STATE OF OREGON
DEPARTMENT OF GEOLOGY AND MINERAL INDUSTRIES 702 Woodlark Building
Portland, Oregon
G M I SHORT PAPKII
JIO. lO
An Inve•t1gat1on or the
'l'YRRi:LL :!ANGAI�&:SE DEPOSI'l'
a.nd
Othor Similar Propertie• in the
LAKE CREIK DISTRICT, OR�GON
by
WALLAC£ D. LOWRY
Junior Geolog1ot1 Depar�ment ot Geology and Mineral Indu1trle1
. •.
STATI: GOVI:IIIIININO 80AIIIIID
W. H. WTIIIIIAYI:IIIII. CHAIIIIMAN • AL.I:RT •UIIIIICH 1:.• • MACNAUGHTON
IEARL K. NIXON DIIIIIII:CTOR
PRICE 15 CI:Nn FCRE�ORD
In the Lake Creek district in Jackson County, Oregon, east of �edforci, there arc several known occurrences of manganese-�earing volcanic turr. The most important of these 1s called the Tyrrell Uine, loc�ted on Lost Creek. In Norld nar I this property produced several carloads or metal lurgic al grade, manganese oxide c oncentrates. Out of the eighty odd man ganese prospects in the State, the Tyrrell is probably the 1nost attractive as regards possible commercial production or manganese.
Some recent exploration at the property, resulting in the discovery of some new ora, ind i cated tha� the Tyrrell Mine might po ssibly become nctlvo &��ln. Therefore, a careful Job of Geologic �appinc and investiga tlon �y the aepartment seemed warranted. The investigation and this re port, covering the work, were done by lal lace D. L�•ry, Junior Geologist of the Department. The author describes other �anGane�e pro$pocts in the ciistrict in addition to the T�rroll, und a lso includes a discussion of the orlcin or the ores.
Earl K. Nixon, Direc tor Janu�ry 10, 1943 AN INVESTIGATION OF THE TYRRELL MANGANESE DEPOSIT
AND OTHER SIWILAR PROPERTIES IN THE LAKE CRE£K DlSTRlCT, OREGON
by
lallaoe D. Lowry Junior Gtologiet, Oregon State Department of Geology and Mineral Induatriee
Table of Content•
Poa-ewoa-cl.
Abetraot. 1
Introduot1oD • l
.looeaeibility and location • 1 IUlci work • l .loknowledge•ent• 2 General feature• 2
The Tyrrell Wine. 2 Bietory and devtlopaent. 2 Literature • 2 et P rology. ' Struot�&ree • a. As•· a. Mineralogy • 4 Geneeia. • ••• 6
or • Tl•e •ineralization 7 Extent ot •ineralization • ...... 7 , .. ..,. . . 8
Other Propertlee. . . '
Newetro• • . . ' Coon Creek . . ' Bulb • 10 Pox. 10
B1bl1oaraphy. . . . 10
Illuetratione
Plate l. Geologic 11ap of Butte Creek dietriot and index map. .opposite page 1 " 2. Tyrrell Manganeee JUne , plan and longitudinal eecti on • end of pap or " " " " 3· ( a ) Cross-section A•A (b) Crose-section B•B . " " " " 4. ( a ) Cro ll•ltction c-c (b) Crou - uot lon D•D • II II fl 5· (a) Crole-uotion E-E ( b ) Croaa-aeoti on ,_, II II 6. ( a ) Croee-eeotlon G•G ( b ) Rakowoky drill•eeotion. fl " II
� Pi sure 1. Rho11boid tor111 in manganite...... 5 II �. a. U&nganite and pyrolusite. . . • . . • . . • . • 5
b. Pyrolullte etructure. . • 5 II 3· Type• of cavity filling• • • . 5 Plat� I
·u
T36S
T 37S
GEOLOGIC MAP Lake Creek District in Jackson Co.. Oregon_ E:xplgnation [Q;jJ Alluvium Vn�onlormify � 'Dark iray h\ore por�yrihc.bosolh § �glomerate (bcualti') Contour inf-ervol lOO f••• ABSTaACT fhe Lake Creek ;ninin13 area, nt>out 15 miles enst of Medford in J o.ckaon .;ounty, south• . nest Gregon, contains a number of de po sita of manganese, one of which, the Tyrrell, was rnineJ and milled during World War I. The area is underlain by a series of Tertiary volcanic rocks consisting of basaltic lavu flows, agglomera tes , and tutfs1 which dip gently to the east and are faulted by north suuth t'aults. �anganese occ urs mainly as fillings in openings in agglomerate, just ab ove the contact uith nn underly ing fine tuff. The manganese o xides occur as p silomelane, pyrolu�ite, mo.n �afiite , and wad. The manganese was ori ginally derived by solution from the mo.nganese ue�ring mineral s of the basal ts which once overlay the agglomerate but have now been lcrgely eroded a�ay. Deposition of the manganese from the circulating meteoric w�ters probably was caused by oxida ti on and was accompanied by the !'ormation of collo id s. Place or deposition was f.O verned by the pos ition of the water table and the porosity of the roo ks , which in turn de pended upon the size or the a eglomerate fragments, the a mo unt of adm ixed clay minerals, and the degree of shearing and Jo inting. The highest degree of mineralization apparently too� place at the Tyrrell in the agglomerate Just above � relatively im�ervious tuff. Gther manganese properties are only pros pects. The Newstrom has 4 geologic setting simil�r to tho Tyrrel l and, �ext to the Tyrrell, shows the best m1neral1zet1on. INTRODUCTION A.ccessioil1ty rn1s aistrict is ·15 miles. east of Medford. From Medford it is reached by way of the �r�ter Lake Hichway ( Oregon 62) to £agle Point (ll mile s), thence east by improved road to Lake Creek (11 ruile�). The drstrict is about 5 miles south of Lake Croak. 'Tho Tyrrell �inc cun be reached from Lake Creek by dirt road the last mile of which is poor, especial ly in the rainj season. Location or pr�perties The properties described in this report are shown on the geologic cap, pla te 1. They t.lre: Tyrrell J.iine W� sec, 101 T. 37 s., R. 2 .:::., t:l. ca. 2300•. NewstroJI ?rosJ>ect E� sec. 341 T. 36 s., R. 2 E., El. ca. 2500•. Coon Croek ?respect SLz sec. 20, T. 37 s., R. 2 E., El. ca. )200•. aush Prospect NE co rner, swi sec. 91 T. 37 s., a. 2 E., �1. ca. 2350•. io'ox Prospect Nk or SE�, sec. 8, T. 37 s., a. 2 E., El. ca. 2600•. r'ield ·.. ork The investigation of these properties Jas made between July 28 and Au�ust 14, 1942 und included the examination or the geological and mineralogical features or all the �rop ertias, the sampling of the two most promising ones - the Tyrrell Mine and Newstrom Pro spect, cna a pl�ne table survey of the Tyrrell Uine. The unde rground workings of the Tyrrell deposit were mapped by means of Brunton compass and tape. -1- Acknowledgments The author desires to express appreciation to �r. George Holmes, engineer, and Mr. Demartini for their helpful assistance and to Mr. George E. �urphy, Jr. who assisted in the field work and the ?lane table survey of the Tyrrell deposit. Mr. John �liot 4llen offered many helpful suggestions in preparation of the manuscript. General features The Lake Creek district, in which these pro?erties are located, is druined by the south fork of Little ilutte Creek and its tributaries. Little Butte Creek empties into the Rogue aiver west of Eagle Point. The relief of the district 1s marked, While the general elevation of the valley areas 1 s 2000 foat, "tho r id�e west of the Tyrrell Mine is over 2800 feet; the ridg·a to the east and southeast, over 4000 feet, Theso are north westerly•south.,�sterly trendin� ridges, with stoep wast slopes and lees steep east slopes, separated by creak valleys, �:any of the oreeke are subsequent, following contacts betTeen lava tlows. Some follow the trena of f�ult displuoements, The climate is mild and is characterized by a dry summer and a somewhat rainy winter season. Scrub oak, madrona, manzanita, chappar&l and poison oak are common on the lower slopes. Douglas fir is common at elevations ao?ve JOOO feat. TH� TY�RELL �IME iiistory ana iJevolopmen<: Aceording to Pardee (21:218) who visited tho property in 1918: «Development of the Tyrrell deposit by open cut and drilling was begun in the fall of 1917 by the Uangoneee �etals Co., which later built a coneen• trating mill capable of treating about 20 tons of crude ore in 24 hour�. Prior to July, 1918, �he mill operated intor�1ttently and produced about 200 tons of concentrates. Late in the su�mor of 1918 Vietor �ako�sky of Joplin, Mo., pros�ected by drilling a part of �he l�nd controlled by the Manganece Metals Co., on which he had obtained �n opti�n." The old open c�t is about 100 feet long Bnd from 20 to JO feet deep. The �nin tunnel at the northern end, which is now caved �ver �uc� o� its distance, trended about N. 65° E. for ubout 110 feet. About 25 feet froo the feoe, � drift along a fault plane runs 20 feet s. 20° �. to a caved winze, then turns s. 80° E. for about JO feet. At the south end of the open cut, 125 feet south of the main tunnel, another crosscut parallels the north side Jf a diabase dike in a s. 60° E. direction for about 75 feet. In May, 19421 George L. Demartini, l2J4 rolsom Street, San Francisco, bought the Tyrrell propurty from a. �. aush, Since then eleven bulldozer cuts, 12 feet vide and up to 10 feet deep, sovoral prospect pits, and two hand-due. trenches have been excavated. All this now development work lies north of the old mill, open cuts, and tunnels, extending for a distance of aoout 1800 feet, the bulldozer cuts being from 50 to 200 feet apart along the northern 1000 feet of that distance, and trending east-westerly across the outcrop of tho mineralized zone. Most or the old �orkings have been reopMnod, At the present time there is no equip ment on the property. The other properties have net �roduced any manganese ore. Exploration is meager ant consists of prospect pits, short open cuts. and one shaft 24 feet deep. Literature The Tyrrell property was discussed at some longth by Pardee (21:2lb-220) who visited it in 1918. Engineers working for Hodge (;7:10) examined and �apped the deposit in 1937. It was viaitea o.nd sampled in 1938 by LibbeJ (42:16) and by Wells (J9). A bibliography is given at the end of this paper. -2- �ccording to the geologic map of this district (Plate 1), reproduced in pnrt !rum '"' .lC.J.o.,:io :.nap ot the lledford quadro.ngle ('fells, J�), all or the district iii l..mcuid.tul�· •.uc.:.. rlo.in by volcanic rocka of Tertiary age. Theae overlie the Umpqua formatit.rl ol' :::ocut.L rhe Tyrrell Uine il situated well up on the west slope of a north-nauL� Lraudln� rlJ.;c ••·••·• of Lost Creek, a tributary of Coon Creek. The ridge is composed ot· vole;o.:,;c roci;s .L:\;. ·.iip several degrees to the east. At the Tyrrell Mine the chief rock•typcs L.re Jrc•.:u �u�: �reocia, basaltic agglomerate, capped by basalt flows. 1he bro•n tuff �recoia has been mapped by Wells (J�) as the buff turf �omuer ol' tl.e r•,rl.l!.try volcanic rockl. lt il described as a buff, fine-grained tuff wi tr. i t-:q:mants of fl' ,, t•ooks. It is believed to be equivalent to the agglomerato formation ol" tiou :Suttc , . ., 11 s '!U�·•I"tngle to the north (Wilkinson, 41). One thin section shows this brown tuff breooia to be 90% glas s (includln� �coriaj, �. �oldspar, and 5� magnetite together with other opaque constituents. The feldspar grains are as much as 1.5 mm. long and have su�hedral to anhedral outlines. Albite twinning with extinction angle values of 2d0-26° o.nd )2°·28°, and an index of refraction of 1.55 - 1.56, indioate labradorite. Uaenetite grains vary from subhedral to anhedral in form. The index of �o fraction of the glass matrix is about 1.535 which is a basic lava value • • nether thin section of the brown breeoia is 45. devitrified �rown glass, �0� cltnlcod �··lc �aterial with Minor calcite, 4. feldspar, and 1- magnetite. The foldspar grains are 2 - 2.) mm. long and have anhedra l outlines. They show albite twinning and give extinction angle values up to 23°, The feldspar has an index of refraction between 1.56 and 1.57 and probably is labrador! te. Subhedral to anhedral grains of magnet! te make up aoout 1;; oL' the section. The chalcedonic portion ia made up of irregularly outlined masees with both spherulitic and bladed �tructures; sometimes these are com �ined, with spherulitio eenters. The brown tuff breccia is overlain1 probably . uncontormaolJ, by a reddish-stained agglomerate composed of fraMments of basalt scoria and associated lithic material. Iron oxides give the rock its red color; the original oolor was a medium gt-ay. The Main manganese :ll1nora1- i�ation occurs in this agglome�ate, which is as much as 35 feet thick and ••hen favorably exposed by ero1ion forma rough columnar �:�asses. On the north end of the ridge, this agglomerate has ueen eroded avay, out it crops out 1outh of the old mill site. To the we1t, it has been faulted down, but cay extend under capping tlows for some distance to �he eaet. The thioknell may va.ry considerably, aa it ae.y have been laid down on an uneven erosion surface. Thin sections of minerali%ed portions of thia rock show it has a oellulnr or fi�cly vc� leu lar texture. The cell wall• are rough and irregular, with t�e total cell S?aec aa�!d� up 25. ot the rock volume. The cells may be filled with opaque minerals �hich �� :r ��•, various canganese oxides. The rock is nearly all glass with an index of refraction value b�tween 1.54 and 1.55• This 1ndioatoa n basaltic lava. Small laths and m1crol1�es of f�ldspar make up 2% of this glass/ matrix and have u t-ough al icn;cent ell" their long axes and a rough parallelism to the long dimension of th9 veoicles. The teldsp�r laths g1ve albite twinning ext1not1on anal• values of )2°·27° lndioat1ng labradorite, and establishing the sooria's bnsaltio character. 1�e manganese oxides partly or completely fill the cells and openings in somo of tl•• ••d·, itself as well as the openings between the individual lithic frag�;�ents. r'urthur -3· d1v�ussion of this feature is given in the section dealins with min eralizat i on . 'the agglomerate is overlain by basaltic flows, which form the to •• and ta� .,,·:�tl.J porphyritic basalt, broken by numerous fractures, Thin sections of the basalt show a trachytic texture, The pheno�r��•J make up but 5� of the rock. Labradorite grains, having subhedral to knheclral outlines, anhedral grains of magnetite, and anhedral grains of auGite ��u ortho pyroxene are present as phenocrysts. The eroundmass is made up of twinned laths of feldspar and grains of a clinopyroxene, constituting 50� of the roc k, situated in a micro - to cryptocrystalline matrix which makes up the rem�ining 45�· South of the mine proper the ridge rises to the east and southeast and is co m�osed of cark �;1·ay, more po1'phyrit1c basalts, All the above-!nentioned basalts and an associated white tuff belong to the same series, Struc;; ures rhe rocks in the area strike a bout N. 45° w., and dip at low angles (10°!) to the east, and are at times broken by faults . The location of one normal fault is shown in the north east qu�rtcr of the geologic map ( plate 1), The displ�cement is vertical; the �est olcck moved down in relation to the block which now forms the ridge top. Slickensides and numer ous fractures and slips shown in the drifts from the Tyrrell mine open-cut indicate that s this is a zone of faulting rather than a ingle fault, The ma.in fault trends 11. 20° W. und dips 8o• t o the west but in places numerou s intersecti ng faults have sheared the basalt rock, convertine it in plac es to a serpentinous-appearing material or "alickentite". There are BOU�e zones several inches wide as well as a breccia zone eigh t feet wide, A bench which lies west of this fault, halfway �P the west slope of the main ridge, and a s pring on ·�he li:1e of faulting are other manifestations of this fau lting . Brown tuff breccia capped by d&.rk •'!ray1 fine�grained, slightly porphyritio ba.aalt for ma the bench block west o 1' the fault. and immediately east of Loat Creek, T his 11 a repetition of the sequence to the east of the rault (along the rldee top) which has been produced by the faulting ac tion. Lost Creek valley with ita nearly north-south trend may be in part of raul� oriei n. �••is trend is not markedly differe nt from the strike trends of th e rocks, ho•ever, and Lost Crook valley may be mainly erosional in origin . The brown tuff breccia forming i ts east '!la.ll is not a resistant rock. It was not found on the ridge west of J.ost Creek which is composed of basalt flows, often amygdaloidal. Contorted pl�ty structures occur in the oas al t. on this ridge near the Fox prospect . If this pl�tina se indicates flow-planes in tho rock• the close "folding'' may be primary; if the platiness represents jointing, actual foldlne of the lava has tak�n p lac e, At the Fox prospect the rocks are faulted along northwest trending lines, The major axes of these local structural domes and basins have a northerly trend , Judginc from their different lithology, attitude, structure and l ocation, these b�sultic rooks are older than the flows east of the Tyrrell Mine. They are not the equiv alent of the latter, faulted down to the west; as might be the case if Lost Creek were .;ev.eloped along a ma J or fault or fault zone, These basalts are si111ilar in c crta1n .:a.y;; to other basalts of Eocene age 1n Oregon . The basalt f lows east of the Tyrrell �ine may be equivalent to Columbia River oasalo of � loceno age ( Nilkinson , 41), The underlying tuff breccias are thought to be late �occno or Oligocene . They contain fossil leaves, and Dr, gthel I. Sanborn ( perso�a l co•��nicat10l!) s�&tcs that the flora is quite c ertain ly not a subtropical or tropical ono ana that it is pro�ably younger than lower Oligocene, �;tlogy Manganese minerals of the Tyrrtll U1ne include psilomelane (49-62� Mn), pyrolusite -4 - (62.J� Mn), aanganite, wad, and possibly manganosiderite and aanganooalcite (?). Aooeaaory mlnerals include oalcit• and aragonite, barite, zeolites, clay mineral•, various iron oxides, and probably gypaua (alabaster variety). The manganese oxides fill openings both within and between fragaents or the aggloaerate, the latter �ype being the more iaportant, Rhoaboid and ooluanar foras or aanganite are pres ent and at tiaes may be altered to divergent radiating structures oharaoterietic or pyrolusite (see figures below), However psiloaelane and pyrolusite are aore prevalent than aanganite. ..... - !A. Pyrolueite a. b. Figure 2. a. Uanganite (?) and pyrolueite (formed from manganite) b, Pyrolueite etruoture Psilomelane most simply written ae {Mn02'B20) appears against the cavity walla. Next oonoentrioally is an inner layer or layere, commonly of _pyrolusite (Mno2) with divergent radiating structure, Often there reaains a central cavity due to incomplete filling. some times pyrolusite alone forms the fillings, Type• or fillings are shown by the figures below, - - -- ��-�'-«:Psiloaelane �- �...:..- =::=--. --� � !IJR . Pyrolulite Figure J, Types of cawity fillings Botryoidal structures of manganese oxides� largely psiloaelane, are common. These have an outer hard layer and an inner soft mass, lad, an indefinite hydrous manganese oxide (perhaps Kn02•nKnO•H20, probably grading into ps1loaelane, Mn02'H20), orten accom panies the other manganese oxides, eepecially pyrolusite and psilomelane, Barite crystals occur in places along with the manganese oxides. This is a oomaon accessory mine�al in many manganese deposita, Calcite and aragonite are also present. -5- Other carbonates containing iron and manganese, possibly manganocalcite1 cangunosiderite and siderite, occur with the calcite. Genesis The poros ity of the agglo=erats fragments themselves must original ly have bean about 25:�. The per�e�b111ty of the rook was further enhanced by its fragme ntal or breooia-like nature. Cracks und other fractures facilitated the circulation of matao·ric waters through the rock mass, allowing it to be�ome thoroughly saturated. The porosity of the agglomerate was decreased by the filling of the various openings by manganese oxides, and carbona tes, at points where marked enrichment occurs as in the lower part of the agglomerate and in a portion of the fractured zona . The lower seven feet of the agglomerate at Station ll•O(see accompanying map and section ) shova manganese minerals forming a consi derable portion of the mass. A six foot sample cut from this location assayed 7·35% manganese. The concentration decre�ses upward and powdery manganese oxides (wud) appear. Atthe lower contact of the agglomerate with brown tuff llreooia at this station (11•0) there is � sharp decrease in the manganese mineralization. While the original porosity of this underlyin g tuff may have been high, its permeallility was re• ducad by the development of clay minerals whioh1 com bined with the s maller sizes of the con stituent fragments and less chance to maintain permanent cracks o� openings, very likely slowed or stagn�ted the circulation of meteoric waters. Due to the slowing down or c1rcula• tion near the contact, the agg lomerate must have been mainly in the zone of oxidation, and the tuff in the zone of saturation. The manganese may have bean taken into solution by meteoric waters along with iron, calcium, magnesium, and other metals, and was precipitated as an oxide of manganese when free oxygen was present in the water. The oxygen content in the zone of saturation is comparatively low1 which may account for the greatly reduced min• cral 1zat1on in the tuff breccia. Mnngan1te1 pyrolusite, psilomelnne and wad are always secondary, formed under the in• fluence of weathe ring avon what'e they descend to eons1dero.ble depths below the water table (L1nderen, JJ:J6J). The formation of the variou& manganese oxides in the openings of the agglomerate 1e believed to have been substantially as follows. �anganese occurs as a primary constituent of minerals in the basaltic lava and agglomerate, making up a minor percentage of these rocks. A. primary manganif arcus oxide (manganiferous magnetite ) .o� ours in soma portions of the dark gray, fine-grained slightly porphyritic basalt. It has the form of small octa hedral grains and may be a syngenetic replacement. Most of the manganese, however, probably originally oame from the weathering of the pyroxene minerals occurring as phenocrysts and in the groundmass of the once overlying basalts and the matrix of the agglomerate. When such pyroxene minerals are acted upon by meteoric waters , one of the results may be as follows: (Carbonated waters) Pyr oxene ( ) + + colloidal si lica (Wg1Ca1Fe1Mn)SiOJ Mn(Hco3)2 � �·· -: 2Hi:t t + 0 2 + H20 �,. loln0 2 + H2o Since the Uno2 is much less soluble than the bicarbonate , the ionization equilibrium for the bicarbonate will be displa c ed towards the right, and the maneanese -6- removed from the solution should be precipitated in the form of the relatively insoluble hydrous oxide. Another type of deposition that may rosult is deposition as a eol, •.which is discussed by Polynov (37:145) who believes that the manganese may go into solution either as a sol or as a manganese bicarbonate, in which latter case, the presence of free carbon dioxide is so u In m nga e sit s ch a ep s he pre necessary to maintain it in l tion. a n se depo s u s de - ea wads, t dominance of manganese over iron is explained by the fact that iron is first precipitated as hydrated ferric oxide and the maneanese is retained loneer in solution as carbonate. Lindgren ()3:)63) aerees that usually the manganese is transporte d as a oicarbonate, �!though if ferrous sulphate is present it may dissolve the manganese from the carbonate w,ith precipitation of calciul:l car�onate; the manganese then being precipitated with excess oxygen. AccordinG to Thiel (24:457) the manganese carbonates are more stable than the ferrous caruonate. Lin d�ren feels th6t colloid solutions must be formed when the b icarbonate solution 1s ox1diz�d, as is indicated by the structures in the various manganose minerals. �s �ay oe seen from tho a�ove conclusions, it is q uite possibl� that the deposition of tho rnan�anose in tho �sglomcrate at the Tyrrell prop erty was n much moro complicated process than is indiccte d by the chemical equilibrium dia0rams given above. The oxides were probably ori3inaily deposited as colloids (psilomelane) which in some i nstances crystal lized to form columnar manganit e or divergent radiating pyrolusite cry stals . Time of mineralization The deposition of m<>nga.nese 1n the agglomerate mass may have ocourred at any time sub• sequent to the extrusion of the basaltic lavast although possibly some of the �anganese was of syngenetic origin. The mineralization in the fault zone took place arter the lavas were faulted. This faultlnz has not been dated nor the age of the basalts ascertained al though a �1 oceno afle has been 1�ferred for tne lntte�. The present cycle of weathering could not account for t�.ll tl-.e 1nineralization1 as the amount of mangane se present in the agglomerate r�prcsents the leaching from a considerable mass of manannirorous rock. The mineralization is Lhus th�ueht �o have beBun �hen thor� �as still a thi ck capping of basalts which could supply maneanese in quant!ty t� the circ�letine waters. If, as indic�ted �t 5tat�o� ll-0, •he m�n£anese concentration in the �gglo�e rate does llrcuk off sha.r;>ly at the contact w!th 'the ur.1er:i.yinc tuff breccia, then some explanation is needed to account for this lowor limit of miner�llzation. Differentia l permeability rather than chemical conditions is thought to be largely responsible for this . If thi s be true, mineralization began as soon as erosion permitted circulation of manganiferous waters in the agglomerate mass. The contact of the agglomerate and tu�f breccia is now about 500 feet above tho nearest creek. The deposition which probablJ began soon aft�r the faulting h�d taken !>lace and erosion had set in is apparently uo longer takine place. Extent of mineralization 7he manganese enrichment in the agglomerate at Station 11-0 is fairly uniform in the lower several feet and is poor above a point ten feet from the oontaot with the underlying tuff. Elsewhere in this ap.�lomerate mass the vertical extent of the manga�cse minerali7.at1on is incompletely exposed. Manganese Roncentration appears only in the_ lower �evoral feet and as the contact with the underlying tuff ��eccia shows in only a few places, t he character of the mineralization downward is also inc�mpletely known. Uineralizatio� is probably not n m to or ct r nd o n u ifor , since it is related has been facilitated _by f aul t, fra u e, a j i t struc tures in the agglomerate. The lateral extent of the manganese deposition in the agglomerate mass is limited on the west by th� ridge slope. On the no rth the agglomerate has also been eroded away. It is found south of the old mill site but the prospect cuts thoro show o nly slight manganese -7- �c;1: ntration. The eastern limits are imperfectly known; easterly-dipping bas�lt flows GOlOn cap the neglomerate form the back slope or this ridge. Manganese enrichment or vari o�u rades can be traced along the ridge front for a distance of 1300 feet south of Station 1 ·•v ��· the nnture of its origin, the agglomerate may be of irreRular extent and varinble :i i. kt�oos, and it" it -..as laid down upon an erosional surface, as believed, the irregularity .•.,,;,!� oe even 1;roc..ter. Also, the 111ere occurrence or the agelornerate is no criterion for r..:.,u:ll�ng the presence of rnan�anese mineralization. � fair estimate of both lateral and vertical extent of the manaane9e deposition may :n• �a ronde at the present stage of development. ��ngnnese concentration in the fault zone appears in the drift and cross-out at tho nor1.l• ond of the southernmost open cut. This mineralization occurs in e. fault z.one oreccia in u�rk cray, fine-graine1 basalt. The mansanoee oxides and aooeasory barite occur within thG �ost highly b�aotlatid portion of the zone and for� two vertical s�ncs of ore each b to 12 incheG wide. No ore or warked enrichment ap?ears in the continuation or drifts oast or this brecciated zono. A �&ved w1cze (see plate 2) is situated in the displacement z.one. The depth of the Ql��ralizat1on is unk�own . No attempt to follow it to de?th along the strike of the zone 111\tl ever made, The bo-:.tom of the open out is covered with caved material and could not be eXaGlned. The souther� end of the open cut and tho WRll of a drift into the east face there is boundHci by a northwest-striking diabase dike, South of this point the dark gray oasalt containo in placos considerable amounts of manganese in the form of manganiferous aaRnetito. In places, coatings of manganese oxides, often dendritic in outline, appear on �he joint surfaces oi the dark gray basalt. �ost of the ore that was mined during World �ar I came from this mineralized displace mo�t zone and from tho adJacent open cut to the south which lies u pon its probable continu ation • .\s�ays of chtmr.el sar.�)lles show that t.he r.�unge.neso content varies from u fraction of c. ptr�Gnt to 7·'35-f.· �ampi.e:J cut durir:g the e:r.·•Uilnatiora ana assayed at the State Asoay Labort>. \Pry, Grant9 Pass, are as follows (see plate 1 for location�): Sam ple no. I - 6• vertical channel cut at Station 11-0, above contact with tuff breccia. 7· 35% Un So.:::ple no, II - .3' vertical channel out at Station 9-0, ore is improving at bottom. 1.70% !ln Sample no. Ill • 4• cut from back and north wall 6• inside drift near Station 7-0, from mineralized fault zone. J.40% Mn r'o 10 :;umplos taken oy r. 11. Libbey in 1937 were assayed at the State Assay Lo.ooratory, Grants :n�' ·•.nd results are s�town below. Checks of separates sent by B. F. llebber to 1'1• .\. l.iarkert, Iror qlver, �ichigan, arl alno given (Holmes, �2); State .tsea,y loiarkert l.ln IJn Su:t;>le no. 1 2.47� 2o55� :ia S�J.::.,ie no. 1 we.s tak11n near Sample no. II (1942, Sta. 9-0), Sample no. 4, near Sample no. 1 (151.2, Sta. 11-0). The percentages shown on the 1eotion1 aade from the Rakowlky drilling prograa (see plate 6 • (b) ) are: Between A and D 2.1 � Un Between A, 81 C )ol)� Mn Between D and C 4.� � Un An average of J� manganese seems 1afe tor the lower several feet of the agglomerate where ·mineralized. Aa stated before, the extent of mineralization both lateral and vortioal is imperfectly known. OTHLR PROPERTIES Newstrom Pro1peot This property il located near the break in elope near the baae of the weat aide of a north·aouth trending ridge (aee platl 1) which lie1 two miles north of the Tyrrell property. The working• are near the oenter of the ea1t t of 1eo. )4, T. J6 s., R. 2 E. The geologic setting ia aimilar to that at the Tyrrell locality. The aeveral proapect outs are situated in a red, lo oriaoeoua, baa altio agglomerate at an elevation or about 2500 feet. This agg�omerate ia much thicker here than at the Tyrrell �ine; eome 200 feet is ex• posed. It forme �ude columna and rough blocka, at timel more than 20 feet high. As at the · Tyrrell Uine this agglomerate 1a underlain by a tuff breccia, sometimes colored green as well as buff or brown. Above the agglomerate occurs a aerie• of basaltic flows and some tuff which strikes N. 35° W. and dipa 5 to 10 degreea to the eaat. Manganese concentration occurs in the aeglomerate. The upper part of its thiokne a s, though showing some mineralization (powdery oxides, wad), appears to have no oommn rcial s1g· nifican oe. The deposition in thia upper part ia cocmonly related to fracture zones. The atrongeat enrichment ia expoaed in the loweat proapeot out where a thic kness of 8 to 10 teet of enriched material ia shown. Wanganese oxides and •�ch calcite a�• present. A 3� foot channel aaaple from the east face of this c�t �•turned 2.1� Mn. The depth of min• e�alization cannot be estimated fro• the available exposurea. Although the enrichme�t is less near the bottom of thia out, there ia no reaaon why it may not increase with depth. Thia cut may be aa muob aa 40 feet above the contact with the underlying tuff brooola. Debris covers the contact but the break in elope and ohange to a light brown soil indicate the apparent location or the contact. The agglomerate can be traced 600 feet north of this out, or to the point where the rid&e turns east , and it extends some 1000 feet to the aouth, but no outcrops of the miner• alizod horizon were seen. The rook of apparently higher horizons shows only alight enrich ment� Coon Creek Prospect This property is located on the northeaat alope or a northward-trending ridge at an elevation of J200 feet, in the SE! of aeo. 20, T. 37 s., R. 2 E. The country rock ia of basaltio character. Amygdule• are common in many of the tlowa. Manganese concentration occurs in a red, aooriaoeoua, basaltic agglomerate. This agglomerate ia more than 100 teet thick near thia locality and volcanic bomba and ropey lava etruotures are present, euggeating that this may be a former center of voloanism. The agglomerate ia underlain by platy baaalt. Although thia agglomerate ia •'milar to that at the Tyrrell Kine, the manganeae mineralization ahown ia auoh lower in grade and ia probably leas widespread than at the Tyrrell. The manganese oxide ia psiloaelane, exhibiting a botryoidal structure. A proepeot shaft ie 6 rt. by 4 ft. by 24 ft . deep, but at the time of examination (mid-summer} it was filled with water to within ten feet of the top. This shows that the ·�- wat'r level and the &one or saturation, above wbioh oxidation ot aangane ii and reaultant proe1p1tation of �anganese oxide largely take• plaoe, is close to the surf�oe even in the sumL"\or !: eason. 3ush and Pox Proape ota It ls no t certainly known whether or not the Bush prospec t was examined. One long abandoned prospect pit was found near the center or sec. ?, T. J7 s., R. 2 E., in the vic in• ity or the loo ation indicated for this prospect on the geologlo map of the Wedford quadrangle. The country rock at this prospect pit ls a dark gray, rlne•grained basalt; no mangane se con• oentration is pre e ent. Dense underbrush may possib ly have oonoealed other pita. The Pox pro apaot is located on the west aida or a saddle in a north•aouth-trendinc riuge composed of basalt flOWI in the S� ot Ito. 8, T. J7 S., R. 2 �. One pit 3 ft. by 5 tt . by 5 rt. deep shows no important mancan••• enrichment. Some ac oriaoe � u• ba1alt occurs near the bottom ot the p it. A aoorlaoeoua horiaon to the northwest down the slopa llkewlae •how• no important mlnerallaation. BIBLIOGRAPHY Hodge, t:. T., l?J7 • Prel ialnary Report on Some Northwelt U&ngan••• De po li t s : U. s. Co rp s or Engineers , Oftioe ot Divlalon Engi ne er, Portland, Oregon. Holmes, George L., 1?42 - Ty rrell Manganese Mine, Private Report. Libbey, et al ., 1?42 - Kanganese tn Orego nr Bull. no. 17, State or Oreeon Department of Geology and �lneral Industries. Lindgren, Waldemar, 1933 - Ore Depo sita: YoGraw Hill, New York. i'o.rdee, J. T., 1921 • U. S. Geological Survey, Bull. 725•C1 p. 218. ;olynov, a. !3., 1?37 - Cyole of iV eathering: Chapter III, The S1l1oon, i..lllml n.m1 �.:.li lron Cyo l e s. 'i'ranllatlon from the Rusalan by A. �u1r, !;.uNy �.nd CJ.1 Londor'l. rl. io!l, li. A., ·.:1 'ts, r'ranc is o., and othe rs, 193? • Pre l iminary Ge ologic Wap of the �edrord Quauranele, Creson : Map ser1os No. 21 State or Oregon Department or Geology and Ulncral lnduetries, Port land, Oregon. �1lk1nson, W. D., and others, 1?41 -Re c onnai ssanc e Oeolog1o Wap of Butte F�l la Quadrangle , 0togon: �ap Ser1 11s No. 4, State ot Oregon Department or Geology and Mineral lut.!,.striba, Portland , Oregon. -10- P\a.te. Z, I I Plan View of Tyr rell Manganes.e Mine ... Station 5·0 Statiof\ 6-0 (Rail fenu) Winze (c.OifCcl l a· Sample No.3 wide tnift&f'oli&e4 � brec.c.ia zone ----- 3.40 ToM" \) longitudinal Sect ion Betwe en Station 1- 0 & Station 7·· 0 Line of e xposu,.� - oliofie i I' lh• /ocofion ol �'�•• roc!< rype is opp r u i m o-1•/y l . Sec..I 0 J T. 3 S.7 ;R 2 E G LaKe Cr. D istric.t Jact w.}). \.O V�� ry A ugu& t \ 942. 1160' I I ll e D Pl a.te. 3 ' aoo ..... Little ,...... ,. Top aoil 1 •••i .... �I �'- a �------� ,. - - ""\-- -' - I ------7,�,�-'-t----����+�.. · .. -���-----1�------,,••. ""' •erret'l 'Iteel . bn wn.• I,.Y I t.. H le1ers ftith tliaht 4ip to cari Cross Sec.tioft A.·A· Tyrrell M antanes� Mine Scale : H •r. r· • so· 'len. 1 • � ao· w.J>. L.owry (0.} --- c .... ., Uoo' - - Srew•ialo frey -twff 1,...... - witll whit� uoa _.--,:;-""'- �" ,,. • .,. t .. H ..,.ecc io, .toined 1>,..,..,. T• ceil po (MontoneM st•i• and !>MOll poc.kct fillint- ) ueo· Crus Sec:tiofl 'B·'B' Ty rrell Mon�tanue Mine Scola: Hor. I" a se· Vert. I"• zo· W.». i..•'t'I•Y A"t••• 1141 (b) Plat� 4 --- E uao· --- bro'l!ln octlom�rote ' / :uoo / / / Litllt llro•11 / �tcaincd tuff �nc.ci11 , , t Millere�liJotioft poor) Croas Se,tion c-c· Tyrrell McaAtenne Millo s�\e : "•· .� •••. v.. t. ,•• ao· W. t. L..,ry (0.) Cross Scdion ])·b' Ty rrell Monconuc Mine $�1o: H«. I" • 5o' v.�t. ,. • ao' (b) Plo.tt 5 --- E lloe4 ------���------aJao' Grodotionol phoae IMtween "tilo111erate • flo... roc.k little mon�onuc min4U'olixa+ion 2Uo' ______, ' ,�,�------2J40 , " ' Cros) Sec.t ion E-E Tyrrell MongcanUCl Mine $c.cde : Hor. 1• • �· "ert. ,. • to' W. ll. Lovwry Au.eust 1942 (0.) ___.. E �OGd I I ueo' ------_...... ___ Grodcationcal hose betw•n ------p --- caeclolllcrotc ond , • / .. flo,.. n<." ; /1-'Red GQtlo"'ercatc lJ (Aste'(eil 2.41 t'. M11) Vcr'( l•ttlc -"C•"•• , minercali..rot io r / l On I'( dendr'ttic. stoins) .... _..... ------2)40' Cross Sedion F • F' Ty rrell MentcaMM Mine . Sc:.le : Hor. I'• .. �crt. ,·.ao· (b) Pta.te 6 --E / � ... a at lo... &rato ------,,... •• (Fairly uni�orlft �vt • low tracfe "'inerolization) / ,..- --11- Atto'(•• 1.70 ,, 1. Mn / Cross Sec.t ion Go-G' T yrr�ll MonjiQnese Mine Sc:al�t : Hor. I" • .SO' Vert. e• • Lo· W . n. Lowr1 A .., ...� IM1 (a) ...... �oles A, C, oncl B Holes A ond D Holoo ]) on4 C Avoratc Mn in ore b_. lwcraac Mn io ore becl Aftr•t• M11ill ore b.d · 3. 13 t. 2. 1•/. -4-. e'f. "R•"•wsky ])rill S.c.tions T"(rr•ll Malltanue Mine Scale : H ... ,. • &o' v..+. a· · so· lto.. •u:ttefl f.-- the ooitit�ol (b) PUBLICJ.TlOlJS State Department of Geology and •:ineral Industries, 702 �oodlark auildine, Portland, Oregon. BULLETINS Price 1. Uining Laws of Oregon, 1942, rev. ed., contains lederal placer mining re�ulations • $0.20 2. Progress Report on_ Coos Bay Coal Field, l9J8 : '·"· Libbey, , • 0.10 J. Geology of Part of tho Wallowa �ountains, 1938 : C.P.Ross , 0,50 4. Qu icksilver in Ore�on, 1938 : H.C. Schuette • • • • • • • • • • • • • • 1.15 5· Geological Report on Part of the Clarno �asin, 19J8 : Donald K. �ae kay (out of print) •• 6. Prelimi nary Re po rt on Some of the Refractory Clays ot �estern Oregon, 1938, Hewitt Jilson and Ray C. Treasher ••.••••, ••, ••••• o.45 ]. The Gem Winerals of Oregon, 1938 : 11 . c. Dake ••••••••••••• , ••••••• 0.10 8. The Feasibility of a Steel Plant in the Lower Columbia Area near Portland, Oregon: Revised edition 1940: a.M. lliller. , • • , • • , • • • , 0.40 9. Chromlte Depo sit s in Ora�on, 19J8 : John Eliot Allen. , • • • • •• , ••••••• 10. Placer �ining on tho aocue River, Oraeon, in Relation to Fish and Fi sh�nc in that Streac, l?JI:S: Henry llaldwin \lard...... • • tout of print) •• 11. Geology and Kineral Resources of Lana County, Oreeon, 1938 : Warren D. Soith •••••• 12. Geology and Physiography of Northern �allowa �tns. , l�41: �.D. Smith, J.g.Allen a others lJ. First Biennial Report of the Department, l9J7·19J8. • • • (out ot print) •• 14. Oregon Me a U1nes Handboo� by tho staff � � i 1 ��±:'i£' ��atfifaeg���tr:�� f��1 :,, �· �; • H�;��w� C: o Coos Cur�y �ougl�s coun• ies, 1 9� o • f, Seeiion , o seplline county • • • • • •••• 1,� • •••• Section 1 ackson county \ID, S&, ) . 15. Geology of Salem Hills � North Santiam River 3as1n,Ore.,l9J9:Thos.P.Thayer (out ot print) 16. Field Identificat on of �ine ra ls for Oregon P rospectors and Collectors, 2nd edition i 9�1 ; compiled by Ray c. Treashtr ••••••••••••••••••• 17. Manganese in Oregon, 1942: by the start, •••••••••..•••••••••••• 18. First Aid to Fossils, or What to Do Before the Paleontologiat Comes, 1939 : J.E. Allen • 19. Dredging of Farmland in Oregon,. l9J9: F.W. Libbey •• , •• , •••• {out ot print} •• 20. Analyses a Other Properties of Ore&on Coals, 19110: H.l". Yanoey and ll.R. Geer •••••• 0.35 21. 2nd Biennial aeport of the Department, 19�9-1940 •••••••••••••••• free 22. Geology ot the Butte Fal ls Qur.drangle, 1�4J: W.D. l1lkinson, et al.. • ••• 23. An Investi gat i 2D of the Reported Oeeurrenoe or Tin at Juniper Ridge, oregon. , :1.,.2 : H . c . Harrison •• . •••••••••••••••• • • •••• o.!Jo 24. Origin of the Black Sands of the Coast of S.W. Oregon, 1!)4J: W. H. Twenhotel •• O.JO 25. Jrd Biennial Report of the Department, 1941·1942 ••• , • , • • , Free G.�.I. SHORT PAP�RS 1. Preliminary Report upon Oreion Saline Lo.keG� 19J?: O.P. Stafford , 0.10 2. Industrial Aluminum: A Brief Surv�y, 1?40: Lealie L. Uotz ••••• 0.10 J. Advance Report on Some Quicksilver Prospects in Butte ?alls �uad. ,Ore.,l940:W. D.Wilk1nson 0.10 4. Flotation of Ore�on Limestone, 1940 : J.a. Cler.uler & B.H. Clemmons •••••• 0.10 5· Survey of Non-Metallic llinero.l Production of Orecon for 1940:1�1�1�Holdrtdge • , ••• 0.10 6. Pumice and Pumieite, 1941 : James A. Adams •••••••••••••••••••, •••. 0.10 7· Geologie Hiltory of the Portland Area, 1!)42: Ray c. Treasher ••• , , •••• 0.15 8. Strategic a Critical Uinarala1 A Guida tor Creaon Pro epectora, 194Z: Lloyd W. Staplea. 0.15 9. Some !Iang&nese Depo a1 te in the Southern Oregon Coastal Region, 1942: Randall E. Brown . • o.1o :o. Investlgatio� or TyrrGll Mangan ese and othe� nearby deposits, 1?4J; J, r. Lowry 0.15 GEOLOGIC KAP SERIES 1. Oto logic Yap of the Wallowa Lake Quad.1l9J8 : J.D. Smith & others (alao in Bull.l2) ••• 0.45 2. Geologic llap ot Kedtord Quad ., 1939: P.o. Jells & others ••••••••••••• o.4o J. Geologie Kap and Geology of Round �ountain QMad. , 1940 : J.D. Wilkinson a others •• 0.25 4. Geologic Kap of the Butte fall• Qua d. ,l94l:i.D.Wilkinson & others (also in Bull.22) o.45 5· Geologie Yap & Geology of the Grants Pass Quad.1194 l: P.G. lalla & othera ••••• 0.30 6. Preliminary Geologie �a p of the Sumpter Quad. 1194l: J.T. Parcee & others ••••• o.4o 7• Geologic Wap of the Portland Area, 1942: Ray c. Trea&her (see alao Short Paper No. 7) • 0.25 MISCELLANEOUS PUBLICATIONS The Or e.-Bin: s t� tf, ••ued �onthly as medium for news item& about the Department, f • • • • • • • • • • • • mines and ainera •· Subscrip� ! on price per �ear 0.25 Sampling of small Prospects and New Discoveries • • • • • • • • • • • • • • • • Free The Spectrographic Laboratory of the State Dept. of Geology & Uineral Industries, 1942. Free Oregon llineral Localities Map • • • • • • • • • • • • • • • • • • • 0.05 Landforms ot Oregon; a phyciographie sketeh--(17 by 22 inches) 1941 • • 0.10 Plo.tt. 2. longit\ldinal Section Between Sta t'�on 1 - 0 & Station 7- 0 Line of exposurf! 11 .1 oF file rocK rypc ,..- "��:;,;,,.,:.1; ��:;:on Ty rrell Manganese Mine Sec.IO,T.37S .,'R.2E G La Ke Cr. District,JacKaon Co. ------ano'------:-::--:- State of Oreton ___ Min•roliz.ation poor uzs· _ B c· Dept. of G eoloay � Mineral Ind. n· �.J� W.'J). \...Owry .I.