u a r t z i t e pebble conglomerate at base 900* Pre-Cambrian (?) Maroon quartzlte*} shales; Pre—Cambrian sedimentary a r g i l l i t e s 1250* + r o o k s Crystalline Schists, gneisses, pegmatites, c o m p l e x g r a n i t e s -29- Pro-Cambrian (?) Rocka

Distribution and nomenclature The oldest sedimentary rocks in the Santaquin Canyon-Spanish Fork area form a sequence of shales, quartzites, and phyllites exposed along the southwest side of Dry

Mountain, east of Santaquin. These beds rest on a basal crystalline complex and are overlain unconforaably by the Tintic quartzite. This

sequence has been mentioned and described by various persons. Hintze

(1915, p. 97) traced the unconformable contact at the base of the Tin­ tic quartzite from the Big Cottonwood area southward tb the vicinity

of the old Union Chief mine, east of Santaquin. Loughlin (1920,

P. 524) measured the Tintic and pre-Tintic quartzites and shales to­

gether as a single unit, evidently failing to notice the unconformity

separating the two. Eardley (1952, p. J12) distinguished the younger

beds as the Tintic quartzite and called the older Algonkian. More

recently, Eardley and Hatch (1940, p. 822) included this outcrop in

their regional discussion of Proterozoic (?) rocks in Utah.

Nomenclature used in connection with the pre-Tintic quartzite

■sedimentary rocks in central Utah has been somewhat various. King

(1878, pp. 229-250) originally used the term "Cottonwood slates" for

the basal unit of a sequence of sedimentary rocks at the mouth of the

Big Cottonwood canyon near Salt Lake City, where 800 feet of dark

slates underlie more than 10,000 feet of quartzites and shales. Hinds

(1958, p. 74) redefined the "Cottonwood series" to include all the

pre-Tintic quartzite sedimentary rockB, and this term has been used

rather frequently for similar units in Central Utah. Muessig (p. 15) - 50 - preferred to use the term "Cottonwood slates" for the rocks of this nature in Long Ridge, arguing that the word "series" implies an epoch

of geologic time. More recently, Granger and Sharp (1952* PP. 5-6) have proposed the terms "Big Cottonwood series", "Mineral Pork till-

ite", and "Mutual formation" for the ascending sequence of pre-Tintic

quartzite sedimentary rocks in the central Wasatch Mountains, where

the Big Cottonwood series is a 16,000-foot succession of white or

greenish quartzites and variegated red, greenish, and blue-purple

shales, the Mineral Fork tilllte is poorly sorted black conglomeratic material varying in thickness from a feather edge to 5,000 feet, and

the Mutual formation is a wedge-shaped unit of red-purple quartzites

and variegated red and green shales, narrowing southward, and appar­

ently pinching out near Little Cottonwood Canyon.

Lithology The rocks designated as pre-Cambrian (?) in the

Santaquin area evidently resemble the Mutual formation, for they con­

sist of a predominance of maroon quartzites and red or green shales.

They rest upon an irregular crystalline complex, and below the old

Union Chief mine, where a section was measured, the basal unit is a

light-gray, medium- to coarse-grained feldspathic sandstone, l|r feet

thick and containing about 20 percent feldspar. ThiB unit is grada­

tional with the weathered upper surface of the underlying pale-pink

granite, and evidently represents a reworking of the residual mantle

by transgressing waters of a basin of deposition. Above it is a 52-

foot bed of poorly sorted, cross-bedded maroon sandstone that contains

streaks of light-gray arkose. -51- Overlying these basal units are beds of maroon quartzites with interbedded shales that range in color from dull-red, chocolate-brown, and maroon, to light-green, yellowish-green, and gray. Shales are more abundant toward the top of the sequence, and range in structure from fissile to blocky. Some are quite micaceous and many are actually phyllites. Other less micaceous varieties are properly termed argil­ lites. Tubular structures resembling worm trails are present along some of the bedding planes of the phyllites and thinner-bedded quart­ zites.

The quartzites in many places form massive ledges, but elsewhere are cross-bedded or broken by shale partings into beds as thin as

1/8 inch. Oscillation ripple marks are common along the partings.

Minor amounts of the quartzite— particularly the very thin-bedded por­ tions— are pale grayish-green in color, and slightly micaceous. The predominant color of the quartziteB, however, is purple or maroon, sometimes obscured by extensive rust-colored weathered surfaces. Very thin dark laminations are present in most of the beds, sometimes show­ ing cross-bedding.

Some of the rocks are thin-bedded siltstones possessing colors similar to those of the shales. About a fourth of the way up in the unit is a fine-gredned, greenish-gray sandstone.

The beds in the Dry Mountain outcrop fit very wellinto the pic­ ture of the foreland or platform depositional facies as described by

Pettijohn (l9^9> PP* The limestone units are missing, but the thin, discontinuous basal feldspathic sandstone, overlain first by thick, massive quartzites and then by alternating, well-defined beds of shale and cross-bedded, ripple-marked quartzite, are consistent with the features proposed as common to the foreland environment.

Thickness The thicknesses of individual beds of pre-Cambrian (?) age between the crystallines and the Tintic quartzite total over 12J0 feet on the ridge below the old Union Chief mine. The thickness varieB because of the angular discordance at the top of the unit, on which progressively younger beds are truncated toward the south.

Age and correlation Correlation of these beds must be based upon lithologic and sequential similarities to rocks in nearby areas.

The Tintic quartzite or its equivalents is rather widespread in central

Utah, and in many areas the base of the Tintic provides a fairly good reference horizon. Unfortunately, no fossils are available for dating the Tintic quartzite, and its basal beds may be of any age from pre-

Cambrian to late Early Cambrian. Therefore, it 1b possible that the older sequence of sedimentary rocks is also Lower Cambrian in part or in entirety.

When one speaks of the Cambrian, or any other period, he is essentially referring to a specific interval of time during which cer­ tain sedimentary rocks in a particular type area were deposited. So far, the best method of comparing the ages of rocks in a given area to those of a type section is by a study of the fossils contained in each. It has to be assumed that in similar environments similar faunas or floras existed at approximately the same times. Thus, when one refers to pre-Cambrian, he should mean the time previous to the deposition of the lowermost beds defined as Cambrian in its type sec­ tion. The only good evidence for saying that certain sedimentary rocks -55- are pre-Cambrian in age would be their sequential position below

strata having fossils identical to those of the lowermost beds of the

type section, and then there would still be a large element of doubt;

the strata immediately below the fossiliferous horizon may merely

have been unsuitable for preservation of plant or animal life, or may

have been deposited in an environment different from that necessary

for the growth of the guide fossils.

Such problems have been discussed more clearly and in considerable

detail by many writers. The situation concerning the pre-Tintic sed­

imentary rocks is even more in doubt, for the oldest fossils identi­

fied in this general area are from the Ophir formation and are upper­

most Lower Cambrian and Middle Cambrian in age. The Tintic quartzite

is conformable and gradational with the Ophir. In many areas the Tin­

tic quartzite is conformable with the next older beds. Nolan (p. 148)

has pointed out that the Tintic evidently transgressed eastward, so

that the basal units were not deposited synchronously. Therefore, if

one calls all pre-Tintic strata pre-Cambrian, and calls the Tintic

Cambrian, he is using a designation of a specific time for a horizon

that transgresses time lines, and which can no place be more accurately

dated than "pre-uppermost Lower Cambrian".

Nevertheless, moat workers in the'region have arbitrarily mapped

the unconformity at the base of the Tintic quartzite as the lower Pal­

eozoic boundary, most of them likewise pointing out the possible errors

involved. The unconformity on Dry Mountain has been previously mapped as such, as was mentioned above, and the author has no additional -54-

proof, pro or con, to contribute.

Cambrian System

Cambrian rocks crop out in two approximately parallel bands on

the western slopes of the two major mountain masses in the Santaquin-

Spanish Pork region of the southern Wasatch Mountains. The more ex­

tensive exposure is along the western 3ide of Dry Mountain, from

Santaquin Canyon northward to Picayune Canyon. A smaller outcrop,

terminated both to the north and to the south by faults, is present on

the western slopes of Loafer Mountain, south of Rock Canyon. The Cam­

brian strata of the area of this report are similar to those through­

out central Utah, although thinner than equivalents to the west. The

lower portion consists of a massive quartzite and overlying shale

unit, whereas the upper portion is nearly all dolomite and limestone—

predominantly medium- to dark-bluish-gray, set off by occasional per­

sistent beds which weather creamy-white or light-gray.

In the central Wasatch Mountains and adjacent areas the carbonate

sequence has generally been called the Maxfield limestone. In the

Tintic district, workers have distinguished several formations, based

upon lithologic criteria which are fairly consistent in that area.

MueBsig was able to map similar units in Long Ridge, which lies between

the East Tintic Mountains and the southern Wasatch Mountains. Since

rocks of lithology and sequence corresponding to the sections of the

Tintic district and Long Ridge are distinguishable in the region dis­

cussed in this report, nomenclature of those areas was used for the

Cambrian system. It cannot be demonstrated, however, that all such -55-

Tint* C. D istr ic t ILovering^ 1141)

■ 3,000

MIS5ISSIPPIAN

u

u mtitan

-500 Tintic ojuo-rtiite

Figure 5. Comparison of Tintic, Long Ridge and Dry Mountain Cambrian sections above the Tintic quartzite. -56-

units represent the same zones in all three areas.

Tintic Quartzite

Definition and distribution The Tintic quartzite was originally

defined by Smith (1900, p. 1) as a sequence of quartzites and slates

lying below the Middle Cambrian limestones in the Tintic mining dis­

trict of central Utah, The name was later restricted by Loughlin

(1919, pp. 25-25) to refer only to the massive light-colored quart­

zites below the Ophir shale. The Tintic quartzite or its equivalent

has been mapped throughout most of central and western Utah, as well

as in central and eastern Nevada, where it is known as the Prospect

Mountain quartzite (Nolan, 19^5* P» 148). In central Utah the Tintic

quartzite is present in the Oquirrh Range (Gilluly, p, 7)> in the

central Wasatch Mountains (Granger, 1952* P« 7> Baker, 19^7)» in the

southern Wasatch Mountains (Eardley, 1955* P* 51^) and In Long Ridge

(Muessig, p, 14).

In the area here studied, the Tintic quartzite extends along the

west side of Dry Mountain, lying about half way up the slope in the

embayment east of Santaquin, but arching down to crop out along the

foot of the mountain southeast of Spring Lake, (See plate 27,) The

southern extension of this outcrop ends abruptly at a normal fault at

the first major gulch north of Santaquin Canyon. The Tintic quartzite

appears in some of the fault blocks east of the sand and gravel pit

located northeast of Santaquin on U.S. Route 91* and it is also exposed

in Payson Canyon above the Nebo Loop road on the west flank of Loafer

Mountain, south of Rock Canyon, A sand pit just below the road here - 57- ia in white silt and sand derived from the Tintic quartzite. The

Payson Oanyon outcrop is rather limited in extent, and is bounded on both north and south by normal faults,

Lithology The Tintic quartzite is a rather easily recognizable unit, fairly uniform in lithology, and bounded above and below by good marker beds. It is primarily a white, pink, and light-gray, fine- to medium-grained quartzite composed of rather clean, subround to round grains. It weathers buff so that distant hills containing the unit have a light-tan appearance, A few beds contain liraonitic cement.

Toward the top of the unit the beds become somewhat micaceous— espec­ ially along bedding planes— and green and lavender tints are common.

Some beds show distinct cross-bedding.

The basal Tintic in the vicinity of the old Union Chief mine con­ sists of a cross-bedded conglomeratic quartzite in which there are rounded pebbles of quartz, quartzite, jasper, and slate up to 2 inches in diameter. The pebbles are white, maroon, and reddish-brown; many are elongate, with long axes parallel to the bedding, but in some places showing imbricate structure. There are a few thin beds of fine­ grained quartzitic conglomerate distributed throughout the formation, and near the top are some more prominent beds of this type, with sub- angular to subrounded quartz pebbles averaging diameter, and brown-weathering surfaces common for the matrix.

On Dry Mountain many of the quartzite units form massive ledges several yards high, but individual beds average no more than 2 or J feet in thickness. The Payson Canyon outcrop is more subdued, and the rock is exposed mainly as float on the hillside. A sill or old -58- lava flow is present in some places in the lower half of the Tintic quartzite, and is found in both outcrop areas, although not uniformly throughout. (See section on igneous rocks.)

Thickness The Tintic quartzite is between 800 and 900 feet thick on Dry Mountain. To the south, near Mount Nebo, its thickness is 800 feet (Loughlin, 1915* pp. ^ 7 ”52)* whereas to the north, in

Slate Oanyon in the central Wasatch mountains, it is 1080 feet thick

(Baker, 19^7). Ib thickens to the west and totals over 55^0 feet in the Tintic district (Lovering, p. 9)* but is only a little over $00 feet thick in the (Gilluly, p. 7).

Stratigraphio relations The upper contact with the Ophir shale is gradational, and is obscured by thrusting in some places. No Ophir shale was observed above the Payson Canyon outcrop. A good exposure of the Ophir shale-Tintic quartzite boundary is present about half a mile south of the Nelson mine on the lower slopes of Dry Mountain, southeast of Spring Lake.

In this area the Tintic quartzite is unconformable over the pre-

Cambrian (?) beds, as is especially well seen on the ridges in the vicinity of the old Union Chief mine (Eardley, 19.55* P» 515). The basal conglomerate of the younger unit shows a distinct angular dis­ cordance with soft shales and thin-bedded quartzites of the older se­ quence right at the base of the old ore-loading bins beside the foot trail to the mine.

This unconformity is by no means universal. For example, Granger

(1955* P* 2) reports its apparent absence in the Salt Lake City area.

In other areas, different workers have voiced differences of opinion -59- as to the presence of such an unconformity. Muessig (p. 1J) reported a conformable contact between the Cottonwood slates and the Tintic quartzite near Slate Jack Canyon in Long Ridge, but Price (1951* P* 75) reports the relationship in this area as unconformable. The author has communicated with neither of these workers and has not visited the area, but would point out that if a section happened to be such that the strikes of the two units were the same, one could easily over­ look a break. This may or may not be the case in the Long Ridge area.

Age and correlation The oldest diagnostic fossils that have been found in Cambrian beds of this region are from the Ophir shale, which has produced a fauna of Early and Middle Cambrian age (G-illuly, p. 11). Since the Ophir shale and Tintic quartzite appear to be grad­ ational, the Tintic is entirely or in part Early Cambrian in age, and possibly partly pre-Cambrian.

The quartzite and overlying shale are found as basal Cambrian units throughout much of the Utah and Nevada area (Nolan, p. 148).

They evidently represent a progressive eastward overlap by the Cambrian sea,

Ophir Formation

Definition and distribution The Ophir formation, generally re­ ferred to as the "Ophir shale", was formally named by Loughlin (1919» p. 25) for shaly beds above the Tintic quartzite at Eureka, Utah, after the name was first suggested by B.S. Butler for beds cropping out at the mining town of Ophir, in eastern Tooele County, Utah. The formation has been found in the Wasatch, Oquirrh, and Tintic ranges -40- in central Utah* forming one of the most distinctive units in the Lower

Paleozoic sequence. The unit has been mapped as far south as the

Pavant Range (Lautenschlager, p. 20), and the Ophir formation or its equivalent is present throughout much of the area in east­ ern Nevada and western Utah (Nolan, p. 148).

In the area of this^report, the Ophir formation crops out along the western face of Dry Mountain from the first major gulch north of

Santaquin Oanyon northward to about half a mile south of Picayune Can­ yon, east of Spring Lake, where it dips below the alluvium. (See plate 27.) It is present in several of the fault blocks along the foot of Dry Mountain just east of Santaquin. The outcrop is discon­ tinuous due to thrusting. For example, immediately north of the old

Union Chief mine, the younger Teutonic limestone lies directly in fault contact on the older Tintic quartzite. (See section on struc­ ture . )

No beds of the Ophir formation were observed in the Cambrian rocks above the Nebo Loop road in Payson Canyon, but both Teutonic limestone and Tintic quartzite are present, and the shaly unit may be under a float,that covers much of the hillside. Eardley (1952, p. ^16) showed a band of Ophir shale in this locality on the map accompanying his report on the southern Wasatch Mountains, but it appears to the writer that the Ophir is probably absent here due to the same thrust­ ing which Eardley (19^4, p. 5^5) referred to as the Santaquin over­ thrust on Dry Mountain. (See section on structure.) Lithology On Dry Mountain the Ophir formation consists of a lower shale member and an upper member of alternating shales and limestones. Although the upper shale member present in the Tintic dis­ trict (Lovering, p. 9) and other areas (Calkins, p. 12) was not seen here, it is possibly present beneath the float on some of the ridges; the upper contact is not exposed in most of this area. The bottom contact w s b drawn at the top of the uppermost massive, greenish-gray quartzite bed of the Tintic quartzite, overlain here by a shale and phyllite unit.

The lower 95 f®et of the Ophir formation on Dry Mountain is pre­ dominantly shale and phyllite, with numerous thin beds of sandstone and quartzite intercalated throughout. The shales and phyllites are mainly grayish-green to olive-green in color, ranging from clayey, fissile shales thru rather micaceous shales to true phyllites. The shales commonly weather to a greenish-brown color and many are silty or sandy. The phyllites have wavy bedding planes, along many of which are a multitude of tubular structures resembling worm trails 1/8- inch to |-inch in diameter.

Sandstones and quartzites are gray to greenish-gray, but weather to a greenish-brown or maroon color. Some have small flecks of limon- ite throughout, some are cross-bedded, and some contain grainB of a mineral which appears to be glauconite. The thickest quartzite layer is 5a' feet, and is near the base of the unit. One interval of 47 feet of shale contains no quartzite or sandstone. Small oscillation ripple marks are present on some of the quartzite beds.

The upper 85 feet of the formation at the northern end of its -42- outcrop consists of interbedded shales and limestones, the shales being similar to those in the lower part of the unit, although perhaps more calcareous. The limestones are dense to fine-grained, dark-gray to lead-gray in color, and in some places contain small rounded pel­ lets of brown, silty material. Their most notable feature is the presence of irregular brown argillaceous partings averaging 1/8 to

•§- inch in thickness and occurring with regularity every 1 or 2 inches.

Some of the partings are fissile but most are not, and many are as resistant to weathering as is the adjacent limestone. The net effect is to give the limestone a banded appearance, characteristic of the

Teutonic and Herkimer limestones. The limestone and shale alternate in beds which are 5 inches to J feet in thickness, with the exception of one limestone 7 f»et thick and an overlying 12-foot shale bed.

Thickness In a section half a mile south of the Kelson mine southeast of Spring Lake the Ophir formation is 177 feet thick. On some of the ridges it appears to be as thick as 2^0 feet, while on others it is much thinner, or even absent, due to thrusting. The shales evidently provided a well-lubricated zone along which Blippage could occur. The Ophir formation is reported to be 410 feet thick in the Tintic district (Lovering, p. 9)* 520 feet in the Oquirrh Mountains

(Gilluly, p. 10), 400 feet in the north-central Wasatch Mountains

(Granger, p. 2) and 2^0 feet near Provo, Utah (Baker, 1947).

Stratigraphic relations The upper boundary of the Ophir forma­ tion is apparently gradational with the Teutonic limestone, and the two formations may possibly intertongue on a regional scale. The limestones near the top of the unit are quite similar to the Teutonic -45-

lime stone. Wherever mapped, the contact was drawn at the base of the

thick, massive limestone ledge overlying the limestone-shale sequence,

but on most ridges on Dry Mountain there is a covered interval below

definite Teutonic limestone.

The lower boundary is gradational with the Tintic quartzite, as

was mentioned above.

Age and correlation Fossils have been found in the Ophir forma­

tion in several localities. On Dry Mountain Eardley (1955* P» 516)

found fragments of the trilobites Bathyurlsous sp., Olenopsis ap.,

and Ptyohoparia sp., which were considered of either uppermost Early

Cambrian or lowermost Middle Cambrian age by Professor B.F. Howell of

Princeton University. Walcott (I89I* pp. 519“520; 1892, pp. 189* 195*

206) reported Lower Cambrian fossils, including Olenellus gilberti, from a horizon near the base of the formation in areas at Ophir and at Big Cottonwood Canyon, Silluly (195^* p. 12) and Lovering (p. 9) assigned an Early and Middle Cambrian age. to the formation in the

Oquirrh Mountains and the Tintic district. Muessig (pp. 15-19) placed the Ophir of Long Ridge in the Middle Cambrian upon the basis of a G-lossopleura-Kootenia fauna and an Ehmania-Bolaspis-Glyphaspis fauna collected in that area.

The writer collected some trilobite fragments from one of the limestone beds in the upper part of the Ophir shale above an old aban­ doned mine near the center of section J2, T.9S., R.2E, The specimens were examined by Christina L, Balk, who concluded,

"The pygidia appear to belong to a genus like Clappaspls. This pygidium suggests that these beds of the Ophir shale correlate with the Bathyuriscus-Elrathina zone -44-

(Rasetti, 1 951* Smithson., miec. Coll., vol. 116, no. 5) which is the new name for the zones extending from the Bolaspis-Grlyphaspis thru the Elrathina-Clappaspis zones on the Cambrian correlation chart. Thus the upper beds of the Ophir at this locality are the approximate equivalent of the middle part of the Cros Ventre formation (Death Canyon member) of Wyoming, and Bomewhere in the middle of the Blacksmith formation,"

Teutonic Limestone

Definition and Distribution The Teutonic limestone was named by

Loughlin (1919, p. 27) for Teutonic Ridge in the Tintic mining district,

Utah, where it is a dark, bluish-gray limestone, banded in part with

ribbons of yellowiBh-brown argillaceous material. It is determined by

its position between the Ophir formation and the Dagmar limestone,

both of which are distinctive units in the Tintic district. The Teu­ tonic limestone has also been distinguished in Cambrian limestone

sequences in Long Ridge (Muessig, p. 22) and in the Pavant range

(Lautenschlager, p. 21).

The Teutonic limestone crops out as a thick, cliff-making ledge

in Santaquin Canyon and can be traced continuously northward along the

base of the carbonate sequence high up on the west side of Dry Moun­ tain, until it dips down and disappears under the alluvium about half a mile south of Picayune Canyon. (See plate 27.) It is also present in some of the fault blocks along the base of Dry Mountain east of

Santaquin. In Payson Canyon the formation crops out above the Uebo

Loop road on the west end of Loafer Mountain, just Bouth of Rock Can­ yon, where the beds are somewhat disturbed due to normal faulting.

At this locality it is also present in a fault block just below the -45- road, south of the old sand pit in the Tintic quartzite.

Lithology Much of the Teutonic limestone is similar to the limestones in the underlying Ophir formation, and also to the younger

Herkimer limestone. (See plate 5»A.) Dark- to medium-gray, dense to fine-grained limestones are banded by irregular light-gray to yellow­ ish-brown argillaceous and silty partings averaging 1/8 to § inch in diameter and occurring \ to 2 Inches apart. Surfaces along the part­ ings are quite pitted and irregular, but from a distance the bands appear quite even, and parallel to one another. In addition, the rock is mottled by small silty or argillaceous bodies (possibly dolomitic) that weather to form light-gray blotches about 4 inch in diameter.

There are occasional layers containing spheroidal structures up to

inch in diameter that resemble algal structures. Toward the top of the unit there are a few beds of oolitic or pisolitic material.

In Santaquin Oanyon the upper JO feet of the unit is dolomite that superficially resembles the rest of the formation. The base of the formation makes a massive ledge, and there seem to be no especially weak or non-resistant zones along the argillaceous bands. Many of the non-banded beds have a shattered appearance on the weathered surfaces due to networks of fine grooves formed by differential solution, possibly along incipient jointing patterns.

Thickness In the type area Loughlin (1919, p. 27) measured ^>66 feet of TeutSnic limestone, but Lovering (p. 9) reports only 4-20 feet in the East Tintic district. Lautenschlager (p, 22) found this for­ mation to be 528 feet thick in the Pavant Range. In Santaquin Oanyon, ■46'

bl6feet of Teutonic limestone was measured, with the base not exposed,

and 5 miles to the north, Brown (p. 555) measured kj6 feet in a com­

plete section. Muessig (p. 195) found only 281 feet of the unit in

Long Ridge. The thin Long Ridge section may be due to the interven­

ing of facies changes. The stratigraphic position of the Dagmar lime­

stone may not be dependable, and the position of the lowest massive

limestone may vary considerably, for the Teutonic limestone and the

Ophir shale probably intertongue on a regional scale.

Stratigraphic relations The Teutonic limestone is gradational

with the Ophir formation and perhaps intertongues with it on e. reg­

ional scale. Its upper limit is set off sharply by the light-weather­

ing, blocky, laminated Dagmar limestone,

is®. and correlation In the Tintic district the Teutonic lime­

stone lies in an interval between beds of known Middle Cambrian age

(Loughlin, 1919, pp. 27-51), but no fossils were reported from the

formation until Muessig (p. 25) found trilobite remains of the

Ehmania-Bolaspis-Giyphaspis zone near the middle of the section at

L6ng Ridge, No fossils were found in the unit in the area discussed

here.

The Teutonic limestone is best correlated by its position between

the Dagmar limestone and the Ophir shale— both of which are among the more readily recognized units in the area. It is probably equivalent to the lower part of the Maxfield limestone of the central satch

Mountains

/ - 4 7 - Plate 5

A. Teutonic limestone in Santaquin Oanyon, showing irregular argillaceous partings typical of many Cambrian carbonate rocks in this area.

B. Bluebird-type bed in the Oole Canyon dolo­ mite. The small white calcite rods are generally called "twiggy bodies". - 4 8 - Plate 6

A. Dagmar-type bed in the Cole Oanyon dolomite. Many of the white-weathering bedB of this type are laminated and may be either dolo­ mite or limestone.

B. Alternating light and dark beds of the Cole Oanyon dolomite. Looking north at spur in the complexly faulted area northeaBt of Santaquin Oanyon. -A9- Plato 7

A. Cole Oanyon dolomite showing two Dagmar- type beds and differential rosistance of various strata. Looking south on slope south of Ficayune Oanyon.

B« Thin-bedded Madison limestone. Looking north on slope south of Picayune Canyon. - 50 -

Dagmar Limestone

Definition and distribution The Dagmar limestone is named for the Dagmar mine near Eureka, Utah (Loughlin, 1919/ P* 27) and is a distinctive laminated white-weathering limestone or dolomite found a few hundred feet above the Ophir formation in many sections of central

Utah. It crops out as a rather prominent thin band along the west side of Dry Mountain, but dips below the alluvium about \ mile south of Picayune Canyon. It is also present on the west side of Loafer

Mountain just south of Rock Canyon, both along the ridge above the

Nebo Loop road and in a fault block below the road. In the vicinity of Santaquin, the Dagmar limestone is present in several normal fault blocks along the foot of Dry Mountain, and is one of the few good hor- izon-markers upon which to base structural deductions; it is, in fact, the best marker bed in the Cambrian carbonate section.

Lithology The Dagmar limestone of Dry Mountain is primarily dolomitic. It is dense to medium-crystalline, light to dark-gray on the fresh surface, distinctly laminated in almost all portions, and it breaks into tabular or blocky fragments. Its weathered surface is creamy-white to light-gray, and the laminations remain quite promin- ent. The Cole Canyon dolomite, which is a few hundred feet higher in the section, possesses several thinner beds of the Dagmar type, but their positions relative to the Ophir formation and to each other help prevent their confusion with the Dagmar limestone.

Thickness The Dagmar limestone is about 80 feet thick in the

Ea9t Tintic district (Lovering, p. 9) ^5 feet in Long Ridge. -51-

In Santaquin Oanyon it was found to be 56 feet thick, and is fairly

uniform throughout the surrounding area, exceeding 40 feet in only a

few places.

Stratigraphic relations and correlation The Dagmar limestone of

Dry Mountain and Payson Canyon contrasts rather sharply with the strata

above and below. In Borne places the upper surface is irregular, and

a small break apparently exists in the sequence of rocks. Although the

contrast with the Teutonic limestone is sharp, no break in deposition

is apparent. The formation quite possibly does not maintain a con­

sistent stratigraphic position throughout central Utah, and no fossils

have been reported from it. In all localities in which it has been

found it lieB in a sequence between beds of established Middle Cambri­

an age.

Herkimer Limestone

Definition and distribution The Herkimer limestone was named

by Loughlin (1919# P» 28) for the Herkimer shaft in the Tintic mining

district of Utah, and was defined as a mottled, banded, shaly lime­

stone overlying the Dagmar limestone. An incomplete section was rec­

ognized by Muessig (p. 25) in Long Ridge, and it is also present in

the Pavant Range (Lautenschlager, p. 25). It crops out on the western

side of Dry Mountain, extending from Santaquin Canyon to Picayune

Canyon, and it overlieB the Dagmar limestone above the Nebo Loop road

in Payson Canyon, just south of Rock Canyon. It also occurs in some

of the down-faulted beds east of Santaquin along the foot of Dry

Mountain. -52-

Lithology Much of the Herkimer limestone is very similar to

the Teutonic limestone, and individual outcrops of the formations

could well be confused with one another. A major part of the unit

consists of dark- to medium-gray, fine-grained to dense limestone with thin, discontinuous, irregular argillaceous partings every inch or two. The argillaceous partings are gray to buff, but weather to brown

or reddish-brown. The partings are less resistant to weathering than

the limestone so that flagstone-like slabs tend to break off the weathered outcrops and accumulate in talus. Some layers are addition­ ally mottled by irregular gray blotches of dolomitic material in a dark-gray limestone matrix.

The upper half of the Herkimer limestone in Dry Mountain contains

shale partings as well as two distinct beds of slate-gray to greenish- gray shale— one 16 and the other 2 feet thick. The upper 40 feet of the unit contain some thin flat-pebble conglomerates and also two or three 2-foot beds of oolitic material, the oolites appearing as small, rounded black nodules 1 millimeter or less in diameter, dispersed abundantly in a lighter gray, Bilty or sandy matrix. Small pyrite crystals are present in the upper portion of the formations.

On Dry Mountain the Herkimer limestone directly above the Dagmar

limestone is a dark-gray, fetid dolomite with several vugs of white calcite and numerous small, white, rod-like calcareous bodies (called

"twiggy bodies" by some workers) ^ to 1 inch long and about 1/16 to

1/8 inch thick. This bed is similar to the Bluebird dolomite, but grades quickly upward into a typical Herkimer lithology. -55-

Thickness The Herkimer limestone is 575 ^25 feet thick in

the East Tintic district according to recent measurements (Lovering,

p. 9), although Loughlin (1919, p. 28) included only 225 to 2J5 feet

in his type section. Lautenschlager (p. 25) found 60 to 100 feet of

the formation in the Pavant. On Dry Mountain the Herkimer limestone

averages about J00 feet in thickness.

Stratigraphic relations The contact of the Herkimer limestone

with the underlying Dagmar limestone is quite abrupt and distinct in

the Dry Mountain area. Just northeast of the road in Santaquin Can­

yon an excellent exposure of the contact is present in a dry wash

about 100 feet above the stream. Here there is 5 or ^ inches of re­

lief on the irregular basal contact. The upper contact with the Blue­

bird dolomite is gradational and was taken arbitrarily at the point where the argillaceous partings become rather indistinct.

Age and correlation Correlation with the Tintic section seems pretty sound upon lithologic grounds. In the Tintic district there

is a 20-foot shale bed 180 feet above the Dagmar limestone (Lovering, p. 8), and in Santaquin Canyon there is a l6-foot shale bed 175 f®«t above the Dagmar. Loughlin (1919# P* 51) assigned the Herkimer to the

Middle Cambrian because of its position in a sequence between units of Middle Cambrian age. Muessig (p. 26) found undiagnostic specimens of Lingulella in the formation.

Trilobite fragments were found in talus from the Herkimer lime­

stone in Santaquin Canyon, evidently from thin-bedded limestones in the middle of the formation. The material was examined by Christina

L. Balk, who reported; -54-

"The material is full of cranidia (which) all belong to one species, but so far as I can find the form has not been described. It is closest in all its features to a form I described as Kneohtelia ann from the very base of the Upper Cambrian and the top of the Middle Cambrian in the Little Rocky Mountains. There are a number of similar forms in the upper part of the Middle Cambrian. The beds from which these fossils came are the approximate equivalent of the lower part of the Marjum, Bloomington, and Park formations.11

Bluebird Dolomite

Definition and distribution The Bluebird dolomite was named by

Loughlin (1919* P. 28) for Bluebird Spur, north of Eureka Gulch in the Tintic district, where it crops out as a dark, bluish-gray, fine­ grained dolomite. In the type area the formation is notable for the abundant content of "twiggy bodies"— short, white rods of dolomite or calcite averaging around 1 centimeter in length and 1 or 2 milli­ meters in breadth. (See plate 5»B.) Rocks of this description have been found by many workers in central Utah: Gilluly (p. 17) in the

Oquirrh Range, Christiansen (194-7* P» 57 and fig. 15) in the Pavant

Range, Nolan (1955* P* ii) in ih® Deep Creek Range, and Muessig (p. 29) in Long Ridge and the Pavant.

In the area here discussed, the Bluebird dolomite crops out along the western face of Dry Mountain from Santaquin Canyon to Picayune

Canyon, as well as in some of the faulted blocks in the foothills northeast of Santaquin. In Payson Canyon the formation iB present on the ridge above the Nebo Loop road south of Rock Canyon, (See plate

27.) -5 5 - Lithology In the southern WaBatch Mountains the rocks assigned to the Bluebird dolomite differ somewhat from those in the type area.

The "twiggy bodies" are not especially abundant, are patchy in their occurrence, and are not very uniform in size. The main masB of rock is a dark- to medium-gray, finely- to medium-crystalline dolomite, with a few light-gray streaks of coarser material. Near the top of the formation in Santaquin Oanyon, ^ or 6 beds, ranging from 2 to 5 feet in thickness, form a cliff. Here there are many irregular light- gray blotches on the weathered surfaces, and, in addition, the weath­ ered surfaces resemble cross-bedded sandy material, although no quartz grains are present. This latter feature is common to many of the clastic carbonate rocks in this area.

Stratigraphic relations The Bluebird dolomite is gradational with the Herkimer limestone below and the Cole Oanyon dolomite above, and both boundaries are somewhat arbitrary. The lower limit in the

Dry Mountain area was placed at the approximate horizon where the banding due to argillaceous partings becomes obscure. However, very faint banding of this type continues upward into dark beds containing

"twiggy bodies" characteristic of the Bluebird dolomite. The upper limit was placed at the base of the first light-weathering bed of the

Cole Oanyon dolomite.

Age and correlation Loughlin (1919* P» 28) and Lovering (p. 8) have called the Bluebird dolomite of the Tintic district Middle Cam­ brian in age, based upon its position in the sequence between beds of

Middle Cambrian age. No fossils have been reported from this forma­ tion. -56-

Cole Canyon Dolomite

Definition and distribution The Cole Canyon dolomite was named

by Loughlin (1919, pp. 28-29) for Cole Canyon, south of Eureka, Utah,

where a sequence of alternating light- and dark-gray dolomites crops

out in scattered exposures. The relative persistence of individual

beds is not known, but similar sequences are present in several areas

in central Utah. Rocks have been mapped as Cole Canyon dolomitein

the Pavant Range (Lautenschlager, pp. 27-29) and in Long Ridge

(Muessig, pp. 30-5^).

In the area discussed in this report, the Cole Canyon dolomite

extends in a nearly continuous band along the west side of Dry Moun­

tain, from Santaquin Canyon to Picayune Canyon, where it is terminated

by faults, (See plate 27.) Part of the unit iB also present on the western slope of Loafer Mountain, along a prominent cliff high above

the Nebo Loop Road south of Rock Canyon. The outcrop here is bounded

to the north, south and west by normal faults, and above by a thrust

surface.

Lithology The Cole Canyon dolomite consists of a sequence of

dolomites that weather white or light-gray and dark-gray, alternating

in layers ranging in thickness from less than an inch to over 40 feet.

(See plate 6.) Some of the dolomites that weather light-gray are

laminated and are very similar to the Dagmar limestone. The lamina­ tions in a few beds show cross-bedding. The most prominent of the

"Dagmar type" beds in Santaquin Canyon is 25 feet thick and is about

200 feet above the base of the formation. -57-

The dark-weathering beds are of several types. Some are fine­ grained to dense, dark- to medium-gray, and full of small white elong­ ate "twiggy bodies"; these are similar to the typical Bluebird dolo­ mite, (See plate 5>B.) The darker beds weather black to medium- bluish-gray, and have many irregular medium-gray blotches on the weathered surfaces. About 1^0 feet above the base of the formation in

Santaquin Oanyon is an 8-foot bed of "Teutonic type" dolomite, with irregular argillaceous partings every inch or so, presenting a banded appearance on the weathered sections.

Thickness Boundaries of the Cole Canyon dolomite are rather ar­ bitrary— particularly for the upper limit; hence, comparisons of thick­ nesses are not necessarily significant. In the Santaquin Canyon sec­ tion, 470 feet of beds are assigned to the formation, Loughlin (1919* p. 29) measured about ^00 feet in the Tintic district, and Lovering

(p. 8) later gave 600 feet as the thickness of the formation in this general a.rea; Muessig (pp. 198-199) found about 550 feet in Long

Ridge,

Stratigraphic relations The Cole Canyon dolomite is conformable with the units both above and below. On Dry Mountain the lower boun­ dary is placed at the base of the first "Dagmar type" bed above the

Herkimer dolomite, and the upper boundary at the base of a sequence of oolitic strata, a little above the uppermost white-weathering bed,

Ho typical Opex dolomite beds are present here to provide a definite upper limit.

Age and correlation No fossils were found either in the Cole

Canyon dolomite or in strata of the immediately adjacent units in the -58-

Dry Mountain area. A specimen of Obolus mcconelli was found by Weeks

in the formation in the Tintic district (Loughlin, 1919# P» 29), and

LautenBchlager (p. 28) found specimens of Eldoradia proapectenais

(Walcott) in the upper shaly beds of the Cole Canyon dolomite in the

Pavant Range, On the basis of this evidence the Cole Canyon of those

two areas has been correlated with the Marjum limestone of the House

Range and is considered of probable upper Middle Cambrian age. The

fossils found in older Cambrian formations in the Dry Mountain area

indicate that the Cole Canyon here is uppermost Middle Cambrian, or

lower Upper Cambrian— either in part or in entirety.

Opex Dolomite

Definition and distribution The Opex dolomite was named by

Loughlin (1919# P« 29) for the Opex mine in the Tintic mining district

of Utah, where a series of shaly limestones and. dolomites is exposed.

The Opex has been distinguished as a separate unit in Long Ridge

(Muessig, p. 54), in the Selma Hills (Rigby, p. 12), and in the Pavant

Range (Lautenschlager, p. 29),

On Dry Mountain there is a sequence of dolomites between the Cole

Canyon dolomite and younger light-gray dolomites containing numerous

specimens of poorly preserved Syringopora. This sequence does not particularly resemble the section at the type area, but is similar in gross aspect to the section of Opex dolomite described in the Selma

Hills (Rigby, pp. 12-14). These beds were mapped as Opex dolomite, and extend in a band along the west face of Dry Mountain, from Santa­ quin Canyon to the vicinity of Picayune Canyon, -59- Lithology Rocks assigned to the Opex dolomite in the area of this report are all dolomites, and are mainly crystalline, with a saccharoidal texture. The lower 50 feet of the unit contains abundant streaks of oolitic dolomite averaging around an inch in thickness, intercalated in a light-gray to blue-gray, fine-grained dolomite. This iB overlain by a 22-foot bed of light-gray dolomite containing vague streaks of argillaceous material and several layers showing penecon- temporaneous brecciation. Just south of Picayune Oanyon at approxi­ mately the same stratigraphic position there is a flat-pebble conglom­ erate, and some of the strata show cross-bedding.

Above the intraformational breccias is a series of light- to dark-gray dolomites, mottled and banded to various extents in the lower portions, and containing thick, ledge-forming, rather homogeneous lay­ ers in the upper portion. About a hundred feet above the Cole Oanyon dolomite there is a 25-foot layer of medium-gray dolomite containing irregular light-gray and tan argillaceous partings less than an inch apart— some paper thin, but most averaging around half an inch in thickness.

Thickness The beds assigned to the Opex dolomite on Dry Mountain are gently truncated by an erosion surface overlain by beds of prob­ able Mississippian age. As a result, the thickness ranges from about

550 feet in Santaquin Canyon to less than 100 feet near Picayune

Oanyon,

Stratigraphic relations The basal beds of the Opex dolomite are gradational to and intertongue with the older Cole Canyon dolomite. -6o«

The Opex on Dry Mountain is unconformably overlain by beds of prob­ able Mississippian age. The unconformity is not obvious in any par­ ticular locality, and its position in a given section is indefinite, for in most places it oocurs within a sequence of light-gray dolomites of similar appearance. It was arbitrarily mapped at the base of the lowermost beds containing specimens of Syringopora, which in all places were the oldest fossils found above the Herkimer limestone.

Age and correlation The only fossils so far reported from the

Opex dolomite were found by Weeks in the beds near the center of the formation in the Tintic district, and these are Late Cambrian in age (Loughlin, 1919# P- 50)* Tbs dolomites mapped as Opex on Dry

Mountain are probably Upper Cambrian, but quite possibly contain young­ er beds. The equivalence of the Opex of this area to that of Long

Ridge or the Tintic district is quite uncertain, and the unit is cor­ related principally upon the basis of its position above a sequence of typical Cole Canyon dolomite. - 6 1 -

Missiseippian System

The Mississippian system of the southern Wasatch Mountains con­ sists of a sequence approximately 5,000 feet thick, dominated by blue- gray to dark-gray carbonate rohks, The formations involved are, from older to younger, the Madison limestone, the Deseret limestone, the

Humbug formation, and the Great Blue limestone. The Manning Canyon shale, which overlies the Great Blue limestone, possibly includes both

Mississippian and Pennsylvanian strata. The Humbug formation contains numerous beds of sandstone, alternating with limestones and dolomites, and the Manning Canyon shale contains only a few limestone beds.

Otherwise, the Mississippian rocks are almost entirely limestones and dolomites, which are extremely cherty in the two older formations.

The nomenclature used in mapping the area of this study is the same as that of the central Wasatch Mountains. The section in the Tin­ tic district has only recently been tentatively redefined, and the

Madison group and Deseret limestone are now provisionally recognized in that area (Hal Morris, personal communication). The Humbug for­ mation, whose type section is in the Tintic district, is the youngest

Paleozoic formation exposed in that area.

The lower three formations of the Mississippian system are quite similar in thickness and lithology in both the southern and central

Wasatch Mountains, (See figure 4.) However, the Great Blue limestone and the Manning Canyon shale are thinner in the Dry Mountain area. Wasatch Range near Salt La-Ke. C.i+y ££ (Granger,1153) tpaer

Great Blue limestone I,1b 0 -

I ,0 0 0 - Deseret limestone

300 -

Opex dolomite

[on Soo - ololomlte

1,000 “

l,»0-

Figure 4. Portions of the Paleozoic sections in the central and southern Wasatch Mountains. 1,000- -65-

MadiBon Limestone

Definition and diBtribution The Madison limestone was named by

Peale (1895* pp. 55“59) for the Madison Range in south-central Mon­

tana, where this formation of blue-gray massive oherty limestones is

well exposed. It has been identified southward through Idaho (Mans­

field, p. 60) and the northern Wasatch Mountains (Richardson, 1915) to

the Oquirrh Range (Gilluly, 1952, pp. 22-25), the central Wasatch

Range, and the southern flank of the (Baker, Huddle,

and Kinney, pp. 1175”!17^). The Madison limestone contains a fauna

which has become one of the standard references for correlations in

the Rocky Mountain region. Loughlin (1920) and Eardley (1955* PP» 520-

521) both collected Madison fossils in the vicinity of Santaquin Can­

yon and referred to the lower portion of the Mississippian rooks in

that area as the Madison formation.

Rooks of the Madison limestone crop out along the west face of

Dry Mountain from Santaquin Canyon to the low hills east of Spring

Lake, generally just below the crest of the mountain but near the foot

of Mollies Nipple. (See plate 27.) The formation is also exposed in

Rock Canyon and at the head of Bear Canyon on the western slope of

Loafer Mountain.

Lithology The Madison limestone consists of thin-bedded to massive medium- to dark-gray limestones and dolomites with an abun­ dance of chert in lenses and irregular thin beds. (See plate 8.)

The more cherty layers in particular are ledge-formers and from a dis­ tance outcrops of the formation appear as dark blue-gray cliffs. (See plate 7#B») A porous light-gray dolomite at the base of the for­ mation in Santaquin Oanyon may actually be correlative with the Jef­ ferson (?) dolomite of the central Wasatch Mountains (Baker, 19^7).

Some of the beds are very fossiliferous, and horn corals, specimens

Syringopora, crinold columnals, and gastropods of the Euomphalus type are quite common. (See plate 10,B.)

The dolomites are principally dark-gray to black, irregularly bedded, and clastic in nature— a feature well shown by the streaked and banded appearance on weathered surfaces. Some contain numerous vugs of white calcite, and some contain numerous horn corals.

The limestones are generally in more regular and thinner beds than the dolomites, and some are extremely fossiliferous. In the upper half of the formation the large flat-spiraled Euomphalus types of gas­ tropods are quite abundant; these are evidently characteristic of the formation in most other areas. A few layers are encrinites, and a few poorly-preserved crinoid caliceB can usually be found on weathered fragments of talus. About 1J5 feet below the top of the formation in

Santaquin Oanyon the limestone weathers out into large flagstones aver­ aging around an inch in thickness. These are generally quite - iferous, are somewhat silicified, are resonant when struck, and some weather reddiBh-orange. About 170 feet above the base of the forma­ tion in this same area there are two thin beds white-weathering dense limestone 6 feet apart. These have undulatory bedding and may be equivalent to one of the "curly beds" of the section in the Tintic district. Plate 8

Chert and limestone bed near the top of the Madison limestone.

Close view of bedded chert and limestone in upper Madison bed on west side of Mollies Nipple. - 6 6 - Plate 9

A* Typical chert lenses in Madison limestone

B. Silioified horn corals on bedding surface near top of Deseret limestone in Santa- quin Canyon* - 6 7 - Plate 10

A. Horn corals of the genus Trlplophyllites in hand specimen of upper Madison lime­ stone*

B. Kirkman limestone. Hand specimen of brecci- ated material composed of fetid laminated arenaceous limestone, typical of this formation. — 6 8 —

The upper portion, of the formation 1b extremely oherty. The

uppermost ledge is about 65 feet thick and is composed of chert in

discontinuous layers up to 10 inohes thick alternating with limestone

beds averaging less them a foot in thickness. (See plate 8.) This

ledge is overlain by the basal phosphate unit of the Deseret limestone

and is one of the best marker zones in the area.

Thickness The Madison limestone in Santaquin Canyon is about

560 feet thick. In the northern Wasatch Mountains it is 650 to 800 feet thick (Eardley, 1944), near Salt Lake City it is 650 feet (Gran­

ger, 1955) in the south-central Wasatch Range it ranges from less

than JOO to about 660 feet (Baker,Huddle, and Kinney, p. 1174). The

beds tentatively assigned to the Madison group in the Tintic district

are about 850 feet thick (Hal Morris, personal communication).

Stratigraphic relations The Madison limestone is overlain by the basal phosphatic shales of the Deseret limestone. The fact that this unit occurs above a massive resistant cherty layer is suggestive of syngenetic or peneeontemporaneous formation of the chert with sub­

sequent minor erosion— perhaps submarine in nature. The variegated black, red, and brown shale unit which is well exposed in an old prospect pit at the base of the Deseret high on the northeast side of

Santaquin Oanyon is certainly similar to shales associated with coal beds in other areas, and may be due to paralic environments of depo­ sition— which could well cause minor unconformities or diastema. The irregular occurrence of the shale unit, the abundance of phosphatic pellets and nodules, and their occurrence at the top of the cherty beds all point toward the presence of a disconformity at the top of - 6 9 -

the Madison.

The lower limit of the Madison limestone is not definite in the

Dry Mountain area, but as mapped in this investigation the formation

lies unconformably over the Cambrian Opex dolomite. Beds called Opex

are gently truncated by Madison strata, thinning from south to north.

Age and correlation The beds mapped as Madison on Dry Mountain

and Loafer Mountain are at least in part clearly the equivalent of the

Madison limestone in other areas. It is possible that some of the

dolomitio beds in the lower portion of the unit are Devonian in age

and correlative with the Jefferson dolomite or even the upper part of

the Bluebell (restricted) formation of the Tintic district, which is now known to be partly of early Late Devonian age (Hal Morris, per­

sonal communication). The only fossils the basal dolomites yielded were some poorly preserved specimens of Syringopora, a few crinoid

columnals, and an unidentifiable brachiopod. These clearly separate the beds from the similar dolomites of the Cambrian system, but they are of no help in differentiating Devonian rocks from those of the lower Misslssippian. There is no quartzite unit recognizable as part of the Devonian Victoria formation although some of the black dolo­ mites containing numerous white calcite vugs are similar to such beds in the Devonian of the Tintic district. For lack of clear-cut evidenoe to the contrary the interval from the lowest Syringopora-bearing dolo­ mites to the basal phosphatic unit of the Deseret limestone was mapped as Madison.

The following specimens of corals were collected from the Madison -70-

limestone at the south end of Dry Mountains

Lithoetrotionella multiradiata Hayasaka Syringopora suroularia Girty Syringopora sp. Triptphyllites sp.

Dr. E.C. Stumm, who made the identifications, stated that the first two are of Madison age, the fourth is of Mississippian age, and the third ranges from Middle through the Mississippian. Deseret Limestone

Definition and distribution The Deseret limestone was named by

Gilluly (1952, p. 25) for its exposure at the Deseret mine in the south­ ern part of the Oquirrh Mountains of Utah, where it consists mainly of blue-gray cherty limestone, separated from the underlying Madison lime­ stone by a phosphatic shale bed, and gradational with the overlying

Humbug formation. It has been mapped in the Wasatch Mountains and along the south flank of the Uinta Mountains (Baker, Huddle, and Kinney, p. 1174). It is now recognized in the Tintic mining district, where it was once included in the upper part of the Pine Canyon limestone

(Hal Morris, personal communication).

The Deseret limestone crops out in a band along the top of Dry

Mountain, broken by several faults, but extending from Santaquin Can­ yon to Mollies Nipple. It is also present on the west slope of Loafer

Mountain, in the vicinity of Bear Canyon and Rock Canyon, above the

Nebo Loop Road. (See plate 27.)

Lithology The basal phosphatic unit of the Deseret limestone can be traced almost continuously along the ridge at the top of Dry

Mountain, but is apparently covered by debris along the road in Santa­ quin Canyon. High on the northeast slope of the canyon the phosphate occurs in thin oolitic and nodular layers in a 5"foot shale bed and scattered through an overlying 30-foot shaly limestone unit. The shale is red and brown at the base, black and oarbonaceous at the top, and in addition to the phosphate contains a £-inch layer of coal.

Northward the phosphatic layers become thicker and the shales thinner, - 7 2 - disappearing in many places. In some localities the phosphate rook is in dense, hard layers 4 or 5 inches thick, and from a short dis­ tance away these resemble the black chert layers that are particularly numerous in the upper Madison bed immediately below. In some places the shaly limestones above the basal unit weather pink or orange, serving as an additional aid in mapping the basal contact of the for­ mation.

The bulk of the Deseret limestone is made up of medium-gray to black, dense to coarse-grained limestones which appear a rather homo­ geneous blue-gray from a distance. Many of the beds contain much black or gray chert in the form of nodules, lenses, and persistent irregular beds. Encrinites are abundant, and are dark-gray to black, fetid, and commonly cross-bedded. Orinoid columnals range from 1/16 to |f inch in diameter, but Beem to be fairly homogeneous in size within a single layer. In a few places they are silicified.

About 120 feet below the top of the formation near Santaquin Can­ yon there are two medium-gray fine-grained sandstones— one 7 feet thick and the other 4 feet. A few light- to medium-gray fine-grained dolomites are present near the center of the formation.

A massive cliff of dark-gray, cherty limestone marks the upper portion of the Deseret and forms a prominent, east-dipping ledge which crosses Santaquin Canyon a short distance below Tinney Flat. The uppermost beds are thick encrinites with abundant silicified horn corals and nodules of chert up to 1 foot thick. (See plate 9,B.)

Thickness In Santaquin Canyon the Deseret limestone is - 7 5 - approximately 720 feet thick. In the central Wasatch Mountains, it ranges in thickness from less than 400 feet near the head of American

Pprk to 900 feet in the Cottonwood-Amerioan Fork district (Baker,

Huddle, and Kinney, p. 1175)* Gilluly (1952, p. 25) assigned 650 feet of beds to the formation at the type locality in the southern

Oquirrh Mountains.

Stratigraphic relations The Deseret limestone on Dry Mountain is unconformable over the Madison limestone and is apparently overlain uneonformably by the Humbug formation. The disconfomity at the base is inferred from the presence of the phosphatic shale unit, and has been so interpreted by workers in other areas of its outcrop. The occurrence of phosphate beds at major and minor unconformities has been discussed by several authors (Pettijohn, 19^9* P» 552)* I* seems significant that the phosphatic unit in the area of this report almost invariably lies directly upon chert beds at the top of a thick resist­ ant layer of alternating chert and limestone.

The uppermost bed of Deseret limestone has irregular relief of about l|- feet over distances of only a few yards in the Santaquin Can­ yon area, and the contact here occurs just above a zone of numerous thick lenses and nodules of chert. The nature of the contact is not clear farther north, and in other areas the Deseret and Humbug are reported to be transitional. It seems quite probable, therefore, that the unconformable relationship here is a rather minor local feature.

Age_ and correlation The Deseret limestone is equivalent to the upper portion of the Pine Canyon formation, originally defined by

Loughlin (1919* PP. 40-4l) in the Tintic mining district and -7 4 -

subsequently recognized in numerous surrounding areas. It is also

equivalent to the lower portion of the Brazer formation of northern

Utah and southeastern Idaho, where a phosphatic shale also appears as

the basal unit (Mansfield, 1927* P* 182). Gilluly (1952, p. 26) sug-

i gested that the boundary between lower and upper Mississippian beds

probably is just below the phosphatic unit in the type area of the

Deseret limestone, and this assumption is also now made in the Tintic

district (Hal Morris, personal communication).

No diagnostic Brazer fossils were collected from the Deseret

limestone in the area of this report. The numerous horn corals in­

clude species of Trip1ophyl1ites, of Mississippian age. Loughlin

(1920, pp. and Eardley (1955* P» 521) both suggested the probable presence of rooks of Brazer age in the Santaquin district,

but were unable to find an upper boundary for the Madison strata.

Humbug Formation

Definition and distribution A sequence of alternating sandstones and limestones on the east elopes of Godiva Mountain and Sioux Peak, near Eureka, Utah, was first referred to as the BHumbug intercalated

series" by Tower and Smith (I889, pp. 625-626), named for the Humbug mine in that area. For promotional reasons the mine has since been

renamed the Uncle Sam mine. Loughlin (1919» PP. 41-42) desoribed this unit in more detail and referred to it as the Humbug formation . It has been mapped in several areas in central Utah— in the Oquirrh

Mountains (Gilluly, 1952 )> the south-central Wasatch Mountains (Baker,

1947), the Selma Hills (Rigby, 1952), Lake Mountain (Bullock, 1951)* -75-

and Long Ridge (Muessig, 1951)• Granger (1955) combined the Humbug

and Great Blue formatione in hia discussion of the Wasatch Mountains

near Salt Lake City.

The Humbug formation crops out on the southeast side of Dry Moun­

tain near Tinney Plat, but disappears to the north beneath Tertiary

beds. In the vicinity of Red Lake on the east side of Dry Mountain

the Humbug again appears, and the outcrop gradually ascends to the

top of the mountain and follows along the ridge to the north, forming

a dip slope and underlying the upper portion of Crooked Canyon at the

north end of the mountain. (See plate 27.) It forms a major portion

of the hilltop just northwest of Mollies Nipple.

In Payson Canyon the Humbug formation is present high on the div­

ide between Rock Canyon and Bear Canyon on the west flank of Loafer

Mountain.

Lithology The Humbug formation consists of a succession of

sandstones, limestones, and dolomites. Individual units are mainly

1 to 10 feet thick, but range from a few inches to over 80 feet. Some are quite lenticular, and others are Bubject to rather rapid facies

changes. The formation is exposed in a cliff face in Santaquin Can­ yon just below Tinney Flat, and it is here notable for its striking buff and gray banded appearance.

The sandstones of the Humbug formation in Santaquin Canyon com­ prise about half of the formation, and are mainly fine-grained and light-gray, weather brown to buff, are quartzitic to a large extent, but are also gradational to dolomite or limestone— particularly toward the top of the unit. Well-defined ripple marks are in one of -76- the sandstone beds 565 feet above the base of the formation. Toward the north end of Dry Mountain some of the sandstones are coarse­ grained, and weather to shades of red, as well as buff.

Near the base of the formation the limestones are quite similar to those of the underlying Deseret formation— dark gray, finely to coarsely crystalline, cherty, and in many cases composed of fossil debris of crinoid oolumnals, brachiopods, and horn corals. Toward the center of the formation the carbonate is principally dolomite which is medium-gray, finely crystalline to fine-grained, commonly lamin­ ated, lenticular, and in many beds shaly or sandy. The carbonate of the upper portion of the Humbug formation in this area is again pri­ marily limestone, but is light- to blue-gray with pink or lavender tints, and iB fine-grained to dense. Some beds are lithographic.

About 580 feet above the base of the Humbug in Santaquin Canyon is a 12-foot dolomite and quartzite unit which is brecciated. About

40 feet below the top of the formation is a flat-pebble conglomerate,

4 inches thick, and containing rounded fragments of coarse-grained limestone quite unlike the limestones immediately below the bed, but similar to some of the beds lower in the formation.

Thickness The Humbug formation in the Santaquin Canyon section is 664 feet thick, but is no more than 400 feet at the north end of

Dry Mountain. Baker (1947) found 646 feet of Humbug near American

Fork Canyon and 5*5 feet in Rock Canyon, near Provo. Gilluly (1952, p. 28) measured 650 feet in the Oquirrh Mountains, but in Long Ridge and in the Tintic district the upper part of the formation is missing. - 7 7 - It is over a thousand feet thick in the mountains west of Utah Lake

(Rigby, p. 49). In the Wasatch Mountains near Salt Lake Oity

Granger (1955* P» 5) measured a combined thickness of 1100 feet of the

Humbug and Great Blue (?) formations, and considered the lower 727

feet as a possible correlative of the Humbug of other areas.

Stratigraphic relations The upper Humbug formation is grada­

tional with the Great Blue formation, and the boundary in the Dry

Mountsin-Loafer Mountain area is arbitrarily placed at the top of the

uppermost notable sandstone bed. The lower boundary is drawn at the

base of the lowermost sandstone, which, in Santaquin Canyon, overlies

an irregular surface of Deseret limestone, having a local relief of

as much as ljjs- feet. Irregular nodules of chert lie in the upper sur­

face of the Deseret, and these appear somewhat abraded. Workers in

other areas have reported gradational contacts between the Deseret

and Humbug formations.

Age and correlation In the Tintic mining district the Humbug

formation is considered to be part of the Brazer group of late Miss-

issippian age. Gilluly (1952, p. 28) concluded that the Humbug of

the Oquirrh Mountains is probably equivalent to part of the type

Brazer. No diagnostic fossils were found in the formation in the Dry

Mountain-Loafer Mountain area but lithologic and sequential similar­

ities strongly suggest its equivalence to the Humbug of surrounding

areas. - 78“ Great Blue Limeatone

Definition and distribution The name "Great Blue limestone" was first applied by Spurr (1895* PP» 57^“576) to “the 000-toot sequence of dark-blue limestones and black shales lying between the "Upper

Intercalated series" (Oquirrh) and the "Lower Intercalated series"

(Humbug) in the Mercur mining district of Utah. Gilluly (1952, p. 29) later redefined the term to refer to a thick unit of thin-bedded lime­ stones with a few minor shaly beds, lying conformably between the older Humbug formation and the younger Manning Canyon shale. The for­ mation has been recognized in the central Wasatch Mountains and the

Oquirrh Mountains (Baker, Huddle, and Kinney, pp. 1176-1178) as well as in the low mountains west of Utah Lake (Bullock, p. 17)•

The Great Blue limestone crops out west of Tinney Flat at the south end of Dry Mountain, but is relatively thin, due to normal and thrust faulting. It continues northward a short distance, forming the eastern dip slope of the peak at the southern end of Dry Mountain, but has been eroded away in the vicinity of Santaquin Meadows. North of

Red Lake the formation reappears and continues northward in unbroken outcrop, forming a prominent ridge between Picayune Canyon and Crooked

Canyon at the north end of Dry Mountain, and dipping steeply eastward on the eastern slopes of Mollies Nipple. A portion of the Great Blue formation is present on the crest of the divide between Bear Canyon and Rock Canyon at the west end of Loafer Mountain.

Lithology In the type area of the Great Blue limestone as rede­ fined by Gilluly, the formation consists of upper and lower thin- bedded limestone members separated by the carbonaceous Long Trail - 7 9 - shale, which has a maximum thickness of 85 feet in the southern

Oquirrh Mountains. A similar shale unit is present in the Wasatch

Mountains near Provo, and shaly beds are present in post-Humbug Miss- issippian rocks in other parts of the Wasatch Range as well as in the

Uinta Mountains (Baker, Huddle, and Kinney, pp. 1176-1178).

Bede corresponding to the lower member of the typical Great Blue formation are definitely present in the area of this report, but the rocks above this member are confusing. A shale unit everywhere over­ lies the post-Humbug Mississippian limestone, but the unit is generally poorly exposed, and stratigraphic relations are not apparent. The

Bhale sequence at Tinney Flat is almost certainly Manning Oanyon shale, and the lithology of the shale units to the north is similar to it.

(See plate 27.) In addition, the intermittent outcrops of the shales— mainly in valleys and gulches— are aligned along the general strike of the beds, so that the outcrops may be parts of a continuous unit.

The estimated thickness of the limestone sequence varies from around

500 or 600 feet to over 1000 feet, which corresponds well with thick­ nesses of the basal Great Blue member in other areas. Thus, from the stratigraphic position of the shale beds, one might be inclined to call them the Long Trail shale member of the Great Blue— particularly at the north end of Dry Mountain.

Thrusting has occurred in the shales, and the overriding beds are of the Oquirrh formation— another case of younger rocks being thrust over older rocks in this area. A few transverse normal faults offset the sequences. It cannot readily be determined whether the shales on

Dry Mountain have been dragged along under the Oquirrh beds and are -80-

definitely Manning Canyon shale, or whether the upper beds slid for­ ward over the Long Trail shale. The writer believes that the shale

sequences are probably Manning Canyon shale and has so mapped them— limiting the Great Blue formation in this area to the limestones be­ tween the Humbug formation and the first unit of carbonaceous Bhale with subordinate quartzite and limestone beds.

The Great Blue limestone in this area is fine-grained to dense, light-gray to dark blue-gray, thin- to medium-bedded, and in many places weathers pink to light-gray. In the upper portion of some seotions there is a bed of medium-gray calcareous shale which contains numerous fragments of phosphatic brachiopod shells. Not far below the top of the unit at the north end of Dry Mountain and on Loafer Moun­ tain there is a limestone which weathers a peculiar shade of olive- brown and in some places is an encrinite.

Thickness The Great Blue limestone is about 56OO feet thick in the Oquirrh Mountains (Gilluly, 1952, p. 29), 2800 feet in the vicin­ ity of Provo (Baker, 19^7)* and 2600 feet in the Pelican Hills, west of Utah Lake (Bullock, p. 17). On Dry Mountain the estimated thick­ ness of Great Blue varies from around $00 to 1200 feet, but a complete seotion of the formation may not be present.

Stratigraphic relations The Great Blue limestone is gradational with the Humbug formation below and the Manning Canyon shale above.

The only place in the area where the upper contact is clearly obser­ vable is on the west side of Tinney Plat in Santaquin Canyon, in the vicinity of the bridge. At this outcrop a sequence of limestones con­ tains progressively more shale beds until at the east end of the - 8 1 - eastward-dipping hogback there is a soft carbonaceous shale which resembles coal and is associated with quartzites and thin-bedded hard limestones typical of the Manning Canyon shale.

Age and correlation No diagnostic fossils were collected from the Great Blue limestone, but the formation is considered to be late

Mississippian in age throughout central Utah. Gilluly (1952, pp. 50-

51) collected fossils from the Great Blue in the Oquirrh Mountains which were considered by Girty to be of Brazer age, and Calderwood

(1951* p« 27) found the brachiopod Ohonetes ohesterensiB, indicative of Chester age, in the lower member of the Great Blue limestone in the

Cedar Valley Hills, west of Utah Lake. - 8 2 -

Miaslssippian and Pennsylvanian Systems

Manning Canyon Shale

Definition and distribution A thick sequence of carbonaoeous shales and minor interbedded limestones and quartzites, which lies con­ formably above the Great Blue limestone in the vicinity of Manning Can­ yon in the southern Oquirrh Mountains of Utah, was named the Manning

Canyon shale by Gilluly (1952, p. 51)• There are several discontinu­ ous outcrops of this formation in the Oquirrh Range, and it is also present in the central Wasatch and the Oquirrh Mountains (Baker, Huddle^ and Kinney, p# 1178)/ in the Gold Hill quadrangle (Nolan, 195*0» an<* in the mountains weBt of Utah Lake (Bullock, p. 18).

The Manning Canyon shale ia exposed at the southeastern end of

Dry Mountain at Tinney Flat— particularly on the south side of the camp grounds and along the road to Santaquin Meadows, but it is also pres-' ent in depressions and gulches along the east side of Dry Mountain, forming a valley above the Great Blue limestone at the head of Pica­ yune Canyon# (See plate 27.) It crops out in two exposures at the western foot of the low hills north of Mollies Nipple, northeast of

Spring Lake. On the west side of Loafer Mountain the Manning Canyon shale is present high on the ridges on either side of Rock Canyon. It crops out in many places on the floor of Bear Canyon, and crosses the

Nebo Loop Road in low hills southwest of Bear Canyon# A small exposure of soft carbonaoeous shale in Santaquin Canyon west of the mountain front is probably a part of this formation.

Lithology The Manning Canyon shale consists of shales interbed­ ded with lesser amounts of limestone and quartzite. The shales are principally black, but minor amounts of fissile brown, gray, and tan

shales are also present. Some are lead-gray and feel soapy. Black

shales range from soft, muddy masses to fairly hard, fissile material,

and some closely resemble poor grades of coal. The soft, muddy mater­

ial is jet black, and contains soattered elongate crystals of clear

selenite, ranging from a few millimeters to 5 or 4 inches in length.

During the years 1955-195^ prospectors found minor amounts of carno- tite in the black shales in this area. Much of the shale— particularly the more fissile beds— contains numerous small irregular nodules of red to greenish-brown jasper, which cover many of the weathered slopes underlain by the formation.

Quartzites in the Manning Canyon shale are massive, hard, fine- to coarse-grained and have a peculiar greenish-brown color. They weather olive-brown and rusty-brown, imparting a distinctive oolor to slopes of the formation. In areas in the central Wasatch Mountains, a basal shale member of the Great Blue formation is reported to have sim­ ilar quartzites (Baker, Huddle, and Kinney, p. 1176). Individual quartzite beds up to JO or 40 feet thick are present in the formation at Tinney Plat. Gilluly (1952, p. 52) found that similar quartzite beds in the Manning Canyon shale in the Oquirrh Mountains are quite lenticular, but in the area of this report lateral relations of indi­ vidual beds cannot be determined. Near Mollies Nipple some of the arenaceous beds are coarse-grained, well-sorted sandstones with angu­ lar grains.

Minor amounts of limestone are present. Some is medium-gray to black, weathers tan to olive-brown, and contains numerous fossil - 8 4 - fragments. It is thin- to medium-bedded, and individual units up to

20 feet thick are present. Some of the limestones are dark-gray, with abundant black chert in irregular layers 1 or 2 inches thick.

Thickness No complete section of Manning Canyon shale was measured, and it is very doubtful that an individual complete section is present in this area, due to folding and thrust faulting. Further­ more, the outcrops are generally the sites of valleys, are covered by alluvium and vegetation, and are only poorly exposed. Gilluly (1952, p. 52) measured 1140 feet of the formation in the Oquirrh Range, and

Baker (1947) found 1645 feet of Manning Canyon shale east of Provo in the Wasatch Mountains.

Stratigraphic relations The Manning Canyon shale is gradational with the underlying Great Blue formation, which becomes progressively more shaly in its upper portions. The boundary between the two is arbitrarily drawn where the beds become predominantly shaly.

The Manning Canyon and the overlying Oquirrh formation are also apparently gradational. The only exposure of this contact is at the outorops in the low hills northeast of Spring Lake, and the formations are apparently conformable here.

Thrusting on a considerable scale has evidently occurred along the incompetent beds of the Manning Canyon. It appears that the

Oquirrh formation at the base of the overthrust portion carried along beds of the underlying shale, smearing them over rocks as old as the

Madison limestone on the surface below the thrust fault on the ridge south of Rook Canyon.

Beds of Manning Canyon shale in Bear Canyon and along the Nebo -85“

Loop Road owe their position to drag foldB and to normal faults* In the area west of the Nebo Loop Road, north of Maple Dell, the scattered outcrops of Manning Canyon shale are due to landslides from the slopes of Dry Mountain.

Age and correlation Gilluly (1952* P» 52) found that the Manning

Canyon of the type area contains beds of both upper Mississippian and lower Pennsylvanian age, and other workers have generally cited his findings as the only evidence on the age of the formation. No diagnos­ tic fossils were collected from the formation in the Dry Mountain-

Loafer Mountain area, but the brachiopod fauna of basal beds of the

Oquirrh formation on Loafer Mountain are thought by some to have more of a Chester than a Pennsylvanian aspect (G.A. Cooper, written commun­ ication). This implies that all of the Manning Canyon shale in this area is probably Mississippian in age. However, Mr. Cooper stated that other workers in the West have considered similar faunas to be of

Pennsylvanian age, so that the age of the strata in thiB area is still in doubt.

It is by no means certain that the beds called Manning Canyon shale in this area are correlative with that formation in the type area and in the central 'Wasatch Mountains. The lithologies are quite similar, however, and in every area the unit is a shaly sequence be­ low the Oquirrh formation. It is possible that the combined Great

Blue and Manning Canyon shale of this area are equivalent to only the lower portion of the Great Blue formation in other areas, and that there is an unconformity at the top of the beds here called Manning -86-

Canyon— a situation similar to that postulated for the post-Humbug

Mississippian beds in the Cottonwood-American Pork district (Baker,

Huddle, and Kinney, p. 1177)•

Pennsylvanian and Permian Systems

Oquirrh Formation

Definition and distribution The Oquirrh formation was named by

Gilluly (1932, pp. 3 ^ 5 8 ) f°r "tt*® Oquirrh Mountains in north-central

Utah. The lower part of the formation includes the thick sequence of interbedded limestones, quartzites, and sandstones formerly called the

"Upper Intercalated series" by Spurr (1895# P» 576). The Oquirrh is probably the thickest formation in Utah and it contains both Pennsyl­ vanian and Permian strata. It forme a large portion of the exposed rocks in the south-central Wasatch Mountains and was recognized as the "Intercalated series" in the southern Wasatch Mountains by both

Loughlin (1913) anci Eardley (1955)* Schoff (1957# P» 25) suggested the probable equivalence of the "Intercalated series" rocks in the southern Wasatch Mountains to the Oquirrh formation.

Usage of the name Oquirrh is confined to regions south and west of the major thrust fault through Heber Valley (Baker, Huddle, and

Kinney, pp. 1183-1184), including outdrops in the Wasatch Range south of American Pork and other nearby ranges in the Great Basin. The formation is absent in the Tintic district but present in Long Ridge

(Muessig, pp. 56-61).

The Oquirrh formation is the principal surface rock on the upper slopes and the southern and northern flanks of Loafer Mountain as well -87- as in the narrow lower portion of Spanish Fork Canyon north of Pole

Canyon. Tithing Mountain, south of Payeon, is composed of Oquirrh

strata, as is the ridge along the western side of Payson Canyon as far

south as Maple Dell. A thin band of beds mapped as Oquirrh crops out along the eastern side of Dry Mountain southward almost to Red Lake, but beds of Tertiary conglomerate lap high up on the slopes in this area. In Santaquin Canyon, about a mile above Tinney Flat, the creek passes through a narrow chasm which cuts almost perpendicularly through thick, blue-gray vertical walls of Oquirrh limestone and sand­

stone. These steeply dipping strata are overlain unconformably by

Tertiary rocks, and are Intermittently exposed in the vicinity of the camping area at Tinney Flat. The outcrop of Carboniferous sandstone and limestone below the Teutonic limestone at the mouth of Santaquin

Canyon is probably Oquirrh. The Teutonic is at the base of the Santa­ quin overthrust allochthon.

Lithology The Oquirrh formation is an extremely thick mass of limestones, sandstones, and quartzites, with rocks gradational between these types. Shales are almost lacking, and those that do occur are highly calcareous or arenaceous. The major portion of the formation consists of a monotonous alternation of buff-weathering sandy lime­ stones and sandstones or quartzites; distinctive lithologic zones are rather rare. Some beds are quite fossiliferQus; others seem almost devoid of organic remains. Portions of the Oquirrh are in gross as­ pect identical with the Humbug formation, and it is possible that the writer has misidentified some Humbug beds as Oquirrh— particularly in the Dry Mountain area. The general lithology of the Oquirrh formation is summarized in the diagrammatic section prepared by Bissell

(1952, p. 585) is shown in figure Sandstones are fine- to coarse-grained, thin-bedded to massive,

and generally weather light-brown or dull reddish-brown. Very fine­

grained varieties are particularly abundant; many are actually silt-

stones. These are medium- to dart-gray, weather brown, are very hard

and dense, and in most cases are somewhat quartzitic. Thin-bedded,

fine-grained, calcareous and micaceous sandstones in many places have

myriads of worm-like trails along the bedding planes. These trails

range from about 0.1 inch to over half an inch in diameter and gener­

ally consist of dark-brown or black films. Brown, white, and pink

sandstones are also present. Many are quartzitic, Bome are argillac­

eous, and many are gradational to limestones. Brecciated zones are apparently due both to penecontemporaneous brecciation and to fault

zones. Quartzite and sandstone sequences are as much as 200 to 500 feet thick, but most are less than 50 feet. Intricate intertonguing with limestone beds is observable, and rapid facies changes occur in

some beds.

Limestones range from light-gray or almost white to dark-gray

or black, and brown-weathering, arenaceous varieties are common.

Some beds are streaked with lenses and tongues of sand and some contain abundant chert in lenses and stringers. Limestones in the upper por*i» tion of the formation generally contain an abundance of large silici­ fied fusulinids, and such beds are mainly dark-gray and fetid. A few limestones are stylolitic, but stylolites on the whole are uncommon. - 8 9 -

In the lower part of the formation some of the beds are soft, very argillaceous, and quite fossiliferous, but there are buff-weathering arenaceous beds which contain an equal abundance of fossils. Dark blue-black limestones on Tithing Mountain contain silicified brachio- pods that stand out in bold relief on weathered surfaces, but the rocks are b o hard and dense that specimens are difficult to collect. Few limestone units are more than $0 or 40 feet thick.

An unusual feature of the Oquirrh formation iB the almost complete lack of shales. Sandstones intertongue with and are gradational to limestones throughout the tremendous thickness of the sequence, and one would ordinarily expect shale facies also to be in evidence. Fine grained olasticB are definitely present. Many of the arenaceous lime­ stones are also argillaceous, and many of the sandstones are poorly sorted, containing an abundanoe of clay-sized material. Much of the quartzite is actually silicified siltstone, and in rocks of this type the sediment is generally well-sorted and homogeneous. The beds with worm-like trails on the bedding planes are quite poorly sorted and contain much fine-grained mica. Nevertheless, clear-cut shale beds are almost lacking.

Conditions which produced this formation must have been unstable.

The source of the sediment was probably the "ancestral Rocky Mount­ ains" which were being uplifted in eastern Utah and western Colorado at approximately the same time. The many clean well-sorted ortho- quartzitee and fossiliferous limestones throughout the formation in­ dicate that the water in which the sediment was deposited was prob­ ably never very deep. If so, subsidence had to be extremely rapid to •90- accommodate the unusually large volume of elastics.

Additional regional petrographic studies of this anomalous form­ ation may clarify the question. Merely referring to the unit as being one of alternating stable and unstable shelf environments does not answer the question as to why there are almost no shales in the Oquirrh formation and its equivalents in the surrounding areas.

Thickness The writer was unable to measure a good complete sec­ tion of the Oquirrh formation in this area. The entire formation is evidently present here, and with time and careful correlation of--key-- beds a complete sequence can probably be found. Four partial seotione totaling over J,000 feet were measured on Loafer Mountain, and the writer believes that there is less than 15,000 feet of the formation here, and possibly less than 12,000 feet. Baker (194-7) found evidence that the Oquirrh formation is about 26,000 feet thick in the south- central Wasatch Mountains, and Gilluly (19?2, p. 55) confident that the thickness of the Oquirrh in the type area is greater than

15,000 feet. Faulting and folding in the formation are difficult to detect and it is still harder to determine the amount of displace­ ment, due both to the great thickness of alternating units of striking similarity and to the rapid lithologic facies changes of some beds.

Stratigraphic relations The Oquirrh formation is conformable over the Manning Canyon shale in undisturbed sections and the boundary is arbitrary in many places, including the type area (Gilluly, 1952, p. 54; Baker, 1947). In the Dry Mountain-Loafer Mountain area the lower contact has been obscured by thrusting, and it is not certain that the lowermost beds there mapped as Oquirrh are actually basal -91-

Qquirrh.

The upper portion of the Oquirrh is conformably overlain by the

Kirkman limestone, and on the ridges at the head of Orab Creek the

Oquirrh and Kirkman apparently intertongue. In the south-central

Wasatch Mountains there may be an unconformity between the Oquirrh and the Kirkman north of Spanish Pork Canyon (Baker, 19^7)•

Age and correlation The published data concerning the age of the Oquirrh formation were summarized by Bissell (1952, P» in a chart which is reproduced In part in figure 5. Other diagrammatic sec­ tions with fauna1 zones indicated for the Oquirrh of the Provo area have been published by Baker (1947) and Baker, Huddle, and Kinney

(p. 1184). Fusulinids seem to be the best aid for the correlation of individual units within the formation, and the interested reader is referred to a series of papers by Bissell and co-authors concerning these guide fossils. The Pennsylvanian fusulinids of the Oquirrh of the south-central Wasatch Range are rather comprehensively discussed by Thompson, Verville, and Bissell (1950).

The Oquirrh formation of the south-central Wasatch Mountains evi­ dently represents continuous deposition from Springeran to Wolfcampian time. The Morgan formation and the Weber quartzite of the north-cen­ tral Wasatch and Uinta Mountains are equivalent to only the lower part of the Oquirrh (Baker, Huddle, and Kinney, p. 1187). *-92-

(AGE) TlON

Sandy Limestone,

7,500 Limes We,

J.SOO

1.300

2.800

3,000

Argillaceous-Calc Or -

1.100

Figure 5» Generalized section of the Oquirrh formation, (From Bissell, 1952, figure 4.) Strata representing the entire age range of the Oquirrh in other

areas are evidently present in the Dry Mountain-Loafer Mountain area.

Brown (1952/ p. 541) collected a megafoesil fauna from beds in the

low hills north of Mollies Nipple which ia identioal with that from

Springeran and Morrowan rooks of the Oquirrh formation near the lower

Bridal Veil Falls in Provo Canyon. Fossils of both Pennsylvanian and

Permian age are present in the Oquirrh formation on Loafer Mountain.

The writer made several collections of fossilb— ohiefly fusu-

linids— at various places on Loafer Mountain and some of them are

listed below. Identifications of corals were made by Dr. B.C. Stumm.

The fusulinids were studied by Mias Pauline Smyth of the Ohio Geolog­

ical Survey. Questionable generic identifications of some of the microfossils are due mainly to the lack of skill of the writer in

preparing slides of the specimens.

A. Permian collections (Wolfcamp);

1, Half way up Flat Canyon, north side. These specimens were found at 94, 150, and 156 feet, respectively, below the Kirkman limestone. Schwagerina sp. Pseudoschwagerina (?) Triticites cf• powwowensis Dunbar and Skinner t 2, Ridge south of Bennie Creek, about 800 feet below the Kirkman limestone. Pseudoschwagerina sp.

5. Mahogany Ridge, about 400 feet below the Kirkman limestone. Schwagerina sp.

4. Ridge between heads of Crab Creek and Left Fork of Maple Canyon, at various horizons throughout the thousand foot interval below the Kirkman limestone. Paraschwagerina sp. Para schwagerina (more elongate form than first) - 9 4 -

Paeudoschwagerina sp* Pseudoschwagerina beedei Dunbar and Skinner Schwagerina sp, Schwagerina (with well-defined aveoli) Schwagerina cf, huecoensis Dunbar and Skinner

B. Pennsylvanian collections*

1. Head of left fork of Loafer Canyon, on ridge extending south from Santaquin Peak, estimated as between 5000 and 6000 feet stratigraphically above the Dry Mountain thrust fault. Intervening normal faults and folding make estimates uncertain, Tritioites cf, springvillensis Oaninia sp, Pleurodictyum sp,

2, Slope ^-mile south of Dream Mine road. Downthrown normal fault blook. Fusulinella sp.

5, Tithing Mountain, southwest slope. Part of Bear Canyon thrust sheet, Ohaetetes milleporaceous Edwards and Haime Lophophyllidium sp.

The former is lower Pennsylvanian in age, according to E.G. Stumm, Baker (1947) described a Ohaetetes zone about 5,500 feet above the base of the Oquirrh near Provo.

The portion of the Oquirrh formation west of a general north-south

line along the upper part of the Left Fork of Maple Canyon is appar­

ently all Pennsylvanian in age, Beds to the east, with the exception

of the area near the mouth of Spanish Fork Canyon, are Permian.

The age of the oldest rocks of the Oquirrh formation in this area

is in doubt. At the time of the writing of this report some brachiopod

collections from the Oquirrh are being studied by G. Arthur Cooper.

One collection is from Oquirrh strata about a hundred feet above the

Dry Mountain thrust in Payson Canyon, and Mr. Cooper has written regarding this collections -95- **1 suggest (a) Chester age, but must report that some question exists as to the correctness of this determin­ ation. Dr;. Mackenzie Gordon, Jr. of the U.S. Geological Survey examined this collection with me and believes that it is Chester rather than Pennsylvanian. However, collections in hie possession from other Utah localities contain additional species which he regards of Mississ- ippian rather than Pennsylvanian affinity. Other col­ lectors and others on the Geological Survey date the same collections as lower Pennsylvanian."

Permian System

Permian rocks above the Oquirrh formation are subdivided into

three units in the southern Wasatch Mountains. The "type section" for

the Permian of this area, near Hobble Creek, east of Springville, has

been discussed by Baker (Baker and Williams, 1940; Baker, 1947J Baker,

Huddle, and Kinney, 1949). The Permian beds differ to a great extent

on either side of a major fault, the Charleston thrust, in the vicin­

ity of Heber, Utah. Worth of the fault the Park City formation lies

on the Weber sandstone, and is 870 feet thick, while near Hobble

Creek the Permian above the Oquirrh is over 4000 feet thick, consisting

of the Kirkman limestone, the Diamond Creek sandstone, and the Park

City formation, in ascending order.

Kirkman Limestone

Definition and distribution The name Kirkman limestone was

given by Baker and Williams (1940, pp. 625-626) to a distinctively

laminated and partially brecciated, dark, fetid limestone which crops out in Kirkman Hollow, a tributary to Hobble Creek about 9 miles east of Springville, Utah. Prom the type area it extends northward a few - 96- mil os and disappears beneath a cover of Tertiary rocksy but reappears

in northern Strawberry Valley (Bissell, 19^2, P« 588). To the south, the Kirkman limestone crops out intermittently between Kirkman Hollow and Spanish Fork Canyon. Bissell also found the formation on the

southeastern part of West Mountain, at the south end of Utah Lake,

Southwest of Spanish Fork the Kirkman is present along the east­

ern slopes of Loafer Mountain, crossing Benny Creek as a prominent, massive, east-dipping ledge, and disappearing a few hundred yards to the south beneath Tertiary rocks. The unit crops out extensively in

Pole Canyon due to the synclinal structure there, and is exposed on most of the spurs of Loafer Ridge, on the ridge between Thurher Canyon and Lone Pine Gulch, and along the south side of the lower portion of

Pole Canyon, An isolated outcrop is present at the head of Flat Can­ yon. Faulting and folding have caused an irregular pattern of outcrop on Loafer Mountain north of Crab Creek, but from Crab Creek to the

southern limit of its exposure the Kirkman is present in a fairly con­ tinuous band.

Lithology The Kirkman limestone is characterized by dark-gray to blaok laminated limestone with subordinate amounts of buff to brown

sandstone, and in most places at least a pQrtion of the section is brecciated. (See plate 10,B.) In addition to the laminated beds the

Kirkman contains dense to medium-grained, medium-gray to black lime­ stone, generally fetid, and locally phosphatic.

Laminated beds consist of alternating light and dark layers rang­ ing from paper-thin to 2 mm. in thickness. The dark laminae are more - 9 7 - uniform in thickness, are dense to medium-crystalline, and are composed

of limestone rich in organic matter* The light laminae are generally

buff or gray, vary in composition from argillaceous material to medi­

um-grained sandstone, vary greatly in thickness, and in some cases

are caloareous. The beds are contorted to various degrees, ranging

from undisturbed, flaggy-weathering types to breccias composed of frag­ ments of both flaggy and blocky shapes up to 2 or 5 feet in diameter*

The breccias are apparently penecontemporaneous in origin, prob­

ably caused by slumping of semi-consolidated material. Interstitial

spaces are filled with buff sand or with medium-gray calcareous cement.

Several of the brecciated layers are quite hard, and form prominent

ledges or cliffs. Lenticular beds of fine-grained, calcareous, tan or

buff sandstone up to 8 or 10 feet thick are interspersed in the forma­

tion, and in many places are also brecciated. SiltBtones which are

both laminated and brecciated are in the basal Kirkman south of Benny

Oreek.

Undisturbed strata are softer, and in many placeB are quite con­ torted due to much younger orogenic movements. On the flanks of the

syncline in the vicinity of Pole Canyon the Kirkman beds have appar­ ently thinned, with an accompanying increase in thickness of the unit in the trough of the fold.

Thickness The thickness of the Kirkman limestone varies con­

siderably. Baker (19^7) found a maximum thickness of nearly 1600 feet of the formation at its type locality, and Bissell (1952, p. 588) measured 575 feet in northern Strawberry Valley. Sections southwest - 9 8 - of Spanish Fork apparently average between 250 and 500 feet in thick­ ness. Immediately south of Grab Greek the Kirkman is quite thin— probably due to thrusting— and in Pole Canyon the unit seems to be much thicker, Aocurate measurements of thickness are difficult to make as a result of the contorted nature of the beds in structurally disturbed areas,

Stratigraphic relations The Kirkman limestone is gradational with the overlying Diamond Creek sandstone and intertongues with it in places. Baker (19^9* P* 1187) h&8 suggeeted that the Kirkman is pos­ sibly unconformaMe on the Oquirrh formation, basing hie conclusion on the sharp lithologic break between the two, basal Kirkman breccia in many sections, and the great variation in thickness of the Kirkman.

Some of the outcrops on Loafer Mountain, however, indicate a conform­ able lower contact, and in some places seem to intertongue. The thin­ ning of the unit on the ridges just south of Crab Greek is possibly due to thrusting, but the contacts are not well exposed and it may be that an unconformable relationship exists here.

Age and correlation Baker (1949, p. 87) found fusulinids of Wolf- camp age in the Gquifrh formation immediately below the Kirkman lime­ stone at Hobble Greek, and Bissell (1952# P* 588) identified specimens of Schwajserina and Pseudoschwagerina from the lower Kirkman near Benny

Creek, Miss Pauline Smyth identified these same genera of fusulinids from collections made by the writer in upper beds of the Oquirrh forma­ tion near the head of Flat Canyon and in the vicinity of Benny Greek.

A specimen of Pseudoschwagerina was also collected in the upper portion —pp*.

of the Kirkman limestone on the ridge between the heads of Pole Can­

yon and Crab Canyon* The Kirkman would therefore eeem to be of Wolf-

camp and possible Leonard age.

Diamond Creek Sandstone

Definition and distribution A thick sandstone unit which is

well exposed at the head of Little Diamond Creek, a tributary of Dia­

mond Pork about 4 miles east of Spanish Pork Canyon (figure 2), was

named the Diamond Creek sandstone by Baker and Williams (1940, pp. 62$-

62J), It has been traced to the northeast as far as Strawberry Valley

(Bissell, 1952* P» 589)» and extends in a nearly continuous outcrop

southward to the vicinity of Benny Creek southeast of Loafer Mountain,

Muessig (p. 6l) found beds of Diamond Creek sandstone in Long Ridge.

It apparently attains its maximum development in the region around

Spanish Pork Canyon.

Southwest from Spanish Fork the Diamond Creek sandstone crops

out on most of the spurs in Pole Canypn, and crosses as a massive

ledge near the head of the canyon. It forms the bulk of the ridge

north of Shurtz Canyon, and from there extends southward in a contin­

uous outcrop along the east side of Loafer Mountain to about a half

a mile south of Benny Creek. Sandstones assigned to the Diamond Creek are also present in fault blocks which protrude above the prominent

Lake Bonneville terrace at the mouth of Spanish Pork Canyon. -100- Plate 11

W"

A. Slope of Diamond Creek sandstone on east side of Loafer Mountain, looking north from lower Left Pork of Crab Creek. Thin-bedded strata above are Park City formation.

B. Outcrop of Diamond Creek sandstone in Crab Creek Canyon showing irregular bedding and cavernous weathering common in the unit in this area. -101 Plato 12

Ridges of east-dipping Permian strata on the east side of Loafer Mountain. Looking northwest from U.S. Route 89 near Birdseye.

Hogback of Nugget sandstone and overlying Twin Creek limestone in Thistle. Slope in right foreground isT Twin Creek. Look­ ing north along U.S. Route 8 9 . Lithology Beds of the Diamond Creek sandstone are principally

massive and buff colored, but shades of red, gray, and white are also

common. Individual units range from ailtstones to coarse-grained sand­

stones, and from very friable material to quartzites. Some of the

strata are cross-bedded, but many are massive and irregular, and are

markedly pitted by cavernous weathering. (See plate 11.) Wooded

slopes are present at moat of the Diamond Creek outcrops, and on many

ridges large rounded bosses of buff or white sandstone are visible at

scattered spots in the vegetation. The quartzites, which are gray or

pink, resemble closely some of those in the Oquirrh formation. Lam­

inated beds are common. In some beds the laminations alternate in

color but maintain constant average grain size, while laminations of

different grain sizes are present in other beds of homogeneously col­

ored material. Occasional layers are brecciated, and lenses of aren­

aceous limestone are present in some sections.

In the vicinity of Benny Creek the unit contains a thick massive

layer of clean, white, friable, medium- to coarse-grained sandstone with numerous laminae of well-rounded grains. Near Spanish Pork Can­ yon some of the beds of Diamond Creek sandstone contain small buff to red nodules of argillaceous and arenaoeous material, embedded in a porous pink siltstone matrix.

Thickness Thickness of the Diamond Creek sandstone ranges from less than 200 to over 800 feet in this area, increasing progressively from south to north. Between Spanish Pork and Hobble Creek it exceeds

1000 feet in some places (Baker, 19^9# P. 1188) but becomes thinner farther north and is only 165 feet thick in northern Strawberry Valley (Bissell, 1952, P. 589).

Stratigraphic relations The Diamond Creek sandstone is gener­

ally gradational with the overlying Park City formation and with the

underlying Kirkman limestone, possibly intertonguing with the latter.

However, in some places the Park City's basal limestones overlie a

sharply irregular Diamond Creek surfaoe, and in such localities the

basal Park City beds are apt to be brecciated and sandy.

Age and correlation The age of the Diamond Creek sandstone is

Permianj it lies between the Kirkman limestone and Park City forma­

tions, of established Permian age. Baker and Williams (19^0) corre­

lated the Diamond Creek sandstone with the of the

San Rafael Swell.

Park City Formation

Definition and distribution The Park City formation was named by Boutwell (1907) for the Park City mining district of Utah, where it conformably overlies the Weber quartzite and is conformbaly overlain by the Woodside shale. The formation has been recognized as far south as Long Ridge (Muessig, p. 62) and the North Fork of Salt Creejp, at the southern end of the Wasatch Mountains (Baker, Huddle, and Kinney, pp. 1188-1189). Rocks which were at first called Park City in south­ western Wyoming and southeastern Idaho were later subdivided into the

Phosphoria formation and the upper part of the Wells formation. Phos- phatio members are characteristically present in both the Phosphoria and Park City, but are apparently represented only by shaly units in the Salt Creek and Long Ridge areas. -104-

The Park Oity formation extends southwest from Spanish Fork Can­ yon in thin outcrops along the ridge on the north side of Shurtz Can­ yon, but on the eastern slopes of Loafer Mountain all but the upper­ most beds of the formation are represented, and the unit attains an unusual thickness south of 0rab Creek. The exposures are continuous

from Shurtz Landing to Thomas Hollow, but in the vicinity of Bennie

Creek only a thin portion of the lower member is present.

Lithology The Park City formation consists of lower and upper

cherty limestone members separated by a phosphatic member. In some areas the upper two members have been beveled by pre-Woodside erosion.

The lower member of the formation consists of thin-bedded to massive,

gray to tan cherty limestones and light-gray to brown sandstones.

The limestones range from extremely arenaceous to fairly pure, and from fine to medium crystalline. In many places they contain numer­

ous small geodes and nodules of white calcite averaging about an inch

in diameter. There are a few thin layers of Kirkman-type dark, lam­

inated, fetid limestones. Chert occurs in tan, black, or white string­ ers and lenses, and in the basal portions in the vicinity of Bennie

Creek there is a persistent bed of white chert averaging 4 or 5 feet in thickness. Some of the ledges are apparently as much as 80 per cent chert. Sandstones range from rather friable well-sorted beds to extremely calcareous poorly sorted rocks gradational with limestones.

Many layers are brecciated, and it is not always apparent whether this is due to faulting, folding, or penecontemporaneous brecciation.

The middle phosphatic member is completely exposed on the ridges — 105—

both north and south of Bennie Creek, where it consists of cherty

sandstones, siltstones, arenaceous phosphatic shales, and black phos­

phatic argillite. The phosphate occurs in dark-gray to blue-black

nodules and ooliteB, and in multitudes of fragments of small, high-

spired gastropods, which are extremely abundant in Borne of the brown- weathering arenaceous shaly beds, SiltstoneB are gray, tan, and

black, and some weather brown and red. Sandstones are gray or tan, fine-grained, and slightly calcareous. Chert is abundant and below the upper black, pyritic, phosphatic shale of the middle member there is a 25-foot bed consisting almost entirely of black chert. Some of the

siltstones are silicified and have a ohert-like appearance.

The upper limestone member is similar to the lower member, but is more cherty— particularly in the lower portions. The basal unit of this member north of Crab Creek is a 45-foot bed of black to dark- gray chert and silicified siltstone, both of which weather out into numerous small angular fragments. Many limestones in this member have pinkish casts, as do many of the sandstones. Some of the sandstones are quite lenticular, friable, and weather cavernously.

The upper member of the Park City formation is equivalent to the

Rex chert member of the Phosphoria formation (Baker and Williams, pp.

627-628). Keller (1941, p. 1297) has concluded that the greater part of the silica in the Rex chert is a primary deposit, supplemented by a considerable amount of diagenetic replacement. His descriptions of the unit could well apply to the cherts of the Park City formation in the southern Wasatch Range, and his arguments for the primary origin apply equally well here. - 106-

Thickness The upper contact of the Park City formation and the

Woodaide shale is not generally exposed, b o that only incomplete measurements of the upper member can be made in many areas. Elsewhere, the upper portions of the formation are beveled by pre-Woodside ero­ sion. The lower member is 885 feet thick in the Right Pork of Hobble

Creek and about 700 feet in the Salt Creek area. The phosphatic mem­ ber is about 200 feet thick on Hobble Creek, and on Salt Creek a middle Bhaly unit 268 feet thick iB correlated with this member. In­ complete measurements of the upper member include 8J0 feet in the

Right Fork of Hobble Creek and 615 feet in the Salt Creek area (Baker,

Huddle, and Kinney, pp. 1188-1189).

On the east flank of Loafer Mountain the formation thickens rapidly. On the ridge north of Crab Creek the lower, middle, and upper members are 515* 245* and 595 feet, respectively, totaling 951- feet. The base may be missing due to faulting and the upper member is incomplete here. Only a mile to the south, Harris (195^* P» 194) found thicknesses of 1440, 5°0* a**d 1577 feet, respectively, for the three members, totaling 5*517 feet— the thickest section yet reported for the Park City formation. The writer measured no detailed sections south of Crab Creek, but graphic calculations of thickness for the

Park City in this area indicate that this is the correct order of mag­ nitude. The lower member on the ridge immediately south of Crab Creek appears to be extremely thick and the writer suspects that there may be duplication of beds here, due either to faulting or to the termin­ ation of the Shurtz Canyon anticlinal structure in this area. Further investigation of the structure in the Crab Creek area is desirable. -107-

Stratigraphic relatione The Park Oity formation conformably

overliee the Diamond Creek sandstone. The boundary in many places is

arbitrary and depends upon one's decision as to where calcareous Band-

stone becomes an arenaceous limestone. Field relationships also sug­

gest that the upper surface of the Diamond Creek sandstone was depos­

ited rather unevenly, so that although there is a conformable rela­

tionship, the contact has a good deal of relief.

The Park City formation of the type area is conformably over-

lain by the Woodside shale, but in the region just north of Spanish

Fork Canyon the relationship is unconformable. In the area of this

report no contact of Park City and Triassic beds is exposed, and Ter­

tiary fanglomerates or alluvium lap against the Permian beds.

Age and correlation The Park City formation is younger than the

Kirkman limestone which contains a fusulinid fauna indicative of Wolf-

campian or possibly Leonardan age. Brachiopods similar to those of the Phosphoria fauna are present in the upper member of the formation, and Baker, Huddle, and Kinney (p. 1188) report an abundance of the

Kaibab productid Dictyoclostus ivesi (Newberry) in the lower member in the Hobble Creek area. The lower member is thus tentatively cor­ related in part with the Kaibab formation, and the upper two members are probably the direct equivalents of the Phosphoria. Unconformity between the Permian and Tri&eaio Systems

In the central and southern Wasatch Mountains the Woodside shale liee unconformably upon eroded rocks of the Park City formation. The pre-Woodside shale surface has a relief of several thousand feet. From the Right Fork of Hobble Creek to about 5 miles north of the mouth of

Diamond Fork, a distance of about 10 miles, the Woodside shale bevels across nearly 2,000 feet of Permian beds (Baker and Williams, p. 624).

From Spanish Fork Canyon, where only a portion of the lowest member of the Park City formation is present, this unit thickens rapidly south­ ward to a maximum development of all three members in the vicinity of

Crab Creek— a distance of less than 5 miles. The Woodside shale is not exposed in the latter area, but its presence both at Spanish Fork and on the North Fork of Salt Creek, east of Mount Nebo (Eardley, 1955* p. 524), suggest that it is probably continuous in the area, beneath the Tertiary beds.

The Triassic Dinwoody formation in western and central Wyoming is also unconformable over the underlying Phosphoria formation, but the contact is conformable in southeastern Idaho (Kummel, 1954, p. 167).

Thomas (1954) demonstrated the absence of a break between the Permian and Triassic in the red bed sequence of central Wyoming. The uncon­ formable relationship of the Permian and Triassic beds of the Wasatch

Mountains apparently extends into the Colorado Plateau province, where a portion of the time represented by Park City beds is unrepresented between the Kaibab and Moenkopi formations (Baker, Huddle, and Kinney, p. 1189; McKee, pp. 55-56). - 109-

Central Wasatch Eastern Central Southeastern Idaho Mountains Uinta Mtns. Wyoming u p Ankareh formation p A Stanaker Chinle Popo Agie £ (Wood shale tongue) N member formation member R K A 0 T R H R Deadman limestone E U I H G A Gartra grit Shlnarump W S Higham grit F member jonglomerate A s 0 T 1 R 15 R -JL. Timothy sandstont M Siltstones A member and T T F sandstones H I 0 L A 0 R Mahogany M 0 Y Portneuf 1st N Alcova Is member A W N member member T E E Lanes I R S ^Tongue of the 0 N. Ankareh N T F fm. R 0 I R A M Sandstone and s A limestone S T Moenkopi I I Upper black formation 0 0 limestone N Tan silty Thaynes Red Peak 1ime stone formation member

Lower black limestone

Lower limestone 'v^woodside Dinwoody fm Woodside formation formation

Dinwoody formation

Figure 6. Triassic correlation chart (From Kummel, 195^). -110-

Triassio System

Baker (19^7) measured a well-exposed section of Triassic rocks on the northeast side of Spanish Fork Canyon, north of Thistle in the vicinity of Diamond Fork, but immediately southwest of Spanish Fork the

Triassic units are poorly exposed and primarily underlie a post-Jur- aasic strike valley which wsb filled with Tertiary sediments. The tri-partite division of Triassic beds used by Baker is the same as that of the Park City district of the central Wasatch Mountains (Bout- well, 1912) and regional stratigraphic relations of these units have been discussed by others in some detail (Kummel, 195^J Williams, 19^5i

Thomas and Krueger, 19^6).

Woodside shale

The Woodside shale, named by Boutwell (1907* P* ^6) for expos­ ures in Woodside Gulch in the Park City mining district, has been map­ ped in northern Utah, western Wyoming, southeastern Idaho, and south­ western Montana, It has been traced southward to Spanish Fork Canyon

(Baker, 19^7)* where it consists of red to reddish-brown shales and siltstones, forming a more subdued topography than do the underlying limestones of the Park City Formation,

No definite outcrops of Woodside stele were found in the area southwest of Spanish Fork. Some of the southern tributaries of Shurtz

Canyon expose ledges of reddish-brown siltstones which were mapped as younger beds, based principally on the attitude of the strata. The

Park City formation here is overlain unconformably by Tertiary forma­ tions or by fan and landslide debris. The Woodside shale is generally considered to be Triassic in age.

It lies below the widespread Meekooeras zone at the base of the Thaynes formation in much of its area of outcrop and intertongues with the

Dinwoody formation, the basal units of which contain lower Scythian ammonites and Early Triassic ceratites (Kummel, 1954* pp. 168, 171).

Baker (194-7) correlated the Woodside with the lower part of the Moen- kopi formation.

Thw Woodside shale is 1180 feet thick at Big Cottonwood Canyon

(Boutwell, 1907i P. 446), but thins to 5^5 feet at Deer Creek, south­ west of Heber, and 150 feet in Spanish Fork (Baker, 1947).

Thaynes Formation

Definition and distribution The Thaynes formation was named by

Boutwell (1907» p. 448) for Thaynes Canyon in the Park City mining district, Utah, and it crops out over a wide area in northern Utah, eastern Idaho, southwestern Montana and western Wyoming. From the

Park City district the Thaynes also extends eastward along the Uinta

Mountains (Williams, 1945) and southward to the vicinity of Salt Creek, east of Mount Nebo (Eardley, 1955* PP« 526-528).

Only a fraction of the section of Thaynes measured by Baker (1947) in Spanish Fork Canyon is exposed on the southwest side of the stream.

The railroad cut opposite the mouth of Diamond Fork is apparently the only exposure of Thaynes between Spanish Fork and the Salt Creek area.

Lithology The Thaynes formation consists, in the type area, of two thicker members of alternating limestones and sandstones, separated -112- by a thinner red shale member (Boutwell, 1912, p. 55)* ln Spanish Fork

Canyon the formation iB made up of grayish-green to pink limestones and sandstones interbedded with reddish-brown, maroon and gray shales.

Viewed from U.S. Route 89, the outcrop at the railroad cut west of the mouth of Diamond Fork appears as a dull grayish-green bank, broadly striped with brown and it consists of a series of alternating lime­ stones and shales, with minor amounts of siltstone and sandstone.

Two types of limestone are present in the Thaynes here. One is fine-grained to dense, reddish or maroon, mottled with olive-green, and weathers brown, pink, orange, gray, or green. It forms massive ledges 5 to 20 feet thick. Some beds contain streaks of crinoidal deb­ ris, and some have zones of small, greenish-gray chert nodules. The other limestones are grayish-green, sandy, micaceous, thin-bedded, in some cases shaly, and are gradational to greenish-gray siltstones.

The latter limestones contain numerous poorly preserved pelecypod remains.

The shales are greenish-gray to chocolate-brown, calcareous, and mioaoeous, and in most units weather to blocky fragments.

Thickness In the type area sfc the Park City district Boutwell

(1907, p. 448) measured 1190 feet of Thaynes. It is much thicker to the north, totaling over 5500 feet in the region of Fort Hall, Idaho

(Kummel, 1954* p. 172). To the east it thins to a feather edge of only a few calcareous laminae in the area just west of Vernal, Utah

(Thomas and Krueger, 1946, p. 1270), and in Spanish Fork Canyon the formation is lj40 feet thick (Baker, 1947). Less than 200 feet of the - 115-

section. is exposed on the west side of Spanish Fork Canyon.

Stratigraphic relations Kummel (195^) ^as discussed in detail

the regional stratigraphic relations of the Thaynes formation. The

Thaynes intertongues to the east with TriasBic red beds~in central

Utah, with the Ankareh formation. In the Uinta Mountains the Ankareh

beds aan be separated from the older Woodside shale only where the

Thaynes is present (Thomas and Krueger, 1946, p. 1267; Williams,

19^5)• Spanish Fork Canyon the Thaynes lies conformably between

the Woodside shale and the Ankareh formation, and actually represents

an intertonguing of Thaynes and Ankareh beds.

Age and correlation The base of the Thaynes formation through­

out much of its area of outcrop in Idaho, Utah, and Montana contains

an abundant ammonite fauna characterized by Meekoceras, but in areas where the Thaynes limestones intertongue with red beds the ammonites are generally not present (Kummel, 1954, pp. 171-172). In Spanish

Fork Canyon many of the grayish-green calcareous beds contain numerous poorly preserved pelecypodB, some of which are apparently specimens of

Aviculopecten. The formation is considered to be Lower Triassic in central Utah, but the upper beds of the formation in the north are partially Late Triassic in age (Kummel, 1954, p. 16 6 ).

Ankareh Formation

Definition and distribution Boutwell (1907, p. 452) originally grouped in the Ankareh formation all rocks exposed above the Thaynes formation in the Park City district, where the formation is well expos­ ed on Ankareh Ridge. The Uinta Ute Indian word for "red" is "ankareh", -114- and Boutwell utilized the term to name both the ridge and formation;

the bright red color of the outcrops and derived soil is one of the

chief characteristics of the unit. The formation originally defined

at Park Oity included at the top a massive white sandstone which proved

to be equivalent to the Nugget sandstone of Veatch (1907)* Therefore,

Boutwell (1912, p. 59) later redefined the Ankareh to include the rockB

between the Thayne3 formation below and the Nugget sandstone above.

Post-Thaynes red beds are found in areas throughout western

Wyoming, southeastern Idaho, and northern and central Utah. To the

east the Thaynes formation pinches out into a continuous red-bed se­

quence-equivalent to the Woodside shale below and the Ankareh forma­ tion above. The name Ankareh has been applied to the post-Thaynes

sequence in much of the area, but many workers have subdividedthe unit into additional formations. Kummel (1954, P» 179) has reviewed the existing nomenclature and correlations and has suggested that the term ''Ankareh formation" be applied in northern Utah and western Wyom­ ing in the sense of Boutwell's 1912 definition , and that all forma- tional names subsequently proposed be reduced to member rank— in particular, the three formational divisions proposed by ThomaB and

Krueger (1946) become the Stanaker, Gartra grit, and Mahogany members.

This is consistent with the work of Baker (1947) and Granger (1955* p. 4) in the Wasatch Range in central Utah. Beds called Ankareh have been mapped as far south as Long Ridge (Muessig) and Salt Greek, east of Mount Nebo (Eardley, p. 528),

The Ankareh formation is not well represented in the area concern­ ed in this report, although a complete section of the unit was measured -115-

by Baker (19^7) directly across Spanish Pork along U.S. Route 89#

south of Diamond Pork. A small portion of the upper part of the for­ mation crops out at the north end of the isolated hill of Nugget sand­

stone about a mile northwest of Thistle on the west side of Spanish

Pork. Most of the red material on the west side of the valley in this area is alluvium from the soft red muds, silts, and conglomerates of the North Horn formation, which forms the erosional scarp bounding the small embayment in the valley here. The best exposure of Ankareh

in the area is on the north side of the lower canyon of Crab Creek,

lying in angular unconformity beneath Tertiary beds, just west of the prominent hogback of Nugget sandstone.

Lithology The Ankareh formation of the south-central Wasatch

Mountains consists of two thick members separated by a relatively thin conglomeratic sandstone. The lower, or Mahogany member, consists mainly of red to reddish-brown shales, siltstones, and sandstones, with a few grayish-green beds and many thin ripple-marked layers. The middle, or Gartra grit member, is a pocrly sorted, coarse-grained to conglomeratic, gray, buff, or purplish-red quartzite or sandstone aver­ aging around 50 feet in thickness. The upper, or Stanaker member, is of variegated shales— mainly red— with interbedded red and purplish- red, fine-grained to conglomeratic sandstone (Baker, 1947* Granger,

1952j Kummel, 1954).

In the Crab Creek section only the upper part of the Ankareh for­ mation is present. The beds here are predominantly sandstone and siltstone, with minor amounts of shale. The lowest shales exposed are red, but a few intercalated sandy layers contain light-green -116- fragments of argillaceous material. Some of the siltstoneB are ripple* marked. The sandstones are thin-bedded to massive and are prominently cross-bedded. The most prominent sandstone here is about 50 feet thick and has a pinkish-gray color due to numerous small flecks of bright red in a light-gray or grayish-green matrix. It is medium- to coarse-grained, porous, moderately well-sorted, and cross-bedded in a manner suggestive of the Nugget sandstone.

Stratigraphic relations The Ankareh formation intertongues with the Thaynes formation in central Utah (Kummel, 195^0, and conformably overlies the Thaynes in many places. The upper boundary is somewhat arbitrary, but is generally drawn at the base of the thick, cross- bedded Nugget sandstone. Some workers have been able to draw the upper boundary efc the top of the red-colored beds, but in central Utah the

Nugget sandstone is also red in many places. The thick, Nugget-type bed in the upper part of the Ankareh suggests a possible intertonguing of Nugget and Ankareh in this region.

Age and correlation The age and correlations of the Ankareh fa: - mation in various areas are indicated in the accompanying chart (Fig­ ure 6), The Stanaker and Gartra grit members are considered equivalent to the and Shinarump conglomerate, respectively, while the Mahogany member intertongues with the Thaynes formation on the west and is equivalent to part ofthe on the east (Kummel, 195^)• No fossils have been found in the Ankareh in this region— in fact, no diagnostic fossils have been found in any of the post-Thaynes Triassic beds of the Middle Rocky Mountains (Kummel, 195^\» p. 188). Jurassic System

Two formations are assigned to the Jurassic System in this area, and both occur in a prominent east-dipping hogback that dominates the community of Thistle, Utah, and formed the east side of a post-Jurassic valley underlain by Triassic beds. (See plate 12,B.) The older unit is the massive cross-bedded Nugget sandstone, whose age is still in question, and the younger is the thin-bedded fossiliferous Twin Creek formation. Still younger Jurassic rocks crop out east of Thistle, but west of Thistle Creek the Mesozoic succession is bounded by a normal strike fault in the Twin Creek formation, and Tertiary beds abut again­ st the Jurassic in fault contact on the east side of the hogback.

Nugget SandBtone

Definition and distribution The Nugget sandstone was named by

Veatch (1907) for Nugget Station, Wyoming, and was further described and redefined by Gale and Richards (l^lO) to include a massive white cross-bedded sandstone and red sandy shales in southeastern Idaho and adjacent areas in Utah and Wyoming. Boutwell (1912, p. 59) later re­ stricted his definition of the Ankareh shale in the Park City mining district, Utah, and included the white sandstone and intercalated red shales in the upper 500 feet of the former unit in the Nugget sand­ stone. Heaton (1959) described occurrences of the Nugget in Idaho and Wyoming, and in Utah as far south as the town of Heber. Eardley

(1955» P« 552) had earlier referred to the sandstones (previously called Jurassic) at Thistle as Nugget (?), and the unit here was later called Nugget by Baker (19^7)» Muessig (p. 66 ) mapped beds of Nugget -118- aandatone in Long Ridge and pointed out the probable Nugget equiva­ lence of beds previously called Ankareh in the vicinity of Salt Creek, east of Mount Nebo (Muessig, p. 65). Use of the term has now also been extended from southwestern Wyoming to the southern edge of the

Black Hills in South Dakota (Imlay, 1952, P»

The Nugget sandstone in the hogback at Thistle extends in a south­ westerly direction parallel to Thistle Creek, gradually diminishing in relief until it disappears beneath down-faulted Tertiary rocks about a mile south of Crab Creek.

Lithology The chief characteristic of the Nugget sandstone in this area is its massive, eolian cross-bedded nature, and its position beneath typical light-colored limestones and shales of the Twin Creek formation. Color is not a criterion. Boutwell (1912, p. 59) described the Nugget at Park City as principally white, but Mansfield (1927, p. 96) referred to the beds to the north as "chiefly massive reddish sandstone, locally deeply colored, and in places much cross-bedded", the upper part being composed locally of several hundred feet of white or yellowish sandstone. Thomas and Krueger (1946, p. 1275) found the

Nugget sandstone in the Uinta Mountains to be white above and Balmon- pink below, the color boundary cutting diagonally across bedding. The

Nugget just north of Thistle is gray or buff in the upper portion and contains beds of orange-brown or red in lower portions— the color boundaries here, too, cutting across bedding in many places. South of Thistle the upper portion becomes deep-red to orange-red, and the lower, portion gray to buff. This color difference may quite well be due to past action of ground water seeping down through the bright -119-

red Tertiary muds and silts which rise in angular unconformity above

the Jurassic beds in the vicinity of Crab Creek, or perhaps to leach­

ing of an originally red sandstone by reducing waters.

In this area the Nugget sandstone is predominantly fine-grained,

fairly well sorted, and is strikingly cross-bedded with the sweeping

festoon patterns associated with eolian action. The upper two thirds

of the unit contains numerous laminations of coarser sand (of a lighter

red color) and is friable. Slopes near the uppermost beds are com­

posed of deep accumulations of silty sand— a feature not found assoc­

iated with sandstones of other formations in this region. Quartz

grains throughout most of the unit are sub-round to round, and frost­

ing is evident on many grains in the upper third of the formation.

The lower third of the formation at Crab Creek is light-brown,

porous, calcareous in part, and cross-bedded, and much of it weathers

to form a talus of large, blocky fragments-— 'some as much as 10 feet

in diameter. Harris (1954, PP» 195“496) refers this portion to the

Wingate (?) sandstone, partly due to the abnormal thickness of the

Nugget resulting if all of the beds are assigned to that formation.

Assigning nearly J00 feet of beds to the in this

area would produce a much more striking abnormality on the Wingate iso- pach map of Baker, Dane and Reeside (1956, fig, 8, p. 45).

Thickness The Nugget sandstone is 1450 feet thick at Thistle

(Baker, 1947), and increases to over 1800 feet near Crab Creek,

Stratigraphic relations The Nugget sandstone is apparently con­ formable with the underlying Ankareh formation, and may actually inter­

tongue with it; thick sandstones in the upper part of the Ankareh are -120- similar to some of the beds in the Nugget, and the boundary between the two formations is somewhat arbitrary. The upper contact is at the base of a thin series of red calcareous BhaleB and silty lime­ stones of the Twin Greek formation— 'evidently representing a minor reworking of the upper Nugget sands as the marine Twin Greek beds overlapped them. Some have considered the top of the Nugget and Nava­ jo sandstones to be an unconformity (Baker, Dane, and Reeside, p. 6).

Age and correlation The Nugget and Navajo sandstones are almost certainly equivalent; the term Navajo is generally applied in the

Colorado Plateau region and the term Nugget is generally used in the

Rocky Mountain province (Baker, Dane, and Reeside, 19^6). No fossils were found in the formation in this area. The Nugget- is no younger than Early Jurassic, as is shown by the abundant marine fauna of Bajocian age in the overlying Twin Creek and Garmel beds in some districts (Imlay, 19^2, pp. 964-966). There is little evidence as to the lower age limit of the base of the formation, but most writers— perhaps mainly for lack of better criteria classify the Nug­ get as entirely Jurassic in age.

Twin Greek Formation

Definition and distribution The name Twin Greek was given by

Veatch (1907, p. 5 6 ) to a thick series of calcareous shales and thin- bedded shaly limestones that crop out along Twin Creek in southwestern

Wyoming. The unit is extensively exposed in southwestern Wyoming and southeastern Idaho, and has been traced southward in Utah along the Wasatch Mountains to the vicinity of Thistle (Imlay, 1952), where -121- it forms the eastern dip slope of a prominent Jurassic hogback which passes through the community and forms a scarp along the western side of Thistle Greek to about a mile south of Crab Creek. (See plate 12,

B.) Some of the road-cuts along the east side of U.S. Route 89 in

Thistle are in the Twin Creek formation.

South of Crab Creek the exposed part of the formation is quite thin, due to normal faulting, and it is partially covered by red muds and conglomerates of younger beds. Several fault blocks of Twin Creek lie amid similar fault blocks of Flagstaff limestone along the foot of the scarp here, (See plate 27,)

Lithology From a distance, outcrops of the Twin Creek formation present a uniform light-gray, thin-bedded appearance, and a thin red basal unit can be readily distinguished in most places, particularly where the underlying Nugget sandstone is gray or buff. (See plate

15,A.) Imlay (1952, p, 965 s-nd chart 8e) has differentiated seven distinct mappable members in the formation in the central Wasatch

Mountains as far south as Thistle, and beds resembling the lower three members are present south of Thistle,

The basal member on the north side of Crab Creek consists of 11 feet of highly calcareous red shale and siltstone, overlain by 2 feet of arenaceous finely crystalline red limestone. Above the basal red beds an 8-foot oolitic limestone is followed by a sequence of brown to gray, fine-grained to lithographic, thin-bedded limestones, the lower beds of which are full of fragments of pelecypods, gastropods, and crinoid columnals. The limestones are overlain by over 100 feet -122- of grayish-brown calcareous shale and shaly limestone. The rocks of this unit weather to form multitudes of prismatic fragments averaging

5 or 4 inches in length.

Above the thick shsly interval light-gray limestones and shales alternate in units varying from 1 to 7° feet in thickness. At the base of this sequence are arenaceous, ripple-marked limestones that weather into large thin slabs. Some of the beds have pinkish and greenish tints, particularly the lithographic and the shaly limestones.

Beds in this unit, and all units other than the second member, are only sparsely fossiliferous.

Twin Greek limestone present in Borne of the fault blocks along the foot of the scarp south of Crab Greek is light-gray to white, and is similar in some respects to adjacent fault blocks of Flagstaff limestone. Weathered fragments of the Twin Greek tend to be more tab­ ular or prismatic, however, and occasional Jurassic marine pelecypod fragments can be found.

Thickness The section Bouth of Thistle is incomplete, due to normal faulting, but between ^00 and 600 feet of the formation is present between Thistle and Crab Creek. The Twin Greek outcrop south of Grab Greek is quite thin, but persists for about a mile before it terminates due to normal faulting.

The Twin Creek formation is 2800 feet thick near Salt Lake City

(Granger, 1955* P« H ) an

Stratigraphic relations In the region south of Thistle the upper limit of the Twin Creek formation is absent due to faulting, but in -125- areas to the north there is apparent conformity with the . The lowest beds of the Twin Creek represent a slight re­ working of the Nugget sandstone as the Jurassic seas advanced, and al­ though slightly unconformable relationships exist, no significant break is indicated (Baker, Dane, and Reeside, 1956). The depositional surface of the Nugget sandstone was undoubtedly very irregular and quite changeable right up until the invasion of the Twin Creek seas.

Age and correlation Imlay (1952, pp. 965-964; 965-966) reviewed the available information as to the ages of the Twin Creek and the similar of the Colorado Plateau province, and agreed with Baker, Dane, and Reeside (1956, p. 6) as to the equivalence of at least portions of the two, particularly the upper beds of each.

Imlay also correlated the Twin Creek formation with the Arapien shale as restricted by Hardy (1952, PP* 91“95)» The lower four members of the formation are considered to be of Middle Jurassic age and the upper three of early Callovian age (Imlay, p. 965)*

Pelecypods found in fault blocks of Twin Creek limestone south of Crab Creek include specimens of Pinna kingii, Meek and Myaoites

(Pleuromya) weberensis, Meek. These forms have been found both in the

Carmel of the (Gilluly and Reeside, 1928) and in the

Twin Creek beds at Weber Canyon, Utah (Meek, 1877)» -124- Plate 15

Even-bedded limestones and shales in the Twin Creek formation. Looking north across mouth of Crab Creek Canyon.

Gently-dipping Flagstaff limestone at Tin- ney Flat. Wooded slopes below conceal occasional exposures of steep-dipping Car­ boniferous strata. Looking north— Dry Mountain out of sight to left. -125- Plate 14

A. Flagstaff, Oolton, and pyroelastics in angular unconformity over and against steeply eastward dipping Paleozoic rocks at Tinney Flat. Triangular mountain on left is Dry Mountain, West slope of Loafer is in background at extreme right. Central Wasatch Range on skyline.

Q. Channel of coarBe conglomerate in Flagstaff limestone on west wall of chasm in Frank Young Canyon. -126' Plate 15

A. Gently dipping beda of Flagstaff and North Horn formations in angular unconformity over steeply dipping Nugget sandstone north of Grab Greek.

B. Algal ball limestone typical of the Flag­ staff formation. -127-

Orstaceous and Tertiary Systems

General Statement

The oldest Cretaceous rocks recognized in central Utah belong to a thick sequence of elastics which Spieker (1946, pp. 126-1JO) desig­ nated the Indianola group. Beds from this group have produced a marine fauna that is of Colorado age, but much of the unit is made up of thick, coarse, unfossiliferous conglomerates. The Indianola group is overlain by the formation, which in central Utah is mainly coarse conglomerate, and in many areas is unconformable over the Indianola beds. The Price River formation is of Montana age at the type locality, but is possibly younger to the west. The Price

River beds are gradational with the overlying North Korn formation, which is evidently of Cretaceous age in the lower portion and of Ter­ tiary age in the upper. In the area of this report the North Horn formation is mainly conglomerate.

Tertiary unitB younger than the North Horn formation in this area include (1) the Flagstaff formation— -a widespread fresh-water lime­ stone with associated shales, sandstones and conglomerates, (2) the

Colton formation, which is chiefly conglomeratic, but also includes shales and sandstones, (J) a thick sequence of pyroclastic rocks and their derived deposits and (4) undifferentiated fanglomerates. A unit of breccia, limestone, and conglomerate provisionally designated the Crab Creek formation is probably a facies of one of the other units.

All of the beds above the Indianola group are continental depos­ its and are quite variable in nature over fairly short distances. All of the units, including the Indianola, contain conglomerates of -128-

similar appearance. As a result, individual outcrops can be very-

difficult to identify. Indianola beds are present in great thickness

in the southern Cedar Hills, but none were recognized in the area of

this report.

Conglomerates of the Price River formation may be clearly differ­

entiated from the younger North Horn formation east of Thistle. How­

ever, in the area immediately to the north and west the two units

cannot be distinguished, and it is possible that beds of Price River

age are present in the area of this report in the lower portions of

rocks mapped as North Horn formation. It is even possible that all

beds mapped as North Horn could be termed Price River. Isolated out­

crops of conglomerate here are also called North Horn, although they

could well belong to either younger or cider formations. However, no

evidence has been found that any of the rocks in this area are of pre-

North Horn Cretaceous age, and, indeed, no evidence is available to

show that any portion of the North Horn beds is of Cretaceous age here.

North Horn Formation

Definition and distribution The North Horn formation was named by Spieker (1946, p. 152) for North Horn Mountain in the east-central part of the WaBatch Plateau, where it consists of a sequence of lacus­ trine and fluviatile deposits divisible into 4 units that lie conform­ ably between the Price River formation and the Flagstaff limestone.

The formation of the type area is noteworthy in that somewhere within the conformable succession of strata of which it is composed the fossil fauna clearly passes from a Cretaceous to a Paleocene aspect. -129- The four-fold division of the Worth Horn formation of the central

Wasatch Plateau disappears in other areas, but the unit as a whole is recognizable over a wide region in central Utah. It haB been found as far west as Long Ridge (Muessig, pp. 11-jb) and on West Mountain, at the south end of Utah Lake (BisBell, 19^8» PP» 121-122).

The Worth Horn formation is present in the Cedar Hills and along the flanks of Loafer Mountain and Dry Mountain. It overlies the eroded

Triassic rocks on the southwest side of Spanish Pork Canyon just north of Thistle, and laps against the west side of the Jurassic hogback there. Conglomerates of an indefinite age near the mouth of Spanish

Pork Canyon are provisionally called Worth Horn as are the various outcrops of conglomerate in Payson Canyon, but no proof of this class­ ification is offered.

Lithology Muessig (1951) an<* Schoff (1957* P» 67) have pointed out the highly variable nature of the Worth Horn formation along its western limits, as well as its intertonguing relationship with the

Flagstaff limestone. This is also a feature of the Worth Horn beds in the area of this report, where the peaks of the present mountains existed as highlands during deposition of beds of late Cretaceous and

Tertiary age. The formation here consists mainly of conglomerates and shales colored bright red to pinkish, with subordinate amounts of light-gray or buff beds and lenses of fresh-water limestone.

South of Loafer Mountain, along Benny Creek and Wimmer Ranch

Creek, the North Horn formation is mainly a massive conglomerate, in most places well cemented and containing cobbles of quartzite and ~150- lime atone in approximately equal numbers. It is colored light red in most places, and contains lenses of brighter-red shale and silt. The beds are similar to those of the Price River formation east of Thistle, and, as was mentioned above, might be equivalent to them.

On the east side of Loafer Mountain the North Horn Btrata are quite red, but are less veil consolidated. Here they consist of brick- red muds, silts, and clays, generally full of cobbles in varying de­ grees of cementation, and in a few places variegated. The uppermost beds in this area, particularly on the hilltops on the southwest side of Spanish Fork, are light-colored conglomerates and sandstones that grade into the Flagstaff limestone.

The conglomerates near the Spanish Fork power house are well- cemented in part, and in gross aspect resemble conglomerates of the

North Horn formation farther south. A fault block of reddish-orange conglomeratic material rising above the Lake Bonneville terrace west of Snell Canyon, about half a mile south of the power house, is for convenience here called North Horn although it is different in appear­ ance from the formation in other parts of the area. Such isolated outcrops could actually belong to the Price River formation, as has been mentioned previously.

In lower Payson Canyon there are scattered outcrops of consoli­ dated conglomerates that superficially resemble North Horn beds, and are both reddish and gray in color. From Maple Dell southward, con­ glomerates lap against the eastern slopes of Dry Mountain, in many places dipping very steeply eastward, and varying in color and average size of fragments. The volcanic debris, which covers much of this area, is eroded away in many places, to display a rather irregular surface on the underlying conglomerate. Absence of beds of Flagstaff limestone in these areas makes it mainly guesswork to determine

/ whether the beds are post-Flagstaff, pre-Flagstaff, or lateral facies of the Flagstaff itself.

Thickness No complete section of North Horn formation was meas­ ured in this area. It ranges from a few feet to several hundred feet in thickness, and totals over 600 feet just north of Thistle. In the

Cedar Hills Schoff (1951, p. 629) found a maximum thickness of about

67OO feet of North Horn in the Hop Creek basin.

Stratigraphio relations The North Horn formation lies in angu­ lar unconformity over beds which range from Mississippian to Jurassic in age, most of which dip steeply to the east. (See plate 1^,A.)

The Flagstaff limestone conformably overlies the North Horn beds, and probably intertongues with them.

Age and correlation Spieker (19^6, pp. 13^-135) has discussed the evidence showing the Cretaceous and Faleocene ages for the lower and upper portions of the North Horn formation in the type area. The scanty fauna found by Schoff (1951* P* 63^) in the North Horn of the

Cedar Hills is indicative of Paleocene age. No fossils were found in the formation in the area discussed here, but it is probable that the unit in this area is mainly Tertiary in age, because (1) fossils col­ lected in the Flagstaff beds of this area imply its equivalence to the uppermost Flagstaff or younger beds in the , and (2) the North Horn beds are intimately associated with beds of the Flag­ staff and are not particularly thick here. - 152- Flag staff Formation

Definition and distribution The "Flagstaff member" of the

"Wasatch formation" was named by Spieker and Reeside (1925> P» 4-48) for Flagstaff Peak, in the southern part of the Wasatch Plateau, but was later given formational rank and redesignated the Flagstaff lime­ stone (Spieker, 19^6, p. 155)• Other workers have preferred the term

"Flagstaff formation" because of the multiplicity of lithologies with­ in the unit. The formation has been recognized over avri.de area in central Utah, including the Wasatch and Gunnison Plateaus, the Pavant

Range, the southern and south-central Wasatch Mountains, and West

Mountain.

Three separated area of outcrops of the Flagstaff formation are present in the region discussed in this report, but it cannot defin­ itely be shown that the beds of the three were continuous'— nor even that they were synchronously deposited. One area is on the northwest side of Loafer Mountain, west of the right fork of Loafer Canyon.

This outcrop is surrounded by beds of the Oquirrh formation and owes its position to thrusting and subsequent normal faulting. A second area of outcrop is west of Thistle, from Aggie Creek northward to

Shurtz Lake and is best exposed along Crab Creek. Some of the beds of

Flagstaff here probably belong to the Green River formation, but since typical Green River lithology is only scantily represented and since no definite separation of the two formations is possible here, the entire limestone sequence of this area is called Flagstaff.

The third area of outcrop of the Flagstaff formation is in the northern Cedar Hills, where thick fresh-water limestone beds are well -155- exposed at Tinney Flat, along Frank Young Canyon, and in a nearly con­ tinuous band west and north of the Nebo Loop Road, extending from the head of Frank Young Canyon to the eastern and northern sides of Bennie

Creek Ridge and lapping against the southwest side of Loafer Mountain above Wimmer Ranch Creek. (See plate 15,B.)

Lithology The Flagstaff formation in this area consists of fresh-water limestones with intercalated shales, sandstones, and con­ glomerates, representing an interfingering of lacustrine and fluvia- tile or piedmont facies. The formation is characterized by fairly extensive beds of algal-ball limestones, but otherwise it changes as­ pect fairly rapidly, both horizontally and vertically.

Limestones in the Flagstaff formation are of three major types here. The widespread algal limestones are made up of calcareous algal pisolites averaging an inch or two in diameter and cemented with cal­ careous cement, which is in many cases somewhat argillaceous or aren­ aceous. (See plate 15,B.) Thick beds of this type crop out at Tinney

Flat, in Frank Young Canyon, and along the southwestern side of Loafer

Mountain, while thinner beds are present near Crab Creek and in Loafer

Canyon. Eardley (1952, pp. 599-4-14) discussed the algal limestones of this region in some detail and referred to the beds as l,ooidal,, to indicate the probable organic origin of the concretions. These lime­ stones are pink, brown, gray, or white, and the algal structures are generally darker or a different color than the matrix. Some of,the color combinations present a rather pleasing pattern, and as a result the stone was once quarried at the Birdseye Quarry, east of U.S. Route

89, for use in interior decoration of many buildings in the <“1 Jo­

inter mountain area and other parts of the United States.

Another type of limestone is light-gray to white, dense, massive,

fairly pure, and weathers chalky white. The rock is commonly mottled

pink and yellow or tan. Such beds yield few or no fossils. The third

major type of limestone is brown to gray, sandy or silty, partially

oolitic and OBtracodal, and thin- to thick-bedded. Such beds may or

may not contain abundant gastropod faunas.

Minor amounts of other varieties of limestone are also present.

Beautiful pink and yellow lithographic limestones in beds 2 or 5 feet

thick crop out near the top of the formation north of Grab Greek. Some

limestones contain rounded pebbles and cobbles of Paleozoic chert,

quartzite, and limestone. Some algal limestones are quite detrital,

and even the abundant algal material is fragmental. The dip slope of

the eastern hogback of Flagstaff on the north side of Grab Greek is

one area covered with large curved slabs of algal limestone with numer­

ous pitted structures penetrating through the laminations.

Conglomerate beds in the Flagstaff formation are lenticular, and

presumably pinch out in a general easterly or southeasterly direction*

On the western side of the gorge in Frank Young Canyon a large channel

of coarse conglomerate is well exposed in cross section, overlain both below and above by thick limestone layers. (See plate l4,B.) The

conglomerates are similar to those of both the North Horn and Colton formations, and probably represent tongues of these units.

Shales are brick-red to greenish-gray, and some are gradational to marls. South of the mouth of Crab Greek some of the marls are -155- tinted pink and Lavender and are similar to beds of the Colton forma­ tion in other areas. Two miles north of Birdseye, west of the aban­ doned Dickson ranch bridge, a small outcrop of greenish-gray shaly limestone has a distinct Green River aspect and contains a fauna simi­ lar to that of parts of the Green River formation.

Thickness The thickness of the Flagstaff formation ranges from a few feet in the feather-edges of the unit lapping against the south­ western slope of Loafer Mountain and the eastern slope of Dry Mountain to about 550 feet north of Crab Creek, The formation may be at least this thick at the head of Frank Young Canyon, for Schoff (195*i P* 651) found about JOO feet of Flagstaff in an incomplete section just to the south, along Beaver Dam Creek, In the chasm in the lower part of

Frank Young Canyon the limestone is over 200 feet thick, unbroken by beds of shale or conglomerate, and the base is not exposed. In Water

Hollow, farther south in the Cedar Hills, the Flagstaff may be as thick as 750 feet (Schoff, 1951# P* 651).

Stratigraphio relations The Flagstaff formation is gradational with the underlying North Horn formation, and possibly intertongues with it locally. Along the southwestern flank of Loafer Mountain and at Tinney Flat the Flagstaff overlaps the North Horn and lies directly on strata of the Oquirrh formation in angular unconformity. (See plate 14,A.) The Flagstaff in Loafer Canyon is also angularly uncon- formable over Oquirrh strata.

The Colton formation intertongues with and conformably overlies the Flagstaff formation. In Shurtz Canyon it is possible that the -156-

Flagstaff is locally unconformably overlain by pyroclastics, as is

the case in several areas in the Cedar Hills.

Age and correlation The following collections of megafossils

are typical of the fauna of the Flagstaff limestone in the area here

discussed:

1. Limestone in gulch and along scarp west of old bridge. NWf Sect. 15, T.10S., R.JE.

Australorbis sp. Oreohelix sp. Phyaa pleromatis Sphaerium sp. Fish scales Fish teeth Bone fragments— -probably from fish

2. Beds above Nugget sandstone on north side of Crab Creek

Bulimulus sp. Goniobasis tenera "Helix" riparia Phyaa pleromatis

5. Road to Santaquin Meadows, above Tinney Flat

Goniobasis tenera '^Helix** riparia

4. Chasm in Frank Young Canyon

Bulimulus sp. Goniobasis tenera "Helix" leaii

The above specimens were identified by A. LaRocque, who considers them to resemble the faunas of the Green River, Colton, and uppermost

Flagstaff formation of the Wasatch Plateau. It is quite unlikely that they come from beds of lower or middle Flagstaff. The fauna of collec­ tion #1 was considered by LaRocque to have a definite Green River as­ pect, and the beds from which the specimens were taken do have an -157- appearance somewhat similar to typical Green,River strata.

Cyprid ostracods from the Flagstaff formation in the area near

Crab Creek were collected by Harris p. 202) and identified by

F.M. Swain, who considered them to be of early Tertiary but not neces­ sarily Paleocene age.

It thus seems clear that the Flagstaff formation of these areas is equivalent to only the uppermost Flagstaff of the Wasatch Plateau, intertongues with beds of Colton which are equivalent to the Colton of areas to the south, and includes strata which are probably contempor­ aneous with part of the Green River formation. The age of the sequence is quite possibly entirely Eocene, The fresh-water limestone in Loafer

Canyon can only tentatively be correlated with the Flagstaff formation to the south.

Colton Formation

Definition and distribution Spieker (19^6, P« 159) defined the

Colton formation as "the strata formerly classified as the upper member of the Wasatch formation" in central Utah, designating the type area as the hills north of Colton, near the head of Price River Canyon. The type section of the formation consists of red fluviatile shales and brown-weathering sandstones, but in areas to the south and west the beds are variegated, and include lacustrine deposits. The unit has been identified on the northern and western marginB of the Wasatch

Plateau, along the southeastern margin of the Valley Mountains, and in the Gunnison Plateau. Schoff (1957* PP» 80-86; 1951, p. 652) -158- differentiated as Colton the dominantly red conglomerates, sandstones, and shales ahove the Flagstaff limestone in the Cedar Hills.

The Colton formation crops out at Tinney Flat, extending east­ ward to the Nebo Loop Road and northward along the east side of Dry

Mountain to the vicinity of Red Lake, where it arches high against the mountain and is clearly visible from the road above Maple Dell.

Benny Creek Ridge, north and east of the Payson reservoirs, is mainly surfaced by Colton beds. West of Thistle the Colton overlies the

Flagstaff limestone from Crab Creek northward to the vicinity of Shurtz

Lake.

Lithology The Colton formation just east of the southern Wasatch

Mountains consists of conglomerates with lesser amounts of shales and sandstones, and in many places the sediments are poorly consolidated.

The predominant color is pink to deep red, but many beds are gray to tan and some of the shales have greenish-gray to lavender tints.

Colton beds along the east side of Dry Mountain and on the ridges on either side of Frank Young Canyon are bright red conglomerates and conglomeratic shales or silts. North and east of the Payson res­ ervoirs they are mainly thick, massive conglomerates ranging in color from light-red to gray. West of Thistle the formation contains loose­ ly consolidated, red to gray conglomeratic shales and sandstones and includes basal scarp-forming red conglomerate. (See plate 16,A.)

The conglomerates vary considerably in nature, both in degree of consolidation and in types and average sizes of fragments. Quartzite cobbles and boulders include typeB present in the pre-Cambrian (?) beds, the Tintic quartzite, and the Oarboniferous beds. Limestone

fragments are predominantly dark- to medium-gray, and seem to repre**

sent most of the Paleozoic formations. Ho fragments of the crystal­

line rocks were found by the writer. Ohert fragments are numerous

but are mainly of pebble size.

The regolith in areas underlain by the Colton formation (and

North Horn) contains numerous rounded bouldets and cobbles of quart­

zite— mainly gray, white, or buff, and ranging in size from pebbles

up to boulders 5 or 6 feet in diameter. In some areas the ground is

literally covered with boulder fields of this type. It cannot readily

be determined whether these have been left as residual material from

weathered and eroded Colton beds, or whether they represent the gravel

covering of a former pediment surface. The writer believeB the former

explanation to be true, and attributes the relatively small number of

limestone fragments to a prolonged weathering and erosional history.

Thickness The maximum original thickness of the Colton forma­

tion in this area is not definitely known, but on the divides in the northern part of the Cedar Hills the interval between the Flagstaff

limestone and the volcanic conglomerates is ae much as 600 to 700 feet.

Schoff (1951# P» 652) found 58O feet of Colton between the Flagstaff

and Green River formations about 5 miles northeast of Fountain Green.

Stratigraphic relations The Colton formation intertongues with and conformably overlies the Flagstaff formation. It appears to be

conformable over North Horn beds in areas where the Flagstaff is mis­

sing, but the two formations are similar in lithology and in such -140- areas one cannot be certain that they are both present.

The Oolton is unconformably overlain by volcanic conglomerates and tuffaceous sandstones, which were deposited upon a surface having considerable relief. In the southern part of the Cedar Hills the

Colton is conformable with overlying beds of the Green River formation.

Age and correlation No fossils were found in the post-Flagstaff

Colton strata in the area of this report, nor were any found by Schoff in the Cedar Hills. The lower portion of the formation intertongues with the Flagstaff limestone, and iB thus equivalent to at least the upper part of the Flagstaff. The upper portion of the Colton forma­ tion northwest of Thistle was probably once continuous with the con­ glomerates along Diamond Fork which Baker (1947) called Uinta forma­ tion. These conformably overlie the Green River formation to the east.

Spieker (1946, p. 159) provisionally assigned a lower Eocene age to the Colton beds of the Wasatch Plateau. The Colton formation west of Thistle is probably entirely Eocene in age, possibly ranging from

Wasatchian to Uintan.

Crab Creek Formation

Definition and distribution The name Crab Creek formation is provisionally applied to a sequence of tufa-like rocks, algal-ball limestones, and conglomerates that is exposed in a large dissected terrace south of the mouth of the upper canyon of Crab Creek in sec­ tions 2 and 11, R.3E., T.10S. The slopes are patchily covered with dense growths of scrub oaks and outcrops are generally neither - 1 4 1 - plentiful nor well exposed. The upper surfaces are covered with loose cobbles and boulders, with minor amounts of pyroclastic material, but much of this debris is of younger origin and was evidently spread as a gravel covering upon a pediment.

Lithology The unit is incompletely exposed, but apparently con­ sists of J members. The lower portion is a sequence of breccia and tufa-like materialj in fact, the latter also serves as the cement for the breccia. Material referred to as tufa-like is an extremely cal­ careous buff-colored siltstone and silty limestone which is quite porous and contains numerous tubular cavities averaging a millimeter or lesB in diameter. Rock fragments in the breccia are as much as a foot in diameter and consist of limestones and sandstones which were evidently derived from the Oquirrh, Diamond Creek, and Park City for­ mations. The brecciaB are fairly well bedded, but poorly sorted, and might be fanglomerates cemented by calcareous material from spring seeps, or they might be fanglomerateB deposited in marshy zones along the edge of a lake.

The breccias are overlain by a sequence of conglomerates and interbedded algal-ball limestones which are similar in most respects to the conglomerates and limestones of the Flagstaff formation. Indi­ vidual limestone beds are lenticular and few are more than 8 or 10 feet thick. Conglomerates in this member are generally limited to fragments of pebble size. Fragments are well rounded and consist of quartzites, cherts, limestones, and fragments of algal detritus. The color is gray and pinkish gray. — 142“

The upper member is massive white to light-gray conglomerate, generally well-oemented, and similar to conglomerates of the North

Horn, Colton, or Flagstaff formations. Shades of red are uncommon.

Fragments of this conglomerate and of those in the middle member are different from the Permian formations which form the bed rock up Crab

Creek Canyon.

Thickness No complete section was measured of any of the units, but the thickness of the entire sequence is estimated as 500 f®*t.

Stratigraphic relations The upper portion of the unit has been eroded and seems to have once been part of a pediment. The base is not exposed. On the west the unit appears to be in fault contact with eastward-dipping beds of the Park City formation.

Age and correlation There is no definite evidence as to the age of the Crah Creek beds, but they are almost definitely Tertiary and pre-volcanic, for they contain no volcanic debris. The writer believes that these beds are probably a shore facies of the Flagstaff formation.

In fact, he so mapped them in the field, but now suggests that they should be further examined.

Conglomerates similar to those of the upper member ore present in the low foothill8 lapping against the east side of Loafer Mountain on several spurs, and although these are probably all equivalent they have been mapped as undifferentiated fanglomerates, for no beds simi­ lar to the lower two members were noted. A mile and a half to the north, at the head of Hyle Hollow, there are thick beds of algal-ball limestone and underlying sandstone and conglomerate typical of the — 145— Flagstaff and North Horn formations, respectively, and these occupy a position similar to the Crab Creek beds.

Early Tertiary Fan Gravels

In the northern Cedar Hills there are thick alluvial fan depo­ sits which are post-Colton but pre-pyroclastic in age. They are only patchily exposed among beds of volcanic conglomerate and post-pyro— clastic fans. The deposits are of typical alluvial fan material, con­ sisting of poorly sorted, partially stratified debris ranging in size from clay and silt to boulders ^ or b feet in diameter. The abundant rounded cobbleB and boulders of Paleozoic quartzites and limestones inthe fans are evidently derived from conglomerates of the North Horn and Colton formations, but no fragments of Flagstaff limestone were noticed during a brief examination of the deposits.

It is difficult to differentiate these gravels from those of later, post-pyroclastic fans, for some of the latter can be distinguished megascopically only by the presence of minor amounts of volcanic cob­ bles, However, volcanic rocks can be found in minor amounts on the surfaces of both, due to post-volcanic alluvial action, and it is quite hard to determine whether the igneous materials are residual or are merely surficial. Furthermore, the regolith above the Colton or North

Horn conglomerates is also in many places similar to the surfaces of the younger fan deposits, which adds to the problem of identification.

Occasional gullies allow clarification of only Bmall areas of outcrop and point out the irregularity of deposition. Neither Schoff nor the writer mapped these gravels as a distinct

unit. Schoff (1957S 1951) included all beds as part of the pyroclas­

tic s, while in this paper some of them are identified as undifferenti­

ated Tertiary fan gravels. It is possible that some of the area map­

ped aa Colton or North Horn, particularly in the upper portion of

Payson Canyon, are actually underlain by fans of similar nature.

Some of the fan remnants southwest of Birdseye are at least 5°0

feet thick. Their relations to the North Horn and Colton formations

( and the volcanic conglomerates suggests an Eocene-01igocene age.

Pyroclastic Rocks

Definition and distribution Extensive deposits of pyroclastic

rocks with associated tuffaceous sandstones and alluvium cover large

areas in upper Payson Canyon, the northern Cedar Hills, and the foot­

hills east of Loafer Mountain along Crab Creek, Thistle Creek, and

Shurtz Canyon. These rocks also cover a large portion of the Cedar

Hills to the south, extend into parts of the southern Wasatch Range,

and are similar to pyroclastic material found in many partB of central

Utah. They have been discussed by Loughlin (1920, pp. 526-527), Eard-

ley (1955* PP» 55?“5^2) and Schoff (1957# PP» 105-156J 195*# PP» 65^-

656).

Schoff originally subdivided the pyroclasties of the Cedar Hills

into 4 major units, designating the sequence as the "Moroni forma­ tion", but in his later paper he used the term "pyroclastic rocks."

Beds mapped as pyroclastics in the area of this report were not -145- synchronously deposited and have been spread by landsliding and as alluvium even in Recent time. Wherever possible the alluvium is dif­ ferentiated, but in many places it cannot be readily determined whet­ her or not volcanic fragments in the regolith are residual and indic­ ative of similar subsurface material, residual remnants of pyroclastic beds which have been eroded, or gravel coverings of pediments and older pre-volcanic alluvial fans.

Lithology The pyroblastic rocks include volcanic breccias, con­ glomerates, tuffs, and tuffaceous sandstones that occur mainly in thick gray, brown, or greenish-gray beds which are stratified to var­ ious degrees. (See plate 17*) Such beds are very similar to the lower two units described by Schoff (I95I, p. 654):

2. Volcanic conglomerate, massive, coarse, gray, crudely bedded; matrix of gray tuff; pebbles, cobbles, and boulders of dark- colored igneous rock, up to 10 feet across; scoria boulder0 suggest derivation from surface flows; locally boulders of quartzite and Pennsylvanian limestone are included; locally includes gray and green tuff, and red strata nearly free of igneous pebbles.

1. Green sands, sandstones, and minor conglomerates, partly cemented by calcite but generally friable; well-rounded pebbles up to 2 inches in diameter consist of gray quart­ zite and igneous rock and are in zones indicating large- scale cross-bedding; green color due to ferrous silicate, probably greenalite.

Beds resembling unit 2 are widespread throughout the area of outcrop, but bed8 resembling unit 1 are evidently limited to Shurtz Qanyon, above Big Springs.

Eardley observed that the pyroclastics in the higher areas, partic­ ularly eaBt of Dry Mountain, contain more angular fragments than do those lower down at Salt Greek, and he therefore subdivided the rocks -146- into breccias and conglomerates. The predominance of rounded frag­ ments or angular fragments in most areas of outcrop is far from being clear-cut, so the writer has not differentiated the two as mappable units.

Individual fragments of the volcanic rocks are mainly glassy.

Many have conspicuous phenocrysts of dark pyroxene, and others have phenocrysts of light-colored material which evidently is altered plagioclase. Loughlin and Eardley found from studies of thin sections that at least two varieties, Maugite andesite11 and Mhornblende-augite andesite", are present.

The material is distinctly bedded in most places, but the bedding is suggestive of mudflows and alluvial fan deposits. Two miles north of Birdseye, west of Thistle Creek, some of the volcanics contain an abundance of free silica, much of it in the form of opal. It is assumed that this is a result of more recent decomposition of the debris by weathering.

Beds along Thistle Creek which are strikingly different from the rest of the pyroclastics are included in the unit, even though more detailed study may indicate desirability of differentiating them as a separate formation. These are best displayed on the east side of U.S.

Route 89 at Birdseye, where they consist of loosely consolidated pink and gray tuffaceous sandstones and conglomerates which are evenly bedded and evidently represent flood plain deposition. Massive beds of pink and gray tuffaceous sandstone are also exposed in the gulches west of the Dickson Ranch buildings along Thistle Creek r|- miles north of Birdseye and near the mouths of canyons entering Thistle Greek in the Cedar Hills south of Birdseye. Spieker (19^9$ P« 88) informally referred to the outcrops just east of Birdseye as the "Salt

Creek formation" for similar strata are present in Salt Creek Canyon,

(See plate l6,B.)

These beds are interpreted to be the result of rapid aggradation of the main stream channels. The main valley filled faster than the tributaries and alluvium therefore penetrated a short distance up the mouths of tributary canyons. Small lakes or ponds may have formed on the flood plain, for some deposits have an even-bedded lacustrine appearance. The materials involved were derived from adjacent exposed

Btrata of the North Horn, Flagstaff, and Colton formations as well as from the pyroclastics. Later dissection has left only remnants of the beds along valley Bides and near the mouths of tributary can­ yons, protected from cutting by the main stream. Some of the material is younger than the normal faulting which has affected beds of the dark gray volcanic conglomerates, but it is probable that some was also laid down at the time of deposition of the bulk of the pyroclastic beds. Eardley (1955) has attributed a similar origin to the beds in

Salt Creek Canyon, and it is possible that the two depoBitB are contem­ poraneous.

Thickness The total thickness of pyroclastic beds is indefinite in this area. Schoff (1951# p. 6^b) found a maximum of about 1560 feet near The Cliff in the southern Cedar Hills. In upper Payson Can­ yon the sequence is at least 800 feet thick in several places, but the uppermost beds have been reduced by erosion and the lowest contacts are rarely exposed. It is obviously thickest where it fills deep - 148- canyons of pre-volcanic age and on some of the ridges the beds seem to be only a few feet thick. The flood-plain facies of the formation southeast of Loafer Mountain is at least 200 feet and possibly 400 or more feet thick.

Stratigraphio relations The pyroclastic rockB are unconformable over the post-Oolton erosional surface. The volcanic debris filled in canyons and lapped over the divides, and, as a result, overlies rocks ranging from Mississippian to Tertiary in age. Subsequent to the orig­ inal deposition of the breccias and conglomerates the material was spread by mud flows, landslides, and stream action, so that the basal contact of rockB mapped as pyroclastics may actually be Recent in some places. Lacustrine and flood-plain deposits of tuffaceous sandstones and conglomerates lap against and possibly intertongue with some of the thicker beds of coarser material.

Age and correlation No fossils have as yet been found in the pyroclastic rocks of the Cedar Hills and southern Wasatch Mountains.

Schoff (1951# P» 655) considers them to be equivalent to the litholog- ically similar rocks of the Wasatch Plateau and to resemble the vol­ canic s of the High Plateaus to the south and the Oquirrh Mountains to the northwest. The pyroclastics of lower Diamond Fork (Baker, 1947) probably came from the same source as the volcanics of Shurtz Canyon.

The pyroclastics cannot be accurately dated, but they are broken by Basin-Range faults which are generally assumed to have been initi­ ated in late Tertiary time. Baker and Schoff both suggest the, pos­ sible equivalence of the pyroclastica in this general area to the -149- Norwood tuff, which has yielded vertebrate remains of unquestionable lower Oligocene age (Eardley, 1944* pp. 845-846). It is possible that ( some of the flood-plain deposits along Thistle Creek were laid down in Pleistocene time.

Tertiary (?) and Pleistocene Terrace Gravels

In the area east of Loafer Mountain in the vicinity of Birdseye and Crab Creek there is a system of dissected terraces composed in large part of crudely stratified alluvial fan material. (See plate 19,

B.) Undissected portions are soil-covered and are cultivated with the aid of irrigation. Rock material in the terraceb is derived from the

Tertiary conglomerates, shales, and volcanics ae well as nearby Carbon­ iferous strata. The lower terraces are well-defined and are assumed to correspond to different levels of Lake Bonneville. Some of the higher areas probably correspond to late Tertiary intervals of stream aggradation.

The terraces formed by the entrenching of Benny Creek in the fan at the southeast foot of Loafer Mountain are underlain by imbricated angular fragments of Carboniferous limestones and sandstones, as is well shown in cuts along the road into the canyon. A fan whose inter­ ior is exposed by slumping half a mile north of Birdseye is composed of roughly stratified boulders, sand, and clay, and some of the rock fragments are lower Paleozoic quartzites and limestones that probably were formerly embedded in some of the Tertiary conglomerates.

Farther north the bulk of some of the terraces is composed of tuffaceous sandstones and volcanic debris. -150- Plate 16

Scarp formed by basal conglomerate in Col­ ton formation. Looking southwest from north­ west of Shurtz Lake.

"Salt Creek formation" on east side of U.S. Route 89 at Birdseye. Friable sands and conglomerates contain pyroclastic debris* but were derived largely from Flagstaff and North Horn formations. -151- Plat© 17

A. Pyroclastic conglomerates weet of U.S. Route 89 a mile south of Crab Creek. Peak of Loafer Mountain in background.

B. Pyroclastios. Note -poorly sorted, rubbly nature of the conglomeratic material. -152- Plate 18

A. Loop moraine at head of Left Pork of Maple Canyon.

B. Loop moraine at head of Left Fork of Loafer Canyon. Light-colored debris is mainly heaps of angular rock fragments resembling rock glaciers. -155- Plate I?

A. Moraine at head of Left Fork of Crab Creek Bedrock is Oquirrh formation*

B# Terraces north of Birdseye. Looking north­ west toward Loafer Mountain. -154-

Quaternary System

The Quaternary system is represented most strikingly by the Lake

Bonneville deposits and associated stream terraces in Utah Valley and

Spanish Fork Canyon, but it also includes glacial drift, fans, land­ slides, and flood-pl&ine of the present streams. Some of the deposits are mapped and some are included as Quaternary alluvium. The undif­ ferentiated Tertiary (?) and Pleistocene terrace deposits near Birds­ eye have been mentioned above.

Lake Bonneville and Associated Deposits

The most entensive and best known Pleistocene deposits in central

Utah are those of Lake Bonneville, These lake sediments have been discussed by numerous authors, and a particularly detailed investiga­ tion of those in southern Uteh Valley was carried out by Bissell (1948).

Lake terraces lap against the western foot of Dry Mountain and the northern and northwestern slopes of Loafer Mountain, the highest level averaging between 5tl6Q and 5*180 feet in elevation. The terraces are quite distinct although not as well developed as those farther north, and they include bbth constructional terraces and wave- or stream-cut benches.

The higher lake levels caused the aggradation of streams entering from the surrounding districts, The deltas at the mouths of the streams, terrace gravels, and high-level alluvial fans are all present in Spanish Fork Canyon as a result of the higher lake stages, and are recognizable both east and south of Thistle. It is not clearly evident .155- whether or not an a m of the lake actually extended up the valley as far as Thistle. Remnants of a ridge across the mouth of Pole Canyon are attributed to blocking by rapid deposition of alluvium in Spanish

Fork Canyon.

Glacial Deposits

DiBtribution Glacial deposits are apparently limited to some of the valley heads on Loafer Mountain, where small cirques have been excavated. Maple Canyon has a double cirque, both lobes of which are elongate in a north-south direction, facing north. Deer Hollow haB a shorter but broader cirque, facing south, while the cirque in Loafer

Canyon is narrow and slightly curved, opening toward the southwest.

In addition, ice apparently occupied the heads of Broad Hollow and the

Left Fork of Crab Creek, and possibly there was a neve7 field in the southern branch of the Right Fork of Crab Creek.

Loop and lateral moraines occupy these basins at different eleva­ tions. The lowest moraine is at about 8800 feet in Maple Canyon, 9100 feet in Loafer Canyon, 9200 feet in Deer Hollow, and a little below

8400 feet in Crab Creek. The material appears fairly freBh and in some places contains depressions evidently caused by ice remnants.

The best-defined moraines are in the main channel of Maple Canyon, where three distinct loops are present and are from Vy to over 50 feet high at the center of the valley. (See plate 18,A.)

The moraine in Loafer Canyon is formed almost entirely of coarse, angular rock debris, which resembles a rock glacier. (See plate 18,B.) -156-

However, the material iB arranged in three distinct loQps and is not continuous, as one would expect in the case of a rock glacier. In addition, the piles of angular cobbles are found only at the lower end of the gently sloping floor at the valley head. Moraine in the other valleys consists of poorly sorted boulders, gravels, and sands.

The arcuate ridge of debris in the Right Fork of Grab Greek may be landslide material, or possibly due to a nevl field. In the Left

Fork of Grab Greek there is one high ridge of lateral moraine on the north side of the valley, and striated cobbles and boulders are pres­ ent. (See plate 19,A.) The extremely hummocky topography here is due mainly to hogbacks of Oquirrh strata, which dip steeply to the east.

Age and correlation Only one period of glaciation is clearly evident on Loafer Mountain. Atwood (1909) found that at least two glacial epochs are indicated in the Uinta and central Wasatch Mountain^ where some of the glaciers were several miles long and extended beyond the mouths of the valleys. Bradley (1956, pp. 194-196) later presented evidence for at least three glacial stages in the Uinta Mountains.

The freshness and the undissected condition of the moraines on Loafer

Mountain shows that they must be no older than Wisconsin, and they probably correlate with the younger glacial deposits in other areas in central Utah.

Alluvial FanB

Older Fans Large older fans are conspicuous on the northwest side of Loafer Mountain, south of Salem, and on the southwest side of -157- Dry Mountain, east of Santaquin Canyon. These fans are pre-lake Bonne­ ville in age, for they are overlapped by the lake deposits and are in­ dented by wave-cut terraces. Each of the fans covers about 2 square miles, and is formed by the coalescing of smaller fans from numerous canyons and gulches along the mountain front. However, each also riseb to an apex. The fans are composed of poorly sorted material, roughly stratified in part, and ranging from clay size to high boulders many feet in diameter. There is a better soil cover on the Loafer

Mountain fan than on the Santaquin one.

The older age limit of the fans can be no more definitely stated than poet-Wasatch frontal faulting, which is probably not meaningful, for minor movements are still taking place along the Wasatch Range fault zone, and acarplets cross the fans. Bissell (1946, p. 138) has discussed in more detail the alluvial fans in southern Utah Valley, and suggests an early Pleistocene age for them.

Younger fans Numerous alluvial fans spread out from the mouths of canyons along the mountain front which are clearly of Recent age.

In many places they overlap Lake Bonneville deposits or extend from the edges of Pleistocene terraces. Only a few of the more prominent of these fans were mapped; the rest are included as Quaternary alluv­ ium.

Landslides

Small landslides are numerous in the area surfaced by the Tertiary rocks, particularly the pyroclastics. The beds are not too well con­ solidated and the shales are readily converted to muds by heavy rains, -158- oreating excellent conditions for landslides. The upper portions of

Payson Canyon and the slopes along the Cedar Hills are surfaced by many areas of landslide debris. The valley and canyons of Crab Creek also contain a considerable amount of landslide material.

The features mentioned above are largely due to slumping, and the material involved is so similar to the regolith of the surrounding undisturbed areas that limits of the slide areas can be determined only with difficulty. There is one area in Payson Canyon, however, which appears to have been the scene of a large landslide of the debris-ava- lanche type. This is on the east side of Dry Mountain, just northwest of Maple Dell, where a broad embayment extends southwestward into the flanks of the mountain. The floor of this valley is severed by allu­ vium, hummocky ridges of coarse gravels, and some consolidated conglom­ erates. There are also isolated outcrops of beds of Manning Canyon shale and the Oquirrh formation— generally in unpredictable attitudes.

The writer believes that there was once a large avalanche here, caused in large part by the steeply dipping beds of Oquirrh lying over the incompetent Manning Canyon shale on the east side of Dry Mountain.

The slide area extended to the northeast slightly beyond the present stream in Payson Canyon, and has since been oovered in many places by alluvium from the upper portions of the canyon* Zones of weakness would have been set up in the strata of this region by the Gear Can­ yon thrust (See section on structure) and a particularly humid interval oould have converted some of the Manning Canyon shale beds to a mud­ like consistency, setting Up the proper conditions for the landslide -159- which seems to have ooourred here.

Quaternary Alluvium

Surface deposits mapped as Quaternary alluvium include clays, silts, sands, and gravels along the major valleys in the area and in some of the alluvial fans. Pleistocene deposits have been different­ iated in some areas. Quaternary material along the Wasatch Mountains in southern Utah Valley has been discussed in detail by Bissell (1948). IGNEOUS ROCKS

Igneous rocks in this area consist of a thick pre-Cambrian com­ plex exposed on the west side of Dry Mountain, a tabular diabase body in the lower portion of the Tintic quartzite on both Dry Mountain and

Loafer Mountain, one and possibly more dikes of probable Tertiary age, and the pyroclastic debris which was discussed with the sedimentary rocks. An adequate study of the igneous rocks would necessitate an independent investigation, and only field identifications were made of

some of the outcrops.

Archean Crystalline Complex

The Archean crystalline oomplex underlying the sedimentary se­ quence on Dry Mountain consists of a variety of rocks including foli­ ates, pegmatites, and granites. These are exposed for about 2-§- miles along the western foot of Dry Mountain, extending from the complexly faulted area northeast of Santaquin southward to a point where the large alluvial fan rises above the base of the pre-Cambrian (?) sedi­ mentary rocks.

Foliates include both schists and gneisses. The most widespread of these are dark-gray to greenish-black hornblende-biotite schists containing abundant quartz. Near contacts with the pegmatite dikes these contain aggregates of small brown and purple garnets. Amphibo- lites and sohists composed almost entirely of biotite are present in minor amounts; some are rather contorted. Gneisses range from por- phyritic granite gneisses containing pink feldspar phenocrysts

- 160- -161- averaging an inch or more in diameter to rocks gradational with the schists. Some are gray, consisting of bands of while plagioclase and quartz alternating with layers of black mica.

Pegmatites are as much as a hundred feet thick, occur both as sills and dikes in the foliated rooks, and are generally quite coarse grained. They contain pink and white feldspars, abundant quartz, bio- tite, and minor amounts of light-green mica. Some of the feldspars contain graphic intergrowths of quartz. In many places stringers of pegmatitic material occur as lit-par-lit structures in the gneisses and schists and show pronounced ptygmatic folding.

The upper portion of the complex is mainly a medium-grained mas­ sive granite or granodiorite having a pale-pink to gray color and con­ taining abundant biotite. Some portions are gneissoid. Near fault zoneB the granite is altered to a considerable extent and near the

Byron mines northeast of Santaquin it contains disseminated malachite.

The upper limit of the granite is an eroaional surface, overlain by pre-Cambrian (?) feldspathic sandstones.

Diabase Body in the Tintic Quartzite

A tabular diabasic body has been found in the lower portion of the Tintic quartzite in several areas in oentral Utah, and exposures have been referred to both as sills and as flows. After a regional study of the outcrops, Abbott (1951) concluded that the material rep­ resents a flow. He examined the unit in the south-central Wasatch

Mountains near Provo, in Long Ridge east of Slate Jack Canyon, on the -162- northwest slope of Mount Nebo, and on the western side of Loafer

Mountain south of Rock Canyon, Eardley (1955» PP» 54J-J44) noted the presenoe of the latter two occurrences and called the bodies sills.

An outcrop of diabase in the Tintic quartzite is also present on the southwestern slope of Dry Mountain, just north of Santaquin Can­ yon, It is best exposed directly northeast of the hill of Missies- ippian limestone which rises above the alluvial fan in the southwest quarter of section 19* where it occurs in duplicate due to normal faulting. On the upthrown side of the fault it is about 50 f©©t above the basal conglomerate in the Tintic quartzite, and is approxi­ mately 45 feet thick. It strikes N.45E. and dips 55° southeast, para­ llel to the bedding of the quartzite. An old mine dump just below is from a prospect pit which followed copper showings down dip along the base of the diabase to a depth of several yards.

A few fraguents of similar igneous material were found two miles to the north in float on the ridge below the old Union Chief Mine, but a search failed to reveal their source. It is therefore presumed that the diabase is present as only a thin layer in this place. Abbott

(p. 5) found the thickness of the flow in the region near Provo to vary from 6 inches to 50 feet.

Megascopically the rock on Dry Mountain and Loafer Mountain can be described as gray-green diabase or dolerite with major amounts of dull-red to purple felBitic material distributed either in bands or in massive layers through the unit. Flow structure is common. Alter­ ation has occurred and the dark minerals are generally chloritlzed or serpentinized. Much of the feldspar appears to have been altered to argillaceous material. Minor amounts of chalcopyrite and garnets are present in some of the highly ohloritio zones near the base of the outcrop on Dry Mountain.

The diabase on Dry Mountain is overlain by a quartz pebble con­ glomerate averaging about a foot in thickness and which has apparently been metamorphosed. It has a greenish color due to the abundance of chlorite or serpentine in the interstices, and it also contains num­ erous aggregates of specularite and garnets. A field examination is insufficient to determine the source of the metamorphism. Hydrothermal activity was evidently prevalent in the area in Tertiary time and the diabase at this location is similar in most respects to the exposures described in other areas whioh seem definitely to be flows. The writer's first impression upon seeing the outcrop was that it was a sill but he would now prefer not to express an opinion until a more detailed microscopic study is made.

Dikes

Loughlin (1918) discussed in considerable detail two small lampro- phyre dikes, one of which is looated on the Black Balsam claim near the top of the crystallines on the first ridge Bouth of the old Union

Chief mine. He classified the dikes as "albite minette" and regarded them as genetically related to the post-Eooene volcanic rocks.

Eardley (1955* P« 5^5) examined a group of small dikes exposed a few miles to the south near mines on Eva Peak and considered them to be similar in lithology and origin to the dikes described by Loughlin.

Looal miners told the writer that there is a dike at Tinney Flat, — 164— but the location is not definitely known. A detailed examination of the numerous abandoned mines and prospects in the Dry Mountain area would probably lead to the discovery of more such dikes.

These intrusives seem to be related to the Tertiary volcanism and probably also to the mineralization in the area. It is possible that fissures or vents from which the pyroclastics emerged are present be­ neath some of the volcanic breccias on the east side of the southern

Wasatch Range and that the dikes are part of the same system. STRUCTURE

General Features

The area here discussed contains two major mountains consisting mainly of tilted Paleozoic sedimentary rocks which have a general east­

erly dip, but which have been thrust, folded, and faulted, in a rather

complex manner. (See plates 27 and 2d) The mountains are bounded on the west and north by the southern portion of the Wasatch frontal fault, the presence of which is generally inferred on physiographic evidence. Gently dipping, relatively undisturbed Tertiary strata lie to the southeast and these overlie and abut against upturned strata of older sedimentary rocks that have been beveled by erosion. These

Tertiary beds have been locally warped into gentle folds, and in some places along the flanks of the mountains they have been rather steeply upturned. Normal faulting of different ages has affected both the mountains and the plateau area. Tear faulting has accompanied some of the folding and warping.

Time was insufficient for detailed investigation of some of the more complexly disturbed areas. Furthermore, much of the region is heavily wooded, and at many places on Loafer Mountain good outcrops are limited to narrow ridge tops, where measurements of strike and dip are not always reliable. (See plate 4,B.) Below is a discussion of some of the salient structural features of the area. Descriptions of the major folds, faults, and angular unconformities are followed by a sum­ mary of the inferred chronological sequence of crustel movements in this area.

-I65- — 166**

Folds

The southern Wasatch Mountains are the remnants of a larger folded mountain system, and the entire area of this report represents a por­ tion of the eastern limb of an anticlinal structure that has been mod­ ified by normal faulting. Other smaller folds of various ageB are also present— some evidently having been formed essentially contempor­ aneously with the large-scale folding.

Southern Wasatch Mountain Anticline

The anticline of which the southern Wasatch Mountains are evi­ dently a part was formed during the early Laramide orogeny. Eardley

(1954, PP» 579"-585) has described this structure between Dry Mountain and Mount Nebo, where the upper portion of the anticline was folded nearly isoclinally, overturned to the east, and thrust eastward over steeply dipping Jurassic strata.

In the region of Dry Mountain the structure is essentially a homo- cline, striking north-south and having an average eastward dip of around 45 degrees. This general trend is also shown in the southeast­ ern part of Loafer Mountain, where the beds of the upper Oquirrh and younger Permian formations strike nearly north-south and dip steeply eastward. (See plate 27.) However, the strike swings sharply east­ ward in the northeastern portion of Loafer Mountain and the upper beds of the Oquirrh formation change from a north-south Btrike and an aver­ age eastward dip of 40 to 60 degrees near Orab Greek to an east-west strike and a southward dip of 25 to 50 degrees north of Lone Pine Gulch*

It is, noteworthy that the anomalous east-west jog in the Wasatch Moun­ tain frontal fault lies just to the north. -l67«-

Although the prominent mountainous masses seen today in the

southern Wasatch Range are formed principally of Paleozoic strata, the younger Mesozoic beds were evidently also affected by this same fold­ ing, for an apparently orderly succession of Triassic, Jurassic, and

Cretaceous rocks can be followed up Spanish Pork and Soldier Fork

Canyons from the Permian outcrops near Shurtz Canyon and Diamond Pork.

These have the same general attitude as the Paleozoic beds to the west, striking northeast and dipping steeply eastward, but they have been truncated by erosion and in many places are covered in angular unconformity by younger formations. This angular unconformity is of importance in the dating of crustal movements in this area and will be discussed later in a separate paragraph.

Folds in the Crab Creek-Pole Canyon Area

General features In the area between Crab Creek and Lone Pine

Gulch, on the northeast side of Loafer Mountain, the high ridge formed by the steeply dipping beds of the upper part of the Oquirrh formation changes from a north-south to an east-west trend, the dip changing from east to south. The younger Permian beds in the inner angle of this turning point have been compressed into a tight syncline in Pole

Canyon and into an anticline to the south, along the ridge between

Pole Canyon and Shurtz Canyon. (See plates 27 and 28.) Tear faulting and normal faulting accompanied the folding. To the east of these steeply dipping Paleozoic beds, Tertiary formations dip in a general westward direction. These are unconformable over truncated Jurassic beds that dip steeply southeastward and seem to be an orderly

sequential continuation of the eastern limb of the southern Wasatch -168-

Mountain anticline.

Pole Canyon syncline The ayncline in Pole Canyon trends south­ west and the axis of the fold approximately coincides with the though of the valley. In the upper part of the canyon the folding becomes rather tight, but is asymmetric. The Diamond Creek sandstone on the northwest limb desoends to the valley floor at an average dip of no more than 50°, but then rises very steeply on the southeast, becoming nearly vertical or even overturned in some places. The syncline ter­ minates at the high narrow ridge of Oquirrh strata at the head of

Pole Canyon, which seems to be the crest of a small anticline whose trend is perpendicular to that of the much larger syncline in Pole

Canyon. The lower part of the divide between Lone Pine Gulch and

Thurber Canyon may be crossed by faults, for small outcrops of Oquirrh beds are present in some places.

Shurtz Canyon anticline The ridge between Pole Canyon and

Shurtz Canyon is formed by an anticline trending essentially parallel to the Pole Canyon syncline and plunging northeast. Flat-lying beds of the Park City formation cap the fold near the mouth of Shurtz Can­ yon, but the underlying beds of Diamond Creek sandstone dip to the southeast and to the northwest on opposite sides of the ridge. (See plate 4-,A*) Farther to the southwest the Park City beds are present only on the southeastern flank of the fold. (See plate 27.) At the head of the Left Fork of Pole Canyon the Oquirrh formation is exposed in an inlier that is apparently near the crest of the fold, which is asymmetric, with the steeper limb on the northwest. -169- The anticline terminates in the area along the right fork of

Shurtz Canyon but seems to continue as a structural terrace in the eastward-dipping beds north of Crab Creek. The writer suspects that the abnormally thick outcrop of beds mapped as Park City immediately south of Crab Creek may be due to a continuation of the anticlinal or terrace strudture and that there is a possible duplication of strata here. The beds at the head of the right fork of Crab Creek are a little puzzling and evidently represent small subsldary folds on the eastward-dipping beds. Two small synclines trend north and south, separated by the small anticlinal ridge at the head of Pole Canyon.

Both follow valleys and are only observable in section on the east- west ridge along the north side of the head of the Right Pork of Crab

Creek.

Minor folding in incompetent beds In this particular area the

Kirkman limestone is the best marker bed for determining structural complexities, but unfortunately this distinctive formation is rather incompetent in many places. As a result, many of the outcrops of

Kirkman present a confusing array of small folds and beds with widely divergent dips and strikes within small areas. An orderly indication of drag folding cannot generally be deciphered. The formation has evidently been thinned on the flanks and thickened on the crests of the larger folds, and this has undoubtedly produced much of the minor folding.

Minor folding is also present in some of the Bhaly beds of the

Twin Creek formation, as can be seen on top of the ridge at the north side of the mouth of Grab Creek. This folding is assumed to be a minor feature caused by the major flexing of the southern Wasatch

Mountain anticline.

Loafer Canyon Anticline

An anticline is present on the southwest flank of Loafer Moun­ tain, north of Wimmer Ranch Creek, and between the Right Pork and Left

Pork of Loafer Canyon. The axis of the fold trends in a general north­ west direction and plunges to the southeast. There are few distinct­ ive beds in most of this area of alternating quartzites and limestones, but the outline of the fold can be inferred from the strike and dip measurements plotted on the geologic map accompanying this report

(plate 27).

The east-west ridge on Loafer Mountain south of Loafer Canyon is crossed by the axis of the fold with no particular topographic break, but with an abrupt change of general dip and strike, and with a con­ torted bed at the approximate position of the axial plane. To the north the axis bends westward, but to the south it apparently continues southeastward to Benny Creek. On the northeastern limb the beds have a general north-south strike and dip 50 to 50 degrees east. The beds on the southwestern limb of the fold strike nearly east-west and dip southward at an average of 40 to 50 degrees. Near the fold axis the strike swings toward the southeast. Farther to the BouthweBt, the trend of the beds swings toward the southwest, evidently returning to the general north-south strike and eastward dip generally found in the Paleozoic beds throughout the area.

Beds below the Oquirrh formation in the Rock Canyon area also -171* reflect this folding, but their attitudes are quite diverse due to normal faulting and thrusting, which will be discussed later.

The cause of this folding is assumed to be the compressive force accompanying the Bear Canyon thrust, which came from the north or a little west of north. (See section on thrust faults.)

Folding in the Northern Cedar Hills

The relatively undissected portion of the northern Cedar Hills is surfaced mainly by gently dipping Tertiary strata that are disturbed by minor flexures and by normal faulting. Pyroclastic debris and veg­ etation mask most structural features. The most useful reference unit is the Flagstaff formation and it is hoped that all the outcrops map­ ped as Flagstaff in this area are in approximately the same strati- graphic position.

Folding of Tertiary beds in this area has been in the form of comparatively gentle flexures. The area near the Payson Lakes is a shallow syncline, with younger pyroclaBtics lying in the hollow of the trough. (See plates 27 and 28.) An inlier of Colton in the center is explainable by pre-volcanic relief, by a minor upwarping of the beds, or by faulting, but beoause the outcrop consists mainly of loose quart- zite boulders on tho surface, the origin of the inlier is not readily apparent.

The edges of the Tertiary beds that lap against Dry Mountain and

Loafer Mountain are warped upward, indicating post-depositional com- pressional movements from both the west and north. The upward bending is much steeper in some areas than could be explained by initial dip.

An anticlinal structure at the head of Frank Young Canyon is a -172- northern continuation of the fold described by Schoff (1951* P* 6 5 8 ) along Beaver Dam Greek. The eastern limb is clearly discernible, but evidence for the western limb is lost in the mass of Burfaoe rubble consisting mainly of quartzite boulders and cobbles. On Shram Greek there are beds of North Horn dipping 25 degrees westward, but the Flag­

staff beds exposed in the cliff face to the east do not seem to reap­ pear anywhere on the surface between Shram Greek and Tinney Flat, where they are overlain by a considerable thickness of Oolton and pyro- clastic material. Therefore the writer has inferred normal faulting to account for the absence of the outcrop of Flagstaff to the west.

Faults

Faults that can be genetically classified as thrusts, gravity faults, and tear faults are present in the Loafer Mountain-Dry Mountain area. The following paragraphs contain a discussion of occurrences of each type. The gravity faults are included under the more general geometrical classification of normal faults, however, for in the steep­ ly dipping beds characteristic of a large portion of this area a tear fault of small displacement can produce essentially the same effect as a transverse gravity fault, and if the fault zone is covered the genet­ ic classification is not always obvious.

Thrust Faults

General Statement There is structural evidence of at least three different episodes of thrusting in the Dry Mountain-Loafer Moun­ tain area. All three involve the thrusting of younger rocks over older— a feature which has been discussed by Billings (1955* PP* 140- *173- 165)• Loughlin earlier suggested the preeenoe of thrust faulting in

the Santaquin area of the southern Wasatch Mountains, He stated,

"Faults which are described as overthrusts are in part so poorly exposed, their courses so nearly parallel to the north-south system of block faults, and the rocks among them so free from severe crumpling or crushing that the writer is not fully convinced of their overthrust character, It is a striking feature throughout the Wasatch country that though the shales and even the thinner-bedded quartzites are much contorted along fault zones the adjacent heavily bedded limestones are practically free from such deformation,"

Eardley (19J4, p. 385) found that there is evidence of thrust­

ing along the beds of the Ophir shale in Dry Mountain and referred to this as the Santaquin overthrust. He also described the more readily

observable Hebo thrust, where overturned beds of the Oquirrh forma­ tion overlie Jurassic beds, Bissell (1948, p. 522) mentioned the presence of a thrust fault in a small canyon east of Spring Lake, and indicated that it continued southward. Brown (1952# p. 3^5) later dis­ cussed this fault, but suggested that it continued eastward to Payeon

Canyon, He also described a tear fault in lower Payson Canyon along which beds of the Oquirrh formation have been thrust southward. The former of these is a part of the Dry Mountain thrust and the latter a part of the Bear Canyon thrust, both of which are described below,

Santaquin overthrust The Santaquin overthrust was named and described by Eardley (193^* P» 383)« It a strip-thrust, as defined by Billings (1933# P» 1^2), in which the major movement has taken place along the imcompetent shales of the Ophir formation, with the younger Teutonic limestone generally lying at the base of the stripped sheet, and the Tintic quartzite or basal Ophir shale lying immediately below. The fault iB not at all obvious in most places. The best -174- evidence for it, cited by both Eardley and Loughlin, involves the presence of beds of Carboniferous rocks lying beneath the Cambrian sequence at the mouth of Santaquin Canyon. (See plateB 20,A; 27; and

28.) Additional evidence mentioned by Eardley is the presence of shattered and slickensided Cambrian limestone (Teutonic) above the

Ophir shale at the Syndicate mine, just east of the complexly faulted area northeast of Santaquin.

The writer found more evidence of this thrust at two locations.

One is at the top of the Tintic quartzite on the ridge just north of the old Union Chief mine, near the center of section 8 , T.10S., R.2E., where the Ophir formation is completely missing and the Teutonic lime­ stone lies directly on beds of Tintic quartzite. The other is in

Payson Canyon above the Nebo Loop road south of Rock Canyon, where the Ophir shale is again apparently missing.

The thrust plane is evidently nearly parallel to the bedding of the adjacent Cambrian strata on Dry Mountain and there is no clear evidence of its existence at any zones far removed from the Ophir for­ mation. There is not much evidence as to the direction of movement.,

Eardley (1954, p. 585) found slickensides at the Syndicate tunnel that strike N.75°W» and that are presumed to parallel the direction of thrusting. Plate 20 -175-

A* Santaquin Canyon. Block of Carboniferous rocks at left side of mouth of canyon is overlain by thick persistent ledge of Cambrian Teutonic limestone.

B. Contorted beds of Oquirrh formation on southwest aide of Santaquin Canyon. Fold­ ing probably accompanied thrusting along Manning Canyon shale. "176- piat© 21

View east toward Rock Canyon and the western ridges of Loafer Mountain* showing complexly faulted area. Left side of oanyon is mainly Mississippian, right side mainly Cambrian. Gently dipping ridge top below peak in extreme upper right is the Dry Mountain thrust sur­ face. •177“ Plate 22

View southeast toward western portion of Loafer Mountain Bear Oanyon in center. Front of Bear Oanyon thrust to left. Normal fault blocks of Mississippian and Cambrian beds to right. Rock Oanyon is at the point of discon­ tinuity of the thick ledges on the slope to the right. -178- Plate 2J

A* Normal fault parallel to Wasatch fault in the Oquirrh formation along northwest side of Loafer Mountain. Triangular Bpurs are down- thrown blocks.

B. Front of thrust in Bear Oanyon. Hills to right are Mississippian, Oanyon is full of small outcrops of Oquirrh and Manning Oanyon shale. - 179- Plato 24

A* Normal fault exposed in cut northeast of main tunnel of Dream Mine, south of Salem. Fault is subsidary to main Wasatoh fault zone* Bedrock is quartzites of the Oquirrh formation.

B. Closer view of fault shown above. Rock below is extremely shattered, and was orig­ inally quartzite similar in nature to down- thrown beds. Plate 25

A. Prominent triangular facets on northern slope of Loafer Mountain between Snell Oanyon and Plat Canyon.

B. Ridge of Diamond Greek sandstone downthrown on north side of normal fault on east side of Snell Oanyon. Mountain slope is of Oquirrh formation. -181- Plate 2 6

0*/'. '‘itli t: A. View down Thistle Creek toward down-faulted beds of pyroclasties, Colton, and Flagstaff south of Crab Creek. Highest peak in center is upthrown Flagstaff limestone dipping gently to left.

B. Closer view of downthrown Flagstaff and Colton beds shown above. Hogback of Nugget sandstone to left. Facing north. -182- Dry Mountain Thrust Thrusting of beds of the Oquirrh formation over older rooks is intermittently shown along the east aide of Dry

Mountain from Mollies Nipple to Santaquin Oanyon, in the hills west of

Dry Mountain on the southwest side of Santaquin Canyon, and on the ridge above the Nebo Loop road on the west flank of Loafer Mountain.

In most places the thrusting has involved the slipping of Oquirrh strata over soft incompetent beds of the Manning Oanyon shale. ThiB fault is here referred to as the Dry Mountain thrust.

On the southwest side of Santaquin Oanyon, west of Dry Mountain, and just off the mapped area, the beds of Oquirrh are quite disturbed by tight folds and faulting. (See plate 20,B.) A few small outcrops of Manning Oanyon shale and shattered beds of Oquirrh are present on the northeast side of the road.

On the east side of the range here, upstream from Tinney Plat, the highly disturbed character of the Oquirrh beds is still in evi­ dence. Slightly downstream from the point where the Oquirrh strata cross the gorge as high, vertical walls, the beds on the west side of the stream lie in a variety of attitudes— some horizontal, some pos­ sibly overturned, some dipping west. Small pockets of carbonaceous

Manning Oanyon shale are generally in evidence. At the head of Water

Oanyon, southwest from Tinney Plat, the basal Oquirrh strata are fold­ ed into forms which have been referred to as the "question mark" beds by the local miners, for their resemblance to that symbol.

The trace of the thruBt can be followed by a topographic break along the east side of Dry Mountain, eroded in the soft Manning Oanyon -185-

shale. It truncates beds of the Great Blue limestone, crosses the divide at the head of Picayune Oanyon, and follows the canyon to the foot of Mollies Nipple, (See plate 2 7 .) The northern portion contin­ ues around the eastern and northern sides of Mollies Nipple as was earlier indicated by Bissell. Manning Canyon shale is absent in some places along the thrust.

The Dry Mountain thrust is of a different nature on the western

slope of Loafer Mountain. On Dry Mountain the thrust surface dips east­ ward, parallel to the bedding. On Loafer Mountain the surface dips

south, due to later tectonic movements. The thrust surface overlies progressively older rocks down dip, from a thin layer of Great Blue limestone at the head of Bear Canyon to Middle Cambrian limestones at the south, beside the Nebo Loop road. Manning Canyon shale is present above the Great Blue formation at the head of Bear Canyon and above the lower Madison beds south of Rock Canyon. The latter occurrence is a rather thin outcrop, and the writer interprets it as due to mat­ erial carried along beneath the thrust plate. The Cambrian limestones along the ridge beneath the thrust surface are quite shattered and are full of thick oalcite veins. It is probably significant that the

shattering has occurred where there is an absence of shale aB a lub­ ricant.

Bear Canyon thrust Thrusting from a general northerly direction is indicated by structural relationships in lower Payson Canyon and in the ridge between Bear Canyon and Loafer Canyon. Brown (1952* p. 5^5) cited some of the evidence for this thrusting, referring to it as the

Payson Canyon thrust, and the author has taken the liberty of referring -184- to it by another name because evidence concerning it is much more in­ formative in the Bear Oanyon area. (See plates 27 and 28.)

The front of the thrust in Bear Oanyon is shown in Plate 22, where steeply dipping and slightly overturned beds of Oquirrh strata are distinctly discordant with those of the surrounding area. Bear

Oanyon is underlain by gently dipping Manning Canyon shale and isolated outcrops of the Oquirrh formation, which would seem to indicate that

(1) the Bear Oanyon thrust plate moved forward over the soft carbon­ aceous shales of the former formation, and (2 ) the thrust plane is close to the surface here.

The most interesting feature of this thrust is the presence of beds of the Flagstaff formation which was deposited during the pre- thruBting period in angular unconformity over truncated Oquirrh strata.

The Flagstaff beds rode in with the thrust sheet, maintaining their initial attitude relative to the Oquirrh strata, and are now best ex­ posed a short distance up the Right Fork of Loafer Canyon,

The thrust surface evidently dips to the north, beneath the large alluvial fan in this area. The allochthon has been cut to the north by the Wasatch Mountain frontal fault, and its southwestern portion has been dropped down 200 to 400 feet by a normal fault along the southwestern side of Bear Canyon, downthrown to the north.

The beds of the Oquirrh formation in Tithing Mountain have an attitude similar to the beds in the allochthon in Bear Oanyon, are alined along the strike of those beds, and are presumably a part of the same thrust block. Lower Payson Canyon is the site, of one edge of the thrust plate, and a tear fault extends up the valley here. -185-

Normal Faults

general statement The most conspicuous normal faults in this

area are those related to the Wasatch frontal fault and presumably to

the general period of Basin and Range faulting. These generally have

a large north-south component in their frtrike. North-south normal

faults east of the may or may not be synchronous with

those to the west, and the same may be said for some of the east-vfest

normal faults along Dry Mountain. However, there are east-west faults

on Dry Mountain and Loafer Mountain that are definitely much older.

Some of the principal faults and areas of faulting are discussed be­

low, in order of probable age.

Carboniferous block at Santaquin Oanyon On the southwestern

flank of Dry Mountain at the mouth of Santaquin Canyon there is a

block of Carboniferous beds which the writer believes are from the

Oquirrh formation, and which underlie the Santaquin overthrust. (See

plate 20,A.) On the north they abut in east-west fault contact

against beds of the Tintic quartzite and the pre-Cambrian (?) unit.

This pre-thrusting normal faulting has been described both by Eardley

(1934, P» 585) an(* by Loughlin (1920).

Faults north of crystalline complex The pre-Cambrian crystalline

complex on the west side of Dry Mountain terminates to the north in a maze of normal faults, many of which evidently pre-date the thrusting

in the Ophir shale which Eardley (1934, p. 585) referred to as the

Santaquin overthrust. Most of the north-south faults are downthrown

to the west— a feature probably indicative of a rdatJonship to the

Basin and Range faulting. The writer believes that the crystallines have acted as a but­ tress which has remained comparatively intact in the face of both com- preesional and tensional forces. The relative thinness of the pre-

Cambrian (?) sedimentary sequence in this area and the absence of a tillite below the Tintic quartzite show that this must have been a former topographic high and that an ancient crystalline mountain under­ lies the area.

Rock Oanyon area In the vicinity of Rock Canyon on the western flank of Loafer Mountain the strata are complexly broken by normal faults. (See plate 21.) Eardley (195^# P* 588) noted the east-strik­ ing fault which has placed beds of Mississippian on the north oppo­ site Cambrian beds on the south. Several subsidary faults are pres­ ent, and slices of both Cambrian and Mississippian rocks are downthrown to the north. The sequence has been overridden by the Dry Mountain thrust plate, folded by compression from the Bear Canyon thruBt, and again broken by normal faults of the Basin and Range type. Oneof the latter is a major fault paralleling Payson Canyon, downthrown to the west, and a probable continuation of the Wasatch frontal fault system.

Subsidiary normal faults parallel to the main one have resulted in the presence of blocks and slices of Cambrian, Mississippian, and Oquirrh limestones both above and below the Nebo Loop Road south of Rock Can­ yon. Additional normal faulting has occurred in front of the Bear

Canyon thrust block, and a fault striking N.55W. and downthrown to the north forms the southwestern side of that canyon. (See plate 2J, -187- Thiatle Oanyon fault The name Thistle Oanyon fault was applied by Harris (195^* P* 205) "to the normal fault parallel to U.S. Route 89 on the west side of Thistle Creek from Aggie Oreek to a point half a mile south of Thistle. The fault continues northward along the east side of the outcrop of the Twin Oreek formation to a point a short distance behind the filling station east of Thistle on U.S. Route 50*

The fault has evidently been controlled to a great extent by incompetent shaly beds in the Twin Creek formation and is a bedding plane fault along much of its length. The throw north of Crab Oreek is over 1200 feet, but it decreases southward to less than 1000 feet.

South of Orab Oreek there is a confusion of small feull.t blocks of con­ glomerates, limestones and marls lying along the foot of the scarp.

(See plate 26.) These include beds of the Twin Oreek, Oolton, and

Flagstaff formations, and most blocks seem to be limited in lithology to beds of a single formation. Beds of pyroclaBtics at the southern end of the fault dip steeply east, possibly as a result of drag. Just south of Orab Oreek deep red shales and large boulders of conglomerate of the North Horn beds lie on the dip slope of the Twin Oreek at steep angles and are also presumably left due to drag.

Faulting near Hyle Hollow At the head of Hyle Hollow is an out­ crop of algal-ball limestone with overlying brown sandstones and con­ glomerates. The beds clearly seem to be a Oolton-Flagstaff-North Horn sequence, but appear to be stratigraphically above the pyroclastics.

The hills just to the east are densely wooded and are covered mainly by loose boulders and cobbles of Paleozoic quartzites and limestones. -188-

It is assumed that a normal fault trending north-south and downthrown to the east lies somewhere within the ridges east of the outcrop.

Northern Oedar Hills No major faulting ie apparent in the north­ ern part of the Oedar Hills. It ie probable that normal faults, down- thrown to the weBt, underlie some of the prominent north-south canyons tributary to Payson Oanyon in the area of volcanics south of Winward

Reservoir, These postulated faults could be extensions of the zone of normal faulting in Payson Canyon in the vicinity of Maple Lake, and would conveniently explain the absence of outcrops of the Flagstaff limestone west of Shram Oreek, It is possible, however, for facies changes or relief on the pre-Flagstaff surface to account for this absence.

Another fault has been postulated across Frank Young Oanyon south of the Nebo Loop Road and west of the Payson Lakes to account for a feature that could also be explained either by a syncline accompanied by facies changes or by post-Flagstaff, pre-Colton erosion. The Flag­

staff iB a fairly thick, south-dipping limestone in the bottom of

Wimmer Ranch Oreek, where it is overlain by a considerable thickness of Oolton conglomerate. It reappears at a higher elevation to the south in cliffs between Frank Young Canyon and Schram Oreek, (See plate 27.) From the Nebo Loop Road to Wimmer Ranch Oreek there is a continuous conglomerate outcrop— of the Oolton formation. At the foot of the Flagstaff outcrop above Shram Oreek, conglomerates and sand­ stones apparently are part of the North Horn formation. The surface from here to the Nebo Loop Road is covered with boulders and cobbles of quartzite, and there are occasional outcrops of conglomerate. -189** Assuming that this indicates a continuous bedrock of conglomerate

below, one can still account for the situation without faulting by

postulating either a pinching-out of the Flagstaff formation or a

post-Flagstaff, pre-Oolton erosion interval, which in either case

would mean that Oolton conglomerates could lie on North Horn conglom­

erates and probably could not be differentiated from them. Either sit­

uation would imply an east-west syncline along Wimmer Ranch Oreek, if

no faulting is assumed.

A normal fault, striking northeast and downthrown to the east, is

present in upper Rock Hill Hollow, where the North Horn and Flagstaff

formations crop out on the west side of the deep, narrow gulch, and

pyroclastics form the east side.

Wasatch frontal fault The Wasatch frontal fault has been dis­

cussed by many writers, Davis (190^)# Gilbert (1928), and Nolan

(pp. 180-182) have written significant papers concerning this fault

or fault zone. The faulting is mainly evidenced by such physiographic

features as triangular facets, piedmont scarps, and occasional slick-

ensided surfaces (See plate 25>A.), but there are several areas where upper surfaces of the downthrown blocks are exposed above the alluvium,

Eardley (193*0 described the faulting in the vicinity of Dry Mountain and Payson Oanyon, where the Basin and Range gravity faults making up the Wasatch fault have a striking en echelon character. The writer

suggests that the crystalline body that is partially exposed on Dry

Mountain has exerted an important influence on the pattern of the

Wasatch frontal faulting in this area, and upon the pattern of folding as well. -190-

At the southern end of Utah Valley the Wasatch fault makes an

anomalous east-west swing away from its general north-south trend.

North of Loafer Mountain it roughly parallels the strike of the beds,

as it does along Dry Mountain, which suggests that longitudinal zones

of weakness in the southern Wasatch Mountain anticline controlled the

faulting. Weaknesses may have developed in rockB of the Payson Oanyon

area due to the bending eastward of the southern Wasatch anticline at

this place, and these proposed zones of weakness could also have in­

fluenced the extension of the normal faulting up Payson Oanyon.

The throw of the frontal fault is not known in most places. Eard­

ley estimated the displacement of the downthrown valley block near

Santaquin Oanyon as between ^>000 and 6000 feet.

Subsidiary normal faults parallel to the main scarp bounding

Loafer Mountain are present between Loafer Oanyon and Flat Oanyon. The

prominent spurs south of Maple Oanyon are in the hanging wall just above the fault surface. (See plate 25*A.) The throw here is estimat­

ed as 600 to 1000 feet. Normal faulting is also quite evident in the vicinity of the Dream mine, between Water Canyon and Flat Canyon. A road cut has exposed a fault just northeast of the mine tunnel, and the fault plane dips 25°-50° northwest. The beds below the fault are quite

shattered, but those above are fairly intact. (See plate 24.)

At the mouth of Snell Canyon, downthrown blocks of North Horn (?) conglomerate and Diamond Oreek sandstone lie at the foot of the Wasatch front, (See plate 25,B.) Hodgson (1951* P» 55) studied the faulting in thiB area and concluded that the frontal fault exhibits a continuous trace here. -191* Transverse faults on Dry Mountain A number of high-angle nor­ mal faults strike east-west aeroab Dry Mountain. These are best seen along the top of the mountain ridge, where vegetation is thin and displacements in the upper massive ledge of Madison limestone are eas­ ily recognizable. The faults have throws of 50 to 200 feet, and may be tear faults. Prominent gulches generally lie along the traces of these faults on the western slope, but they are less pronounced on the east. It is not evident whether the faults are post-volcanic or pre- volcanic.

Normal faults on Loafer Mountain A number of small normal faults are mapped on Loafer Mountain. Evidence for most is confined to ridge tops. One long east-west fault, downthrown to the north, lies along the southeast portion of the mountain and can be followed mainly by topographic breaks. These faults are generally transverse to the struc­ ture. They are probably connected with the early Laramide folding which produced Loafer Mountain, and many are possibly tear faults.

Tear "aults

The tear fault in the lower portion of Payson Oanyon has already been mentioned in connection with the Bear Oanyon thrust. Tear fault­ ing of a different nature is evident in other areas.

Orab Oreek-Pole Oanyon area Tear faults are present in Grab

Oreek and the Right Pork of Shurtz Oanyon. In both the northern side has moved eastward with respect to the southern side, and in both this is shown by the presence of beds of Diamond Oreek sandstone on the north lying opposite strata of the Park Oity formation on the south sides of the canyons, which trend perpendicular to the strike. The -192- extent and nature of the faulting farther up the canyons is not clear because the slopes are heavily wooded and soil covered. It is assumed that the tear faulting accompanied the formation of the folds in this area and the bending eastward of the southern Wasatch anticline.

Faulting near Picayune Oanyon In the vicinity of Picayune Oan­ yon and Mollies Nipple there is evidence of tear faulting. Beds to the south increase sharply in dip and swing westward, and some are over­ turned. These structures are evidently drag folds on the southern block, which moved eastward relative to the northern side. Brown

(p. 544) named this fault the Picayune Oanyon tear and suggested that it is the northern limit of the Santaquin overthrust. The writer sug­ gests that another explanation for the tear faulting here might be that the Dry Mountain block was tilted further eastward in post-Oolton time, and the tear faulting marks the northern limit of this late movement. The extremely steep dips of the conglomerates lapping against the mountain west of Maple Lake definitely imply additional tilting after deposition, and at least some of the conglomerates are

Colton in age. This proposed tilting could have taken place in several episodes over a considerable period of time, starting after the early

Laramide orogeny. The major east-west normal faults cutting across

Dry Mountain are assumed to have originated at approximately the same time, and some or all may be tear faults.

The likelihood of this interpretation is strengthened by the fact that there are other tear faults of a Bimilar nature and age in cen­ tral Utah. Near Hjork Creek, about 5 miles north of Indianola and 16 miles southeast of Picayune Canyon an east-west tear fault involves -195-

beds of the Indianola group, which are overlain unconformably by

Price River conglomerates. Beds on the south side of this fault are

tilted sharply eastward while those on the north remain nearly flat

(E •M. Spieker, personal communication).

Chronology of Orustal Disturbances

The sequence of crustal movements in central Utah since late Jur­

assic time has been outlined in considerable detail by Spieker (1946,

pp. 149; 1949* pp. 78-81). Bissell (1955* PP» 25) has summarized the

structural evolution of the Utah Lake basin. Walton (1944, pp. 125-

129) summarized the late Mesozoic and Tertiary structural history of

the . The present work has produced no additional evi­

dence for the dating of individual crustal disturbances in this area,

but it has introduced new evidence concerning thrust faulting, and

has led to the recognition of a succession of at least three thrust

movements. It has also produced further evidence of normal faulting

and of folding of various ages.

Movements older than Jurassic were probably mainly epeirogenic

in nature, with the exception of probable pre-Cambrian orogenio dis­

turbances. There are no notable angular divergences in the strati-

graphic succession and no coarse clastic sediments indicative of near­

by orogenic movements. Most of the strata resemble those attributed to shelf-type deposits. A possible exception is indicated by the ang­ ular unconformity at the base of the Tintic quartzite, which may be due to orogenic movements in early Cambrian or late pre-Cambrian time.

There are large gaps in the Paleozoic stratigraphic Bection, but the -194- bed 8 below and above have approximately the same attitudes.

The only absolute date that can be established for orogenic move­ ments in the area of this report is that of the early Laramide oro­ geny. Spieker (1946, 1949a, 1949b) has shown that the angular uncon­ formity of the Price River formation over beds of the Indianola group in the region of Thistle can be definitely attributed to a major orogeny originally thought to have occurred between middle and late

Montana times. Now, in terms of later paleontologic opinion as to the ages of the critical strata, the orogeny seems probably to have occurred a little earlier. This angular unconformity resulted from beveling of the strata of the Indianola group and older formations immediately following the orogenic movement that produced the southern

WaBatch Mountain anticline. The Cretaceous beds of the Indianola group Beem to be in orderly sequence above a succession of steeply eastward-dipping strata that can be traced westward to Loafer Moun­ tain.

Conglomerates of the Price River formation eaBt of Thistle were evidently derived from erosion of rocks farther to the west. As these were reduced by erosion they in turn were covered by similar conglom­ erates produced by erosion still farther to the west (or, at least, from a region higher in elevation). Thus, the unconformity is theor­ etically younger to the west, but the folding concerned is almost certainly a continuation of the folding to the east. In the area of this report the truncated Permian strata at the mouth of Benny Creek, and directly west of Thistle, are overlain by a thick layer of North

Horn conglomerates, but to the west the Flagstaff formation and -195- local ly the Oolton formation lie directly over Carboniferous beds— in accordance with the picture of events as described above.

The Dry Mountain thrust seems definitely to be a feature of the

Early Laramide orogeny because it is directly associated with the fold whose bevelled eastern flank is overlain by the Price River conglom­ erate, The beds of the upper thrust sheet are in some places quite complexly folded, but the folding parallels the general trend of the

Wasatch Range in this area. On the east Bide of Dry Mountain, trun­ cated beds of Oquirrh above the fault are overlain by the Flagstaff and North Horn formations, and on Loafer Mountain the same situation prevails.

The Santaquin overthrust is older, for in the Rock Canyon area this thrust is cut by east-west normal faulting that pre-dates the

Dry Mountain thrustj beds of the Oquirrh formation are thrust over

Mississippian strata on the north side and over Cambrian strata on the south side of Rock Canyon. The Bear Canyon thrust is younger, for beds of Flagstaff limestone are a part of its allochthon.

In terms of this purely ordinal succession, the writer has pro­ posed a chronology of crustal disturbances in this general area, ex­ tending back to the time of the normal faulting preceding the Santa­ quin overthrust. An attempt has been made to fit the chronology into the regional sequence of events as has been discussed and summarized by Spieker (19^6» 19^9a» 19^9b)*

Below are tabulated and briefly discussed the crustal movements recognizable in the Dry Mountain-Loafer Mountain area. The sequence is -196- believed to be correct, but most of the proposed ages are questionable

Crustal Movements in the Dry Mountain- Loafer Mountain Area

Type

1. Normal faulting Late Jurassic (?)

2. Thrusting (Santaquin overthrust) Colorado (?)

5, Normal faulting Colorado (?)

Orogeny and thrusting (Early Laramide) Middle-late Montana

5. Warping (post-Colton) Eocene (?)

6. Thrusting (Bear Canyon thrust) Uintan (?)

7. Normal faulting (post-volcanic) Late Tertiary

8 . Normal faulting (Basin and Range) Late Tertiary, Quaternary

1, Early normal faulting Beds of the Oquirrh (?) formation are in east-west normal fault contact with pre-Cambrian (?) and Tintic quartzite beds at the mouth of Santaquin Canyon. Both sides are over- lain by the thrust plate of the Santaquin overthrust. Similar fault blocks of older rooks lie below this thrust in the area northeast of

Santaquin. No definite evidence is available as to an older age limit, but the faulting may be connected with late Jurassic movements to the west. Hunt (pp. 128-129) proposed a Mid-Cretaceous (?) age for high- angle post-Twist Gulch normal faults with large east-west components of strike that were formed prior to the deposition of beds of the

Indianola group in the northern part of the Gunnison Plateau. These faults may be of the same general age as those mentioned above. The presence of coarse conglomerates in the Morrison (?) formation of areas to the south and west have suggested a probable late Jurassic

or lower Cretaceous orogeny (Spieker, 1946, 1949).

2. Santaquin overthrust The thrusting along the Ophir shale

possibly occurred in Colorado time, but evidence is lacking to provide

a definite date. It is not even certain that the thrusting ever reach­

ed the Burface. This movement may have originally been a thrust in

the foothills of ancient mountains to the west, similar to thrusts

found in the northern Rocky Mountains today. This could well have

been coincident with one of the two orogenic pulses reflected in the

upper and lower members of the Indianola group (Spieker, 1946, 1949;

Schoff, 1951)» which are certainly in part and probably all Colorado

in age.

5. Colorado (?) normal faulting In Rock Canyon, beds of Miss-

isBippian limestone have been downfaulted to positions opposite Cam­

brian formations cut by the Santaquin overthrust. All are overlain

by the Dry Mountain thrust. This episode of east-west normal faulting

therefore must have occurred between the Santaquin overthrust, of

possible Colorado age, and the Dry Mountain thrust, which is almost

certainly a feature of the early Laramide orogeny.

4. Early Laramide orogeny, Dry Mountain thrust The Dry Moun­ tain thrust involved the movement of Oquirrh strata eastward, in this area generally over beds of Great Blue limestone. This probably occur­ red at essentially the same time as the thrusting at Mount Nebo. As was previously mentioned, this movement seems closely related to the general early Laramide orogeny that folded the southern Wasatch -198- Mountains into a large anticlinal structure.

5. Eocene (?) warping Tertiary beds in the Payson Lakes area

were warped into gentle folds. A gentle west-dipping cuesta was formed

west of Thistle. Conglomerate beds were turned up slightly along the

east side of Dry Mountain. The warping was post-Colton and possibly

post-volcanic, and is probably related to the Picayune Canyon tear

faulting. It may be more accurate to date this as post-early Eocene,

pre-Wasatch frontal faulting.

6. Uintan (?) thrusting The Bear Canyon thrust from the north

occurred after deposition of the Flagstaff formation and possibly coin­

cided with the strong uplifting of the Uinta Mountains, which occurred

in two pulses and resulted in east-west folds in the central Wasatch

Mountains, with deposition of beds of the Uinta and Duschesne River

formations in the Uinta Basin (Walton, p. 127; Bissell, 1955# P* 52).

7. Late Tertiary normal faulting The Thistle Canyon fault is post-volcanic in age, and may be a part of a system of normal faults,

downthrown on the east, which are present in the Cedar Hills. The

Thistle Canyon fault is on the west side of a graben. Harris (195^) has mapped normal faults to the east which are downthrown on the west.

This system of faults may be related to the flexing and faulting of the Wasatch monocline, which probably occurred between late Eocene and the Miocene (Spieker, 19^6).

8. Late normal faulting The normal faulting of the Basin-and-

Range type that produced the Wasatch frontal fault and subsidiary fractures began in late Tertiary time, and the major movement had *-199“ occurred before the time of Lake Bonneville, for Lake Bonneville oc­ cupied a baein in Utah Valley that was essentially the same as it 1b today. Small movements still oocur along the fault, as is shown by formation of piedmont scarps in the past few decades. The major fualting in this area evidently begah after the deposition of the pyroclastics, which are thought to be of Oligocene age. GEOLOGIC HISTORY

The geologic history of central Utah has been discussed by many authors. For comprehensive presentations of the geologic history of areas adjacent to and including parts of the area of this report, the interested reader is referred to works by Nolan (19^5)* Spieker (19^6»

19^9)* Sardley (1951)* Baker, Huddle, and Kinney (19^9)* and Bissell

(1955)* The above listing is far from complete, but these works com­ bined give detailed discussions of the major phasea. of the strati- graphic and structural history of the region. The summary below applies mainly to the immediate area of this report, although the term

"immediate area" may not be entirely correct if the thrusting evident here involved movements of any notable distance.

The history of the crystalline complex has not yet been worked out, and it is not known whether or not the foliated rockB were orig­ inally sedimentary. The first definitely known deposition of sedi­ mentary material occurred after the crystallines had been orogenic- ally disturbed and eroded to a series of highlands and troughs, some of which were probably open to the sea. Within these basins, of prob­ able pre-Cambrian age, sande and muds were deposited in flood-plain, deltaic, and shallow-water environments. Glaciation occurred in some of the highlands to the north, but evidence of such occurrence is not present in the Dry Mountain area, due either to non-deposition or to late pre-Cambrian erosion. Tilting or gentle folding brought an end to dedimentation, and the beds were truncated by erosion.

Deposition was continuous throughout latest pre-Cambrian and

• - - - 200 - - 2 0 1 - Cambrian time in the geosyncline to the west, and some time after the uplift and erosion of the sedimentary beds mentioned above, presumably in Early Cambrian time, the seas encroached eastward, depositing a layer of pebbly sand overlain by a thick unit of clean, well-sorted quartz sand (Tintic quartzite). With further subsidence the littoral zone moved farther eastward and during Middle Cambrian time the clean sand was covered by muds, clays, and silts that intertongued with sands and calcareous muds or ooze (Ophir formation). Then began a period of dominantly carbonate deposition, lasting through most, if not all, of Cambrian time. The seas were shallow, and at times wave action caused the formation of flat-pebble conglomerates. Much of the material was calcarenitic, in part oolitic, and in some ways sim­ ilar to sediments being deposited in warm shallow seas today (llling,

1954). Clayey or silty material was introduced from time to time, and mixed with the carbonate muds at fairly regular intervals to form alternating thin irregular layers of fairly pure carbonate and argil­ laceous carbonate. Much of the carbonate either was deposited as dolomite or was quickly dolomitized.

Ordovician and possibly Silurian sediments may have been deposit­ ed, but if so they were subsequently removed by erosion* Positive conditions and eroBion prevailed during all or part of the time from

Late Cambrian to Middle or Late Devonian time, and gentle beveling of Upper Cambrian dolomites resulted. A brief Late Devonian reinvas­ ion by the sea resulted in deposition of dolomite to the north (Jef­ ferson) which possibly extended into the Dry Mountain area. Its . “202" deposition was followed by gentle uplift and additional erosion in

some areas.

Early in Mississippian time epeirogenic movements in Utah and

adjacent areas to the north resulted in widespread invasion by the

Madison sea and uniform deposition of carbonate over wide areas. An unusual abundance of silica was present, possibly due to volcanism

far to the west. Much of the deposition was of calcarenitie material— particularly encrinal debris. The carbonate material was deposited throughout most of Mississippian time, modified during the Brazer sed­

imentation by intertonguing of numerous sheets and tongues of sand

(Humbug). A relatively clastic-free interval of carbonate deposition followed until late in Mississippian time elastics became predominant in the form of black, highly carbonaceous muds, dirty sands, varie­ gated clays and muds, and a few intercalated beds of calcareous mat­ erial. The environment may possibly have been a paralic swamp, and deposition may have occurred on a partially eroded surface of lime­

stones of the present Great Blue formation. The eastern portion of the Uinta Basin was positive and subjected to erosion at this time, but thick beds of the Great Blue limestone and Manning Oanyon forma­ tion are present a short distance to the north and west, with no indi­ cation of any break in sedimentation.

Early in Pennsylvanian time (Springeran) central Utah became the site of a rapidly subsiding basin in which a tremendous thickness of arenaceous and calcareous material accumulated (Oquirrh formation), continuing uninterrupted into Permian time until a total of at least

2 miles, and in areas near Provo almost 5 miles, of these Bediments -205- were present. The elastics were possibly derived from the ancestral

Rooky Mountains to the east, which were evidently being actively uplifted at this time. This body of sediment was unusual not only because of its great thickness, but also because of the lack of any appreciable quantity of mud in the basin of deposition.

Sedimentation continued, but environment changed, and fetid, lam­ inated, carbonaceous and limy muds were deposited, only to become brecciated due to slumping. Sand in varying amounts was deposited intermittently— sometimes as laminations, at other times aa thick lenses (Kirkman limestone). The littoral zone moved westward, and sand was deposited in beach, channel, dune, and shelf environments. A re­ invasion of the sea from the west late in Permian time resulted in the limy and clastic deposition of the Park City beds. Much silica was again present in the waters and an interval of highly phosphatic dep­ osition also occurred.

Late Permian or Early Triassic epeirogenic uplift and erosion resulted in a surface of considerable relief in the Loafer Mountain area, and it is possible that the portion of the Park City formation now present in the vicinity of Crab Creek originally stood as a prom­ inent hill above the surrounding area of shal1ow-water red-bed deposi­ tion (Woodside). The red bedB probably were deposited in mud flats which were alternately wet and dry, and an interval of marine lime­ stone deposition (Thaynes) resulted in an intertonguing of the two facies in Early Triassic time. The marine mud flats were superseded by extensive flood-plains and lakes, which were gradually covered by eolian sands (Nugget) as a desert occupied a vast area in Utah and areas both to the north and south, probably early in Jurassic time.

A marine invasion again occurred during Middle and Late Jurassic times, and thin-bedded limy muds (Twin Oreek) were deposited in shal­ low areas, possibly lagoonal in nature. The calcareous deposits were followed by littoral sands and shales, and shortly thereafter by the coarse piedmont conglomerates and shales of the Morrison (?) formation- probably resulting from orogenic uplift only a short distance to the west during Late Jurassic or Early Cretaceous time. The original western limit of deposition of these beds is not known and their near­ est outcrop is a short distance east of Thistle.

No rocks deposited during the interval from Middle Jurassic to early Tertiary time are definitely recognizable in this area. ThiB time interval was marked by four, possibly five, major orogenic pulses

(Spieker, 19^9* PP» 78-79J Hunt, 1954) which resulted in the deposi­ tion of the lower and upper coarse conglomerates of the Indianola group and the South Flat formation in nearby areas to the south and east, and, during medial and late Montana time, the deposition of

Price River conglomerates over a widespread angular unconformity formed by the folding, thrusting, and subsequent erosion of beds ranging from pre-Cambrian to Cretaceous (South Flat) in age. This last orogeny, the early Laramide, caused the folding of the present southern Wasatch

Mountains into a large anticlinal structure, the thrusting at Mount

Nebo, and the Dry Mountain thrust. The eastern steeply dipping beds of the fold were rapidly beveled by erosion, and a valley was cut in

Triassic rocks along the east side of Loafer Mountain, west of the -205“

Nugget sandstone. The Price River conglomerates to the east were derived from these rapidly eroding beds. As the eastern portion of the anticlinal fold was removed, piedmont followed by floodplain and lacu­

strine environments moved westward. Conglomerates left along the moun­ tain fronts during the times of Price River and North Horn deposition are apparently undifferentiatable in this area.

Limestones of the Flagstaff lake were deposited over coarse con­ glomerates and red shales of the North Horn formation, and this lake, or another of similar nature, existed both north and west of Dry Moun­ tain, The lake lapped around the eastern and southern flanks of

Loafer Mountain and the southeastern end of Dry Mountain, but so far no evidence has been found of its shore line along the northeastern flank of Dry Mountain. Biseell (19^8) reported that Tertiary lake deposits, presumably Flagstaff, lie on top of West Mountain, west of

Payson. Local disturbances caused intertonguing of conglomerates with the fine lake sediments, and a stronger deformation or uplift caused coarse conglomerates of the Colton formation to cover the limestones of the Flagstaff lake,

Post-Colton Tertiary events include thrusting from the north of the Bear Canyon allochthon (possibly Uintan in age), gentle warping of the newly deposited Tertiary beds, the deposition of pyroclastio material, and normal faulting. Considerable erosion preceded the dep­ osition of the volcanics, and essentially the present drainage was es­ tablished. Deep valleys were filled by the igneous debris— possibly in the form of mudflows. The volcanics were spread as alluvium over - 2 0 6 - pediment a that had been cut across the Colton, Flagstaff, and North

Horn beds, and they contributed material to choke the large lower valleys, causing rapid aggradation by the streams.

Post-volcanic normal faulting along north-south lines, downthrown to the east, occurred in the areas east of the mountains, and during late Tertiary time the Basin and Range normal faulting initiated the formation of the great Wasatch frontal scarp, with its associated sub- sidary faults. The major movement along this fault occurred before the rising of Lake Bonneville, for large alluvial fans formed along the young scarp and were later covered or cut by the lake deposits, which left terraces and benches all along the Wasatch front. Move­ ment has continued along this fracture even to historically recent times.

During Pleistocene time small glaciers ocouppied valley heads on

Loafer Mountain and systems of terraces were formed in the lower val­ leys. The passage from Pleistocene to Recent time has been accompan­ ied mainly by dissection of fans and terraces and by continued erosion of the uplands. ECONOMIC GEOLOGY

General Statement

Metallic and industrial minerals are of minor commercial impor­ tance in this area at the present time. Although some parts of the region are literally honeycombed with old prospect pits and drifts, moat have proven unprofitable and have been abandoned. Almost every large zone of iron-stained rock seems to have been explored. However, new claims are still being filed, a few small mining operations are being maintained, and it is quite possible that, with additional ex­ ploration, ore concentrations of considerable size may be found,

Nonmetallic Deposits

Sand and Gravel Numerous band and gravel pits have been opened in the Lake Bonneville deposits around the flanks of the mountains.

The only major commercial operation of this nature is a pit just east of U.S. Route pi, about a mile northeast of Santaquin. Small, unat­ tended pits are present east of Santaquin and in the old Bonneville beach ridges and bars in the embayment south of Salem. Another small gravel pit has been dug in terrace gravels a mile Bouth of Birdseye, west of Thistle Creek.

The gray stucco covering the walls of some of the old houses in

Payson was made with sand derived from fault-gouge of the Tintic quart- zite on the weBt slope of Loafer Mountain in Payson Canyon. The old pit is just below the Nebo Loop Road beyond the hairpin turn a quarter of a mile above Maple Dell.

-207- -208-

The possibility of utilizing material weathered from the Nugget

sandstone for molding sand has been considered, and in 1952 a claim

was staked out about a thousand yards south of the mouth of Grab Creek

near the south end of the Nugget outcrop. No developmental work was

evident the following year.

Crushed and broken stone No quarrifes are now being operated in

the area. During the summer of 1952 the Denver and Rio Grande Western

railroad company quarried Twin Creek limestone from the hogback just

southwest of Thistle to use as riprap for repairs to the road bed,

which was severely damaged by heavy floods that year. Large slabs of

stone were readily removed from the steeply dipping beds.

Another small quariying operation was once carried on in the Tin-

tic quartzite at the west end of a prominent spur of Dry Mountain a

mile east of Santaquin, but there is no evidence as to the use made

of the stone.

Metallic Deposits

The geology and status of mining in 1917 *n "the Dry Mountain sec­

tion of the Santaquin mining district were summarized by Loughlin and

Heikes (1920, pp. 320-33^)• 0re minerals consist mainly of both sul­

fides and oxidized secondary minerals of lead, zinc, and copper, with

traces of silver and gold. These occur as fissure fillings and bedded

replacement deposits, none of which have been very productive so far.-

Galena and cerussite are generally most abundant in pockets or re­ placements in fairly pure limestone or dolomite beds, whereas chalco-

pyrite, malachite, and cuprite have been found in greatest abundance

in the crystallines or in the Cambrian quartzites and shales. -209-

At the time of the Loughlin and Heikes report many claims had also been filed in the Spanish Fork and Payson mining districts, but ore— principally lead, with minor amounts of silver and copper--had been shipped only from the Santaquin district. Since that time several small mining operations have been carried on in this general area, and ore in varying amounts has been shipped from time to time.

The most important activity in the area in 1952-1955 was by

Syndicate Oil and Mineral Company, of Provo, Utah, and most of its work at that time involved construction of exploratory tunnels. The company owns drifts and prospects in the Cambrian limestones, the Tin- tic quartzite, and the Archean crystalline complex, and ore produced has mainly been valuable for its content of galena. Veins of limonite and barite are also present in the walls of some of the drifts.

Mr. Kelson, of Spring Lake, reports that his mine near Picayune

Canyon, east of that community, has produced small amounts of lead and silver, with traces of gold. His drift heads east into east-dipping

Cambrian limestones, but fragments of Mississippian limestone are also present on the mine dump. Galena and pyrite are present in some of the fragments on the dump, and pieces of porous limonite— apparently from a gossan— are present in float on the ridge above the Nelson mine.

Many mines and prospect pits are present in the complexly faulted area at the north end of the outcrop of the pre-Cambrian crystalline complex. Some of the workings are still being improved by week-end operators.

Although there is a rather large number of abandoned mines and -210- prospect pits throughout the area of this report, the Dry Mountain mines are the only ones that show much evidence of the presence of ore. The Dream Mine, south of Salem, representing a tremendous expend­ iture of funds and effort, consists of a main drift in the gulch back of the ore bins, and several exploratory tunnels which have followed limonitic stains into the ridge at various places along the mine road in Water Oanyon, but the owners still seem to operate purely upon optimism.

During the summer of 195^ several claims were filed by persons who have discovered radioactive material in outcrops of the Manning

Oanyon shale. A claim immediately west of the Nebo Loop Road about half a mile north of Maple Dell is in the Manning Oanyon shale, which here contains a small amount of carnotite.

Future Possibilities

Among the deposits that might be of future value,are the clays and shales of the Flagstaff formation and the Manning Oanyon shale,

Ceramic properties of samples from these formations in this area have already been investigated to some extent (Hyatt, pp. b~J, 5°)*

The phosphate rock in the Park Oity formation has been utilized in other areas, but is not readily accessible at the Loafer Mountain outcrops. It might be worth a more detailed investigation to determine the productive potential of phosphate in this area. The phosphate zone at the top of the Madison limestone on Dry Mountain is not of suffic­ ient thickness to be of value.

The most importance resource of the area has been and will con­ tinue to be water. REFERENCES CITED

Abbott, Ward 0. (1951) Cambrian diabase flow in central Utah: Com­ pass, vol. 29# PP* 5-10.

Atwood, W.W. (1909) Glaciation of the Uinta and Wasatch Mountains: U.S. Greol. Survey Prof. Paper 6l, 96 pages.

Baker, Dane, and Reeside (1956) Correlation of the Jurassic forma­ tions of parts of Utah, Arizona, New Mexico, and Colorado: U.S. Geol. Survey Prof. Paper 185, 66 pages.

•______, and Williams, J.S. (1940) Permian in parts of Rocky Mountain and Colorado Plateau regions: Bull. Amer. Assoc. Pet. Geol., vol. 24, pp. 619-55*

, (19^7) Stratigraphy of the Wasatch Mountains in the vicinity of Provo, Utah: U.S. Geol. Survey, Oil and Gas Investi­ gations, Prelim. Ch. 50*

______, Huddle, J.W., and Kinney, D.M. (19^9) Paleozoic geology of north and west sides of Uinta Basin, Utah: Bull. Amer. Assoc. Pet. Geol., vol. 55* no» 7* PP. 1161-1197*

Billings, M. (1955) Thrusting younger rocks over older: Amer. Jour. Sci., ser,, vol. 25* pp. 140-165*

Bissell, H.J. (1959) Fusulinids as an aid in zoning the Oquirrh series of Utah: Proc. Utah Acad. Sci., Arts, Letters, vol. 16, pp. 87-89*

, (1948) Pleistooene sedimentation in southern Utah Valley, Utah: Unpub. dissertation, State University of Iowa.

______, (1952) Stratigraphy and structure of NE Strawberry Valley Quadrangle, Utah: Bull. Amer. Assoc. Pet. Geol., vol. 56, PP. 575-654.

, (1955) Summary of the structural evolution of the Utah Lake Basin, central Utah: Compass, vol. 51* PP* 25-55*

______, Thompson, and Verville (1950) Pennsylvanian fusu- linids of the south-central Wasatch Mountains, Utah: Jour. Paleon., vol. 24, pp. 450-465.

Boutwell, J.M. (1912) Geology and ore deposits of the Park City district, Utah: U.S. Geol. Survey Prof. Paper 77* 251 pages.

Bradley, W.M. (1956) Geomorphology of the north flank of the Uinta Mountains: U.S. Geol, Survey Prof. Paper 185-1* PP. 165-204*

- 2 1 1 - Brown, R.S. (1952) Geology of the Payson Oanyon area, southern Was­ atch Mountains, Utah: Compass, vol. 29, pp. 551

Buss, P.E. (1924) The physiography of the southern Wasatch Mountains and the adjacent valley lands with especial reference to the origin of topographic forms: Unpub. thesis, Stanford University.

Butler, B.S., Loughlin, G.F., and Heikes, V.O. (1920) Ore deposits of Utah: U.S. Geol. Survey Prof. Paper 111, 672 pages.

Oalderwood, K. (1951) Geology of the Cedar Valley Hills area, Lake Mountain, Utah: Compass, vol. 29, no. 1, pp. 21-52.

Campbell, M.R. (1922) Guidebook of the western United States, Part E. the Denver and R.G.W. Route: U.S. Geol. Survey Bull. 707» 266 pages.

Dutton, C.E. (1880) Geology of the High Plateaus of Utah: U.S. Geogr. and Geol. Surv. of the Rocky Mtn. Reg., 5^7 pages.

Eardley, A.J. (1952) A limestone chiefly of algal origin in the Wasatch conglomerate, Southern Wasatch Mountains, Utah: Pap. Mich. Acad. Sci., Arts, Letters, vol. 16, pp. 599“4l4.

, (1955) Stratigraphy of the Southern Wasatch Mountains, Utah: Pap. Mich, Acad. Sci., Arts, Letters, vol. 18 (Reprint).

, (195^0 Structure and physiography of the Southern Wasatch Mountains, Utah: Pap. Mich. Acad. Sci., Arts, Letters, vol. 19 (Reprint).

, (1944) Geology of the North-Central Wasatch Moun­ tains, Utah: Bull. Geol. Soc. Amer., vol. 55* PP» 819-894.

, (1947) Paleozoic Cordilleran geosyncline and related orogeny: Jour. Geol., vol. 55

______, (1951) Structural geology of North America: Harper Bros., New York, 624 pages.

______, and Hatch, R.A. (1940) Proterozoic (?) rocks in Utah: Bull. Geol. Soc. Amer., vol. 51> PP» 795“^ ^ »

Fenneman, N.M. (1951) Physiography of western United States: Mc-Graw Hill Book Co., Inc., N.Y. and London, 55^- pages.

Fox, J.M. and Woolley, R.R. (1959) Altitude-precipitarion relation­ ships for Utah: Proc. of Utah Acad, of Sci., Arts, Letters, vol. 16, p. 91* ■215-

Granger, A.E. and Sharp, B.J. (1952) Geology of the Wasatch Moun­ tains east of Salt Lake City; City Greek to Parleys Canyon: Utah Geol, and Mineral Survey, Guidebook to the , No. 8, pp. 1-57.

______, (1955) Stratigraphy of the Wasatoh Range near Salt Lake City, Utah: U.S. Geol. Survey Circular 296.

Harris, H.D. (195*0 Geology of the Birdseye area, Thistle Oreek canyon, Utah: Compass, vol. 51, pp. 189-208.

Hintze, F.P. (1915) A contribution to the geology of the Wasatch Mtns., Utah: N.Y. Acad. Sci. Ann., vol. 25, pp. 85-145.

Hodgson, Robert M. (1951) Geology of the Wasatch Mountain front in the vicinity of Spanish Fork Oanyon, Utah: Compass, vol. 29, PP. 47-55.

Howell, E. (1875) Report on the geology of portions of Utah, Nevada, Arizona and New Mexico: U.S. Geogr. and Geol. Surv. W. of 100th Mer., vol. 5, pp. 227~5°1«

Hunt, R.E. (1954) South Flat formation, new Upper Cretaceous for­ mation of central Utah: Bull. Amer. Assoc. Pet. Geol., vol. 56, pp. 118-128.

Hyatt, E.P. (1955) Clays of Utah County, Utah: Compass, vol. 51# pp. 44-51.

IIling, L.V. (1954) Bahaman calcareous sands: Bull. Amer. Assoc. Pet. Geol., vol. 58, PP* 1-95*

Imlay, R.W. (195?) Correlation of the Jurassic formations of North America, exclusive of Canada: Geol. Soc, Amer, Bull., vol. 65, PP. 955-992.

Keller, W.D. (1941) Petrography and origin of the Rex chert: Geol. Soc. Amer, Bull., vol. 52, pp. 1279-1297.

Kummel (1954) TriasBic stratigraphy of southeastern Idaho and adja­ cent areas: U.S. Geol. Survey Prof. Paper 254-H, pp. 165-194.

Lautenschlager, K. (1952) The geology of the central part of the Pavant Range, Utah: Unpub. dissertation, The Ohio State Univ.

Loughlin, G.F. (1915) Reconnaissance in the southern Wasatch Moun­ tains, Utah: Jour. Geol., vol. 21, pp. 456-452.

_ , (1919) Two Lamprophyre dikes near Santaquin and Mt. Nebo, Utah: U.S. Geol. Survey Prof. Paper 120-E, pp. 101-109. •*2l4»

Loughlin, G.F., in Butler, Loughlin and Heikea (1920) The ore de­ posits of Utahs U.S. Geol. Survey Prof. Paper ill, 672 pages.

McKee, E.D. (195^) Stratigraphy and history of the Moenkopi forma­ tion of. Triassic age: Geol. Soc. Amer. Memoir 61, 155 pages.

Mansfield, G.R. (1927) Geography, geology, and mineral resources of part of southeastern Idaho: U.S. Geol. Survey Prof. Paper 152, 455 pagee.

MueBsig, S.J. (1951) Geology of a part of Long Ridge, Utah: Unpub. dissertation, The Ohio State Univ.

Nolan, T.B. (1945) The Basin and Range Province in Utah, Nevada, and California: U.S. Geol. Survey Prof. Paper 197-U, 196 pages.

Peale, A.C. (1895) The Paleozoic section in the vicinity of Three Forks, Montana: U.S. Geol.Survey Bull. 110, 56 pages.

Peterson, P.R. (1952 ) Geology of the Thistle area, Utah: Unpub. thesis, Brigham Young Univ.

Pettijohn, F.J. (1949) Sedimentary rocks: Harper and Bros., New York, 526 pages.

Richardson, G.B. (1906) Underground water in the valleys of Utah Lake and , Utah: U.S. Geol. Survey Water Sup. Pap, 157, 81 pages.

, (1915) Th® Paleozoic section in northern Utah: Am. Jour. Sci., 4th ser., vol. 56 , pp. 406-415.

Schneider* H., and Perkes, W. (1957) Meteorite craters in Spanish Fork Oanyon: Proc. of Utah Acad, of Sci., Arts, Letters, vol. 14, p. 6l.

Schoff, S.L. (1957) Geology of the Cedar Hills, Utah: Unpub, dis­ sertation, the Ohio State Univ.

______, (1951) Geology of the Cedar Hills, Utah: Geol. Soc. Amer. Bull., vol. 62, pp. 619-646.

Silliman, B. (1872) Geological and mineralogical notes on some of the mining districts of , and especially those of the Wasatch and Oquirrh Ranges of Mountains: Am. Jour. Sci., 5rd. ser., No. 5 (105), pp. 195-201. Spieker, E.M. (1946) Late Mesozoic and early Cenozoic history of central Utah: U.S. Geol. Survey Prof. Paper 205-D, pp. 117-161*

______, (1949a) Sedimentary facies and associated diastro- phism in the Upper Cretaceous of central and eastern Utah; in Sedimentary Facies in Geologic History: Geol. Soc. Amer. Memoir 59* PP. 55“82.

, (1949b) The transition between the Colorado Plateaus and the Great Basin in central Utah: Utah Geol. Soc., Guidebook to the geology of Utah, no. 4, 106 pages.

Spurr, J.E. (1895) Economic geology of the Mercur mining district, Utah: U.S. Geol. Survey l6th Ann. Rept., 1894-95* Part Il-d, pp. 545-455.

Thomas, H.D., and Krueger, M.L. (1946) Late Paleozoic and early Mesozoic stratigraphy of the Uinta Mountains, Utah: Bull. Amer. Assoc. Pet. Geol., vol. 50* PP* 1255-1295*

Walton, P.T. (1944) Geology of the Cretaceous of the Uinta Basin, Utah: Bull. Geol. Soc. Amer., vol. 55* PP« 91-150*

Wheeler, G.M. (1875) Report on explorations and surveys west of the 100th Meridian, vol. 5* 681 pages.

Williams, J.S. (1945) Nomenclature of Triassic rocks in northeastern Utah: Am. Jour. Sci,, vol. 245, PP* 475-479*

Woolley, R.R. (1946) Cloudburst floods in Utah, 1850-1958t Water- Supply Paper 994, U.S. Govt. Printing office, 128 pages. APPENDIX MEASURED SECTIONS

Section 1; Meaaured on west slope of Dry Mountain on ridge west of old Union Chief mine in south half of Section 7* T.10S., R.2E.

Teutonic limestone

Thrust fault Feet Tintic quartzite

16. Quartzite, white, light-gray, and pink, weathers buff, massive, cross-bedded in part; conglomer­ atic at base and near top, with subangular to subrounded pebbles of quartz up to 2 inches in diameter but averaging 4' inch. 810 15* Conglomerate, light-gray to maroon, quartzitic, slightly micaceous, cross-bedded. Pebbles of white and maroon quartz, red jasper or slate, average 1 inch in diameter, have long axes parallel to bedding, are well-rounded. 12

Total Tintic 822

Angular unconformity

Proterozoic (?) beds

14. Shale, quartzite, and siltstonej shale green­ ish-gray, micaceous; quartzite light-gray, thin-bedded, partly ripple-marked with mica­ ceous bedding planes; siltstone gray, green­ ish-gray, and maroon. At very top is 2 feet of red-brown siliceous shale. 155 15* Siltstone, shale, and quartzite, maroon and greenish-gray, 4-foot bed of red and light- green shale at base. 405 12, Quartzite, maroon, light-gray cross-bedded streaks near top, massive. 25 11. Quartzite and siltstone with shale partings, maroon and light-gray, thin- to medium- bedded, many ripple marks, some cross bedding. 79 10. Quartzite, maroon, massive, cross-bedded; thin, pale-green, ripple-marked, shale part­ ings in upper 45 feet. 195 9, Shale, reddish-brown and yellowish-green, fissile, blocky weathering. 62 8. Shale, dull-red and maroon, arenaceous. 18

-217- -218- Feet

7. Quartzite, pale maroon and gray, arose-bedded, shale partings 6 inches to 4 feet apart, oscillation ripple marks. 28 6. Quartzite, pale purple, cross, bedded, massive. 15 5. Sandstone, greenish-gray, fine-grained, shaly. 8 4. Quartzite, maroon, streaked buff and gray. 250. J. Quartzite, maroon. 11 2, Sandstone, maroon, feldspathic, silty to coarse­ grained, crosB-bedded, contains streaks of light-gray arkose. 5*5 1, Sandstone, feldspathic, light-gray, mottled purple, medium- to coarse-grained, 80$ quartz. 1.5

Total 1256

Crystalline complex

Section 2s Measured on northwest slope of Dry Mountain near center of Section J2, T.9S., R.2B., above abandoned mine.

Teutonic limestone Feet

Ophir shale

9. Limestone and shale; limestone is lead-gray with irregular brown argillaceous partings 1 to 2 inohes apart, and in beds 3 or k feet thick, separated by intervals of shale, green to gray, silty and micaceous. Trilobite fragments, similar to Olappaspis. 44 8. Shale, green to gray, silty, micaceous. 12 7. Limestone, like unit 9» 7 6. Shale and limestone interbedded in beds 1 to 5 inches thick. Limestones similar to unit 9; shales gray, fissile, calcareous in lower part, but like unit 8 in upper part. 19 5 . Shale and sandstone; shale medium-gray, mica­ ceous; sandstones gray-brown, thin-bedded, partly oalcareous, partly cross-bedded. 25 4. Shale, gray-green, micaceous, silty, wavy- bedded. 47 5. Shale and phyllite, greenish-brown and greenish- gray, wavy-bedded, quite micaceous (sericite), abundant worm-like trails. Numerous thin beds of quartzite and sandstone, glauconitic. 14 •-219“* Feet

2, Quartzite, me dim-gray, weathers maroon and greenish-brown, contains numerous small limonitic bodies. 5*5 1. Shale and phyllite, greenish-brown and green­ ish-gray. 7*5

Total Ophir 177

Tintic quartzite

Quartzite, medium-gray and greenish gray, weathers brown and greenish-brown, micaceous, thin- to medium-bedded.

Section 5 s Measured in Santaquin Canyon from Tinney Flat to base of Cambrian above Trumbolt Park in sections 29» 50, and 52, R.2E., T.10S.

Southwest side of canyon:

Great Blue Formation— upper beds removed by erosion. Feet

154. Covered interval— talus like unit 44 155. Limestone, light- to medium-gray, weathers light blue-gray, beds less than 2 feet thick, crinoidal near base. 26 152. Limestone, dark-gray, finely crystalline to dense, bedding 4 inches to 5 feet, a 2-inch chert bed at 6 feet. 25 151. Dolomite, light-gray, dense, thin sandstone partings above and below. 5 150. Limestone, light-gray, dense. 2 149* Covered— talus like unit 148. 27 148. Limestone, medium to dark blue-gray, dense, weathers light- to blue-gray 15 147. Sandstone, grayish-tan, fine-grained, calcareous. 1 146. Limestone, dense, bluish-grayj thin, wavy bedding. 4 145. Covered interval. 29

Total Great Blue limestone exposed 128 - 2 2 0 - Humbug formation (in nearby areas* Great Blue is conformable over Humbug)*

144. Sandstone* light-gray* calcareous, 145. Sandstone, tan, fine-grained, calcareous. 142. Flat-pebble conglomerate, coarse-grained limestone pebbles. 0.5 141. Limestone, light-gray, dense to finely crystal­ line, some beds tinted lavender, weathers blue-gray. 46 140. Quartzite, gray to tan, alternating with lime­ stone, medium-gray, fine-grained to dense; beds 1 inch to 5 feet. 15 159. Limestone, light-gray* lithographic, tints of lavender. 10 158. Limestone, sandstone, and dolomite alternating in beds 4 inches to 4 feet thick. Deep recesses weather in limestones. Limestone: light-gray, dense, pinkish tints. Sandstone; like unit 157/ laminated in part. Dolomite: medium-gray, finely crystalline. 51 157. Sandstone, buff, blue-gray and greenish-gray, hard, slightly calcareous, bedding to 10 inches, weathers orange-brown. 4 156. Sandstone, gray tinted pink and green, very calcareous, laminated at top. 2 155* Limestone, olive-gray, lithographic. 8 154. Quartzite, light-gray, laminated. 5 155* Dolomite, medium-gray, finely crystalline. 6 152. Limestone, medium-gray, finely crystalline. 25 151. Quartzite and dolomite alternating in beds 1 to 5 feet thick. 9 150. Limestone* da”k-gray* dense to finely crystalline, partially laminated* bedding up to 5 feet. 51 129* Dolomite and quartzite alternating in beds 4 inches to 7 feet thick. Brecciated in lower 12 feet. Dolomite: medium-gray, finely crystalline, partly laminated. Quartzite: medium-gray, fine- to medium- grained, weathers buff 48 128. Dolomite, dark-gray, finely crystalline. 1.5 127. Quartzite, limestone, and dolomite in beds 1 to 5 feet thick. Ripple marks 20 feet above base. 50 126. Dolomite, with laminations of quartz grains, weathers platy. 1 125. Quartzite* medium-gray, weathers tan. 29 124. Dolomite, medium-gray, finely crystalline. 5 125. Quartzite, medium-gray, fine-grained. 28 122. Quartzite and limestone in beds 6 inches to 5 feet thick. 75• 121, Limestone, medium-gray, dens© to finely crystalline, siliceous. 120, Quartzite, light-gray, 119, Quartzite, medium-gray, fine-grained to dense. 118, Dolomite, medium-gray, finely crystalline. 117, Limestone, medium-gray, finely crystalline, sandy, weathers light-gray, 116. Sandstone, light-gray, grades upward into quartzite. 115, Dolomite, medium-gray, finely crystalline, oherty at top, weathers greenish-gray, Feneatella-type bryozoan at top, 114, Covered, 115, Limestone, dark-gray, finely crystalline, fossiliferous, cherty, weathers light-gray. 112, Dolomite, dark-gray, finely crystalline and limestone, black, dense; highly fossilifer- ous-crinoid columnals, braehiopods, horn corals. 111. Limestone, dark-gray, dense to coarsely crystal line, sandy, cross-bedded, like top bed of Deseret. 110. Sandstone, light-gray, fine-grained, weathers tan, siliceous.

Total Humbug formation

Irregular surface at base, with local relief of 1-g- feet

Deseret limestone

109, Limestone, dark-gray, coarsely crystalline— orinoidal, fetid, black chert nodules 1 foot thick at top, 108. Limestone, dark-gray to black, coarsely crystal line to dense, fetid, argillaceous, rapid textural changes. 107. Limestone, black, shaly-weathering, lenticular, 106. Limestone and dolomite, black, dense to medium-crystalline 10^. Limestone, carbonaceous, silicified, lenticular

Section continued on northeast side of canyon

104. Chert, black. lOJ. Limestone, dark-gray, coarsely crystalline, orinoidal, horn corals and braehiopods -222- Feet

102. Limestone, medium-gray, finely crystalline, irregular. 2 101. Limestone, dark-gray, coarsely crystalline, cross­ bedded. 2 100. Dolomite, dark-gray to black, finely crystalline. 1 99. Limestone, medium-gray, finely crystalline, black bands of chert, horn corals. 18 98. Limestone, medium-gray, coarsely crystalline, cherty, a few crinoid columnals and horn corals. 4 97. Sandstone, medium-gray, fine-grained. 4 98. Dolomite, medium-gray, fine crystalline, weathered surface shows brown, sandy streaks. 8 95. Sandstone, medium-gray, medium- to fine-grained, numerous calcite vugs averaging 1 inch in diameter. 7 94. Dolomite, dark-gray, finely crystalline. 6 95. Limestone, dark-gray, coarsely crystalline, orinoidal. 14 92. Limestone, dark-gray, dense. 5 91. Limestone, dark-gray, coarsely crystalline, orinoidal. 1 90. Dolomite, light-gray, finely crystalline, chert in beds. 4 89. Limestone, medium-gray, medium-grained, sandy. 12 88. Limestone, dark-gray to black, dense, very cherty. 16 87. Limestone, light blue-gray, coarsely crystalline, crinoidal in streaks, some cross-bedding, 5-inch bed of chert at base, 5° 86. Limestone, light-gray, finely crystalline, sandy. 6 85. Dolomite, medium-gray, finely crystalline, numerous chert beds : black, weathering tan 15 84. Limestone, light-gray, coarsely crystalline, crinoidal, cross-bedded. 8 85. Limestone, light-gray, dense, lenticular. 4 82. Limestone, medium-gray, finely crystalline, very irregular chert lendes. 15 81. Limestone, dark-gray, coarsely crystalline, massive, partly crinoidal; contains numerous beds, lenses, and nodules of black chert. 55 80. Limestone and chert alternating in beds averaging 4 inches thick, a few layers of crinoidal limestone with columnals up to half an inch in diameter, horn corals numerous in some beds. 55 79. Limestone, similar to 78, numerous, horn corals, top crinoidal. 5 78. Limestone, dark-gray to black, finely crystalline to dense, lenseB of black chert; contains argillaceous streaks which weather reddish-brown to gray. 57 77. Limestone, black to gray, finely crystalline, fetid, beds up to 5 feet thick, irregular lenses of black chert, a few horn corals and other fossil fragments. 55 -225- Feet

76. Limestone, medium-gray, finely crystalline, weathered surfaces streaked light gray, a few stringers of black chert. 22 75* Limestone, black, finely crystalline, numerous irregular and contorted black chert beds up to 6 inches thick. 26 74. Covered. 9 75. Limestone, medium-gray, medium crystalline, slightly arenaceous, chert in numerous irreg­ ular nodules, lenses, and stringers in beds 2 to 4 inches thick. 60 72. Limestone, medium-gray, medium crystalline, sandy. 4 71. Limestone, medium-gray, massive, sandy, cherty. 17 70. Covered. 19 69. Limestone, medium-gray, fine-grained, laminated and thin-beddedj some thin laminae of black chert. Some fragments weather orange-red. 9 68, Covered--float resembles unit 69. 40 67. Limestone, medium-gray to black, finely to coarsely crystalline, some croBB-bedding, numerous layers and nodules of black chert. 10 66, Covered— probably shaly limestone. 21 65. Limestone, like unit 65. 11 64. Shale, phosphatic, grayish-tan, silty, several black chert beds and layers of oolitic and nodular phosphate rock, 22 65. Limestone, black, dense, cherty. 8 62. Shale, chert and phosphate rock. Shale and chert alternate in bands up to 4 inches thick. Lower shales are red and brown, upper are oar- bonaceous. Oolitic phosphatic rock intercalated in thin layers throughout. Coal seam ^-inch thick near base. 5

Total Deseret limestone 717 feet

Madison limestone

61. Limestone, medium-gray, finely crystalline, interbedded with irregular and discontinuous layers of chert up to 10 inches thick and occurring less than a foot apart. Limestone weathera medium blue-gray, and some layers con­ tain fossil fragments. Chert weathers dark-brown to black. 66 60. Dolomite, medium- to dark-gray, scattered nodules of tan chert elongate along bedding planes. 29 -224- Feet

59. Dolomite, medium- to dark-gray, medium-cryatal- line to coarsely crystalline, fetid, bedding 2 inches to massive, intraformational conglom­ erates and crinoidal beds in upper 12 feet. 58 58. Limestone, dark-gray, dense to fine-grained, partly siliceous, cherty and shaly at top, very fossiliferous with numerous specimens of Euomphalus. Weathers to large, thin slabs which are resonant when struck. A few layers weather pinkish-ormnge. 10 57. Limestone, dark-gray, dense to fine-grained, numerous dark-gray chert nodules, thin light and dark banding on weathered surfaces, 42 56. Dolomite, dark-gray, finely to medium crystalline, banded light and dark on weathered surfaces. At 52 feet is a zone of lenses and irregular nodules of dark-gray chert, weathering tan. Scattered horn corals. 48 55* Limestone, dark-gray, finely to medium-crystalline, bedding 2 inches to 1 foot, scattered nodules of black chert, many beds fossiliferous— Borne are enorinites. From 15 feet to 50 feet there are argillaceous partings similar to those of the Teutonic limestone. At 97 feet - Trip1ophy11itea sp. At 57 feet - Litho strotionella multirodiata Hayasaki. At 50 feet - Triplophyllites sp. 104 54. Dolomite, dark-gray with streaks of black, medium- crystalline, 5 feet of intraformational breccia at base; massive in lower part but thin- to medium-bedded in upper part. Numerous stringers and vugs of calcite are present above basal breccia. At 9 feet - a zone of light-gray and buff chert lenses, 5 inches thick. At 25 feet - horn corals become abundant. 44 55. Limestone, like unit 51• 2 52. Limestone, medium-gray, coarsely crystalline. 6 51. Limestone, light-gray, dense, weathers white, "curly bedding". 1 50. Dolomite, dark-gray and black, medium- to coarsely crystalline, weathers dark-gray, fetid. Starting at 7 feet are medium-gray chert lenses, nodules and beds up to 1 foot thick. At 12 feet is a 2-foot brecciated layer. Weathered surface has a sandy texture. 57 49. Dolomite, dark-gray to black, medium- to finely crystalline, thin tan streaks on weathered surface. 19 -225- Feet

48. Dolomite, like unit 46. Streaks of black and blue-black on weathered surfaces, scattered crinoid columnals throughout, a few horn corals and specimens of Syrlngopora. At 17 feet white calcite vugs average 2 inches in diameter and are conspicuous. jh 47. Shale, medium-gray, fissile. 1 46. Dolomite, dark-gray, finely crystalline, bedding 2 feet and less, numerous small white calcite vugs, light-gray blotoheB on weathered surfaces. 6 45* Shale and dolomite interbedded in units 1 to 4 inches thick. Dolomite like unit 44. Shale is medium-gray to blue-gray, fissile, calcareous. 5 44. Dolomite, medium- to dark-gray, finely crystal­ line, bedding 4 to 8 inches. 7 45. Dolomite, light-gray, finely to coarsely crystal­ line, porous. At 2 feet and at JO feet above the base poorly preserved specimens of Syringo- pora were found— the oldest fossils found in the section above the Herkimer limestone. At 59 feet, a few poorly crinoid columnals. This unit is possibly equivalent to the Jefferson (?) dolomite to the north. 59

Total Madison limestone 558 feet

Contact covered by float.

Op ex dolomite

42. Dolomite, dark-gray, finely crystalline, massive. 19 41. Dolomite, medium-gray, medium crystalline. 25 4o. Dolomite, light-gray, medium-crystalline. 6 59. Dolomite, like unit 57. 14 58. Dolomite, light-gray, finely crystalline, thin medium-gray streaks. 9 57. Dolomite, dark blue-gray, finely crystalline, faint irregular banding, scattered vugs of calcite. 5 56. Dolomite, light- to medium-gray, sugary. 24 55. Dolomite, grayish-tan blotched lavender-brown, weathers light gray. 22 5*. Dolomite, medium-gray, medium-crystalline, faintly banded at base, mottled at top. 75 55. Dolomite, medium-gray, medium-crystalline, faint textural banding. 22 —226— Feet

52. Dolomite, medium-gray, medium-crystalline, irregular gray and tan argillaceous bands less than an inch apart, a few paper-thin brown argillaceous partings at top. Weathered surface mottled with light-gray blotches. 2J 51. Dolomite, light-gray, medium-crystalline* 5 50. Dolomite, medium blue-gray, finely crystalline, rapid vertical changes in shade of gray. 1J 29. Dolomite, light-gray, sugary; vague streaks of argillaceous material— some contorted and brecciated to form flat-pebble conglomerates. 22 28. Dolomite, light blue-gray, sugary. 20 27. Dolomite, light-gray, faint medium-gray streaks, fine-grained to dense, oolitic material in bands | to 1 inch thick at irregular intervals. JO

Total Opex dolomite JJ2 feet

Cole Canyon dolomite

26 , Dolomite, alternating light-gray and medium- or dark-gray layers, finely crystalline, to dense, beds near top weather light blue-gray. 270 25. Dolomite, light-gray, dense, laminated (Dagmar type). 2J Dolomite, alternating light-gray and medium-gray. 17 24. Dolomite, medium-gray, argillaceous banding similar to Teutonic limestone. 8 2J. Dolomite, alternating beds of light-gray and medium- to dark-gray of varying thicknesses, finely crystalline to dense, base at lowest creamy-weathering layer (1 foot thick). Some dark layers containing "twiggy bodies" are similar-to the Bluebird dolomite; some light layers are similar to the Dagmar limestone and are laminated. Many beds are mottled on weathered surfaces. 1J0

Total Cole Canyon dolomite 470 feet

Bluebird dolomite

22. Dolomite, medium- to dark-gray, finely to medium crystalline, gradations1 contact with the Herkimer limestone (argillaceous banding gradu­ ally grows fainter and disappears), occasional light-gray streaks of coarser material. "Twiggy bodies" typical of the Bluebird are scattered -227- Feet throughout the formation— sometimes in abundance, sometimes almost entirely absent. At top there is a cliff 25 to JO feet high, mottled with light-gray blotches on the weathered surfaces. 187

Total Bluebird dolomite 187 feet

Herkimer limestone

21, Dolomite, medium-gray, finely to medium crystalline, argillaceous partings 1 to 2 inches apart. Partings are light-gray but weather brown and buff, 9 20. Limestone, like unit 18. At 15 feet is a 2-foot bed of flat-pebble conglomerate; at 18 feet and at 42 feet are 2-foot beds of oolitic material. Small pyrite crystals and aggregates are scattered throughout the upper JO feet. 44 19* Shale, medium-gray, fissile. 2 18, Limestone, dark-gray to black, dense to finely crystalline, argillaceous partings, which weather buff to light-gray. 55 17. Shale, medium-gray, fissile, calcareous, 16 16, Limestone, dark- to medium-gray, dense to fine­ grained; irregular light-gray to buff argillac­ eous partings which weather brown and reddish- brown are spaced 1 to 2 inches apart. Some layers are mottled with irregular gray blotches of dolomite. At JO feet there is a 2-foot bed of oolitic material; the oolites are small black spheroids in a dark-gray limestone matrix. At 65 feet there are scattered limonitid? nodules Isbs than 4 inch in diameter. J2 15. Dolomite, dark- to brownish-gray, medium to finely crystalline, fetid, irregular argillaceous partings, scattered calcite vugs, "twiggy bodies" especially prominent at base, occasional cross­ bedding. 101

Total Herkimer limestone 299 feet

Sharp undulating contact

Dagmar limestone

14. Dolomite, dark-gray, dense, laminated, weathers medium-gray. 6 -228- Feet

15. Dolomite, medium-gray, finely cryetalline, laminated, weathers light-gray, irregular surface at top with structures resembling large ripple marks having amplitude of 5 inches. 2 12. Dolomite, light-gray, dense to finely crystalline, faintly laminated, weathers white to light-gray. 8 11. Dolomite, medium- to dark-gray, finely crystalline, laminated, weathers light-gray. 16 10. Dolomite, dark-gray, medium crystalline. 1 9. Dolomite, medium-gray, laminated, weathers creamy white. 1 8. Limestone, medium-gray, dense to finely crystal­ line, laminated, weathers light-gray with dark streaks. 1*5 7. Dolomite, dark-gray, medium crystalline. 0.4 6. Dolomite, medium-gray, finely crystalline, lamin­ ated, weathers light-gray. 0.6

Total Dagmar limestone 56.5 f®et

Teutonic limestone

5. Dolomite, dark-gray, argillaceous partings, occasional light-gray "twiggy bodies". 52 4. Limestone, like unit 2 but with more numerous algal-like structures, occasional vugs and blebs of white calcite. 46 5. Dolomite, medium-gray, medium-crystalline, predominantly oolitic, a few argillaceous partings near the top, weathered surface has shattered appearance. 7 2, Limestone, dark- to medium-gray, dense to finely crystalline, irregular argillaceous partings, mottled, occasional layers with structures up to half an inch in diameter which resemble algal-balls. 551

Total Teutonic limestone 416 feet

1. Covered interval. -229“

Section 4; Partial section of Oquirrh formation (lower portion) measured on west slope of Loafer Mountain along ridge on south side of Rock Canyon, starting in S.E.^# Station 2, ^ T.10S., R.2E.

Oquirrh formation Feet 57. Limestone, medium- to dark-gray, platy, poorly exposed. 56. Covered interval, sandstone float. - 55 55. Limestone, medium-gray, finely crystalline, platy. 17 54. Covered interval. 15 55. Sandstone and quartzite, light-gray to tan, fine-grained. 45 52. Limestone, medium-gray, finely to coarsely crystalline, cherty, thin- to medium- bedded. Bryozoans and crinoid columnals. 85 51. Covered. 55 50. Limestone, medium-gray, finely crystalline, partly sandy. 5 49. Covered— probably limestone. 55 48. Limestone, medium-gray, finely crystalline, cherty, Crinoid columnals. 10 47. Covered. 60 46. Limestone, medium-gray, finely crystalline, cherty, numerous crinoid columnals. 10 45. Quartzite, light-gray, fine-grained. 12 t. Displacement undetermined. 44. Limestone, medium-gray, finely crystalline, 40cherty, numerous crinoid columnals. 40cherty, 45. Covered. Probably sandstone. 15 42. Sandstone, tan, fine-grained, porous. 11 4l. Limestone, medium-gray, fine- to medium- crystalline, chert stringers, crinoids, bryozoans. 27 4o. Covered. Probably sandstone. 14 59. Limestone, light- to medium-gray, finely to coarsely crystalline, cherty, abundant crinoid columnals. 64 58. Covered. 6 57. Limestone, dark-gray, finely crystalline, cherty. 5 56. Covered. 50 55- Limestone, gray to tan, finely crystalline, cherty, numerous sand lenses. 16 54. Sandstone and quartzite, tan, fine-grained. At 20 feeti 2 feet of breccia. 24 55. Limestone, medium-gray, dense to finely crystalline, platy. 5 52. Quartzite, gray to tan, fine-grained. 16 - 250'

Feet

51. Covered. 6 50. Limestone, medium-gray, finely crystalline, cherty. Oaninia, sp. 50 2p. Limestone, dark-gray, dense, platy, very fossiliferous. 8 28. Covered; cherty limestone and quartzite in float. 158 27. Limestone, medium-gray, cherty, sandy. 5 26. Covered. 11 25. Limestone, medium-gray, finely crystalline, black chert nodules and stringers, a few thin sandy limestone beds. 18 24. Sandstone, tan, fine-grained, calcareous. 1 Fault (?) 25. Limestone, light- to medium-gray, very sandy, brecciated, 4 22. Limestone, light- to dark-gray, finely crystalline, argillaceous, cherty, partly platy. 65 21. Covered. 150

Fault (?)

20. Limestone, medium-gray, arenaceous. 14 19# Covered. Quartzite float. 20 18. Limestone, dark-gray, silty, platy. 17 17* Limestone, medium-gray, finely crystalline. 5 16. Covered. 54 15. Limestone, medium-gray, finely crystalline, fossiliferous. 11 14. Quartzite, light-gray, fine-grained. 54 15. Limestone, tan, sandy, dense. 12 12. Covered. Quartzite and limestone in float. 105 11. Limestone, medium-gray, sandy, interbedded with thin sandstones. 25 10, Limestone, like 5» Forms ledge. 21 9. Limestone, tan, finely crystalline, platy, very fossiliferous. 4 8. Limestone, dark- to medium-gray, dense, fossiliferous, brecciated at base. 6 7. Quartzite, sandstone, limestone interbedded. Quartzite; medium- to light-gray. Limestones; medium- to light-gray, sandy, finely crystalline, cherty, thin-bedded, 146 6. Limestone, medium-gray, finely crystalline, brecciated. 5 5* Quartzite, white, fine-grained, partly brecciated. 8 -251- Feet

4. Limestone, tan, dense, weathers nearlywhite, A few thin sandstone beds, 9 5. Limestone, light-gray, sandy,laminated, 20 2. Covered, (?)

Total Oquirrh measured 1625+-

Thrust fault (Dry Mountain thrust)

Manning Canyon shale

1. Shale, blaok, surface rubble of rust-weathering greenish-gray quartzite.

Section 5* Partial section of Oquirrh formation, measured on west slope of Loafer Mountain along ridge on south side of Loafer Canyon, starting in S,E,^-, S.E.^-, Section 1, T.10S., R.2E. Base of section is thought to be approximately equi­ valent to top of section$4.

Oquirrh formation

76. Sandstone, medium-gray, fine-grained, weathers buff, some beds highly calcareous. 102 75. Quartzite, light-gray, fine-grained. 54 74. Limestone, light-gray, finely crystalline, arenaceous. 42 75. Quartzite, light-gray to tan, fine-grained. 16 72. Alternating sandstone and limestone in beds 2 inches to 5 feet thick. 24 71. Limestone, light-gray, finely crystalline, a few lenses of sandstone. 51 70. Sandstone, like unit 68. A few thin sandy limestone layers. 56 69. Limestone, medium-gray, finely crystalline, oherty. 4 68. Sandstone, tan to gray, fine-grained, cal­ careous, platy. 14 67. Quartzite, pink to light-gray, fine-grained. 54 66. Limestone, medium-gray, finely crystalline^ platy. 9 65. Quartzite, light-gray to buff, fine-grained. 15 64. Limestone, medium-gray, dense to finely crystalline, cherty, 8 65. Sandstone, tan, finely to medium-crystalline, porous. 12 -252- Feet

62. Quartzite, light-gray to buff, fine-grained. 40 61. Limestone, dark-gray, finely crystalline, platy. 36 60. Sandstone, tan, fine-grained, porous, grada­ tional with platy buff arenaceous limestone, 44 59. Limestone, medium-gray, finely crystalline. 2 58, Quartzite, light-gray to tan, fine-grained. 15 57« Limestone, dark-gray, finely crystalline, cherty. Scattered nodules of orange-red fine-grained sandstone, up to 6 inches in diameter. 42 56. Quartzite, light- to pinkish-gray. 26 55. Limestone, tan, medium crystalline, platy. 6 54. Limestone, light-gray, finely crystalline, a few sandstone beds. 12 55. Quartzite, light-gray, fine-grained. 25 52. Limestone, medium-gray, medium-crystalline, many beds blue-gray and dense. FrequenA aggregates of small spheres of argillaceous material resembling oolites. Very cherty for top 50 feet. Rapid facies changes thr oughout. 115 51. Quartzite, pinkish-gray to pale greenish-gray, fine-grained. 64 50. Limestone, medium-gray, oolitic, cherty, crinoid columnals abundant at top. 6 49. Limestone, gray to tan, upper portion extremely cherty. Lower portion contains numerous large crinoid columnals almost an inch in diameter. Bryozoans abundant. 42 48. Sandstone, tan, fine-grained, porous. 9 47. Quartzite, pink to gray, fine-grained, laminated, 120 46. Limestone, medium-gray, finely to coarsely crystalline, irregular chett beds every 1 to 8 inches. Some beds very fossiliferous. Pleurodictyum sp• 158 45. Sandstone and limestone, like unit 45. 12 44. Sandstone, tan to gray, fine-grained, porous. 9 4j. Sandstone and limestone alternating in thin beds. Sandstones light-gray, shaly, fine-grained. Limestones gray to orange-red, sandy. 47 42. Limestone, medium-gray, finely crystalline, cherty, arenaceous. 42 4l. Quartzite, light-gray, fine-grained. 27 40. Sandstone, tan, fine-grained, calcareous. 5 59* Limestone, dark-gray, finely crystalline. 29 58. Limestone, tan and gray, sandy, platy. 12 57. Limestone, grayish-tan, dense to finely crystalline, cherty, sand-streaked. 21 56. Sandstone, tan, brecciated. 4 -255-

Feet 55. Limestone, medium-gray, dense and brecciated at base, finely crystalline and platy at top. Cherty. 60 54. Sandstone, tan, fine-grained, porous. 5 55. Quartzite, light- to medium-gray. 7 52. Breccia, quartzite and limestone. 6 51. Sandstone, tan to gray, fine-grained, shaly. 20 50. Limestone, medium-gray, finely crystalline, cherty, a few thin quartzite bedB. 66 29« Quartzite, light-gray, fine-grained. 29 28. Limestone, dark-gray to tan, dense, cherty, numerous crinoid columnals, weathers blue-gray. 40 27. Quartzite, light-gray, fine-grained. 14 26. Limestone, like unit 24. 52 25. Quartzite, light-gray, fine-grained. 29 24. Limestone, dark-gray to black, dense to finely crystalline, platy, weathers tan, cherty. Numerous braehiopods, 42 25. Covered interval. Sandstone float, 144 22. Limestone, light-gray, coarsely crystalline, arenaceous. 5 21. Quartzite, light-gray, fine-grained. 24 20, Sandstone, tan, fine-grained, porous. 2 19. Limestone, dark-gray, finely crystalline, cherty. 50 18. Quartzite and sandstone, light-gray, fine­ grained, a few thin limestones. 76 17* Covered. 12 16. Limestone, light-gray,tliin-bedded, arenaceous. 4 15* Limestone, medium-gray, dense to finely crystalline, very cherty, 5 14. Limestone, dark-gray to tan, finely crystalline, sandy, platy. 5° 15. Sandstone and limestone, like unitB 11 and 12, interbedded in thin layers. 19 12. Sandstone, tan, fine-grained, porous, partly croBs-bedded. - 12 11. Limestone, medium-gray, finely crystalline, cherty, weathers blue-gray. 21 10. Sandstone, tan, fine-grained, porous. 20 9, Sandstone and limestone, like unit J, 24 8. Limestone, medium-gray, finely crystalline, cherty, weathers blue-gray. 28 7. Sandstone and limestone, interbedded and interlaminated• Sandstones gray, weathers tan. Limestones medium-gray, finely crystalline, cherty, 106 Feet

6. Limestone, medium-gray, finely crystalline, cherty. 5 5. Sandstone, light-gray, fine-grained, hard. 21 4. Limestone, medium-gray, sandy. 9 5* Sandstone, tan, fine-grained. 10 2. Limestone, light-gray, coarsely crystalline, cherty, thin sandstone lenses, 28

Total Oquirrh measured 2J70 ft,

1. Limestone, light-gray, finely crystalline, platy, cherty.

Section 6: Partial section of Oquirrh formation measured at head of Left Fork of Loafer Canyon, up spur on west side leading to Santaquin Peak. Upper part of measured section is mainly in section 52, T.9S., R.JE. Lowermost unit is assumed to be approximately equivalent to the upper unit of section #5.

Eroded surface

Oquirrh formation

27. Sandstone, dark-gray, fine-grained, platy, calcareous, weathers brown. 158 + 26. Sandstone, white to pink, fine-grained, clean. 46 25. Conglomerate and breccia, light- to medium-gray. Pebbles of sandstone and limestone averaging -§- inch in diameter. Sandy limestone matrix. 21 24. Sandstone and limestone interbedded. Sandstone is tan, fine-grained, calcareous. Limestone is light- to dark-gray, finely crystalline, hard. 81 25. Limestone, light-gray, finely crystalline, hard, numerous dandy laminations. 42 22. Sandstone, light-gray, fine-grained, dense, calcareous. 96 21. Sandstone and limestone interbedded. Sandstone is tan, fine-grained, calcareous, hard. Lime­ stone is gray to tan, finely crystalline to dense, fossiliferous, and full of thin irregular sandy layers, Oaninia, sp, 48 -255- Feet 20. LimeBtone, medium-gray, finely crystalline, massive, sandy, pitted near base with small irregular lenses of ferruginous sand. 29 19. Sandstone and limestone interbedded. Sandstone like unit 22. Limestones like unit 20. Thin- to medium-bedded. 86 18. Limestone, gray to tan, coarsely crystalline, hard, very fossiliferous. Weathered surfaces have brown stripes up to 8 inches thick. Fusulina (?) 70 17» Sandstone and limestone interbedded. Sandstone is gray to tan, fine-grained, hard, calcareous, weathers brown. Limestone is li&ht- to medium- gray, dense to finely crystalline. At 520 feet is a 10-foot zone of breccia. 575 16. Limestone, gray to tan, coarsely crystalline, weathered surface has brown, sandy streaks up to 2 feet thick. Very fossiliferous, Triticites cf. sprinRvillenBis. 90 15. Limestone, dark-gray, sandy,weathers tan, gradational to calcareous sandstone, 102 14. Sandstone, dark-grayj fine-grained, calcareous, weathers light-brown. I65 15. Sandstone, dark-gray, laminated. 2 12, Sandstone, grayish-tan, fine-grained, pla$yj a few thin sandy limestones, 254 11. Limestone, dark-gray, finely crystalline, cherty, sandy. At 15 feet is a 4-foot fusulinal lime­ stone. Triticites cf. springvillensls. 10. Sandstone, grayish-tan, fine-grained. 9 9 . Limestone, dark-gray, finely crystalline, sandy. Upper portion streaked with brown sandy beds up to 6 inches thick. Middle of unit contains numerous brown chert bands and specimens of Oaniinia Bp, 64 8. Ohert and limestone. 0,5 7, Quartzite, light-gray, fine-grained. 11 6. Sandstone, light-gray, laminated, calcareous, hard. 57 5 . Limestone and sandstone, medium-gray, fossiliferous. Limestones stylolitic. 45 4, Sandstone, light- to medium-gray, fine-grained, hard, calcareous, weathers gray to brown. Some bedding planes have "worm" trails. Some beds contain bryozoansj others contain crinoid columnals. 200 5. Limestone, medium- to dark-gray, sandy. 15 2. Quartzite, light-gray, fine-grained, clean, 88 «2J6~ Feet 1. Sandstone, grayish-tan,, fine-grained, porous, faint cross-bedding. 15

Total Oquirrh measured 2144

Base not exposed.

Section 7* Kirktnan limestone and uppermost Oquirrh formation measured along animal trail half way up north side of Flat Canyon.

Diamond Creek sandstone

Kirkman limestone

19. Breccia, dark- to medium-gray laminated lime­ stone add tan fine-grained sandstone. A few specimens of Pseudoschwagerina (?). 90 18. Sandstone, tan, fine-grained, calcareous, platy- weathering. 1 17. Breccia and sandstone. Brecciated dark- to medium-gray laminated limestone in matrix of fine-grained yellow sandstone. Upper portion is mainly sandy limestone and calcareous sand­ stone, with a few scattered fragments of the laminated sandstone. 70 16. Limestone, medium- to dark-gray, arenaceous. 4 15* Limestone, brecciated, like unit 1, A few layers of buff sandstone. 15 14. Sandstone, yellowish-tan, fine-grained, calcar­ eous, lenticular. Contains a few angular fragments of laminated limestone, 8 15. Breccia. Angular fragments of medium- to dark- gray limestone interlaminated with fine­ grained yellow sandstone. Fragments up to 1 foot in diameter. 81

Total Kirkman limestone 269

Oquirrh formation

12, Quartzite, tan, fine-grained, with lenses of dark-gray, argillaceous limestone, Brecciated at top. 25 -257- Feet 11, Limestone, dark-gray, thin bandB of brown argillaceous material. 5 10, Sandstone, tan, fine-grained, hard, calcareous, 66 9, Covered interval. Float of brown, red, and tan sandstone, Schwagerina sp, 15 8. Limestone, dark-gray, finely crystalline. 4 7. Quartzite, dark-gray, fine-grained, weathers tan, 4 6. Limestone, dark- to medium-gray, sandy. 5 5* Quartzite, dark-gray, fine-grained, calcareous. Some beds brecciated, 6 4. Limestone, medium-gray, finely crystalline, arenaceous, black chert nodules. Schwagerina sp, 5 5. Covered. Float of grayish-tan, very fine­ grained sandstone and cherty dark-gray lime­ stones, Triticites cf. powwowensis. 245 2. Sandstone, grayish-tan, very fine-grained, weathers reddish-brown to light-brown. Worm trails on bedding planes. 80 1. Quartzite, dark-gray, very fine-grained, weathers brown and platy. Worm trails on bedding planes, 50

Partial section of Oquirrh measured 486

Covered interval.

Section 8 j Measured along ridge on north side of upper Crab Creek Canyon, mainly in section 55* T,9S., R,5E,

Tertiary fanglomerates

Covered interval i Park City formation

51. Sandstone, gray to pink, medium-grained, calcareous, grades laterally to buff limestone, 20 50, Limestone, medium-gray, finely crystalline, platy. 8 29. Covered interval. Probably pink to buff sandstone, 16 “258- Feet 28. Lime stone, light-gray, finely crystalline, slightly arenaceous. Much is finely brecci­ ated, with additional fragments of fine­ grained buff sandstone up to 5 inches in diameter. Contains irregular lendes of pink, buff, and gray calcareous sandstone. 48 27. Sandstone, light-gray and tan, very fine­ grained, weathers buff or brown, irregular bedding, cavernous weathering. 90 26. Breccia, fragments up to 5 inches in diameter of light-gray finely crystalline limestone and fine-grained medium-gray sandstone. A few thin beds of irregularly bedded light- gray limestone. 24 25. Limestone, light-gray, hard, very silty and very cherty, contains many vugs of calcite 1 to 2 inches in diameter. Bottom bed is 54-foot layer of light- to dark-gray chert. 125 24. Sandstone, grayish-brown, fine-grained. 4 25. Limestone, light-gray, very silty, contains numerous gray chert nodules and vugs of calcite. 15 22. Siltstone and chert, black to dark-gray. Chert weathers light-brown and is rubbly. 45 21. Shale, black, hard, phosphatic, pyritic. 45 20. Chert, black to dark-gray. 25 19. Siltstone, black to dark-gray, siliceous, weathers brown and red. Interbedded with phosphatic shales and dark-gray chert. Num­ erous small gastropods. 60 18. Siltstone and fine-grained sandstone, grayish- tan, thin-bedded, numerous crinoid columnals and fragments of braehiopods. 55 17. Phosphate rock, shale, and sandstone. Phosphate in shale beds as dark- to bluish- gray nodules and broken gastropod fragments. Sandstone is medium-gray, thin-bedded, cherty, and slightly calcareous. 60 16. Covered, probably sandstone. 25 15. Sandstone, light-tan, fine-grained. 16 14. Covered, 15 15. Limestone, medium-gray, medium-crystalline, very cherty. 10 12. Sandstone, light-gray, fine-grained, partly quartzitic. Grades upward into medium-gray to tan siltstone. Dark-gray chert is abundant in the upper part of the unit, and there are numerous small calcite geodes. 4o -259- Feet 11. Sandstone, light-gray, very fine-grained, numerous small caloite geodes and abundant white chert. Calcareous, and gradational to arenaoeous limestone. 65 10. Sandstone, tan, fine-grained, calcareous, weathers buff. 5 9. Limestone, medium-gray, finely crystalline, light-gray chert stringers. 15 8. Sandstone, grayish^brown, fine-grained, calcareous, blebs of white calcite, gray chert lenses. 15 7. Sandstone, light-gray, weathers buff, fine­ grained, many frosted quartz grains, 4 6. Limestone, dark-gray, medium-crystalline, weathers light-gray, irregular bedding. Con­ tains irregular lenses and stringers ofblack, grajt, and white chert. Thin breccia at base. 20 5. Breccia and sandstone. Breccia contains frag­ ments of light-gray Bandy limestone and buff sandstone in a sandy limestone matrix. Sand­ stone is tan, fine-grained, calcareous, con­ tains small lenses of sandy limestone (6 inches deep and 2 feet wide). At 55 feet, a thin laminated limestone layer similar to the Kirkman. 55 4. Limestone, light-gray, sandy, fetid, broken gastropod fragments. 5 5. Sandstone, gray, fine-grained, weathers buff. 4 2, Limestone, medium-gray, finely crystalline, a few calcite blebs. 11 1. Breccia, light-gray, sandy limestone matrix. Fragments up to 4 inches in diameter of lime­ stone and Diamond Creek sandstone. 12

Total Park City formation 951

Diamond Creek sandstone

Section 9 : Twin Creek formation measured on north side of mouth of Crab Creek. S.W.^f, Section 5i T.10S., R.4E.

Colton formation

Normal fault -240- Feet Twin Greek formation

55* Covered dip elope. 52. Limestone, grayish-brown, to purplish-tan, lithographic. Beds up to 1 foot thick. JO Jim Limestone, grayish-tan to pink, dense, silty, thin-bedded. 5 50. Limestone, grayish-brown, dense. 14 29. Limestone, tan to gray, laminated. 11 28 Limestone, light-gray to pink, platy-weathering. J 27. Covered. 20 26 , Limestone, tan to gray, dense to lithographic, bedding up to 1 foot thick. 25 25* Covered. 5 24. Limestone, gray-tan, thin-bedded, platy. 4 25* Covered. 18 22. Limestone, light-gray to tan, lithographic, blocky-weathering, beds up to 1 foot thick. 75 21. Covered. Probably like unit 20. 60 20. Shale and shaly limestone, pink to pale green. 8 19* Limestone, pink, gray, and brown, lithographic, beds up to 1§ feet thick, JO 18. Shale, gray, calcareous. 0.5 17. Limestone, grayish-brown, dense, blocky-weathering. 14 16 , Limestone, tan, dense, bedding up to 4 feet thick, rubbly at base, forms prominent ledge. 14 15* Limestone, shaly, like unit 12. 12 14. Limestone, light-gray, thin-bedded, sandy, ripple-marked, weathers to large thin slabs. 19 15. Limestone, medium-gray, ripple-marked, platy- weathering, thin-bedded. J 12. Shale, grayish-brown, very calcareous. Slopes covered with prismatic fragments averaging 4 inches in length. 106 11. Covered. 16 10. Limestone, brown, lithographic, blocky and platy. 4 9. Limestone, medium-gray, dense, weathers to large flagstones. 15 8 . Covered. 15 7. Limestone, pinkish-tan, dense. 2 6 . Limestone, gray, very fossiliferous— pelecypods and gastropods, 1 5. Limestone, mottled yellow and pinkish-gray, dense, green fossil fragments. 6 4. Limestone, tan, dense, platy. Pelecypod fragments, J 5. Limestone, tan, oolitic. 8 2. Limestone, red, finely crystalline, Bandy. 2 -241- Feet

1, Shale and siltstone, red, very calcareous. 11

Total Twin Greek formation 555*5

Nugget sandstone

Section 10i Measured on north side of lower canyon of Crab Creek#

Colton formation

26. Conglomerate.

Flagstaff formation

25# Limestone, tan to light-gray, large algal- balls numerous. 4 24# Limestone, creamy-gray, lithographic, mottled pink and buff, weathers white. 5 25# Conglomerate, light- to medium-gray, pebbles up to 5 inches in diameter. 50 percent lime­ stone. 5 22. Covered interval 6j 21. Limestone, light-gray to white, dense, weath­ ers chalky white, contains numerous small algal ballsj averaging 3, inch in diameter, 9 20. Covered interval, 68 19. Limestone, light-gray, dense. 4 18# Covered interval. 5 17# Mudstone, variegated red and green. 12 16* Covered interval. 10 15# Limestone, light-tan, dense, scattered quartz grains; numerous large, curved slabs of algal-like laminated material with pitted structures. 10 14, Covered; talus like unit 15# 5 15# Limestone, light-gray, finely crystalline to dense, porous, scattered algal balls# 7 12. Limestone, light-brown, dense, a few ostracodes. 6 11, Covered interval, limestone talus. 17 10, Limestone, light-gray, oolitic, gradational to tan ostracodal limestone. 22 9# Limestone, grayish-tan, dense, hard. 15 -242- Feet

8. Limestone and conglomerate. Limestone is oolitic and ostracodal, contains pebbles of chert, grades upward into coarser chert pebble conglomerate. 15 7. Limestone, tan, arenaceous, oolitic and ostracodal, contains many small algal con­ cretions. 4 6m Limestone, light-gray, dense, massive, a few scattered algal balls. At 10 feet col­ lected specimens of Helix riparia and Physa pleuromatis. 18 5. Limestone, dark-brown, thin-bedded, dense. 4 4. Limestone, tan, dense, massive, contains small angular fragments of porcelain-like limestone. 19 5» Shale, variegated red and brown, silty, cal­ careous nodules near top, contains numerous algal-coated specimens of SoniobaBis tenera. 19 2. Limestone, light-gray, sandy. 2 1, Limestone, variegated white and red, rubbly. 2

Total Flagstaff formation 550

North Horn formation

Red silts and muds containing nodules of limestone.

Section 11s Measured in chasm in Frank Young Canyon, S.W.-g, Sect. 24, T.10S., R.2E.

Colton formation

Conglomerate

Flagstaff formation

8. Limestone, deep pink to light-brown, dense, tan algal-balls 7 7. Limestone, gray mottled pink and tan, numerous algal-balls, weathers white and pink, 56 6. Limestone, brownish-gray, dense, numerous fragments of chert, quartz, and limestone. Scattered pockets of algal-ball limestone. 57 5. Limestone, graylsh-tan, algal-balls numerous. 4. Limestone, pink and tan, dense, weathers rose and yellow, contains scattered rounded frag­ ments of chert, limestone, and clay. 5. Limestone, light-brown mottled red, dense, scattered pebbles of chert, limestone, quartzite, limonite. Several irregular layers .of algal-balls, which range in diameter from less than an inch to over 4 inches. 2. Limestone, deep pink, weathers pink and white, a few small algal balls, 1. Limestone, deep pink, dense, scattered granules of chert and quartz, a few small algal-balls.

Total Flagstaff measured

Covered interval in creek bed ■244—

AUTOBIOGRAPHY

I, Raymond Earl Matter, was born in Champaign, Illinois, August

25, 1925. I received my secondary school eduoation in the training

school of Eastern Illinois State College, Charleston, Illinois. My

undergraduate training was obtained at Eastern Illinois State College,

from which I received the degree Bachelor of Science in 1948, My

undergraduate training was interrupted by my service in the United

States Marine CorpB, from 194-5 to 1945. Prom the Ohio State Univer­

sity, I received the degree Master of Science in 1952. While in

residence at the Ohio State University, I served as graduate assist- I ant and assistant instructor in the Department of Mathematics during

the years 1948-1949, and as graduate assistant in the Department of

Geology during the years 1950‘-*1952. For the year 1952-1955 * held a National Science Foundation fellowship at the Ohio State University, where I specialized in the Department of Geology. During the year

1955-1954 I held the position Research Associate in the Ohio State

University Research Foundation while completing most of the require­ ments for the degree Doctor of Philosophy. Spun,,I, lo ik Spanish fo lk Po a k

Tin;; Mop

S antaqm n Penk

HASP MAP PROM INDICATED QUADRANGLES

AND AERIAL PHOTOGRAPHS SALEM PAYSON JL! JL j| )(Jl ][J(p□uUL.OL.LJ ULUL'jl OJL'JL.lICII JL LlLULUL...! L"J ): _ jl jL L u m a tu Lxzocxjnnno luRHflfTT, □LJL JLJULOJ ICL1I n n m u u u n UtJI 'JL n n u u x i riJLJLJL'JI II i m n p - p □LI "inrXJL □ a . _ izir

L i t M»- M on 11 f n nV /l l ;

M cuntcji

//l/J SPRANG Nipple. LAKE1

tin I i-.tr I Qx I

SANTAQUIN -<«sX\ lAi tA.X □□□□□ □□□□□ / 1% / V SALEM

Mountain d r y

M 0 (j N

Pit

Right /,/ Canyon

For k

Winwafd Resprvoj-f

Pay son Lakes

/. <2>- '/ L izard Lake

GEOLOGIC MAP OF PART OF THE SOUTHERN WASATCH \

24,000 Snell PLATE 27

EXPLA NATION x-vus I Sedimentary Rocks ) ,y[/<^ t G T 1 1 A I I.I1VUIM1 ll\/ I I I M

L ° j :: .. I YO UN G E R FANG

MORAINE I I Older fans XP " | Q "o 1 TERRACEr: GRAVELS PY R O C L A STI CS C Tuf UNDIFFERENTIATED FANGLOMERATES L.T“ I CRAB CREEK FORMATION i:: COLTONTON FORMATION r . : 'J FLAGSTAFF.STAFF FORM ATION I > N O R TH HORN FORMATION } r Jtc TWIN CREEK FORMATION

NUGGET SANDSTONE

fS3 Iso) |~ To "j

THISTL ANKAREH FORMATION

THAYNES FORMATION j-'- PP E |

PARK CITY FORMATION

Pdc

DIAMOND CREEK SANDSTONE

sssssasmmmmm ORY MOUNTAIN

SANTAOUIN OVERTMRUST

9,000.

8,000-

6,0 00.

7 ,0 0 0

6 ,000.

5,000.

8,0 0 0 .

7,000 BEAR CANYON

%4>RY MOUNTAIN THRUST

lEAR CANYON THRUST 5,000. V

NORTHERN CEDAR

Tt *rI

LOAFER MOUNTAIN

LOAFER c a n y o n a n t ic l in e

SHURTZ CANYON ANTICLINE

POLE CANYON SYN CLINE ■ Vj ^ ^0

8 ,0 0 0 D‘ 9 ,0 0 0 DRY MOUNTAIN

-8 ,0 0 0 7,000.

6,000. 7,000

5,000. .8 ,0 0 0

4 ,0 0 0 5 .0 0 0

STRUCTURE SECTIONS

Sco I e 1 /2 4 ,0 0 0 IOOO O IOOO 2 0 0 0 3 0 0 0 4000 9 0 0 0 FEi CEDAR HILLS

l o a f e r m o u n t a in

.9,0

ANTICLINE

-7,0'

6,C

10,000

9 ,0 0 0 DRY MOUNTAIN 8,000

7 ,0 0 0 8,000

6, 0 0 0 7 ,0 0 0 .

5 ,0 0 0 6,000.

4 ,0 0 0

'URE SECTIONS

Scole 1/24,000

IOOO 2000 3000 4000 30C0 FEET PLATE 28

-6 ,0 0 0

S.OOO

10.000

9 , 0 0 0

8,000

-

6,000

5 ,0 0 0 i •9 ,0 0 0

■8 ,0 0 0

-7 ,0 0 0

. 6,000

- 5 , 0 0 0

#

10,000

9 ,0 0 0

8,000

7 ,0 0 0

6,000

R. Wetter DRV MOUNTAIN

SANTAOUIN OVERTHRUSX

9,000.

6,000.

5 ,0 0 0

9,000-|

8,000.

7 ,0 0 0

6 ,0 0 0 .

5,000

9,000.

8,000

7,000 7,000 BEAR CANYON

n^RV m o untain t h r u s t

lEAR CANYON THRUST 5,000. 5,000 V v

northern CEDAR

LOAFER M OUNTAIN

LOAFER CANYON ANTICLINE

SHLIRT2 CANYON ANTICLINE

POLE CANYON SYNCLiNE

8000 9 , 0 0 0 , . DRY MOUNTAIN

• 8,000 7 , 0 0 0

6,000. 7 ,0 0 0

5 ,0 0 0 . 6,000

4 , 0 0 0 5 , 0 0 0

STRUCTURE SECTIONS

Scale 1/24,000

I0OO 2000 3000 4000 3000 FEf

9 CEDAR HILLS

KTr

l o a f e r m o u n t a i n

ANTICLINE

;KTr

10,000

9 ,0 0 0 DRY MOUNTAIN 8,000

7 ,0 0 0

7 ,0 0 0 .

5 ,0 0 0 6,000.

4 ,0 0 0

URE SECTIONS

Scale 1/24,000

IOOO 2000 3000 4000 5000 FEET PLATE 28

•8 ,0 0 0

- 6 ,0 0 0

s.ooo

r 10,000

.9,000

8,000

• 7 ,0 0 0

6,000

5 ,0 0 0

9 ,0 0 0

.8,000

-7,000

.6,000

- 5 ,0 0 0

#

10,000

9 ,0 0 0

8,000

.7 ,0 0 0

6,000

R Wetter