STATE OF WASHINGTON DEPARTMENT OF NATURAL RESOURCES
BERT L. COLE, Commissioner of Public Lands DON LEE FRASER, Supervisor
DIVISION OF GEOLOGY AND EARTH RESOURCES
VAUGHN E. LIVINGSTON. JR .. State Geologist
Geologic Map GM-8
PRELIMINARY GEOLOGIC MAP OF THE NEWPORT NUMBER 2 QUADRANGLE, PEND OREILLE AND STEVENS COUNTIES, WASHINGTON
By FRED K. MILLER U.S. GEOLOGICAL SURVEY
Prepared cooperatively by the U.S. Geological Survey
1974 STATE OF WASHINGTON . TO ACCOMPANY PRELIMINARY DEPARTMENT OF NATURAL RESOURCES GEOLOGIC MAP GM-8 DIVISION OF GEOLOGY AND EARTH RESOURCES
PRELIMINARY GEOLOGIC MAP OF THE NEWPORT NUMBER 2 QUADRANGLE, PEND OREILLE AND STEVENS COUNTIES, WASHING TON
By
Fred K. Miller
INTRODUCTION the western part of the area for the 1 :500,000 scale geologic map of Washington (Huntting and others, The Newport Number 2 quadrangle covers most of 1961). Although Schroeder recognized that the Precam the Pend Oreille River valley between latitude 48°15' brian rocks were correlative with parts of the Belt and 48°30' N. The west half of the quadrangle includes Supergroup, he did not use Belt names or stratigraphic the east flank of the mountains that divide the Pend units, but called them the Newport Group. He also Oreille River valley and the Colville River valley. All included a quartzite unit in the Precambrian Newport the quadrangle is in Pend Oreille County except for an Group that is here considered to be the Lower Cam approximately 200-foot wide strip of Stevens County brian Addy Quartzite. along the west edge. The area is a 15-minute composite of four preliminary 7.5-minute quadrangles prepared by STRATIGRAPHY the U.S. Geological Survey: Jared, northeast quarter; PRECAMBRIAN ROCKS Tacoma Peak, northwest quarter; Winchester Peak, southwest quarter; and Cusick, southeast quarter. BELT SUPERGROUP In the initial stages of preparing modern topographic Metamorphic rocks maps of the Newport 30-minute quadrangle, the U.S. Geological Survey divided the area into four 15-minute This unit contains a variety of rock types. Most of it quadrangles and sixteen 7.5-minute quadrangles. No is composed of rusty weathering, pyritic or pyrrhotitic 15-minute quadrangles of the area were published, so muscovite-biotite schist and micaceous quartzite. Nea; the tempo:ary name, Newport Number 2, is used for the the southern border of the quadrangle along the north area of this report. fork of Calispell Creek, the rocks are locally gneissic. Geologic mapping in the Newport Number 2 quad Layers and pods of amphibolite are common in the unit. ran~le was begun by the author in 1969 under the coop A gradational migmatic zone as much as 1,000 feet wide erative arrangement between the Division of Mines and containing as much as 30 percent plutonic rock is and Geology* of the Washington State Department of included in the unit where it is adjacent to the Phillips ~atural _Resources and t~e U.S. Geological Survey. Able Lake Granodiorite. field assistance was provided by J. S. Tinker in 1969 and The metamorphic rock unit is probably correlative P. N. Castle in 1970. with the Prichard Formation. The correlation is some The quadrangle can be divided geologically into three what equivocal, but the weight of evidence suggests parts. Schist, gneiss, and quartzite, all intruded by that the two units differ only in amount of metamor quartz monzonite, alaskite, pegmatite and aplite are phism. An area of about one square mile at the juncture exposed in the western half of the quadrangle. They of secs. 20, 21, 28 and 29, T. 33 N., R. 43 E. is less meta are separated from relatively unmetamorphosed Paleo morphosed than most of the unit and strongly resembles zoic rocks and from rocks of the Belt Supergroup by a the Prichard Formation. Elsewhere, metamorphic rocks large east-dipping thrust fault, the Newport fault. Ter are along strike with known Prichard, and discontinu tiary conglomerate and arkose are confined to the Pend ous exposures show gradually increasing metamorphism Oreille River valley below elevations of 3 500 feet and toward the metamorphic rock unit.Both units have similar overlie the thrust fault. Most of the Pend Oreille River chemistry, are rusty weathering, and contain mafic-rich _valley and the surrounding low hills are covered by rock layers (diorite sills in Prichard, amphibolite layers glacial and alluvial material. in the metamorphic unit). Exposures in most of the quadrangle are relatively On Calispell Peak, west of the quadrangle, and north poor; a large part of the bedrock is capped by a heavy and west of Little Calispell Peak, much of the rock is forest cover and by patchy glacial debris. On parts of quartz-plagioclase-actinolite hornfels and schist and Ruby Mountain, however, and in places along the east may have been formed from higher parts of the Belt Supergroup, including the Wallace Formation. Locally edge of the mountains in the west half of the quadran the actinolite-bearing rock contains diopside, scapolite gle, the rocks are very well exposed. Roadcuts along nu vesuvianite, epidote, and clinozoisite. ' merous new logging roads have furnished valuable information in areas free of natural exposure. Previous work includes detailed geologic mapping by Burke Formation M. C. Schroeder (1952) in the area east of the Pend The Burke Formation crops out in one small area in Oreille River and reconnaissance geologic mapping in the northeast corner of the quadrangle. The rock there *Name changed to Division of Geology and Earth Resources (i973) 1 is mostly muscovite-biotite-plagioclase-quartz hornfels per argillite and dolomite part. The division probably and schist, but within a short distance east of the quad corresponds roughly to the division made by Hobbs and rangle boundary, the rock grades into the medium-gray others (1965, p. 43) in the Coeur d'Alene district and by siltite characteristic of the formation. Metamorphism Miller (1969, p. 2) in the Loon Lake quadrangle. is due to proximity to the Galena Point Granodiorite. The contact with the Revett Formation is gradational Lower part of the Wallace Formation.-The lower over a stratigraphic interval of about 200 to 300 feet. part of the Wallace Formation consists of about 1,800 Near the Burke-Revett contact, some of the rocks con feet of calc-silicate hornfels, quartzite, and siltite. The tain sparse iron and copper sulfides, possibly related to rock is pale green and white, and commonly has a the Galena Point Granodiorite. Even though metamor streaked appearance. Irregular bedding, characteristic phosed, the Burke Formation shows well-developed bed of the lower Wallace in the Coeur d'Alene district, ding, 2 to 6 inches thick, but other sedimentary features is found locally, but most of the rock has thinner have been destroyed. layers. Many of the layers are lensoidal because of shearing either during or before metamorphism. The Revett Formation metamorphic assemblage includes rocks as different as The Revett Formation, along the east border of the quartzite and amphibolite, but the most typical mineral quadrangle and on the east flank of Ruby Mountain, is assemblage is tremolite (or actinolite)-quartz-plagio predominantly a well-bedded white to light-gray or clase, and, in some, biotite. tan fine-grained quartzite about 2,300 to 2,600 feet thick. Numerous quartzitic siltite beds are mainly re Upper part of the Wallace Formation.- The upper stricted to a 200- to 500-foot zone near the middle and part of the Wallace Formation is or was mostly to the gradational upper and lower contacts. Argillite argillite. On the upper slopes of Ruby Mountain, it has beds are thin and sparse. The beds range in thickness been metamorphosed to andalusite-cordierite -mus - from about an inch to more than 5 feet and average covite-biotite-quartz-oligoclase hornfels or schist. On the lower slopes, the rock is phyllite and, locally, rel about 1.5 feet. Cross bedding and ripple marks, reported by Harrison and Jobin (1963, p. K12) in the Clark Fork atively unmetamorphosed dark-gray laminated argillite. quadrangle and by Hobbs and others (1965, p. 38) in the Recrystallization resulted from contact metamorphism Coeur d'Alene district, are rare in the Revett in the by a hornblende-biotite quartz monzonite pluton exposed Newport Number 2 quadrangle. outside the quadrangle on the northern flank of Ruby The contact with the St. Regis Formation is grada Mountain. About 500 feet above the contact with the tional and well exposed in the S 1hsec. 9, T. 34 N., R. 44 E. lower part of the formation, a zone of tan and gray do The rocks grade from medium- to fine-bedded siltite, lomite about 300 feet thick is interbedded with the quartzite, and argillite of the St. Regis Formation argillaceous rock. The dolomite is now recrystallized through a stratigraphic interval of about 100 to 200 at the north edge of the quadrangle to fairly coarse feet. The typical color gradation between these two grained dolomitic marble that contains no calc-silicate formations is not obvious in this area, because some of minerals. It is thin bedded and contains abundant thin the St. Regis Formation is bleached. siliceous layers along bedding planes, but it forms mas sive, blocky outcrops. Almost all sedimentary structures have been destroyed by metamorphism. St. Regis Formation The contact between the Wallace Formation and the The St. Regis Formation, which is well exposed on overlying Striped Peak Formation is covered; but if both sides of the westward-flowing creek in sec. 9, gradational, like most contacts in the Belt, it appears T. 34 N., R. 44 E., consists predominantly of siltite, nu to occur over a relatively small stratigraphic interval merous argillite beds and partings, and lesser numbers of for the Belt Supergroup. quartzite beds. It is dark red to maroon, but is locally bleached to white, green, or gray, and in places is slightly phyllitic. Thickness of beds ranges from thin lamina tions in the argillite layers to 2-foot-thick quartzite Striped Peak Formation beds. Most of the unit consists of siltite beds from 3 to 6 inches thick. Green carbonate-bearing siliceous argil lite, which is characteristic of the upper part of the for About 1,000 feet of siltite, argillite, and quartzite on mation at most nearby localities, is not obvious in the the west flank of Ruby Mountain has been mapped as Newport Number 2 quadrangle because of alteration the Striped Peak Formation. The formation is not well and bleaching of the rocks. This alteration, however, exposed, and it may include dolomite and dolomitic has not destroyed the sedimentary structures such as rocks that occur in the lower Striped Peak in the New ripple marks, mud cracks, and mud-chip breccia, that port Number 1 quadrangle to the east. Recrystallization characterize the formation. A complete section is not has erased much of the original character of the rock, preserved in the Newport Number 2 quadrangle, but in although the degree of recrystallization is less than in the quadrangle to the east (Newport Number 1), the the Wallace Formation. formation is about 1,000 feet thick. The exposed part of the section is medium-gray siltite and quartzite and dark-gray argillite. Much of the rock Wallace Formation has a definite pink cast that may reflect the original About 4,500 feet of calc-silicate hornfels, quartzite, red and maroon colors of the formation in other areas. siltite, andalusite schist, phyllite, and argillite has been Beds range in thickness from thin laminae in the argil mapped as Wallace Formation on Ruby Mountain in the lite to 5 feet in the siltite and quartzite. Mud cracks, northern part of the quadrangle. The formation is mud-chip breccia, cross laminations, and ripple marks divided into a lower carbonate-bearing part and an up- are preserved locally.
2 PALEOZOIC ROCKS No distinctive features are found in the unit, and no satisfactory correlation with known carbonate units can CAMBRIAN SYSTEM be made. Addy Quartzite Phyllite and quartzite The Addy Quartzite, which crops out along the east border of the quadrangle on both sides of Browns Creek As much as 2,400 feet of phyllite and quartzite and and on the west flank of Ruby Mountain, is predomi minor amounts of interbedded dolomite is exposed just nantly a thick-bedded white or light-gray medium west and southeast of the Silver King mine near the north border of the quadrangle. The unit is about 60 grained vitreous quartzite. Approximately the lower 75 feet is dark purple; the color then grades upward , percent phyllite and 40 percent quartzite. Zones made up predominantly of phyllite, which are as much as 200 through pink to white. The formation appears to rest unconformably on the Striped Peak Formation, but the feet thick, alternate with zones made up predominantly of quartzite that rarely exceed 100 feet in thickness. contact is not well exposed in the quadrangle. Much of The phyllite is medium to dark gray and shows only in the rock, especially on Ruby Mountain, is moderately distinct bedding. It crops out poorly but in places it can brecciated, possibly due to the proximity of the Newport be reliably mapped from float. Most of the quartzite is fault zone. white, medium grained, vitreous, and thick to massively The rocks within the Newport Number 2 quadrangle bedded; some, however, is dark brown to dark gray, is resembles quartzite at the type sections of both the medium bedded, and contains abundant impurities. Lower Cambrian Gypsy Quartzite (Park and Cannon, Sandy dark-brown dolomite is commonly found inter 1943, p. 13) and the Addy Quartzite. The name Addy bedded with the impure quartzite. A single 5- to 10- rather than Gypsy was selected because Park and Can foot-thick bed of pink dolomite is interbedded with non reported no purple quartzite at or near the base of the Gypsy whereas the Addy characteristically contains quartzite and phyllite about a quarter of a mile south such beds. No fossils were found in the formation within east of the Silver King mine. the quadrangle, but Early Cambrian trilobites and brach, The age of this unit, and even the age relative to most iopods have been found elsewhere (Okulitch, 1951, p. 405). of the other post-Addy units is unknown. Because the lower dolomite appears to have been deposited on the Addy Quartzite, the phyllite-quartzite unit is considered PALEOZOIC ROCKS, UNDIVIDED younger than the dolomite. Lower dolomite MESOZOIC(?) ROCKS Light-colored dolomite, 700 to 900 feet thick, overlies Hornblende-biotite quartz diorite the Addy Quartzite on the west flank of Ruby Mountain in apparent depositional contact. The dolomite is in A small prong of hornblende-biotite quartz diorite fault contact with a generally darker dolomite to the protrudes into secs. 28 and 33, T. 35 N., R. 43 E., along west. Most of the dolomite is white, pale gray, or pale the north border of the quadrangle. The rock is medium tan, but medium- to dark-gray beds are common. Much to coarse grained and highly mafic. It has a hypidio of the rock is brecciated and recemented, making rec morphic granular texture but shows some cataclasis in ognition of bedding difficult. Where distinguishable, thin section. Plagioclase is andesine, Almost all horn the beds range in thickness from a few inches to more blende has pyroxene cores and is altered. Biotite is dark than 10 feet; the average thickness is about 2 feet. The brown and partly chloritiz~d. Apatite, sphene, opaque rocks range from fine to coarse grained, but most are minerals, and zircon are the accessory minerals. coarsely crystalline. They are relatively pure carbonate Part of the body is considerably more potassic than and have almost no distinctive characteristics; sedimen the rock name indicates. Along Cusick Creek the rock tary structures other than bedding were not recognized. contains about 15 percent mafic minerals and about 10 The contact with the Addy Quartzite is nowhere ex percent potassium feldspar. North of there, however, posed, although the two formations can be located within the rock contains over 35 percent mafic minerals and 100 feet of one another. less than 4 percent potassium fe'ldspar. The small No fossils were found in the dolomite, so its age is not amount of the body within the quadrangle may repre known. The unit could be part of the Cambrian Meta sent· a mafic-rich, potassium-deficient border phase of a . line Formation, but any distinctive features that might larger hornblende-biotite quartz monzonite that is ex have been used for correlation have been destroyed by posed over a fairly large area just north of the quad brecciation or recrystallization. rangle. The age of the pluton and its age relative to the other plutonic rocks in the area are unknown. The Upper dolomite rocks bear some resemblance to the Triassic or Jurassic Flowery Trail Granodiorite in the Chewelah Mountain About 1,000 feet of medium-gray and pale-tan dolo quadrangle. However, because some of the Cretaceous mite is faulted against the lower dolomite. The range plutons contain variants that resemble the quartz dio of color in this unit is the same as that of the lower rite, it is assigned a Mesozoic(?) age. dolomite, and the two can be distinguished only because the upper dolomite unit appears to have a greater num MESOZOIC ROCKS ber of darker gray beds. It may be that both are part CRETACEOUS SYSTEM of a single unit that cannot be divided everywhere. Galena Point Granodiorite Thickness of beds in the unit is the same as in the lower dolomite and averages about 2 feet. Like the The Galena Point Granodiorite, which crops out only lower unit, the dolomite is brecciated and recemented. in the northeast corner of the quadrangle, is exposed
3 over more than 50 square miles in the Newport Number about 50 percent of the complex. In the northwest 1 quadrangle to the east (Miller, 1974). There it is a quarter of the Newport Number 2 quadrangle, the pro porphyritic biotite granodiorite (see modal diagram on portion of Phillips Lake Granodiorite to other rocks in map). Within the Newport Number 2 quadrangle, most the complex remains about 50-50. To the south and east of the pluton is a finer grained border phase of the main the leucocratic rocks, especially the pegmatites, increase part of the pluton to the east. in number and proportion. In addition to the mixture Along the east border of the quadrangle the rock is of plutonic rocks making up this unit, it also contains typical of the porphyritic, medium- to coarse-grained many remnants of metamorphic rocks, especially around rock that makes up the bulk of the pluton. The pheno the borders of the complex and in the area between crysts are euhedral untwinned potassium feldspar that Calispell and Little Calispell Peaks. range from 1h to 21h inches long. Plagioclase is oligo The Phillips Lake Granodiorite was named by Miller clase, but is zoned from sodic andesine to calcic albite. and Clark (1974) for the exposures around Phillips Lake Biotite, the only mafic mineral, commonly forms about in the Chewelah Mountain quadrangle. It is also prob 12 percent of the rock. Traces of muscovite occur near ably similar to Park and Cannon's (1943, p. 24) musco the border. It is not clear whether muscovite is pri vite facies of the Kaniksu batholith. The rock ranges mary, secondary, or the result of contamination by the in composition from quartz monzonite to quartz diorite host rock. On the east flank of Ruby Mountain where (see modal diagram on map). It is made up of the same the pluton appears to have assimilated argillaceous mineralogy almost everywhere: oligoclase, microcline, rocks, some muscovite crystals in the granodiorite con quartz, muscovite, biotite, apatite, zircon, and magnetite. tain numerous thin needles of sillimanite. Hornblende Locally it contains allanite, epidote, garnet, and tourma makes up 1 to 4 percent of the rock locally but is not line. The fine-grained two-mica quartz monzonite has found where the rock contains muscovite. Accessory an identical mineralogy. The alaskite is chiefly medium minerals commonly found in the rock include zircon, grained and is made up of calcic albite or sodic oligo apatite, and opaque minerals. clase, microcline, quartz, muscovite, traces of biotite, zir Contact metamorphic aureoles showing similar meta con, and apatite. The pegmatites commonly contain morphic effects are found around the Galena Point graphic intergrowths of al bite, microcline, and quartz. Granodiorite and also around a pluton immediately Crystals of muscovite, biotite (locally), garnet, and tour north of the quadrangle boundary. Recrystallization of maline are common. the Revett and lower Wall ace Formations in the area The Phillips Lake Granodiorite is considered to be east of Ruby Mountain is probably related to thermal Cretaceous in age (Miller and Clark, 1974), but some of effects of the Galena Point Granodiorite, whereas meta the rocks included in the complex may be Tertiary. morphism to the west may be due to either pluton. Joan C. Engels, of the U.S. Geological Survey, obtained CENOZOIC ROCKS an age of 98.3±3.2 m.y. on biotite from this pluton TERTIARY SYSTEM using the potassium-argon method. Although only a Cataclastic rock single mineral was dated, the age obtained is considered to be the age of emplacement and not a reset age, be This unit consists of shattered and, in places, myloni cause mineral pairs from other plutons in the area have tized plutonic rock associated with the Newport fault been dated and given concordant numbers of about the zone. It is generally a green or gray rock that ranges same age. The pluton is considered Cretaceous. in grain size from medium grained to aphanitic. The mineralogy is generally the same regardless of the plu Phillips Lake Granodiorite and associated rocks tonic rock from which it was derived: quartz, albite, chlorite, carbonate minerals, and opaque minerals. The The rocks included in this unit on the geologic map physical character of the zone is described in the section form an igneous complex made up of four distinct but on structure. intimately mixed and closely related plutonic rock types. The most abundant and oldest is the Phillips Lake Tectonic breccia associated with the Newport fault zone Granodiorite, which is a medium- to coarse-grained mus This unit is a breccia derived probably from all the covite-biotite granodiorite. Dikes and small bodies of previously described Paleozoic units, and possibly from finer grained, more leucocratic muscovite-biotite quartz some others. It is a mixture of gouge and breccia monzonite intrude the Phillips Lake Granodiorite. Dikes ranging in size from powder to large boulders. Most and small bodies of alaskite, and pegmatite dikes cut of the larger blocks are themselves made up of rece both older rock types, although locally the finer grained mented breccia. Locally the unit includes house-size two-mica rock has been observed cutting alaskite and blocks of highly broken rock in which traces of bedding pegmatite. can still be recognized. Some of the tectonic breccia has The Phillips Lake Granodiorite and associated rocks been recemented and is fairly cohesive. The eastern con are exposed over about 60 square miles in the Newport tact is poorly defined and gradational over a wide inter Number 2 quadrangle, and over about the same area in val. The contact with the mylonite and cataclasite of the the Chewelah Mountain quadrangle to the west. In the fault zone on the west appears to be relatively sharp. western part of the Chewelah Mountain quadrangle, almost all the rocks that make up this igneous complex are Phillips Lake Granodiorite (F. K. Miller and L. D. Tiger Formation Clark, 1974). The proportion of fine-grained quartz mon Moderately well indurated conglomerate and arkosic zonite, alaskite, and pegmatite increases eastward, and, conglomerate form scattered outcrops in the eastern at the boundary of the Chewelah Mountain and New half of the quadrangle and appear to be restricted to port Number 2 quadrangles, these rock types make up elevations below 3,500 feet in the Pend Oreille River
4 valley. The unit is poorly stratified except where ar the point where it intersects the east edge of the New kosic beds are found. Conglomerate clasts consist of port Number 4 quadrangle due east of Newport. Alorig argillite, quartzite, siltite, and dolomite that are from part of this segment, a dip of 45 ° -50 ° NE. has been the Belt Supergroup and Paleozoic formations, and of measured. From the limited indications, the-fault ap granitic and volcanic rocks. The granitic clasts are con pears to be an east-dipping thrust along which local fined chiefly to the west side of the valley and volcanic steepening has occurred. The fault has not been mapped rocks to the east side, suggesting that the clasts were outside the Newport 30-minute quadrangle. derived from presently exposed local sources. Both That part of the Newport fault zone shown on the sorting and degree of roundness are generally very geologic map is only the zone of cataclastic rock and poor, although at a few places the clasts are fairly well mylonite derived from crystalline rocks on the west side rounded. of the fault. Intense brecciation in rocks on the east Plant fossils and abundant carbonaceous material side of the fault is apparent fq; as much as a mile. The have been found on the eastern edge of the quadrangle contact between the cataclastic rock and mylonite on in sec. 4, T. 33 N., R. 44 E., in the SE1/2 sec. 34, T. 35 N., the west and the brecciated rocks on the east is rela R. 43 E., and along the west edge of sec. 4, T. 32 N., tively shltl'p at the few localities where it has been seen. R. 43 E. None have been identified yet. Park and Can The western border of the zone is gradational into nor non (1943, p. 23) described similar rocks in the Metaline mal plutonic rock. Eastward from the zone, brecciation quadrangle to the north, which they named the Tiger in the upper plate rocks diminishes, but local breccia Formation and assigned to the Tertiary. The conglom zones along faults possibly associated with the Newport eratic unit in this quadrangle is a lithologic correlative fault zone are numerous. of the Tiger Formation in the MetaHne quadrangle, but The cataclastic rock or mylonite within the zone has the formation in either quadrangle may represent depo very little fabric. Locally, poorly developed, wide-spaced sition during more than one epoch of the Tertiary. fractures can be measured, and at some places the rock is slightly foliated. The rock has no well-developed QUATERNARY SYSTEM planar structure, however, even where the mylonite is Glacial, alluvial, and talus deposits, undifferentiated reduced to a pseudotachylyte. The lack of any foliation or pronounced metamorphism in the zone, in addition Quaternary surficial debris of various kinds covers to the ubiquitous brecciation and crushing associated about half the quadrangle. Glacial debris, including with the fault suggests that the zone is not as deep thick deposits of drift in the Tacoma Creek drainage, seated a structure as some of the better known mylon is the most common surficial deposit. Thin patches of ites in the world. It may be that the mylonite and some glacial debris, too small to show at the scale of the map, of the cataclastic rock formed relatively deep and later are common on some of the higher slopes. Next most movements along the zone brought them in contact with abundant is alluvium, which is extensive in the flat val the non-mylonitized brecciated rock. ley of the Pend Oreille River and covers the valley bot Some faults and folds exist in the igneous-metamor toms of its tributary streams. Least abundant is talus, phic complex on the west side of the Newport fault which occurs in small areas in some cirques. zone, but none have been traced for a significant dis Extent of the surficial deposits in the Pend Oreille tance. A few block faults were mapped on the east side River valley is probably not as great as shown on the of the zone, but the amount of movement on these faults map. The low hills in the valley represent an older to could not be determined because they cut Paleozoic rocks pography formed on the Tiger Formation and later whose stratigraphy is poorly known. buried under glacial debris; the hills are now being ex humed. Forest cover is so extensive and outcrops so poor in these hills, however, that the exact extent of Tiger Formation outcrop and float is difficult to deter mine. The amount of Tiger Formation shown in these hills should be considered a minimum, and the amount REFERENCES CITED of surficial debris a maximum. Becraft, G. E.; Weis, P. L., 1963, Geology and mineral STRUCTURE deposits of the Turtle Lake quadrangle, Washing ton: U.S. Geo!. Survey Bull. 1131, 73 p. The major structural feature in the Newport Number Becraft, G. E., 1966, Geologic map of the Wilmont Creek 2 quadrangle, the Newport fault zone, is a zone of cata quadrangle, Ferry and Stevens Counties, Washing clastic rock and mylonite that averages about 1,000 feet ton: U.S. Geo!. Survey Geo!. Quad. Map GQ-538, in width and extends the length of the quadrangle. The scale 1 :62,500. fault places essentially unmetamorphosed (except along Bowman, E. C., 1950, Stratigraphy and structure of the the north border of the quadrangle) Precambrian and Orient area, Washington: Harvard Univ. Ph.D. Paleozoic rocks on the east side against high-grade thesis, 149 p. metamorphic and plutonic igneous rocks on the west Campbell, A. B.; Raup, 0. B., 1964, Preliminary geologic side. At the north end of the quadrangle, the zone map of the Hunters quadrangle, Stevens and Ferry strikes about north and dips 30° east. Near the center Counties, Washington: U.S. Geo!. Survey Mineral of the area it has several gentle bends but maintains Inv. Field Studies Map MF-276, scale 1:48,000. the generally north-south strike. At the south end of Campbell, Ian,; Loofbourow, J. S., Jr., 1962, Geology of the quadrangle, the zone bends sharply to the east and the magnesite belt of Stevens County, Washington: its strike changes to N. 75° W., which is maintained to U.S. Geo!. Survey Bull. 1142-F, p. Fl-F53.
5 Clark, L. D.; Miller, F. K., 1968, Geology of the Chewelah Miller, F. K., 1974, Preliminary geologic map of the New Mountain quadrangle, Stevens County, Washington: port Number 1 quadrangle, Pend Oreille County, Washington Div. Mines and Geology Geo!. Map Washington, and Bonner County, Idaho: Washing GM-5, scale 1:62,500, 2 sheets accompanied by 6 ton Div. of Geology and Earth Resources Geo!. Map pages of text. GM-7, scalel:62,500, accompanied by 6pages of text. Dings, M .G.; Whitebread, D. H., 1965, Geology and ore Miller, F. K.; Clark, L. D., 1974, Geology of the Chewelah deposits of the Metaline zinc-lead district, Pend Loon Lake area, Stevens and Spokane Counties, Oreille County, Washington: U.S. Geo!. Survey Prof. Washington: U.S. Geol. Survey Prof. Paper 806, Paper 489, 109 p. 7 4 p. (In press) Harrison, J.E.; Jobin, D. A., 1963, Geology of the Clark Okulitch, V. J., 1951, A Lower Cambrian fossil locality Fork quadrangle, Idaho-Montana: U.S. Geo!. Survey near Addy, Washington: Jour. Paleontology, v. 25, Bull. 1141-K, p. Kl-K38. no. 3, p. 405-407. Harrison, J.E.; Jobin, D. A., 1965, Geologic map of the Park, C. F., Jr.; Cannon, R. S., Jr., 1943, Geology and ore Packsaddle Mountain quadrangle, Idaho: U.S. Geo!. deposits of the Metaline quadrangle, Washington: Survey Geo!. Quad. Map GQ-375, scale 1:62,500, ac U.S. Geo!. Survey Prof. Paper 202, 81 p. companied by 4 pages of text. Schroeder, M. C., 1952, Geology of the Bead Lake dis Harrison, J.E., 1969, Geologic map of part of the Mount trict, Pend Oreille County, Washington: Washington Pend Oreille quadrangle, Idaho-Montana: U.S. Geo!. Div. Mines and Geology Bull. 40, 57 p . . Survey open-file map, scale 1:48,000. Weis, P. L., 1968, Geologic map of the Greenacres quad Harrison, J.E.; Schmidt, P. W., 1971, Geologic map of rangle, Washington and Idaho: U.S. Geo!. Survey the Elmira quadrangle, Bonner County, Idaho: U.S. Geo!. Quad. Map GQ-734, scale 1:62,500, accompa Geo!. Survey Geo!. Quad. Map GQ-953, scale 1 :62,500. nied by 4 pages of text. Hobbs, S. W.; Griggs, A. B.; Wallace, R. E.; Campbell, Yates, R. G., 1964, Geologic map and sections of the Deep A. B., 1965, Geology of the Coeur d'Alene district, Creek area, Stevens and Pend Oreille Counties, Shoshone County, Idaho: U.S. Geol. Survey Prof. Washington: U.S. Geol. Survey Misc. Geo!. Inv. Map Paper 478, 139 p. I-412, scale 1:31,680. Huntting, M. T.; Bennett, W. A.G.; Livingston, V. E., Yates, R. G., 1971, Geologic map of the Northport quad Jr.; Moen, W. S., 1961, Geologic map of Washington: rangle, Washington: U.S. Geo!. Survey Misc. Geol. Washington Div. Mines and Geology, scale 1:500,000, Inv. Map I-603, scale 1:31,680. 2 sheets. Miller, F. K., 1969, Preliminary geologic map of the Loon Lake quadrangle, Stevens and Spokane Counties, Washington: Washington Div. Mines and Geology Geo!. Map GM-6, scale 1:62,500, accompanied by 7 pages of text.
6 WASHINGTON DEPARTMENT OF NATURAL RESOURCES PREPARED COOPERATIVELY BY THE GEOLOGIC MAP DIVISION OF GEOLOGY AND EART.H RESOURCES U.S. GEOLOGICAL SURVEY GM - 8 27' 30" R, d2 E, R. 43 [. 111·2;>'30" EXPL ANATION > Kg Cl'. <( z TKpa ~ Cl'. ,1 w Glacial, alluvia!, and talus deposits, f-- undifferentiated <( T. j?I N , :, T. 35 II. p Ckiefly WWQ'll./loli.dated gravel, ,iand, and clay I 0 T. J4 IL l. j.\ ., • ,t• UNCONFORMITY , F[[T
> Tiger Formation Qa"g •• Omg/omera.te, arko,ie, and iriltsWne. Contains ,' / TKpa abundant. carbonact:ous m(lterial and, locally, plrnitfossils
tf~i'j,~ , , \ UNCONFORMITY > u Cl'. 0 2/'JO" ~: l 27'30'' <( I N !f)f!lffJ"(///; f-- 0 ' Yl/1/i · It (l'. z ' J f.fbJ;) w w Cataclastic rock Tectonic breccia associated with the f--- I u ' Mylcmite aT1d cataclasUc rock within tM New Newport fault zone wrt J'u·ult z,m.-e. Ranoes/rom hif}My sheared Dolomite, quartzite, and ·phyllite brecda a71d and broken p/uWnic rock l-0 pseud;,W{:h·ylytc gouge. AU litko/ogieq randomly ,nixed. 'I C.mtai-,u; anomalous umounts of sulfide -m.in en1. ls. chufiy pyrite a-nd pyrrlwtite
\ p£sr Qag •' \ ,, n [J IJl TKpa \ :, u Galena Point Granodiorite Phillips Lake Granodiorite (Cretaceous) 0 Qag w 0 \~ Biolite grunodiorit.f!, ·medium/.- to conr86- and aso;ociat.ed rocks u N grai11e1l. 'J)Qrphyrilic Mu.,c{)1n'.te-bi{)tite quartz wwnzonite and ynnw <( 0 • TKpa di,nite ·intriided by alaskile, pegmatite, f-- IJl aplite, n11dfine-gra1.ned mu.scovite-biotite w w quartz mvnzonite. The c01nplex contain.s Cl'. nu·m.ero·us smal.l pods rJf highly recrysttd u " '11 . lhed metamorphic rock, especia/1-y near the ('Qnlnct.11 with olMr rocks " .. .-.... u 0 ,_, Hornblende-biotite quartz diorit.e N , . " Quortz diorite; i:0 1dai11 s over· /J5 pen·e,it m<.,Jfr 0 ····- T. 34 IL IJl \ ' ___;,. ._J T. 3.l rL mi·11eralN; slightly sheared and ullered. w r. M " ! ' FQund Qnly in (me wmuU area west of Rub1_1 r. HU. ,' ..... Mo1rnt1ci1i " :, _, n , ' I, Upper dolomite Phyllite and quartzite · ~g - ' Do/o11iite, med-iwm-gruy to pule-tun . .fine- to Phy/lite, medi,iw- to dn,rk-gray, highly cleaved; ' / ' 11 1·oa1'.~e-grf1ined, I.hick-bedded. Brecciated ·i11te·rbedded wit,h wh'ite tr, gray, ·med-i·1nn ~ ,,;,.: ,, ·- I ' , a-nd reM,111mted at many loca.Uties bedded fo mus8i·vdy bedded qiwrtzite tho.I. •18°22'30'' . r 48°22'30" is i11 part ca.rbon,tte bea.r-ing a,1d ·is high{y ·' - , !' Tt brect,ialed {1/ ·mnwy places. Brown, maroon, ) 11.11d gru·y dolomite foll'lu.i -in lesser 1wwa11t.~ TKpa "< •. I l J ,, 1 u 0 N Lower dolomite 0 ,. " ,/_ I " I w Qag Doiondle, whil-e to pule-tu,11.,fine- to cuar,;e _J r;rn-ined, /,hick-bedded; contain.~ some me <( diwm-gray dalomile. Th.is rmU is genernlly IL ' no/ u.s dark o.~ the wµper dolomite. Brec -~ ciated u'l!d recemented al many l.0<·0/it>'" s ~ ,1 Qag z I· ; ..... ,,! '\ ~ ! Addy Quartzite "Cl'. t • 00 Q,uirt.z ile. me dium.-_qr11.imed, f,ki11-bedded /.Q 2 ,, " "'"ts~foel·y bedded. Abvul fiO - /(}(! feet of p11r <( ~ p/e qmir!zi/e ,.,1 ba8c. Much of ,,uartzile -i,; u h1·erriuted, l!'nd /Jeddimg 'is not t'U8il11 rec(}(J 11 nized r \ / UNCONF'ORMIT\' ( r (. ,l -· ' J 3. ... 1:,· "I . , •' ,,1i··- · "' Striped Peak Formation / ).....,.1,,.... "· ,· • , ; Q1wrtzile. 8ilt,ite, (lmd. 1irai/.l-ile. Selvist amd ,... hr; ·rnfe/.~ iii ma3t 1ilaces i,1 the q11(1dra.ngle dm· lo contud ·metu11wrph·ilwi ..,, ~,, 1, B ll. 1 . 3J "· • / 1, 32 N. T. 32 IL ? } \ \ ,, \ B f ,/,,. \., \· \ \ B I Q~ Wall ace Formation ,_ ) J l Tt.',,.. __ , ' ..,.. p£wu. uppe·r purl; u.rgilNtc, du:rk-gray, latn·i Tt mited; und /011 W grn.y d,.,/omite.- Rocks are f I/ 17'~0 " \ i /'30" re,· r .,la/ Ii ze d to a ndalii. ~ite-cord i e rit~ schist ' I rrnd medi-u.m.- l.o cou.r ,se-grrid ned warble in ' the 1wrlhenwwst 'J)(trt of the quudrn11glt' ·, pCwl, h1wer ·pa.rl; cu:rl.,,.mate-bew,·i.ng quorlzite ';...,' 1n1,d ~ilt,il.e wit.Ii. {rregn/.a,rly -i11/.e·rbedded, \ .I d(lrk·-yra'!1 nrqill-ite. Jt,!etu.mQrphosed (o c11fr-si/ica/e rock and q1rn.rtz-pfogioc/a.~e ' (l ' trem0Ute .~rhist at. most pl/1,ces ' ) I )i-1 z <( J Cl'. .J [J 4BOOOO St. Regis Formation Ff.El ' Argi/Ute, .~lUUe, (111d qu(irtzi:te; lavender amd - <( / 11111-Tvun: light grne-n and carbonate beari'l!{J "u ut top. Phyl/it.ic and bleached ·in 7w.r/ of w the 11uudra11gle Cl'. IL
48']5' Revett Formation 11 7°30' Qu1rrlzite. white,Jine-gmined. well-bedded. SiltitW, e~pec/111/.1111,za.r rniddU! Base from U.S. Geolog,cal Survey SCALE 1:62 500 Geology by F. K. Miller, 1969-70: assisted by J. S. Tinker, 1969, adva 11 ce sheets. sca le 1:24,000: 0 2 3 4 5 MILES Winchester Peak. Tacoma Peak. and P. N Castle, 1970 Cusick, Jared, 1968 10.000-foot grid based on Washington .5 0 2 3 4 5 6 7 KI LOMETERS coordinate system , north zone.and Idaho Burke Formation coordinate system, west zone. CONTOUR INTERVAL 40 FEET Siitite, medimn- and right-gray, well-bedded. DASHED LINES REPRESENT lO·FOOT CO NT OURS Most is m efnm.orphosed f.o fi11 e-gra-ined. DATUM IS MEAN SEA LEVEL schist or Jwr,ifel.'<
.g,V '".,:t Metamorphic rocks .- ,.' Sc.hist. (JU{)1·tz1 '. te, and a1nphibolit.e. Probab/.y IDAHO al/. derived.from. lfu Prkhard FormatUm. of ••••0 .. MAll' M\.• ,a the Bel/. S11peraronp. !rijected by, omd com. o,eusrnoN. '°'" posed. oj as ,nuch us 20 percent of, Phillips Lake Gramod.ioril.e om.d ,,,;1qociated rocks. QUADRArtlGLE LOCATION All cont«ct.~ wi.th phlton·ic rocks are grada tUmn/ A A' 5000' 5000' ,, 4000' _._ __.._ ...... _._. h.? ... 4000' Tc -+- - j---_.,;;Og•~·~-T~KcpCa'....~ 3000' Contact, approximately located Thrust fault, approximately Inclined Vertical Inclined, 3000' - Qag loeated strike and dip variable 2000' 2000' - ~--····?··· Dotted w h~re ccmcealed; qr,cried Strike and dip of foliation 1000'- 1000' where ,wcerlnin. Swwteeth on Fault, approximately located 1,p~r plate SEA LEVEL - SEA LEVEL Dotted where concealed; q·ueried. " 1000' -'------~,,;,_,::,;c::OC":__c---'=:::__ _J______._1000 ' where u1u:erta.i-n. U, uptkr()W/!. -+- • .p'' Inclined- Horizontal Mineral lineations Breccia al)d boundarie~ !iide: D, downthrown $ide Inclined Vertical Horizontal Overturnetl minor fold axes of breccla are highly Bearing and plunge of lineation diagrammatic Strike and dip of beds
~ Strike of vertical beds with parallel cleavage
.,. I IS' 11 6· L Togo Mountain quadrangle.- R. C. Pearson 2. Orient area.-E. C. Bowman (1950) 1 2 4 3. Northport area.-R. G. Yates (1971) 4. Deep Creek area.-R. G. Yates (1964) 5. Kettle Falls area (west of river}.-C. D. Campbell ·" 6. Kettle Falls area (east of river).-J. W. Mills 5 -Ji 7 7. Colville area.-J. E. Sehuster 8. Twin Lakes quadrangle.-G. E. Becraft EXPLANATION Quartz <:..1" 6 9. Inchelium quadrangle.-A. B. Campbell 0 10. Bead Lake area.-M. C. Schroeder (1952) Galena Point so l-~---~---~-----"'50 11. Wilmont Creek quadrangle.-G. E. Becraft (1966) 8 9 21 18 Granodiorite 12. Hunters quadrangle.-A. B. Campbell and 0. B. Raup (1964) 13. Turtle Lake quadr.mgle.-G. E. Becraft and P. L. Weis (196.1) Phillips Lake Granodiorite 17 14. Mt. Spokane quadrangle.-A. E. Weissenborn and associated rocks
Plagioclase 10 35 65 Potash feldspar MODAL DIAGRAM SHOWING VAR IATION IN COMPOSITION OF THE IND EX MAP SHOWING LOCATION OF THE NEWPORT NUMBER GALENA POINT GRANODIOR ITE AND THE PHILLIPS LAKE GRANO 2 QUADRANGLE AND STATUS OF GEOLOGIC MAPPING DIORITE ANO ASSOCIATED ROCKS . CIRCLED PO INT IS THE 0 :62 500 SCALE OR LARGER\ IN SURROUNDING AREAS . AVERAGE FOR EACH PL UTON . SOME MODES ARE FOR SPECI DATES INDICATE PUBLISHED REPORTS (SEE REFERENCE MENS COLLECTED OUTSIDE THE QUADRANGLE LIST IN PAMPHLET) PRELIMINARY GEOLOGIC MAP OF THE NEWPORT NUMBER 2 QUADRANGLE PEND OREILLE AND STEVENS COUNTIES, WASHINGTON By Fred K. Miller U.S. Geological Sur~ey
1974 For sale by Department of Natural Resources. Olympia, Washington Price $1.00