The area to be surveyed was divided up into sections add each crew of three or four members was assigned one of these sections. The first two days were spent in studying and mapping the geologic section in the South Boulder Canyon where we obtained practice in alidade surveying, brunton, pacing, and auto traverse

Archibald, Frank W.

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Montana Tech LibraryDigital Commons @ Montana TechBachelors Theses and Reports, 1928 - 1970 Student Scholarship1-15-1940The Geology of the Limespur-Sappington AreaFrank W. ArchibaldFollow this and additional works at: http://digitalcommons.mtech.edu/bach_thesesPart of the Ceramic Materials Commons, Environmental Engineering Commons, GeologyCommons, Geophysics and Seismology Commons, Metallurgy Commons, Other EngineeringCommons, and the Other Materials Science and Engineering CommonsThis Report is brought to you for free and open access by the Student Scholarship at Digital Commons @ Montana Tech. It has been accepted forinclusion in Bachelors Theses and Reports, 1928 - 1970 by an authorized administrator of Digital Commons @ Montana Tech. For more information,please contact ccote@mtech.edu.Recommended CitationArchibald, Frank W., "The Geology of the Limespur-Sappington Area" (1940). Bachelors Theses and Reports, 1928 - 1970. Paper 233.1. tI \\!;10NT.\NA SCH')OL OF lUN:SSGT':OLOCTIC FI'SL9 I1APPIITGGEOL. 63THE GEOLOGYOFTHE LD!IESPLJh-5AP"?H GTe:;' AR.2AFrank W. ArchibaldJan. 15, 1940/INDEXIntroduction------------------------Page1Physiography------------------- ------- laStratigraphy---------------------------2Pre-Cambrian--- -----------------2Cambrian-------------------------3Devonian-------------------------3Mississippian----- --------------4Pennsylvanian--------------------4Permian--------------------------4Jurassic------------------------~-5Cretaceous-----------------------5Historical Geology--- -----------------7Geology of Limespur-Sappington Area---lOEconomic Geology----------------------13Acknowledgements----------------------14•ILLUSTRATIONSPageP!ate 1. Index map of Montana showingloc~tion of area surveyed---------- lbPlate 2. North-south section of SouthBoulder Canyon-~--------------------2aPlate 3. Geologic section of South BoulderCanyon---------- ..------ -------------2'0Plate.';4.Geologic map of Limespur-Sappington area--------------------under separatecover ( one map'for three reports)-1-The Limespur-Sappington AreaIn partial fulfillment of Geology 63, Geological Field Mapping,held from eptember 5 to eptember 22, 1939. Phe party consistedof 33 members of the Senior Class at the Montana School of,1 ines whohad ?amp accomodab i.onsat La.Hood Park, Montana where tents andtourist cabins were available; two meals a day were served bythe U•• C. C. C. which h",d a camp at this place, tie third mealwas ca ried by the party members and eaten in the field. The areasurveyed is in a region unmapped except for the original U. S. G. S.in 1896 and is located in the ea.st, central part of Jefferson County,Montana.}The area to be surveyed was divided up into sections add eachcrew of three or four members was assigned one of these sections.The first two days were spent in studyine; and mapping thegeologic section in the South Boulder Canyon 'where we obtainedpractice in alidade surveying, brunton, pacing, and auto tr6verse.My crew consistingff l[illiam Brodrick, Wesley Moore, end myselfweressigned en area known as the Li"Tespur-Sa.ppingt..;nregion extendingabout nine miles east and west along the Jefferson River fromLimespur-to Sappington. This area is serviced by two main railrotl.ds,the N. P. R. R. and the C. M. st. P. & M. , along with tl e Uontana-U. S. HighYiay No. 10 s.-la-PHYSIOGRAPHY.This area is quite rugged, varying from an elevationof 5000 feet above sea level at the Jefferson River toover 7000 feet on some of the mountain ,tops. Theresistant limestones and quartzites form the major reliefwith the softer shales forming the valleys. Steep'bluffs are quite common and in sections travel isalmost impossible.This region is semi-arid, having only 10-15 inchesof rain~'3.llper year, but it supports a few conifersand some small bushes. Drainage is ¢~ the ~ast byIthe Jefferson River.It may be said that practically all of theerosion is mechanical due to the lack of moisture and tothe extremely rigorous climate, (varying from minus 509Fto plus 1000 F.The ac cornpanyLng index map (see Plate I) gives thegeneral location of the area.PLA(LTh I-~-- - ----- --INDEX MAP OF IIJONT,1 '.// 5HOWINGLOCATION Or AREA 5UF(V£Y.ED-2-STATIGRAPHY:The geologic column of the South Boulder Area was studied in detailand mapped vrith care so that a fairly accurate section was obtained.ARCHAEZOIC At'JD PROTERZOICAt the base, or southern end of the outh Boulder Canyon arethe Pony Gneisses, the oldest rocks of the section. These recksconsist of light gray feldsparneiss with subordinate hornblende andmica, also occuring "liththe Pony Gneiss is a white feldsp'rgneiss having the apoear'ance of metamorphosed pegmatIteo These gneissesshow evidence of gree.tcompressive forces in Pre-Cambr-Lan times.Not shovnng in this section, but present in many parts of tileareaere the Pre-Cambrian shales known as the Belt -fonnation. 'I'rie se arethe oldest, unaltered sedimentary rocks in the area and vary inthickness from 2300 to uOOO feet. r he lower part of the formationconsists of an alternation of coarse arkosic sandstone and conll'lomerLte.he middle part consists of argillites, while_in the top partsiliceous limestones are found \nth Some s~ndstone. Normally thisformation occurs directly below the Flathead ~uartzite.C• ...l.' •• 1..1.I:t the base of the Cambrian formation i1the Flathead '-I:u~xtzite.This rock is pinkish and is prob~bly a mosaic of quartz g~ins cmentedwith silica. ~ear the base are some qu.rtz pebbles which evi.derrtLyhave come from the Pony Gneiss.Above.the Fl~thead is a soft, greenish, shale called the "olsey Shale.'he beds are thinly bedded and micaceous. It might be interesting tonote that Peale, Geologist of the U. S. G. S., who surveyed the areain 1894 included the Wolshey ShuLe in the lathead -formation.Immediately following the l'folseyb rmabi.onand lying conformablyon it is the Meagher Limestone. This limestone is charecteristicallyfossiliferous containing trilobites especi lly at the base. In theupper part the distinctive "black and goldll marble is found. ThisSond,.!! sho Ie/770/1 led 10__ 6n::_U7 0_1,q Ie ::____::1BlocA .J Cold I -5 _~~_+=.=-~_";:"'= + --+-" __ !?_~~er:_soocW Sh4/~ ~#0&51 vc _LJ/n It C/IL//C ~- .: .; ~uJi ~~.~v ., /J.9/jU /7 r / .s -.S ,I- .R A ,-vr- _lre/aceoaso ..,. 0 .., :J ..'10""OuO'oo·~\)o .....\)Uou \) v l: 0 1>"o",.~o'" I" '" <> e 0" 0 3000,.• 0 o () <.. <>01>0\:>0"<>D Q C)()OOO()OOC..JO-00000(" ..lo~ooooco&!I~oe"()O'O,"" .c> "..,,, 0 tII oJ VOO~QO.... e o e e e eJU/,qSSic/(oo!eoo;'/fol'riSo/)Ilmsdea7lJrt% rol"A5 LJfrJe/'teI'Jo/J ::- Djf:fo~o ' f!:/IJIjICreeA {de~ /'t9/lmAflf7 /orrr cr a resupper cfJel"& Isffl/dd/e - hlo ,-11'-/ IshOje' : son~ /sII- - -- - _j(/rEe// _s /lo/e J£)0"-)., Is WI rr ) 9/L ,9cod~ I1/~,Page 21;).PIatE.: III,.- -(")»~CD::0»Z• "-3-formation is about 350 feet thick.The Park+ormation, a soft, sandy, green shale lies directlyabove the Meagher Lin.es+one and is void of fossils except for an.undetermined species of Obolella. This formdtion is about 175 feetin thickness.Next are the massive, mottled Pilgrim limestones which forma distinctive topographic feature wherever they occur. They derivethe name mottled from the d~rk spots seen in the centrtllportion ofthe beds. ~feobt~ined a thickness of 540 feet on this formation.Closing the Cc.Wlbrian aries with 300 feet of sediments erethe Dry Creek Shales, a series of brovmish, red, saccharoidel shalesand thinly bedded liJ.est.ones, Some limestone pebbles, are found inthe shale and fossils are found throur;h out.DE70l.IAH.t the base of the Devonian are about 600 ~ eet of black orcmud colored cryst.a'lLi.nemagne si.anlimestone. There are a few fossils,and some of the beds have a fetid odor when freshly broken.i'heThree Forks shale makes up the top of the Devonian. Thisformation can be divided into three parts: the lower or orana;ecolored shales, then a oand of grayish-brown argillaceous lir.estoneand the upper a green, black argillaceous shale. crowded vrithDevonianfossils. In.Bome ragions;a1coal-black shale or slate is near the upperpa.rt and this has developed into a coal seem in the Jefferson Canyon.IS.3I::>SIP IImmediately following the deposition of Devonian sh.les, therewas a period favorable to deposition of cs Lce.reous deposits r.ndthebsse of the period is marked b a tremendous thickness of l.~adison-4-limestones. Fossils of brachiopods, bryo zoa, and other inv~rtebratesare plentiful in the formation. The Madison formation can bedivided into three pL·._rts.The lower pert of lamin,-.!tedlimestonewith many fossils, the middle light colored, argillaceous, thinly-bedded limestone and the top of massive, white limestone referredto as the Castle member. The Madison is 2250 feet thick.Following the deposition of the Madison li~estone, there wasa period of erosion and an erosional unconformity marks the base ofthe Amsden, a red sh~le member having in places conglomerates of·limestone pebbles. The Amsden limestones are magnesidn and it isconspicuous because of its brilliant red color. 'I'hi s formation isabout 250 feet thick.P:S_ r SThe Quadrant formation is composed of pink sandstones andquartzites with interbedded limestone members. The interbeddedlimestones are sugary and contain micro-fossils. This formetionis the only member of the Pennsylvanian period and is about 175feet thick.The permirm formation is charac(;erized by a n rrow, phosphatebearin~ formation hich is difficult to identify unless weatheredrock of this oolitic phosphate is found. Also occurring in thePhosphoria formation are some fine, paper-thin, black shalt.s. Thisformation is only 70 feet vride.-5-MESOZOICJURASSICJust above the Phosphoria is the Ellis formationwhich is characterized by a quartzite leage at the baseand the top. However, the formation consists mostly offossiliferous, calcareous beds which gradually gradeinto a sandstone which is devoid of fossils. The thicknessof this formation is about 300 feet.The Morrison shales which are made up of variegatedgreen and red shales and sandstones lie directly abovethe Ellis formation •. On a whole th~s formation is diff-icult to identify and in places has been mebamorphosedto dark slates. These beds are about 200'feet thick.CRETACEOUSThe Kootenai formation, basal Cretaceous, is oneof the easiest to identify as its base is marked bya distinctive "salt and pepper" sandstone with some redcross-bedding. These basal sandstones grade into reddishand greenish shales followed by a light blue limestonecomposed largely of fresh-water gastropods. Thethickness i~ 900 feet.The Colorado formation is identified by its fine-grained, dark, marine shale. Because of the softness,the beds are usually covered and hard to find. Theformation is about 200 feet thick.-0-The a:<~eof tIle L'i.vi.ngst.onvole mics has not been definitely set,but it is believed that they ar'eupoer Cretaceous but transpiredafter the post-Cretaceous uplifting of the region. After the Laram"deRevolution there was a period of intense volcanic eruption and the baseof the period is marked by large thicknesses of agglomerates made upof lava pebbles in a matrix of l'1vas"nd or mud. The andesite floVlsassociat~d with the above breccias are sometLmes referred to as"oatmeal," rock because of the occurrence of fdlldspar in 9 beown matrix._1_HISTORICAL GEOLOGYThe oldest formation encountered in the districtis the Pre-Cambrian Pony Gneiss of which the geologichistory is very indefinite. Lying unconformably on thisformation are the Cambrian formations which were deposited,during the middle and upper part of the period. Thistends to indicate a widespread land mass in Montanaat the beginning of the Paleozoic era. The Cambrianseas altho of shallow ~editerranean type, were widespreadand deposited about 1000 feet of sediments. Near the endIof the Cambrian period the seas withdrew and most of theState became a Low __lying land mas s,In the middle Devonian the dark-colored magnesianlimestones of the Jefferson formation were laid down.The Three Forks shales were laid down as a result ofa slight elevation of the land masses.During the Mississippian, immediately followingthe Devonian, the state was again submerged andabout 2000 feet of crystalline limestones werelaid down (Madison). Following the deposition of theMadison limestone, a land surface prevailed and the topof the limestone was eroded. Finally the land wasagain inundated and the Amsden formation was laiddown on the Madison.The Pennsylvanian period in Montana started withmarine waters covering the s uthwestern part of the state.-8-This resulted in the deposition of the Quadrantformation.Bec~use the geological history of the Permianin Ivlontanais still vague, the Phosphoria formationoverlying the QUadrant in southwestern Montana isof questionable ~ermian age, but it seems probable thatcentral and northern Montana were land.At the end of the Paleozoic era and during most ofthe Jurassic, Montana was a land mass, but a sea spreadover the state in middle Jurassic and deposited thelimestones, shales, and sandstones 6f the Ellisforma tion. The Juras sic ended with I'1:ontanas a landmass and the Morisson shales were laid down duringtransitional time between upper Jurassic and lowerCretaceous.Land conditions of the late Jurassic extended into thelower Cretaceous. Most of the material laid down seemsto have been of the piedmont type. It is also knownth~t a high and mountainous land extended fromthe Gulf of Mexico northward into ''lyomingand duringthis time most of Montana was a low, swampy landand coal formations were formed.During the beginning of upper eretaceous,all of the eastern and central parts of Montana werecovered by a sea which extended from the Arctic Ocean tothe Gulf of Mexico and accounts for the accumulation ofabout 2000 feet of shaly sediments. (Colorado formation)-9-The Livingston formation consisting of ash, ag3lomer-ates and pyro-clastics was accumulated in a synclinal basinduring upper Cretaceous.The uplifting of the Rocky Mountains began near theclose of the Cretaceous and continued into early Paleoceneand Eocene. From the erosion of these mts., many feetof sediments were laid down in lake beds and as alluvium.-10-GEOLOGY OF THE LIMESPUR-SAPPINGTON AREALOCATION:The area surveyed is loc~ted for nine miles E~Wjust south of Highway U.S. lOS between Limespur andSappington JunctionTOPOGRAPHY AND PH1SIOGRAPHY:The western part is characterized by high uplandsdipping sharply to the north into the Jefferson RiverCanyon. The prominent ridges of the area are formed bylimestone, quartzite, and sandstone ledges while thevalleys are formed by the shales.AREAL GEOLOGY:The control point for our survey was at the S.W.cor of Sec. 25, T.l.N., R.3.W •• To the east from thispoint the region is covered with a thin layer of lakebeds and Livingston agglomerates showing in the gulches.The rest of this region (N part of Sec. 31) ischaracterized by one large E-W fault with a displacementof 2500 feet to the W which greatly complicated the areaand no attempt was made to correlate ~he beds. However,it is interesting to note that an outcropping of Coloradoshale was noticed right next to a ledge of sa~dstone fullof 6astropods.Two thousand feet N.E. of the above area, a N-Sfault has thrown Kootenai against a large block of Madisonlimestone. The "salt and pepper" sandstone of basal Kootenai-11-at this point outlines a plunging anticline withthe basal Kootenai on the outside and Jurassic Morrisonand Ellis inside.To the east, the next two miles were skipped inhopes that the beds could be plotted after work hadbeen done further to the East. But this was not thecase as the area left out was too great to be correl-ated.Our next control point was established by runningan auto traverse from the cut~off to ~orrison Caveon Highway U. S. lOS to a point two miles away wherethe Jefferson River leaves the highway and turns south.On following thru the canyon made by the JeffersonRiver cutting the beds, we encountered a normalsection starting with the Livingston,' Kootenai, Morrison,Ellis, Quadrant, Phosphoria, and Madison. The Amsdenwas missing at this point, but no evidence of faultingcould be seen, so the 'Amsden could have been buried.At the base of the Madison is what we suppose to be anextension of the E-W fault mentioned above which throws~uadrant against the base of the Madison. Thisfault st~rts another normal section including; Quadrant,Amsden, and Madison, with the rest of the beds dippingunder the alluvium.After going thru this section, we turned east forabout 1500 feet and then turned north in order to traverse-12-the beds once more. But we picked a poor ~laceas we followed up the limb of a: fold and the geologywas very mixed up.The final part of our survey consisted of travellingalong the strike of the beds and then running a sectionacross the beds. Here (atout 3000' from the abovementioned fold) we encountered another normal sectionincluding from the gastropod limestone of the Kootenaithru the Amsden. At a point about 200' from MontanaI·Highway No. 89 the beds dipped under and were coveredby alluvium which fills the entire Jefferson Valley.Our survey was closed by tying in with the pier on theN. W. corner of the tiighway bridge on Montana U. S. 89over the Jefferson River,. ~,-13-ECONOMIC GEOLOGYThis area we surveyed has suprising1y few economicmineral deposits of any significance. There areseveral small abandoned coal mines in the Kootenai,but the coal here was of a very low grade.Near Morrison Cave is an abandoned gypsumquarry which was given up because of the intermixingof the gypsum with Jefferson and Madison limestones.Along the Jefferson River Canyon are flumes thathg,d evidently been used for hyd rau.lLc' mining. Recordsshow that the New London Placer Mining Co. exploiteda bench on the Jefferson River about a mile east ofLimespur, but whether the venture was profitable isnot known. The origin of this placer gold is undoubtedlysome point further up the JeFferson River or one ofits tributaries and has been deposited here' by the water-,The most outstanding venture was the quarryingoperations of the East Butte Mining Co. which usedthis limestone for flux. It was first exploited in1910 and given up in 1930 when the East Butte Co.was liquidated. The limestone here was of extremepurity, running up to as high as 99% calcium carbonateand consequently some of the li~estone was used forpurifying sugar in the refineries in Billings.-14-ACKNOWLEDGMENTSI wish to express my gratituae to the instructors/. in charge of the party for their valuable ~id inmaking the trip a great success.REFERE~CES:U. S.G.S. Bulletin.No. 24, The Three Forks FolioIMontana Bureau of Mines, Memoir No.3. "NaturalGas in MontanaJl by Dr. E. S. Perry.Pre~ious reports by Montana School of·Mines Students

The Geology of the Limespur-Sappington Area

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The Geology of the Limespur-Sappington Area

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