Adobe Brick Production in New Mexico

TABLE l-Esttulrep 1980 nposr BRIcK PRoDUc- Adobebrick production in TIONTOTALS.

Av.n8.' p.oducdon Edm.cd ol tobl ol rdoh pdc./.dobc tobl doll.r vdu. prodrcdon NewMexico Stabilizcd 36,9c 4@,000 I 169.7,1000 llq. byEdward W. Smith, Geologist/Planner, EightNorthern Indian Pueblos Council, Scmisabilizcd 27 E 2,320,(m 544,960m 56qt SanJuan Pueblo. NM Traditional 266c 1,153,00 l59.t9t m t3qo Totals 304c 4,131.0m $.174,59E00 rmqb Introduction The 1980estimated combined dollar value of .summcr .dobc bncl pricc avcragcs fot thirtvritht (38) tradhionel, cight (E) scml In 1980,the New Mexico Bureau of Mines of production for the three major types srabilizcd, and six (6) strbilizcd adotEbricl produccrs and Mineral Resourcesundertook a study of adobe bricks (traditional, semi-stabilized, the adobebrick industry in New Mexico. The and stabilized)totaled $1,174,598. This figure distribution and location of accountsfor the commercialproduction of study includedthe History the commercial adobe brick producers, soil 4,133,000adobe bricks (table l) and places types, geology and mineralogy, methods of New Mexico as the leading producer of adobe The word "adobe" hasits rootsin an Egyp- production, market trends, and economicfac- bricks in the southwesternUnited States.Not tian hieroglyph (fig. 2) denoting brick and tors. Adobe samples,collected from 56 loca- includedin the production totals are the values evolved through Arabic and Spanish to its tions and the 48 active adobe producers(fig. for the thousandsof adobebricks producedby presentform. Today,adobe is usedto describe l), were testedin the Rock MechanicsLabora- individual homeowners for their own con- various earth-building materials and tech- tory at the New Mexico Institute of Mining structionprojects, which may representan ad' niques, usually referring to the sun-dried and Technology. ditional3-4 million adobesper year. adobe brick now most widely used in the United States.The word also applies to pud- dled structures, adobe-plastered logs or branches,and evento rammed-earthconstruc- ( Riyu tion (pis6). , R! 43 Among the oldest of technologiesmastered SAN 39 by prehistoricman, the useof mud as a build- JUAN t7 1 ing material parallelsthe birth and spread of the greatancient civilizations of the world. To this day, soil remains the primary building ^?^?n material of at least 50 percent of the world's Y"?r population. The Neolithic Period (10,(n0- 3,000 B.C.) marks the beginningof stable, 33 5 sAN Mt^"-' nonmigratory civilization, and with it efforts a_,,.>-, at building the world's first permanentstruc- \ tures. Remainsof adobe structureshave been otrotil - r'f eL,r,ti ( \ villages through- : 31 nrot found in Neolithic farming al 2- o _i datingas far back 6 out the Nearand Mid-East, -;;-&--t" vALENCI -r-l- as 7,fiD B.C. (Steen,1972). Hand- and form- t-SOCORR molded bricks from this era are seenin the ruins of structuresthroughout Mesopotamia, Crete,Egypt, and India. The useof mud con- struction rapidly spread eastward through Asia and westwardthrough North Africa and the Mediterranean Basin; as the Ice Age re- c cededin northern Europe, thesepeoples also beganto useadobe in construction. rF

I IN THISISSUE I -1 Adobebrick production in NewMexico P.17

OTERO CenozoicstratigraphY and structure,Socorro Peak P.22 o 30 somi StorrieLake State Park P.25 I Service/News P.26 48 Nonfuelmineral Production in NewMexico P.32 FIGURE l-Loclrrox oF ADoBEBRrcK pRoDUcERs Acrrve rx 1980(for namesof producersand information, seetable 3). the shrinkageand prevent cracking (Califor- that has undergonea modified low-firing pro- nia ResearchCorporation, 1963). cess.Combustible materials are burned in a fffiilH$rq#,l%ll[^trfr2) Stabilizers-Moisture reentering an stacked-brick-pileoven configuration, and the ,u^n^n Z1 adobebrick causesthe clay to swelland release resultantburnt-adobe brick is much stronger ofi.' its bonding so that the entire mass disinte- in both compressivestrength and modulus of - t^t grates.To prevent disintegration,various rupture a standardunfired brick. The L-U+t soil than {eH stabilizersare added to the basic soil mix to majority of quemadosused in New Mexicoare [[f5[mmwaterproof or increasethe weatheringresis- producedin the northern border areasof Mex- tanceof the adobebrick. The most commonly ico and are shippedinto the United Statesduty used stabilizersare sand, straw, portland ce- free. Njqment,lime, and bituminousand asphaltemul- il.ffi:8n sion (Clifton, 1977),although as many as 20 Geology different materials have been found in usage Usable adobe materials are found in large *4 (Wolfskill, 1970). areasof New Mexicoand constitutea virtually For commercial purposesin New Mexico, inexhaustiblereserve. The adobematerials are ililffir asphaltemulsion is usedexclusively because of obtained principally from the Quaternary al- _fiA#its superiormixing and waterproofing proper- luvial deposits in stream channels, flood ties. plains, terracesand alluvial fans. The major- 3) Traditional adobe brick-Often referred ity of depositsconsist of clay, silt, sand, and to as an untreated,unstabilized, or standard gravelmixed in the samedeposits. sun-driedadobe brick, the traditional adobeis The largest number of adobe-brick pro- made with soil composedof a uniform mix- ducersare located in the Albuquerqueand FIGURE 2-RnpnooucnoN or EcyprrAN HtERo- ture of clay, sand, and silt. Usually straw is Espaffolabasin areasof the Rio Grandevalley ct-ypn oF QurtN FlnrsnEpsur MAKTNo A MUD addedto the adobebrick to preventthe brick where significant quantities good adobe nnrcr (Fathy, 1973). of from crackingwhile beingcured. materials are obtained from the flood plains Meanwhile,the New World was undergoing 4) Semistabilized-adobebrick-Essentially of the Rio Grande and adjacent terracesand a similar development.Younger civilizations the sameas a traditional brick, the semista- plains.For detailedinformation on the major in the westernhemisphere, dating from 3,000 bilized adobe is classifiedas a water-resis- locations of adobe materials, seethe geologic B.C. in the Chicama Valley in Peru, used tant brick becauseof the addition of a small reports and maps of the Espafiola and Albu- adobe(Steen, 1972).The first adobeconstruc- amount of asphalt emulsion(4 percentor less querquebasin areas(Kelly, 1977and 1978). tion in what is now the United Statesprobably by weight). The adobe contains a sufficient Several large-scaleadobe manufacturers lo- amount protect doesnot predatethe l0th or I lth centuryA.D. of stabilizer to stockpiled catedin the basinareas also use crusher waste Traces of hand-formed brick and puddled adobes from local rains and the production or fines purchasedfrom the local sand and gravel adobealong with stonemasonry are evident in cost is significantly lower than that of a fully operations.These fines usually contain stabilized 15-18 percent produces good many of the famous archaeologicalruins of brick. clay which a 5) Stabilized-adobe adobe the southwest United States, including old brick-The fully stabi- brick. Picuris Pueblo, Sapaweand Pajarito Plateau lized adobe, referred to by the New Mexico Building sites (Steen, 1977)within the state of New Code as a treatedadobe, is definedas Mexico. With the arrival of the Spanishcolo- containing a sufficient amount of stabilizerto nials in the 16th century, the standardformed- Iimit the brick's water absorption to lessthan percent. adobe brick made by using a wooden mold 2.5 The fully stabilizedadobe, usually wasintroduced to thesouthwest. manufacturedwith 5-12 percentasphalt emul- sion, is a Adobe bricks are still made in the tradi- completelywaterproof building ma- New A4exfic@ terial which will resist without tional way by hand methodsat the site of con- water even a protective struction. Today, however, even on smaller coating. GEOLOGV jobs, the trendhas been to purchasethe bricks 6) Pressed-adobe Dricks-This type of o Scisncsand Ssrvice ready-made.These adobebrick is manufacturedfrom traditional bricks are manufactured VolumeS, Numb€r2, Mey 19ei commercially on a large scale at centrally or stabilized adobe materials pressed into located adobe yards where the right soil is densebricks of various sizesusing either a publishedquanerly by gasoline-poweredhydraulically New MexicoBurcau of Min6 and Mineral Resources available. The controlled conditions of operatedma- a divisionof New MexicoInstitute of Mining& Tshnology manufactureassure a uniformly good product chineor a hand-operatedpress referred to as a "cinva-ram." Becauseof the high mechanical BOARD OF RMENTS and a continuous supply of adobe bricks; the Ex Officio increasinglyimportant commercial manufac- pressureapplied by the press,the resultant Bruce King, Oovemor of NewMexko ture of adobeswill paper. bricks test very high on the compressiveand Leonard Delayo, Srp?zz lendenl o! Public Ins!ruction be discussedin this Appointed modulus of rupture tests(these tests are ex- William G. Abbott, Pres.,| 961-1985,Itorhs plainedin the sectionon physicalproperties). Judy Floyd, 1977-19t7,Los Cruc6 Terminologyand generalcharacteristics Osen Lopez, 1917-1983,Sonta Fe 7) Terrone-This Spanish word meaning Dave Rice, 1972-198!, Corlsbqd Some of the common terms used in the "a flat clod of earth" refers to the type of SteveTores, Sety/Tres. , I 967- I 985, Strouo adobetrade are: adobe brick made of cut sod or turf material New Mexicolnstitutc of Mining& Ttrhnology l) Adobe soi/s-A term applied to clay and found in boggy river-bottomlocations, par- President- .... Kennethw.Ford silt depositsusually occurring in the basin ticularly in the Rio Grande flood plain areas Nes MexicoBureau of Minc & Mineral Rercurces Director . .. FmnkE.Koftlowski areasof the state. Adobe bricks can be made (McHenry, 1976).The terrone usually mea- Deputy Director Georg€S , Austin from a widevariety of localsoils, but the most sures8" x 6u x 14", is cut from thesod areas Editor-Geologbt ...... Robenw.Kelley suitable soil found in the Rio Grande basin usinga flat spade,and then is stackedin a dry Subsriptio6: Issued qwnerly, February, May, August, area is a sandy loam composedof roughly areato properlycure. Probably because of the Novmber; sub$dprion price$4.00/yr. 55-75 percent sand and 25-45 percent finer sod-rootstructure and the high clay content of Editoriol molter Contributionsof lDssiblematerial for con- siderationin future issueso.f NMC are welcome.Addre$ material (generallyequal parts of silt and the soil, the terroneshave a high compressive inquiriG to Neq Mexis Gslogy, N€w Mexico Bur6u of clay). A proper balance of clay and sand is strengthand modulus of rupture. Mines& Mineral Resourcc,S6ono, NM 87801 critical to insure a quality adobe. Clay gives 8) Quemado (burnt adobe)-Having the Arflhtior: |,2@ strengthto the brick but in excessiveamounts samesoil compositionas a traditionaladobe, Prirrer. UniveNity of New MexicoPrinting Plant will causeshrinkage; sand is addedto decrease the quemadois simply a sun-driedadobe brick

May l98l New Mexico Geology Mineralogy of adobeclays 2405of the 1977revision of the New Mexico sorptiontest is importantonly if the bricksare (Commerce left unplasteredor if necessitatedby a building Clay-sizematerial is the chief binding agent State Code and Industries Divi- requirementof the architector federalhousing in adobebricks and the majority of the clay- sion, 1979).The sectionsof the code on un- agency. In general, a considerablerange of sizematerial consistsof clay minerals.Four burned clay masonry statebasic requirements valuesexists for the physicalproperties of the clay-mineral goups are commonly repre- concerningadobe brick, including regulations adobebricks testedfrom 56 locationsthrough- sentedin New Mexico'sadobe clays. The high- on soil composition,standards of water ab- the state. This variability in data is the aluminum kaolinite group and the high-potas- sorption,compressive strength, and modulus out result of differences in the composition of sium illite group generallymake up about one of rupture, as well as construction specifica- adobe soils, methods of producing adobe half of the clay present in the 39 samples tions. The New Mexico Code requiresthat an bricks, and the quality of workmanship.The tested.Both groupsare regardedas nonexpan- adobebrick have a compressivestrength aver- range of compressive-strengthvalues for the ding or only slightly expandablein the pres- aging 300p.s.i. This standardassures that all adobe brick varied from a low of ence of water. The calcium- or sodium-rich units from the tested-brickbatch will resist a sun-dried 196to a high of 1,071p.s.i. The modulusof smectite group and the mixed-layer illite- compressiveforce equal to 300 lbs for each rupture ranged from a low of 20 to a high of smectitegroup contain varying expandingclay square inch of surface area. The importance p.s.i. Resultsof the seven-daywater-ab- mineralsand alsomake up about 50 percentof of this test for a relatively heavymaterial such 89 testson the stabilizedadobes ranged the clay minerals present. A member of the as adobe brick is apparent when considering sorption 1.3 5.0 percent,and the moisturecon- chlorite group was found in only one New the great amount of weight a typical wall unit from to rangedfrom 0.4 to 1.5per- Mexico adobeclay material and the vermicu- must resist.In addition to the weight of the tent of the adobes The New Mexico State Code requires lite group was not represented. roof structure supported by a load-bearing cent. (stabilized)adobe brick the The presenceor absenceof a particular min- wall, each layer of bricks must support all that for a treated not exceed4 percentand eral and total amount of clay mineralspresent others aboveit and must dependon the com- moisturecontent will will not exceed2.5 per- affect the physical properties of the adobe pressivestrength of the lowerlayers to support the water absorption weight. The physical test results on bricks. A clay material with a high percentage it. cent by different types and sizes of adobe of nonexpandableclay minerals, particularly The other test requiredon all typesof adobe several in table2. the kaolinite group, tends to be more brittle bricks is the rupture test. This test helpsin- bricks are shown dicate the relative cohesion of the materials than one with moreexpandable clay minerals. Techniquesof adobebrick production Similarly, a clay material with a large percen- that make up the adobeand the ability of the brick operation is a labor-inten- tage of expandableminerals will produce a material to resist the tension or shear forces The adobe industry employing easily brick of greatercompressive strength than one that might result from settling of foundations sive, fuel-efficient materials. Production containing the sameamount of clay, but with or wind action. In testing for modulus of rup- extracted, indigenous is a seasonaloperation and a larger percentageof nonexpandableclay ture, the adobeunit is placedon two supports of adobebricks number of frost-free minerals. Thus, an adobematerial with more and a force is appliedto the centerof the unit. usually is limited by the particular adobeyard. In general expandableclay minerals, but less total clay, Strength of the brick can be calculatedfrom daysfor that production variesfrom 5 to 9 mos, will have a strength equal to one with more the amount of applied force that is taken to the season climate and weather condi- clay but fewer expandableclay minerals. break it. Other testsare usedon semistabilized dependingon the in various sizes ac- However, a clay material with an abundance and stabilizedadobes to determinethe water- tions, Bricks are made of expandableclay minerals, particularly the resistancequality of the bricks. The water ab- smectitegroup which is the most expandable, may make a poor adobeclay. In suchclays, TABLE 2-PHysrcAL TESTREsuLTs oN vARrous rypEs ANDsrzEs oF ADoBEBRIcKs (average of samples/test). expansionand contractionof the clay minerals may causeexcessive cracks in the adobebrick. Type adobe Size Compressive Modulus of rupture(p.s.i.) Remarks More silt- or sand-sizematerial, or evenstraw, brick in inches strength(p.s.i.) can be added to the mix to minimize this ef- Traditional l0x4x14 383 Averagetest results fect. from 34 adobe makers Calcite (CaCOr) is also found in the major- Traditional 8x 3/z x 16 426 5l Adobe from Las ity of the adobe-claysoils testedin New Mex- Palomas,Mexico ico and is typical of adobesoils throughout the Traditional 8x 4x 12 615 68 Adobe from Rancho de arid Southwest.Calcite in the clay-size frac- Taos area tion also may act as a binder in adobebricks. Traditional 8%x4Vzx17 451 )) Old adobe(45 + yrs) If heat at moderatetemperatures is applied, a from Chamisal brick of this type of clay may have increased Terrone 8x6x14 53 Terrone from Isleta strength. However, if the temperatureis ele- Pueblo vated to structural-brick temperatures (ap- Terrone 7%x4xl5V2 261 20 Old terrone (145+ yrs) proximately1,800o F or l,000oC),the calcium from Algodones,NM ion of the calcite acts as a flux, lowering the Quemado 8x3%x16 w 180 Burnt adobe from Las firing temperature and narrowing the firing Palomas,Mexico rangeto the point wherea brick with relatively Pressed l0x3x137/8 1,071 Machine-operatedpress low bonding strength becomesa melted blob located in Mora area of glassin a very short rangeof temperatures. Pressed SVzx3t/+xll7z 769 69 Made using a cinva-ram Therefore, such clays make very poor struc- press tural brick clays. Pressed SVzxSY4xll% 580 54 Asphalt emulsionadded to adobemade using a Physicalproperties cinva ram Certain minimum requirementsor specifi- Semistabilized l0x4x14 388 76 Averagetest results cations have been developed regarding the from 6 adobe makers durability, strength, thermal characteristics, Stabilized l0x4x14 426 9l Averagetest results and fire safety of various building materials from 6 adobe makers g5 used in construction(Long, 1946). In New Stabilized 7%x3Vzx15 2N Test resultsfrom Hans Mexico the building of adobe structures is Sumpf Company, CA regulatedby specificationsadopted from the Traditional l0x4x14 tl4 5t Old adobe(100+ yrs) Uniform Building Code outlined in Section from San Juan Pueblo

New Mexico Geolog! May l98l cording to intended use; the principal cal breakdowns,an averageof 5,000to 7,000 Mining and Technology, for their excellent standard-sizeadobe brick used in this state adobesper day can be produced. work in testing the various physical properties measures4" x 10" x l4,,and weighsapprox- The second mechanizedmethod of large- of adobes and to Sharon Murray and Florence imately30 lbs. An averageof one (l) cu yd of scaleadobe production uses a 7.5-cu-ydready- Maestas of the Eight Northern Indian Pueblos adobesoil is usedto produceapproximately 80 mix truck. The adobe soil is loaded into the Council for their assistance and preparation bricks.Other sizes and typesof adobesusually truck cementmixer and the proper amount of of the manuscript. I wish to thank the various are made upon specialorder. The three major asphalt emulsion and water are added. The adobe manufacturers, adoberos, geologists, techniques of adobe production have been truck then deliversthe mixed mud to a series architects, engineers, soil scientists, ar- classifiedas follows (University of New Mex- of wooden forms laid out in the adobe yard. chaeologists, and adobe contractors who re- ico, 1970): The owners of the Adobe Patch in Alamo- viewed the original manuscript and offered l) Traditional hondcrafted method-This gordo have constructed a mechanical adobe many helpful suggestions. relatively simple processinvolves the mixing layer (fig. 4) that attachesto the ready-mix of soil, water, and sometimesstraw in a shal- truck and operatesoff its power equipment. References low mud pit by using a hoe or by foot tread- The systemmolds adobessimilarly to the self- California ResearchCorporation, 1963,The manu- ing. Wooden forms that will produce a single propelledadobe layer. facture and use of asphalt emulsion stabilized brick or multiplebricks are laid out on smooth adobe bricks: Richmond, California, California and level ground and the mud is placed in ResearchCorporation, 16 p. them and tamped into the corners.The top is Clifton, James R., 1977, Preservationof historic smoothed off and the form removed. The adobe structures-a status report: Washington, D.C., Institute for Applied forms are then washedclean and the processis Technology,National repeated. Bureauof Standards,NBS TechnicalNote 934, 30 As the bricks dry e-3 days in sum- p. mer) they are turned on edge,trimmed of ex- Commerceand IndustriesDivision, 1979,New Mex- cessmaterial or rough edgesand, sometime ico uniform building code amendments:Com- later, are stacked for delivery. This system, merceand IndustriesDivision, GeneralConstruc- utilizing two to three adobemakers, can pro- tion Bureau,p. l8-20 FICURE 3-Serr-pnopnllED MEcHANTCALADoBE duce300-500 adobe bricks per Fathy, Hassan, 1973, Architecture for the poor: day. LAyER LocATED AT THE ADoBE yARD rN Slr.t Juax Chicago, Illinois, University of Chicago p. 2) Semimechanizedmethod-This Pusnro, Press, method NBw Msxrco. 236 of production is similar to the traditional Kelley, V. C., 1977,Geology of Albuquerque handcrafted method Basin, except for the addition New Medco: New Mexico Bureauof Mines and of mechanicalequipment, most frequently a Mineral Resources,Mem. 33, 60 p. front-end loader. The loader is usedto move 1978, Geology of Espaffola Basin, New or excavatethe soil, to mix the soil in the mud Mexico: New Mexico Bureauof Mines and Min- pit, and to carrythe adobemud to the wooden eral Resources, Geol. Map 48, text, scale forms. Dependingon the weather, the bricks l:125,000 are allowed to dry in the forms for several Long, J. D., l9K, Adobe construction: California hours or until they haveshrunk from the form Agricultural ExperimentStation, Bull. 472, 63 p. McHenry, P. G., 1976,Adobe, build it yourself: sides. The forms are then removed and the Tucson, Arizona, University of Arizona Press, adobesallowed to dry for 2 to 3 daysat which 157p. time they are turned on edge, trimmed, and Steen,C. R., 1977,Pajariro Plateauarchaeological later stacked for delivery or storage. The FICURE 4-Use or A 7.5-cu-yDREADy-Mrx rRUcK survey and excavations:l.os Alamos Scientific -4, adobemakers may useas many as severalhun- TO POUR MUD TNTO AN ATTACHED MECHANICAL Laboratory, LASL-77 70 p. dred of the woodenforms at a time to achieve ADoBELAYERATTnT Aoogp Percn, Le Luz, New 1972, kr archaeologist's summary of a productioncapacity of 1,500-3,000adobes Mexrco. adobe:Musuem of New Mexico, p.29-39 perday. Universityof New Mexico, Center for Environmen- AcKNOWLEDGMENTS-Grateful acknowl- tal Researchand Development,and 3l Mechanized method-Two large-scale Four Corners edgmentis made to Dr. GeorgeAustin, Dep- RegionalCommission, 1970, A study of the feasi- mechanizedtechniques for adobe production uty Director, New Mexico Bureau of Mines bility of mechanizedadobe production: University include the use of the pugmill mixer with the and Mineral Resources,for his support of this of New Mexico, Center for Environmental Re- mechanicaladobe layer and the useof a readv- project and his work in identifying the various searchand Development,and Four Corners Re- mix truck. Examplesof the first typeof gional Commission,48 p. opera- minerals associatedwith the adobe clays. Ac- tion are the WesternAdobe Plant Wolfskill, L. A., 1970, Handbook for building located in knowledgment is made to Drs. Tibor Roz- Albuquerque and the Eight Northern Indian homesof earth: Office of International Affairs, gonyi and Kalman Oraveczof the Rock Me- PueblosNative ProductsDivision plant at San Departmentof Housingand Urban Development, chanicsLaboratory, New Mexico Institute of 160p. Juan Pueblo.In both of theseoperations, the ! sandy loam soil of the areais removedeither by grading and levelingof the production site TABLE 3-LIsror epoBEBRrcK pRoDUcERs AcrtvE rN l9E0(for locations,see fig. l). or by delivery from nearby deposits.The soil is screenedand conveyed Approrlmrtc to one end of the rntrrd trough of the pugmill. Two shafts, studded Mrpoo. CouBay Nmc rtrd Ioqalotr TclcphoDc preducdot Typc preducdon cqulpmetrt with paddles,rotate in the trough of the pug- New McxicoEarth 898-1271 700,000 Front4nd loaq€s, pugmill, woodm foms, mill, and an operator controls the feed of P.O. Box 10506 md d€livsy trucks soil, water,and asphalt Alameda, NM emulsion.The materi- Richard kvine, Owner als are thoroughly mixed in the trough and Westm Adobe E3erE39 250,0@ Front-md loada, pugmill, Hms Smpf type dumped into a mud pit where they are re- 7800TowerRoad, SW mchmical adobe layer, md deliyery trucks moved by a front-end Albuquerque,NM loader which carriesthe DeanLeach, Owner mud mix to a nearby molding machine. This Manu€lRuiz t9E-t913 175.0@ Front-end loadq, woodm fom, md delivery self-propelled mechanized adobe layer or P.O. Box 104 trucks molding machine,mounted on wheels,molds Conales,NM twenty-five4" >< Frank Cutienez Front-md lmder, wmden foms, md delivery 10,, x l4,,adobe bricks at N.S. Rt. Box 595 truck one time (fie. 3). Different molds of various Conales,NM sizesand brick shapescan be mounted on the Pcte Garcia t98-27t0 45,000 Front-end lmder, wmden foms, and dclivqy Rt. 464, Box DOR truck machine.With good weatherand no mechani- Conales,NM

May l9El New Mexico Geolog/ Bemalillo AdobeEntcrpriFs, lnc. 87743t5 500,000 Front-end loader, wooden forms, and delivery 6000Poweruay, SW trucks Albuquerque,NM ErnestSanchez, owner Bemalillo lswrenceTenorio 898-8792 10,000 Front-endloader, plaster mixer, wooden Geographicnames P.O. Box555 foms, and deliv€rytruck Corrales,NM U.S.Board on Geographic Names Cahon Aragon/GarciaAdobes 533-641l, 15,0@ Front-endloader, wooden forms, ald delivery c/o CeneralD€livery 533{313 truck Aragon, NM Bennett Mountain-mountain, highest point Eddy Adobworks 1464455 30,0@ Front-€ndload€r, ready-mix truck, 2,187m (7,175 ft) in the San Andres Moun- l2O4Dalld Ave. m€chmicaladob€ layer, and deliverytruck north 5.6 km (3.5 mi) from Artesia,NM tains, extends Jeny and GladysHolt, Owners Bear Canyon 37 km (23 mi) northeastof Las l0 Luna HachitaAdobe 546-6&6 45,000 Front-endload€r, cement mixer otrtractor' Cruces,Doffa Ana County,'NewMexico; T. truck 100E. PeachSt. woodenfoms, and delivcry 20 S., Rgs.4 and 5 E.; New MexicoPrincipal Deming,NM ' GordonGarland, Owner Meridian 32" 34' 50'N., 106' 27 50'W. Mora David Griego 387-5183 7,000 Pona-pressadobe machine (northend), 32o 32' 20' N', 106' 28' 55' W' P.O. Box 66 (south nol.'GoatMountain. Le Doux, NM end); t2 Mora RobertGarcia No phon€ l8,O0O Hoe, shovel,wheelbilrow, and woodenforms c/o G€neralDelivery Compana, Cerro de la-mountain, elevation Le Dou, NM ' (5,712ft) in Jornadadel Muerto 17.7 Otero TheAdobePatch 437-9932 350,000 Front-endloader, ready-mix tluck, 1,741m Rt. I, Box 240 mechanicaladobe layer, and deliverytruck km (11 mi) east-southeastof San Antonio; Alamogordo,NM descriptive name meaning "Bell Roben Godby and Spanish Howard Scoggins,Owners Mountain," Socorro County, New Mexico; Rio Arriba Eight North€m Indian Pueblos 7534tr'6 436,000 Front-endloader, pugmill, Hms Sumpf sec.25, T. 5 S., R. 2 E'; New MexicoPrincipal P.O. Box 969 mshanical adob€layer, and deliverytrucks Meridian33o 50' 47' N., 106"4l' 4l" W.; SanJuan Pu€blo, NM D€nnisDuran, Mgr. not: Cefio Colorado, Cerro Colorado Moun- Rio Arriba RobertOnega 5794261 30,000 Ho€, shovel,wheelbarow, and woodenforns tain, Red Mountain. c/oGeneralDelivery Dixon, NM t6 Rio Arriba Medina'sAdobe Factory 852-2467 50,000 Front-endloader, ready-mix truck' Goat Mountain-mountain, highest elevation P.O.Box65l mechanicaladobe layer, and deliverytruck 2,073 m (6,800 ft) in the San Andres Moun- Alcald€,NM JG and Mel Medina,Owners tains westof BennettMountain and 37 km (23 Rio Arriba Atrtonio Senano 538-5530 1,000 Hoe, shovel,whtrlburow, and woodenfoms mi) northeast of Las Cruces, Dofla Ana P.O.Box64 New Mexico;secs. 14' 23, and?-6,T' Canon6, NM County, 20 S., R.4 E.; New MexicoPrincipalMeridian Rio Ariba FelixVald€z 63t-5446 5,0oo Front-€ndloader, wooden forms, and d€liv€ry ',55'w. c/oGcneml D€livery truck 32"33',30',N., 106'29 Caflon€s,NM Rio Arriba Andy Trujillo No phone 6,000 Hoe, shovel,wheelb&row, and woodenfoms c/o GeneralDelivery Laborcita-populated place, in the Rio Abiquiu, NM Grandevalley, 3'2 km (2 mi) north of SanAn- Smdoval Big "M" Sand& Cinder E67-5498 9,000 Front-endloader, wooden forms, and delivery patch of P.O.Box 33 trucks tonio; Spanishname meaning "small B€rnalillo,NM tilled land" and originally applied to this area Tim Montoya, Mgr. becauseit was a cluster of small farms; So- Smdoval D. Sandoval/E.Trujillo 455-2972 2,000 Hoe, shovel,whelbarrow, and woodenforms secs.19 and 20, P.O.Box 1283 corro County, New Mexico; Peia Blan€, NM T. 4 S., R. I E.; New Mexico PrincipalMeri- SanJuan D. T. wiley tt4-6341 12,000 Front-endloader, wooden forms, and deLivcry dian33' 56' 45'N., 106o52' OsnW.; nol.'La P.O. Box 879 truck Aztec,NM Borcita,Lavorcita, River View. Su Migucl Marino Rom€ro 425-8202 10,000 Front-endloadq and woodenforms 324Commerce Rd. Las vegas,NM Luis Lopez-populated place, in the Rio Su Miguel Danny Portcr 7574422 14,0@ Front-endloader and woodenfoms Grande valley, 8 km (5 mi) north of San An- P.O.Box lt, Rt. I tonio; namedfor the eighteenthcentury owner Pecos,NM County, New Mexico; tt SanMiguel Robe(Leyba 7 51-6234 8,000 Hoe, shovel,wheelburow, and woodenforms of the land; Socorro P.O.Box 92 sec.l, T. 4 S.,R. I W. andsec' 6, T. 4 S.' R' I Rowe,NM E.; New Mexico Principal Meridian 33o 59' 26 SmB Fe Adobe Fams 7534628 300,0m Front-endloader, ready-mix truck, wooden W.; not: La Borcita, Rt l, Box l93B foms, and deliverylrucks 20'N., 106"53'05" Espaf,ola,NM Luis Lopez Ranch. RalphRivera, Owner t1 Smta F€ Oliver Trujillo 455-2414 60,000 Hoe, shovcls,wheelbarrow, and wooden Rt. l, Box ltTC forms Malone Draw-watercourse, ll.3 km (7 mi) SantaF€, NM long, in the TularosaValley, headsat the iunc- 2t SantaFe ChillescdcBa€ 41t-1 9 4,000 Hoe, shovcls,shwlbmows, andwooden Creekat Rt. 2, Box 246 foms tion ofan unnameddraw and LaLuz l: Cienega,NM 32o 57' 53' N., 106' 02' l3o W., trends 29 SantaF€ EdwardSandoval 455-1447 5,000 Hoe, shovels,whelbarrows, and wooden southwestto join Ritas Draw at the head of Rt. I, Boxt34 foms (9 west of Alamo- SantaFe, NM Lost River 14.5 km mi) Suta Fe RamonValdez/James Lujan 455-2t03 12,000 Ho€, shovels,wheelbarrows, and woden gordo; named for an early settler; Otero Rr. I, Box l0+D forms County,New Mexico; sec.27, T. 16 S.' R. 9 SantaFe, NM E.; New Mexico Principal Meridian 34o 54' Smta F€ Adrian Maddd 983-E616 20,000 Hoe, shovels,whclbdrow, and wooden ' 1580Cero Gordo foms 02' N., 106'06 48' W., ,?ot"Lost River. SantaFe, NM Suta Fe Victor Montano 471-2038 265,000 Front-endloader, wooden foms, and delivcry Rt. 6, Box 79A trucks by StephenJ. Frost, Silta Fe, NM NMBMMR 33 Silta Fe Eloy MonBno 9E3-1532 235,000 Front-€ndloader, h@ and shovels,wooden Correspondent Box517 foms, and d€liverytrucks SantaFe' NM (continuedon p. 24)

New MexicoGeology May l98l uplift (Chapin, 1979),exhumed the Socorro 1980, Cenozoic stratigraphy and structure Eggleston,T. L., in progress,Geology of the central and Lemitar blocks and elevatedthem suffi- of the Socorro Peak volcaniccenter, central New and southern Chupadera Mountains, Socorro Mexico: New Mexico Bureauof Mines and Min- County, New Mexico: M.S. thesis,New Mexico eral Resources,Open-file Rept. ll8, 2 vols., 495 Institute of Mining and Technology p. Morton, W. H., and Black,R., 1975,Crustal atten- Chapin,C. E., 1979,Evolution of the Rio Grande uation in Af ar, in Afar depressionof Ethiopia, A. rift-a summary, lz Rio Grande rift-tectonics Pilger and A. Rosler,eds.: Stuttgart, Schweizer- and magmatism,R. E. Riecker,ed.: Washington, bart, p. 55-65 D.C., AmericanGeophysical Union, p. l-5 Osburn,G. R., and Chapin,C. E., in preparation, Sierra Ladrones Formation form westward- Chapin,C. E., Chamberlin,R. M., Osburn,C. R., Stratigraphicnomenclature for Cenozoicrocks thickening of wedgesin the Socorroand La Jen- White,D. L., and Sanford,A. R., 1978,Explora- the northeasternDatil-Mogollon volcanic field, cia Basinsto the east and west of Socorro tion framework of the Socorro geothermalarea, New Mexico: New Mexico Bureauof Mines and Peak (fig. l). Just east of the high-angle New Mexico, rz Field guide to selectedcauldrons Mineral Resources,Stratigraphic Chart I (65-75 degrees)range-bounding fault zone at and mining districtsof the Datil-Mogollon vol- Osburn,C. R., and Petty, D. L,, in preparation, the foot ofSocorro Peak,the SierraLadrones canicfield: New Mexico GeologicalSociety, Spec. Geologyof the Molino Peakquadrangle, Socorro Pub. No. 7, p. 114-129 Formationis at least350 m thick and may be County, New Mexico tr significantly thicker. About 4 m.y. ago, ChacoEnergy olivine basalt lavas that were erupted from donates$6,500 to Bureauof Mines Chaco Energy Co. has given to the New ventsnear Sedillo Hill (basaltof SedilloHill) $6,500 Mexico Bureau of Mines and Mineral Re- sources,a division of New Mexico Institute of Mining and Technology,as flowed eastwarddown a broad valley cut on second-yearfunding to study fossil plant remainsnear Hospahin northwestNew Mexico. the upper Popotosa playa facies and onto The nature of the plants is significant in channel sandsof the ancestralRio Grande _ the formation of the coal depositsleased by Chaco EnergyCo. Theseplant remainsinclude anci€nt (SierraLadrones fluvial facies).Since 4 m.y. tree stumps,leaves, and roots fossilizedin place in the Cretaceousswamps, well ago, the modernranges have continued as as driftwood bar and beach deposits.Standing fossii tree to rise trunksin growthposition and shed piedmont gravelsthat areknown from scatteredareas of the san JuanBasin. intertongue A. T. Cross,professor of geology with the fluvial sands. at MichiganState University, and co-workerA. Jameos- sanaieare interpreting the plant collections.John Taylor of the ChacoEnergy staff hasmapped In late Quaternarytime continueduplift, - thegeology of the fossillocalities and providedcores of fossil-bearingrockrfrom Chaco'sdiiu- faulting, and entrenchmentof tributariesto ing program. Studiesof nearbyvertebrate fossils in coal-bearingCretaceous rock bedsare the Rio Grandehave all enhancedthe modern being conductedby D. L. Wolbergand studiesof marinefossils by S. C. Hook, both paleontologisti topography.Upper Popotosa playa claystones with theNew MexicoBureau of Minesand MineralResources. on the flanks of the Socorro Mountains are largely masked by landslide blocks derived AdobeV oducton rc", fi ,r, df , from the Socorro Peak Rhyolite. patterns of elevation variation in late Miocene and plio- ADproximr(e rtrnurl cenelavas, when coupledwith moderndrain- Mrpno. Counly Nrme rnd locralotr Tclcphonc producdon Type productlonequipmcal age patterns,suggest the possibility of late magmatic Suta Fc Al Montano 47 t4227 2,0@ Hoe, shovels,front-end loader, and wooden Quaternary doming along an axis Rt 2, Box224 forms trendingwest-southwest from Socorropeak. SantaFc, NM Snta Fe Albcn E. Baca 455-1542 3,000 Hoe, shovels,and woodenforms Rt. I, Box99 Conclusion SantaFe, NM The primary controlof recurrentmagma in- SantaFc RodriguczBrothers 47t-1510 100,000 Hoc, shovcls,front-end loadcr, woden Rt. 6, Box22 foms, and deliverytrucks trusion, hydrothermal activity, and silicic SantaFc, NM volcanism at Socorro Peak has been the SantaFc Tod Brown No phone 3,000 Hoe, shov€I,and woodenforms "leaky" Morenci lineament,expressed as a c/oGeneral Dcliverr Ccrrillos,NM transverseshear zone of the Rio Grande rift. SantaFe Montoya Adobes 988-3504 10,000 Hoe, shovel,and woodenforms Eruptiveperiods in the Socorropeak volcanic 420Arroyo Tenorio centerhave beendated at 33-29, l2-9,7, and, SantaFe, NM 4 m.y. In light of this pasthistory, it is not sur- Taos Emilio Abeyta 158-3022 12,000 Hoe, shovcls,wheelbarrow, and wooden prising P.O.Box 177 foms that geophysically defined magma Ranchod€ Taos,NM bodies,which provide a heat sourcefor the Taos TaosPucblo 758-8761 47,000 Backh@,hoe, shovels, wheelbarrow, and presentgeothermal anomaly, are again rising Nativeproducts woodenfoms P.O.Box 1846 under the SocorroPeak volcanic center. Taos,NM ACKNoWLEDGMENTS-C.E. Chapin and G. Maniotr Thrcehawks,Mgr 4l R. Osburn,both of the New MexicoBureau of Taos JcTrujillo 758-976t 60,000 Front-endloader, ready-mix mounred on P O. Box633 ground,wooden foms, and deliverytruck Mines and Mineral Resources,critically re- Ranchode Taos,NM viewedthis manuscript.Many of the key inter- Taos RalphMondragon 758-3644 15,000 Pugmill, mud vehicle,and woodenfoms pretations presentedhere were initiated P.O.Box 199 by C. Ranchode Taos,NM E. Chapin or developedjointly with him dur- Taos JcPachrco 758-9E48 2,000 Hoe, shovel,whe€lbarrow, and woodenforms ing the author'smapping of the Socorropeak P.O.Box 174 area. Financial support for the dissertation Taos,NM was provided by the New Mexico Tonance HumbertoCamacho No phone 5,000 Hoe, shovcls,wheelbarrow, and wooden Bureau of P.O.Box63l foms Mines and Mineral Resourcesand by a grant Mounrainair,NM Valencia Q6-nl) from the New Mexico Energy Re- Rio Abajo Adobcs t64-6191 150,000 Fronr-endloader, wooden forms, and delivery sourcesBoard 105W. Aragon truck throughthe EnergyInstitute at Belcn,NM New Mexico StateUniversity. Jeny Sanchez,Mgr. Valencia Otero Brothcrs 864454 40,000 Fron[-endload€r, woodcn forms, and delivcry Rt. 2, Box 774 trucks References Los Lunas,NM Chamberlin,R. M., 1978,Structural development Stateof Alfon$Canillo No phonc 30,000 Hoe, shovels,and woodcnforms Chihuahua, Las Palomas,Mexico of theLemitar Mountains, an intrarift tiltedfault- Mexico blockuplift, centralNew Mexico (abs.): Los AIa- Stat€of LconardoDunn No phone 5,0m Hoe, shovel,and woodenforms mos ScientificLaboratory, Conference proc.. Chihuahua, Ils Palomas,Mexico LA-7487-C,p.22-Vl Mexico

May l98l New Mexico Geology