The Santa Fe Group of North-Central New Mexico Brewster Baldwin, 1956, Pp

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The Santa Fe Group of north-central New Mexico Brewster Baldwin, 1956, pp. 115-121 in: Southeastern Sangre de Cristo Mountains, Rosenweig, A.; [ed.], New Mexico Geological Society 7th Annual Fall Field Conference Guidebook, 151 p.

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THE SANTA FE GROUP posits.The marlof Haydenis now recognizedas caliche. OF NORTH-CENTRAL NEW MEXICO For manyyears, interest in the SantaFe was confinedto studyof theabundant fossils collected near Espanola, By untilBryan began a systematicstudy of the Rio Grande BrewsterBaldwin troughand its sedimentsin the1930’s. A detailedstudy New MexicoBureau of Minesand MineralResources of the Rio Puertoarea by Bryanand McCann(1937, 1938) was followedby Bryan’s(1938) regional study of theRio INTRODUCTION GrandeValley, and Bryan’sstudents mapped contiguous The SantaFe groupis a complexsequence of basin- areas(see Stearns, 1953a, fig. 6, formap showingthe fillingsedimentary and someassociated volcanic rocks areasstudied). Bryan (1938) concluded that the bulk depositedin the RioGrande trough during late Cenozoic theSanta Fe wasdeposited in closedstructural basins; time.The workof KirkBryan, his students,and V.C. alsothe SantaFe was subdividedinto three units: the Kelleyhas clarifiedmany of therelationships between LowerGray, Middle Red, and UpperBuff members of the structure,stratigraphy, andphysiography of this struc- SantaFe formation(Bryan and McCann,1937). These units ’ruraltrough. R~cent work (Spiegel and Baldwin,manu- appearto be validtoday in the areaof figure1. Whereas script)by Baldwinand Kottlowskiin the SantaFe area the reportsby Bryanand hisstudents emphasized the hasled to a revisionof thedefinition of "SantaFe". stratigraphyand physiography,Kelly (1952, 1954) was Thisarticle is notintended as a formalpublication concernedprimarily with tectonics of the RioGrande trough eitherof theproposed revision of ’*SantaFe" or of andits relation to stratigraphyand physiography. proposedformation names; the purposeis to summarize the presentunderstanding of the SantaFe group. The faunacollected near Espanolawerestudied by Cope (1874),Matthew (1909), Osborn (1918), and Simpson (1933). Hayden’s(1869, pp. 166-170)original definition of the In tb~1920’s faunal collections attracted the attention of SantaFe marlsfollows: Dr.Childs Frick (1926a), and the FrickLaboratory of the "FromSanta Fe to the banksof the Gallisteo Creek, AmericanMuseum of NaturalHistory has beenmaking eighteen miles, we pass over the recent marls and sands carefulcollections and studies of thefauna to thepresent which seem to occupy the greater portion of the valley of time.Several monographic studies of certainmammal the Rio Grande, above and below Santa Fe, which I have calledSanta Fe marls..... " groupshave been published (Frick, 1926b, 1933, 1937), but theseare not accompaniedby specificstatements re- "From Santcl Fe to Fmbudo Creek, and mostly even to gardingposition of the collections.However, Frick (1937) Toes, the Santa Fe marls cover the country. On the east appearedto be in generalagreement with the upperBar- side of the Rio Grande i did not observe a single dike, from the Cerillos to the mouth of the Chama Creek. North stolon-lowerClarendonian (Miocene-Pliocene transition of that the melted material has been poured over the marl zone)age assigned by the others.It is generallybelieved so as to form broad mesas. On the west side there are thatthe collectionswere from the "typicalSanta Fe", numerousoutbursts of igneousmatter. These Santa Fe the mainmiddle unit of Bryanand McCann’sSanta Fe marls reach o great thicknessnorth of Santa Fe, in the formation. Rio Grande Valleys from one thousand two hundred to one thousand five hundred feet, and have a tendency to weather into similar monumental and castellatedforms, as in the Althoughthe Santa Fe has been subdividedin some "Bad Lands".The upper portions are yellow and cream areas,the paucity of vertebrateremains has made it diffi- coloredsandstones, sands, and marls.Lower down are cultto correlatesubdivisions from one part of thetrough some gray coarse sand beds with layers of sandstone. All to another.Correlation by lithologic type and local se- these marls dip from the range westward three to five de- grees. The Rio Grande we’ors its way through these marls quence is hinderedby theextreme lithologic variability of with a bottom about two miles wide. On the west Side are the sediments.The "SantaFe formation"of some re- distinctterraces with the summits planed off smoothly portsrefers to allthree units of thebasin-filling sequence, likemesas. The first one is eighty feetabove the river; whereasthe same term in otherreports is restrictedto the the second one, two hundred feet. These marls extend all middleunit. incorrect correlations have further compli- the way between the margins of the Santa Fe Mountains on the east side and the Jemez Range on the west. Most catedthe meaning,for in some reports"Santa Fe" is of the Chorea Hills, and I think the entire hills, are cam- inadvertentlyused in botha restrictedand unrestricted posedof it ...... " sense.

Johnson(1903) demonstrated that the "SantaFe marls" ThereforeBaldwin and Kottlowski(Spiegel and Baldwin, in thevicinity of theCerrillos were in factalluvial de- manuscript)propose that the term"Santa Fe" be raisedto

115 NEW MEXICO GEOLOGICAL SOCIETY * SEVENTH FIELD CONFERENCE

groupstatus, and that it includeall three of theunits re- Theintermediate voJcanics of the Cienegaarea are cognizedby Bryanand h~s students,The name*~Tesuque overlain,possibly with unconformity, by the flows of f~ formationis proposedfor the middle ;unit in theSanta the Cieneguilla[imburgite (Stearns t 1953b).Just west Fe area,the unit hitherto called "Santa Fe formation"in of theCienega area limburgite flows are in turnoverlaln its restrictedsense. The SantaFe groupas definedre- by tuffaceousand volcanicsedimentary rocks which presentsthe basin-fillingsedimentaryand volcanic rocks Stearns(1953a) named the Abiquiu(?)formation associatedwith the RioGrande trough, and it rangesin age tentativelycorrelated with the Abiquiu tuff (Smith, frommiddle Miocene (?) to Pleistocene(?). In the Santa 1938),the basalunit of the SantaFe group.Indirect Fe area~the lower limit of the SantaFe groupis takenas evidencesuggests that the Abiquiutuff and the Abi- the top of the Espinasovolcanics and Cieneguilla limbur- quiu(?)formation are middle Miocene in age;if so,the gite,and as thebase of theAbiquiu(?) formation Espinasovolcanism occupied some or all of the inter- Stearns(1953o). The upperlimit of theSanta Fe group val betweenlatest Eocene and middleMiocene. Stearns is chosento excludeonly alluvium and terraces of present (1953a)suggests that there was a significantinterval drainage,and thusthe basalt flows west of SantaFe are of deformationand erosionbetween Espinaso and Abi- in the upperpart of theSanta Fe group.Future studies quiutime; the Cieneguilla limburgite was extruded at maylead to modificationof these limits, sometime within this interval.

EARLY CENOZOIC HISTORY SANTA FE GROUP Laramidedeformation in the SantaFe arearesulted Correlation in the formationof mountainsand intermontanebasins. Descriptionof the three main units of theSanta Fe Stearns(1943) outlined the depositionalbasin of the groupis simplifiedby firstestablishing certain cor- Galisteoformation, generally south andsouthwest of relations.Figure 2 showsthe subdivisionsof theSanta thecity of SantaFe. The Gallsteo formation, an Eo- Fe groupas usedin the severalreports by Bryanand cenealluvial deposit 900 to 4000feet thick, is over- his students,as wellas two columnslabeled "This lainconformably by a sequenceof latiticto andesitic Report"which refer to the manuscriptby Spiegeland flowsand flow-breccias,named the Espinasovolcanics Baldwin.The correlationssuggested in the figureare (Stearns,1953b). Vertebrate remains collected a few onlyincidentally based on fossilsand are therefore hundredfeet below the topof the Galisteoformation subjectto modification. andalso in the transitioninterval just above the Gal- isteoformation have been identified as DuchesneRiver TheSanta Fe groupconsists of threeunits that are in age;Stearns (lC~43, p. 311) arbitrarilytreated the fairlypersistent in thearea of Figure1. Bryanand DuchesneRiver and the Galisteoformation as Oligo- McCann(1937) named these three units the Lower cene,but later (1953b, p. 430)he putthe Duchesne Gray,Middle Red, and UpperBuff members of the Santa Riverin the latestEocene. Thus Espinaso volcanism Fe formation.Later reports restricted the useof Santa beganat aboutthe beginningof the Oligoceneepoch. Fe formationto themiddle unit. Stearns (1953a) tentativelycorrelated his Abiquiu(?) formation with the In theCerrillost 20 milessouthwest of thecity of Abiquiutuff (Smith, 1938) some 60 milesto thenorth, SantaFe detailsof the Espinasovolcanism have been and Stearnsalso suggested that the LowerGray mere- clarifiedby Disbrow(Disbrow and Stall,manuscript). ~r of Bryanand McCannwas equivalentto his Abiquiu(?) Fourperiods of igneousactivity are demonstrated.In formation.Cabot (1938) and Smith(1938) correlated eachperiod there was near-surfaceintrusion of stocks, SantaFe formationin theirareas with the similar-appear- and all but the firstperiod were marked by accompany- ing sedimentaryrocks of the EspanolaValley that con- ing extrusionof flow-brecciasand someflows. Five tainthe lateMiocene-early Pliocene Santa Fe fauna. milesnorthwest of the Cerrillos,Sun andBaldwin (1956) Denny(1940a) studied theSanta Fe formationnear Espa- haveshown that two latiticflow and flow-breccia units nola,and Stearns(1953a) correlated his Santa Fe farina- in the Cienegaarea were extruded after the youngestof tionwith the MiddleRed memberand withDenny’s Santa Disbrowand Stall’svolcanic units. Thus the Espinaso Fe formation. volcanicsinclude four periods of intrusionand four or fiveperiods of extrusion,a total of fiveor sixdistinct Whereascorrelation of the lower two units was fairly periodsof igneousactivity, with the forceful intrusion wellestablished by Stearnsand others,the uppermost ofstockscausing local but pronouncedangular uncon- unitwas not correlatedsatisfactorily. Bryan (19%) formitiesduring Espinaso time. placedthe rivergravel of theancestral Rio Grande in

116 NEW MEXICO GEOLOGICAL SOCIETY * SEVENTH FIELD CONFERENCE

-~- ~,.~ ...... ~,~_ .~.f- °~ -~-_-~_ ._ ~ .... _1~f-"J~J

c.~bo ,///~ ""- .... -~c --X-/)’ Q.~_..----c ~-~------"---’---""Jy. ,~----j,.;_,pono,o...... f~:_...- s, ~.--.:) _

~L~- ...... J .------i_-- ’ -J-:~X’~-----__ ------~ . ~- - ~.~_!! -.- _ --"A’-~- o\°~h,~--ZT~-, " / ,~ ~ ~ Rock .>~-~----’-""’ANTA ~:’- . ~.- J- ~ ¯ c~f~- y--

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~__ ...... -~~ .... _amy: ...... J L.-:~--- _____~~--~_"-~L-~__. ~ ~,~rJllo $ ~ ~,3J.~,o,,0,o ....

-~ ~-.-"~ ...... , ’ Creek ..... -- " ...... -~...... ~--____~~:_~J," __ :-- ~ ...... ~, " ------r---~-:~_.-~ ?~ ...... ;;~/~ I,...... ?.- ~-~ ~,~ " ~~ - ...... ~ , ....f ~"~ .....~ ~-- , Esfonc/a _...... _.~:~ ~"-~---~-’~- / Valley I ...... ;7 ..... ~ >...... _~ ,~-~ ~___~~ -, I .... ,p ,~o, ~p ~, .~_~_-’-L.-~ ~’~’~-...... - r ;,,~"S~’--~-~-----~ FIGURE l, REGIONAL SKETCH MAP the Santa Fe formation; moreover, the Upper Buff mere- Moreover~ he (p. 411) suggestedthat the river gravel was ~er was 6elieved to 6e overlain with angular unconformity equivalent to the Upper Buff. Unforfunately~the Tuerto by sand and gravel (Bryan and McCann, 1937,fig. 8). gravel, which Stearns properly considered to be younger Wright (1946, p. 404, 406; pl. 3, fig. I; fig. 10) showed than his Santa Fe formation, is exposed in one part of that the angular unconformityis within the Upper Buff his area, and the river gravel in another;the two are not member, stating that "the beds of gravel and sand inter- seen in stratigraphiccontact. So Stearns concluded, as finger with the main unit of the Upper Buff member." had Denny and Wright, that the river gravel:wasin the

117 NEW MEXICO GEOLOGICAL SOCIETY * SEVENTH FIELD CONFERENCE

GoGRAVEL Basalunit Smith(1938) described the Abiquiu tuff, 500 to 1200feet ~ PuYE t SANTAFE ABIOUIU in thickness,as a light-graystream-depositedtuffand GRAVEL FORMATION TUFF ~ volcanicconglomerate underlying the SantaFe formation. ~-~--~ i angular Becauseof thenorthward coarsening of theconglomerate, , .....r0r~t~.~ ~nithstated that the Abiquiu tuff was deposited as a -~ ~ "- piedmontfan by streamsdraining from the north,although FF~r~ I~ ab.... ~ SANTA FE i PICURIS (_~ ~ _~ TUFF some contemporaneousvolcanism was indicated by tuff ~- ~ ~FORMATION bedsand by interbeddedbasalt flows. I I iI I Stearns(1953a, pp. 469,493-497; fig. B)expanded the ypl;...... te Md..... ~ PUYE t .... ~ interpretationof the origin of theAbiquiu tuff. The fan SANTA FE FM. covered GRAVE1 I I.,~ ’~_ extendedsouth from a sourcein the TagsPlateau, meeting ~i the southeast-drainingmaster stream northwest of Ber- nalillo.Southwest of themaster stream, sediments of the z LowerGray member were deposited by northeast-draining ¢£ ~" ~=~ TESUQUE "~ ’ streams.Relief in Abiquiutime was only locally pro. ~ ~ J ! ~...... d BASALTI’"YP"L~’%~II~1\ \ rM ~M .~ nounced,for much of theAbiquiu tuff and Abiquiu(?)formationis fine-grained.Although the Abiquiutuff consists ~, ....’0-~,’,o~foce ~ ~ largelyof volcanicmaterial, the Abiquiu(?) formation ~ . generallynon-tuffaceous. The Abiquiu(?)formation was u. ~ ~ SANTA., -- FE GROUP derived primarilyfrom the Espinasovolcanics, the Gal- ~ ~ ~ ’IeASALTI~ TEGUQUE FORMATION ANC.A~M ~ ...... ’~g°~"~" i steoformation, and Cretaceousand Jurassic sedimentary rocks,but notfrom Precambrian rocks. // Sedimentarymaterial derived from Precambrian rocks is, ~ ,~. TUERTO ~" SANTAFE FM, however,present in thetuffaceous sediments farther north. ~ ~ \GRAVEL_ FORMATIoNABIOUIU(?) Smith(1938) mentioned o basal gravel of Precambriangra- \\ nitepebbles and Precambrian pebbles are presentin gravel \\correlation8,suggested ~ interbeddedin the water- laid Picuris tuff (Cabot, 1938, p. \\.Sb~st..... 91).Just north of SantaFe, 50 to 530feet of light-gray SAND ANO ~ ~" I .EO,,00~ ~R~L0w~R .~R-" ~ GRAVEL volcanic-derivedsandstone and silt, with minor tuff beds, ~ ~I L~ ~ ~ SANTA FE FORMATION ~ / weremeasured by Kottlowsk,(Spiegel and Baldwin,manu- /~ ~ ~ // script).

e: ~ zl~r ~ ~ Thistuffaceous unit in placesrests conformably on as ~ ,T, uJI ~ o° muchas 100 feetof pinkish-tanPrecambrian-derived ~ ~ ~ sandstonetypical of the Tesuqueformation. Although Cabot(1938) extended the Picuristuff southward to in- FIGURE 2. NOMENCLATURE AND TENTATIVE cludethe exposuresjust north of SantaFe, Kottlowski CORRELATIONS OF UNITS IN THE SANTA FE is proposingthe nameBishop’s Lodge member of the GROUP Tesuqueformation for several reasons: (1) the Bishop’s LodgeMember is interbeddedwith the lowerpart of the upperpart of theSanta Fe formation(restricted), although Tesuqueformation; (2) Cabot’streatment of thePicuris thiswas puzzling,for Denny(1940b, p. 93) and Needham tuffis generalized,whereas the study of theSanta Fe (1936)had reportedupper Pliocene fossils from beds equiv- areais detailed;and (3) exact correlation with the type alentto the UpperBuff member. Reconnaissance by the Picuristuff is notpossible at thepresent. writerin the Buckmanarea (on the Rio Grandebetween SantaFe and LosAlamos) suggested that the rivergravel Middleunit is interbeddedwith the Anchaand Puyegravels, and by Themiddle unit which forms the bulkof the SantaFe Correlation,with the Tuerto gravel; the UpperBuff member group,is a thickcomplex of alluvialfans, variable in is thencorrelative with these gravels of the uppermost sorting,source material, and cementation.North of Santa partof theSanta Fe group. Fe, nearthe mountains,boulder beds are abundant in the

118 NEW MEXICO GEOLOGICAL SOCIETY * SEVENTH FIELD CONFERENCE

lowerpart of the Tesuqueformation, but fartherwest, near former.Lithologies of the two aresimilar, although the the RioGrande, the upper part of the formationis charac- Tesuqueformation is commonlya veryfine- grained sand- terizedby siltstoneand fine sandstone with minor con- stonewhereas the Anchaformation contains a largepro- glomeraticbeds. Many of the sandstonesare fairly well portionof graveland coarsesand. In the Buckmanarea the sortedand are cementedby crystallinecalcium carbonate Anchaformation appears to intertonguewith Puye gravel thatgives the rocka glitteringappearance. Crossbedding andwith river gravel that was assigned by Bryan(1938) and linticularbedding are common.The Tesuqueformation theancestral Rio Grande.In thisarea the contact be- is composedalmost entirely of materialderived from Pre- tweenthe Tesuqueand the Anchaformation is difficult cambrianand Pennsylvanianrocks of the Sangre.deCristo to recognize,for thelatter is scarcelydeformed. There Mountains,although correlative sedimentary rocks farther may havebeen no markedbreak in depositionnear Buck- westmay includeother sourse materials. The Tesuque man,which was so far fromthe risingmountains. formatinndips westward about 10 ° andit is exposedin an east-westdirection for about8 miles;thus the forma- SUMMARY tionmay be 7000feet thick northwest of SantaFe. The The mountain-building of Laramidetime formed inter- truethickness may be as littleas halfthis figure, how- montanebasins, such as the one in whichthe Galisteo ever,because of repetitionof bedsby unrecognized formationwas depositedduring the Eoceneepoch. The faults.For example, a peculiaroccurence of 15-foot streamsthat deposited the Galisteoformation were block- blocksof quartzite,4 miles west of pre-Santa Fe ex- ed by the extrusionof Espinasovolcanics at aboutthe posures,may indicatethat the basementrocks have beginningof the Oligocene.Probably large areas were beenfaulted nearly to thesurface at thatlocality, coveredby tuff,flows~ and breccias, though locally there was erosionof domesformed by near-surface intrusions. In the EspanolaValley (Denny, 1940a) the "typical Thefive or sixperiods of volcanicactivity assigned to SantaFe" dipswestward and was derivedfrom the Sangre the Espinasovolcanism may have continuedspasmodic- de Cr~stoMountains. Channeling and channelbreccias allythrough the Oligoceneinto the Miocene.The Ciene- are fairlycommon, and there are manythin tuffaceous inter- guillalimburgite was extrudedas flowsin somelocal- beds.The abundantmammal fauna collected from these ities,probably in theearly part of theMiocene. bedsindicates semi- arid to humidclimate during late Miocene-earlyPliocene time. AlthoughSteams (1953a) placed a majorhiatus, repre- sentedby deformationand erosionand by extrusionof Upperunit llmburgite,between Espinaso and Abiquiutime, only fos- The Puyegravel (Smith, 1938), the Anchaformation, silswill indiacate the relative lenths of timeoccupied by andthe Tuertogravel all rest with angular unconformity Espinasovolcanism, deformation and erosion,and Abi- on deformedbeds of the Tesuqueformation. These units quiudeposition. On the Other hand, it is possiblethat of gravelare 500,300, and 150 feetin maximumthick- Espinasoand Abiquiutime overlapped, for therewas at heSS,respectively, and thusthey are more than a pedi- leastminor contemporary volcanic activity during deposi- mentveneer. Both the base and the up~oersurfaces of tionof theAbiquiu tuff and Abiquiu(?)formation, and the theAneha and theTuerto were referred to indiscrimi- basaltflows associated with these units might possibly natelyas the "Ortizsurface" by Bryan(1938), but, be correlativewith the Cieneguilla limburgite. In any event Stearns(oral communication) has pointedout, the Ortiz event,the Abiquiuis presumedto be middleMiocene in surfaceis compound.Further reference in thisarticle age,and althoughthere may havebeen some warping at to theOrtiz surface is to the "lowerOrtiz surface" (the thistime the faulting characteristic of the Rio Grande surfaceof angularunconformity) and the*’upper Ortiz troughprobably had notbegun. surface"(the physiographic surface). TheRio Grandetrough probably began to format the The Tuertogravel was derivedfrom Mesozoic sediment- beginningof Tesuquetime, for the Abiquiugrades up in- ary rocksand Cenozoicvolcanic rocks of the OrtizMoun- to sedimentsderived form Precambrian rocks, suggest- tains;the Anchaformation was derivedfrom the Tesuque ingthat uplift in theareas had by thistime accel- formationand fromPrecambrian rocks of the Sangrede eratederosion, which in turnexposed the mountaincore CristoMountains; the Puyegravel was derivedfrom the of Precambrianrocks. The structuralbasins, which make volcanicrocks of the JemezMountains west of Los Ala- up the complexgraben- structure of the RioGrande trough, mos. Distinctionbetween the Tesuqueand Anchaforma- wereapparently filled to overflowingbefore the end of the tionsin the SantaFe areais basedlargely on the west- upfaultingof themargins, for deformation of the "typical warddip and the somewhatbetter consolidation of the SantaFe" was succeededby considerableerosion, at least

119 NEW MEXICO GEOLOGICAL SOCIETY * SEVENTH FIELD CONFERENCE

alongthe borders.The Tesuqueformation was entirely REFERENCES erodedfrom the Cerrillosarea, and erosion in theSanta Fe areamay havecontinued from early into late PJiocene. Bryan, Kirk,1938, Geology and ground-water conditionsof the However, farther west, deposition may havebeen without Rio Grande depressionin Coloradoand New Mexico: Re- major in,eruption, gionalPlanning; pt. 6, Upper Rio Grande,pp. 197-225, Washington,Nat. Res. Commission Stearns’ map (1953a,fig. 9) of middle and late Santa Fe Bryan,Kirk, and McCann,F. T., 1937, The Ceja del Rio Puerto, time is largely a representationof Ortiz time. The Ortiz a border featureof the Basin and Range provincein New Mountains, the Sangre de Cristo Mountains, and the males- Mexico;pt. 1, Stratigraphyand structure:Jour. Geology, vol. tic volcanowest of Los Alamaswere eroded to form,re- 45,pp. 801-828. spectJvely,the Tuertogravel, the Anchaformation, and 1938, The Ceja del Rio Puerco,a border feature the Puyegravel. These sediments were deposited on the of theBasin and Range province in NewMexico; pt. 2, Geo- lowerOrtiz surface, beveling earlier rocks, and an onces- morphology:Jour.Geology, vol. 46, pp.1-16. tralcourse of the Rio Grandewas establishedin aboutthe present position of the river. Deposition may havebuilt Cabot,E. C., 1938, Fault borderof the Sangre de CristoMoun- up the landsurface considerab|y above the remnantsof tainsnorth of SantaFe, New Mexico: Jour. Geology, voi. 46,pp. 88-105. theupper Ortiz surface, for Cabot (1938) described sur- facesome 500 feethigher than the surface that he car- Cope,E. D.,1874, Notes on theSanta Fe marlsand some of the relatedwith the upper Ortiz, and themesa- like Cerros del containedvertebrate fossils: Philadelphia Acad. Sci. Proc. Rio westof SantaFe, whichstand some 1,000 feet above for1874, pp. 147-152. the Anchaformation, may conceivablyhave been planed Denny,C. S., 1940a,Santa Fe formationin the FspanoiaV_alley, off by erosionbeforestreams cut downto formthe upper NewMexico: Geol. Sac. America Bull., vol. 51, pp.677-694. Ortizgraded surface. In any eventbasalt flows that issued fromcenters near the Rio Grandedammed the ancestralRio , 1940b,Tertiary geology of theSan Acacia area, New Grande,buried the upper Ortiz surface and divertedthe Mexico:Jour. Geology, vol. 48, pp. 73-106. westwarddrainage of the ancestralSanta Fe River.Ortiz Disbrow,A. E., and Stall,W. C., 1956, Geologyof Cerrillosarea, time,including the basalt flows, probably continued into Santa Fe County, New Mexico: N~ Mex. Bur. Mines and Min- the Pleistocene. eral Resources,Bull. 48 (in manuscript).

Activityof the Jemezvolcano culminated in the Pleis- Frick,Childs, 1926a, Prehistoric evidence.: Natural History (Am. toceneabout at the end of SantaFe time.Large volumes Mus.Nat. History Jour.), vol. 26, pp. 440-448. of pumicewere blown out-a line of pumicedeposits ex- 1926b, The Hernicyoninaeand an AmericanTerti- tendssoutheast across the SantaFe area-and thennuees arybear; Tooth sequence in certaintrilophodont-tetrabelo- ardentesspread great thicknesses of weldedtuff as an dontmastodons and Trilophdon (Serridentinus)pojaaquensis, apronon the eastside of the volcanoas the volcanocol- n..sp.:Am. Mus. Nat. History Bull., vol. 26, pp. 1-119. lapsed.Only the base of the volcanois left,forming the 123-178 (1930). ringof mountainswest of Los Alamos,but thelarge grass- _ ; 1933,New remains of trilophodont-tetrabeladont ed valleysinside the ringare the subduedremains of one mastodons:Am. Mus. Nat. History Bull., voi. 59, pp. 505- of the largestcalderas in the world.The Rio Grande, 652. shuntedeastward by the weldedtuff, cut downwardto form WhiteRock Canyon. Downfaulting near L_a Bajaclaaccel- , 1937, Horned ruminantsof North America:Am. Mu~ Nat.History Bull., vol. 69. eratedthe canyon- cutting, I x~th of theRio Grande and of the SantaFe River.Although no post-Anchafaulting is Hayden,F. V., 1869, First,second, and third annualreports of recognizedin theSanta Fe area,faulting in otherparts of theUnited States Geological Survey of theTerritories forthe thetrough continued after Ortiz time (Stearns, 1953a, fig. years1867, 1868, and 1869 (1873). 10). ( Continuedon nextpage

120 NEW MEXICO GEOLOGICAL SOCIETY . SEVENTH FIELD CONFERENCE

Johnson,D. W., 1903, The geologyof the CerrillosHilts, New Spiegel,Zane, and Baldwin,i3rewster, 1956, Geologyand water Mexico:Sch. Mines Quart.(Colombia University), vol. 24, pp. resourcesof the Santa Fe areal New Mexico,with contribu- 173-246, 303- 350,456- 500; vol. 25, pp. 69- 98. tions by F. F. Kottlowskiand E. L. Barrowsand a part on geophysicsby H. A. Winkler:U. S. Geol. Survey Water-Sup- Kelley,V. C.a 1952, Tectonicsof the Rio Grand,depression of ply Paper(in manuscript). centralNew Mexico:N. Mex. Geol.,in Guild,book of the Rio Grand,country, Third Field Conf.,pp. 92-105. Stearns,C. E., 1943, The Galisteoformation of north-central New Mexico:Jour. Geology,vol. 51, pp. 301-319. 1954,Tectonic map of a part of the upper Rio Grande area, New Mexico: U. S. Geol. Survey Oil and Gas ~ 1953a~Tertiary geology of the Galisteo-Tonque Inv., Map aM 157. area, New Mexico:Geol. Sac. AmericaBull., vol. 54, pp. 459- 508. Matthew,W. D., 1909, Faunallists of the TertiaryMammalio of the West: U. S. Geol. SurveyBull. 361,pp. 91- 120. ..1953b~Early tertiaryvulcanism in the Galisteo- Tonque area, north-centralNew Mexico:Am. Jour. Sci.t vol. Needham,C. E., 1936, Vertebrateremains from Cenozoicbeds: 251s pp. 415-452. Sciencesn. s., vol.84, p. 537. Sun, M. S., and Baldwin,Brewster, 1956, Sequenceand geochem- Osborn,H. F., 1918, Fquldaeof the Oligocene,Miocene, and istry of volcanicrocks of Ceinegaareat Santa Fe County, PlioceneofNorth America,iconographic type revision:Am. New Mexico: N. Mex. Bur. Mines and Mineral ResourcesBull. Mus.Nat. HistoryMem., n. s., vol.2, pt. 1, pp. 1-330. 54 (in manuscript).

Simpson~G. G., 1933, Glossaryand Correlationcharts of North Wood, H. E.0 2nd, and others,1941, Nomenclatureand correlation American Tertiarymammal-bearing formations: Am. Mus. of the North Americancontinental q’ertiary: Geol. Sac. Amer- Nat. HistoryBull., vol. 57, pp. 79-121(1935). ica Bull.,vol. 52, pp. 1-48.

Smith,H. T. U., 1938, Tertiarygeology of the Abiquiuquadrangle, Wright,H. E.r Jr.~ 1946,Tertiary and Quaternaryhistory and gee- New Mexico:Jour. Geology,vol. 46, pp. 933-965. Iogy of the lower Rio Puerco area, New Mexico:Geol. Sac. AmericaBulI.s vol. 57, pp. 383-456.

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