Reinterpretation of Bioherms As Submarine Channels, San Andres

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Reinterpretationofbioherms assubmarine channels, SanAndres Formation and Gherry Ganyon Tongue (upperLeonardian and lower Guadalupian, Permian), Brokeotfand Guadalupe Mountains, southeastern New Mexico byCtifford A. Cutfey,Deparlnent ol Geological Sciences, Ohio State University, Columbus, Ohio 43210; and iohn T.Lembcke,-school of Geology and Geophysics, University ol Oklahoma, Norman, 0klahoma 73019

(1958)and Hayes Abstract Iupe Mountains, Boyd Stratigraphy (1964) organicbioherms. reported several The Brokeoff and central Guadalupe The San Andres Formation and Cherry Boyd them as consisting of a described Mountains of southeasternNew Mexico, Canyon Tongue (upper Leonardian and core surrounded by flank beds. The cores specificallywestern Eddy and eastern lower Guadalupian, Permian) of south- were described as being sparsely fossil- eastem New Mexico (Otero and Eddy Otero Counties (Figs. 1.,2), exposea thick iferous, massivecarbonate mud (now dol- Counties) include submarine-slopede- sequence of Permian carbonate and ter- with sponges and lyttoniid posits and contain carbonatebodies pre- omitized) rigenous rocks (Fig. 3; Boyd, 1.958;Hayes, brachiopods. The flank beds were de- viously interpreted as organicbioherms. 1954). The upper Leonardian (Roadian) scribed as consisting of skeletal-rich car- Examination of these bodies in outcrop and lower Guadalupian (Wordian) San yields significant observationsand per- bonate beds that dip away from the core Andres Formation and Cherrv Canvon mits a reinterpretation of their origin. edge; these layers reportedly contain Tongue(Figs. 3,4; Cooperand Grant,1972; Six lithofacies are recognized: massive abundant lyttoniid brachiopods. These Sarg and Lehmann, L986; tNilde, 1986; carbonate mudstone, cherty carbonate features thus appear to be poorly pre- Ross, 1987) were deposited along the mudstone, fusulinid packstone,skeletal served analogs of the sponge-bryozoan- packstone,skeletal siltstone, and unfos- northwestem margin of the Delaware Ba- brachiopod bioherms described by Bain siliferous siltstone. The most important sin. In this region depositionalstrike trends (1967)and Cooper and Grant (1972)ftom stratigraphic features are channelforms southwest to northeast, parallel to the ba- the Glass Mountains. Consequently,they filled with low-angle inclined beds of sin margin (Boyd, 1958).Here, Boyd (1958) would be important becausethey would skeletal packstone,fusulinid packstone, recognized three primary faciesbelts: the and skeletal siltstone. These lithofacies provide evidence of similar depositional contain the only significant faunas, con- settings on opposite sidesof the Delaware sisting of brachiopods, bryozoans, horn Basin and would provide additional in- corals, crinoids, pelecypods, and fusu- formation pertaining to the paleoecology linids. The tabular accumulations of loose Alsoin thisissue especially the niches filled fossilsare intelpreted taphonomicallyas of lyttoniids, shell heaps of allochthonous skeletal by these brachiopods in reef building and MiddleJurassic Summerville material. The massive carbonate-mud- dwelling. However, carbonate lenses in Formation-replyto the Bone Spring and Getaway Limestones stone lithofacies does not contain evi- p.33 dence of in situ biologic activity nor (both slope and basin deposits exposedin Andersonand Lucas exhibit mound-shaped geometry and the Guadalupe Mountains) that previ- ZuniSandstone and Acoma therefore does not represent bioherm (New- ously were interpreted asbioherms p. cores. Thus, the channelforms are in- ell et al., 1953),now are considered Tonguedefined 38 terpreted as broad, shallow submarine allochthonous blocks of bank and bio- scoursand channelsfilled by lateral and Precambrianisotopic ages P.40 hermal sediment derived from the shelf vertical aggradation of skeletal debris that Service/News 43 was transported downslope from the edge and transported into slope or basin P. bank edge by bottom currents. The mas- environments (Pray and Stehli, 1952;Har- Upcomingmeetings p.44 sive carbonate-mudstone units are re- ris and Wiggins, 1985;Cuffey, 1987).Fur- interpreted as part of the interchannel thermore, Jacka et al. (1985) recognized NewU.S.G.S. map products P. 44 (possibly slope highs channel levees), Iarge-scalechanneling in the San Andres p.47 part of the channel fill, or initial man- Formation and Cherry Canyon Tongue of Staffnotes tling deposits. the transition belt and interpreted those units as slope, fan, and submarine-can- Introduction yon deposits,thus similar to the deposi- Gomingsoon Bone Spring The Permian rocks of the Permian Basin tional setting of the luoritedeposits (west the intelpretation Sulfide/barite/f region Texas and southeastem New Formation. Therefore, Mountains Mexico), especially the Glass Mountains, of the San Andres Formation carbonate Guadalupe contain abundant sponge-bryozoan- bodies as bioherms seemed suspect. The Proterozoicplutonism and regional brachiopod bioherms (Newell et al., 1953; purpose of this researchwas to reevaluate deformation-newconstraints Bain, 1967; Cooper and Grant, L972). In the origin of these carbonate bodies in fromthe southernManzano the San Andres Formation and Cherry light of more recent sedimentologicinter- Mountains Canyon Tongue exposed in the Guada- pretations of the area. Northwestern shelf, transition belt, and in the transition belt the basal Grayburg Delaware Basin (Fig. 2). Stratigraphic re- interfingers with the uppermost Cherry lationshipsare complexbut elucidatedby Canyon Tongue (Feketeet al., t986;Pray, careful lithostratigraphy, sequence stra- 1988a). tigraphy, and biostratigraphy. Strati- graphic details have been describedby Methods Boyd (1958),Hayes (1959,1964), Fekete To determine the origin of the San et al. (1986),Sarg (1986),Sarg and Leh- Andres carbonate bodies, the two exam- mann (1986),Wilde (1986), and Pray ples considered most likely to be bioh- (1988a);only a summaryof the criticalin- erms, basedon Boyd's (1958)descriptions, terval is provided here. were studied in detail. These are in West In the interval considered, Sarg and Dog Canyon (locality5002) and Cork Draw Lehmann (1986)recognized two major se- (locality 5004; Fig. l, Table1 ). Severalnon- quences.The lower and middle parts of biohermal outcrops also were studied for the San Andres Formation comprise the comparison (Fig. 1, Table 1). First, out- lower sequence(Fig. 4). On the North- crop-scalefield observation permitted western shelf they consistof evenly and recognition of important geometric rela- FIGURE l-Brokeoff and Guadalupe Moun- horizontally bedded cherty carbonatesthat tions of the beds and hence large-scale tains with outcropsof San Andres Formation were deposited on a carbonate platform sedimentary features. Second,macro- and Cherry Canyon Tonguestudied; large stars and bank margin (Sarg and Lehmann, scopic field observationof fresh and : principal : outcrops. small diamonds sub- 1986). To the southeast this facies is re- weathered rock surfaces permitted rec- sidiary outcrops. placed by cherty carbonates exhibiting ognition of six lithofacies. Their attributes large-scale intraformational truncation and distribution within the outcrops were surfacesand channeling, strata inter- recorded.Third, the fossilcontent and their preted as part of the slope into the Del- mode of occurrence within each lithofa- aware Basin (Jackaet al., t985; Sarg and cies were recorded. These data were in- Lehmann, 1986).Farther to the southeast tegrated to provide a more reasonable the lower and middle San Andres For- interpretation of the strata under consid- mation grades into the carbonate muds eration. and terrigenous rocks of the Cutoff For- mation (Fig. a), deposited at the toe of slope and on the basin floor (Boyd, 1958; Wilde, 1985).The tops of theseunits are truncatedby a major unconformity (Hayes, 1959, 7964), interpreted as a sequence boundary by Sargand Lehmann (1986). New A4exfic@ The basalpart of the upper sequenceis the Brushy Canyon Formation, which is GEOLOGY restrictedio the basin and equivalent to o the unconformity on the shelf (Fig. 4; Scienceand Service Wilde, 1986).Subsequent onlapping re- rssN 0196-948X sulted in renewed deposition in the tran- Volume 15, No. 2, May 1993 sition belt and on the Northwesternshelf, Editor: Carol A. Hjellming where noncherty carbonatesof the upper Publishedquarterly by San Andres Formation were deposited New Mexico Bureau of Mines and (Fig. a). Sarg (1986)interpreted this facies Mineral Resources a division of New Mexico lnstitute of as carbonate-platformand bank deposits. Mining & Technology To the southeastin the transition belt, the BOARD OF REGENTS carbonatesinterfinger laterally with sand- Ex-Officio stonesof the upper Cherry CanyonTongue Bruce King, Goaernor ol Nru Muico (Fig. Alan Morgan, Supetintendent of Public lnstructiotl 4; Hayes,1959,1964; Sarg, 1986; Son- Appointed nenfeld, 1990).The upper Cherry Canyon Charles Zimmerly, Pres., 1991-1997, Socorro Tongue consists of interbedded sand- Diane D. Denish, Sec.lTreas., 192-7997, Albuquerque J. Michael Kelly, 1992-1997, Roswell ,l stones and carbonateswith large-scalein- Steve Torres, 7991-1997, Albuquerque oro traformational truncation surfaces and Lt. Cen. Leo Marquez,7989 1995, Albuquerque New Mexico of Mining channeling and is interpreted as slope de- Institute & Technology -l Prnident. . Laurence H. Lattman New Mexico Bureau of Mines & Mineral Resources I posits(Jacka et al., 1985).Basinward these L beds grade into sandstonesof the lower Director and Stote Geologist .. . Charles E. Chapin ^ nl'tn" Sub{iptions: lssued quarterly, February May, August. Cherry Canyon Formation (Fig. 4), inter- November; subscription price $6.o0/calendar year. preted as toe-of-slope,distal-fan, and ba- Editoinl matter Articles submitted for oublication "odoZ sin sedimentsby Jackaet al. (1985). should be in the editor's hands a minimum o[ five (5) months before date of publication (February, The Grayburg Formation, which con- Mat August, or November) and should be no longer sists of interbedded than 20 typewritten, double-spaced pages. All scale(milss) dolomitesand sand- ,l / stones, scientific papers will be reviewed by at Ieast two l./o5ro overliesboth the upper SanAndres people in the appropriate field of study. Address \ f ;Tlr- and Cherry Canyon Tongue (Fig. 4). Sarg inquiris to Carot A- Hlellming, Editor of Nru Merico I Ciberson co. .1"6 trtt and Lehmann (1986)interpreted the Geolo31i,New Mexico Bureau of Mines & Mineral Resources, Socono, NM 87801-4796. Grayburg as carbonate FIGURE 2-A, Permian depositional features a bank that pro- Published as public domain, therefore reproducible without of west Texasand southeasternNew Mexico; graded basinward over the Cherry Can- permission. Source credit requested. B, faciesbelts along the northwestern margin yon Tongue.On the Northwesterrishelf, Circulelion:1,600 of the Delaware Basin. Modified from Boyd the upper San Andres-Grayburg contact P/irleri University of New Mexico Printing Seruices (1958)and Cooperand Grant (1972). is unconformable (Hayes, 1959,1964), but

May 1993 New Mexico Geology TABLE 1-Outcrops examined for this re- search.

Outcrop Location no. 5000 south side of Last Chance Canvon. oppositemouth of Wilson Canyon, NErA SWIA sec. 33 T23SR22E, Red Bluff Draw 1:24,000-scaletopographic map, Eddy County

5001 north side of Last Chance Canvon. opposite mouth of White Oaks Can- yon, SEr/rSElLsec. 32 T23S R228, Red Bluff Draw 1:24,000-scaletopographic map, Eddy County

5002 base of west side of West Dog Can- yon, SW1/+NWtl+sec. 2 T265 R19E, PantherCanyon 1:24,000-scaletopographic map, Otero County

middle of west side of West Dog Can- yon, opposite mouth of PantherCan- yon, NE1/+SW1/nsec. 34 T25SRfgE, FIGURE 3-Permian stratigraphy of the Brokeoff and Guadalupe Mountains; abbreviationsare C. Panther Canyon 1:24,000-scaletopo- and Cath. : Cathedralian. Basedon King (1948),Fekete et al. (1986),Sarg and Lehmann (1986), graphic map, Otero County Pray (1988a),Rossen and Sarg(1988), Sarg et al. (1988). 5004 south side of Cork Draw, SE1/qNW 1l+sec. 17'1265 M0E, PantherCanyon 1:24,000-scaletopographic map, Otero County

Lithofacies At the WestDog Canyonand Cork Draw outcrops six lithofacies are recognized in the lower San Andres Formation and Cherry CanyonTongue. They are:1) massive carbonatemudstone, 2) cherty car- L. Cherry bonatemudstone, 3) fusulinid packstone, 4) skeletalpackstone, 5) skeletalsiltstone, Canyon and 6) unfossiliferoussiltstone. Fm The massivecarbonate-mudstone lithofacies(Fig. 5A) consistsof medium-gray, massive carbonate mudstone with rare chert noduies. It containsvery few sponges, crinoids, and lyttoniids. Me- dium-gray, tabular and evenly bedded, cherty carbonatemudstone constitutesthe cherty carbonate-mudstonelithofacies (Fig. 5B). Large-scaleintraformational truncation surfacesare presentthroughout this FIGURE 4-Correlation chart of upper Leonardian (Roadian)and lower Guadalupian (Wordian) lithofacies.The fusulinid-packstonelith- stratigraphicunits;modifiedfrom Cooperand Grant(7972),Feketeetal. (1986), Sargand Lehmann ofaciesconsists of medium-gray carbon- (1986),Ross (1987),Pray (1988a),and Rossenand Sarg (1988).Stratigraphic position of outcrops ate mud repletewith fusulinids(Fig. 5G). examined based on Darton and Reeside(1926),Boyd (1958),Hayes (1964), and Sarg (1985).Ab- It exhibits tabular bedding that is com- breviations are Cath. : Cathedralian,C. T. = China Tank Member, W. R. = Willis RanchMember, monly inclined at low angles(5'-15). A. R. : Appell Ranch Member, V : Vidrio Member. Fossil-richand skeletal-rich,medium- gray carbonate mud constitutes the skeletal-packstonelithofacies (Fig. 5C, D). This (Fig. 5E). This lithofaciescontains broad, mudstones that exhibit broad concave-up lithofacies is tabular bedded, but normally shallow channels that resemblethe intra- (listric) geometry. At least 40 ft of relief the beds exhibit low-angle inclination (5"- formational truncation surfaces of the existsbetween the sidesand center of this 15").The skeletal-siltstonelithofacies con- cherty carbonate-mudstonelithofacies. channelform; the total depth of the chan- sists of abundantly fossiliferous, tan, me- nelform cannot be determined becauseits dium-bedded to shaly-beddedquartz extremities extend beyond the limits of siltstone (Fig. 5F, H). Tabularbed geom- Outcrop descriptions the outcrop. The channelform contains etry and low-angle inclination also char- The West Dog Canyon outcrop (locality low-angle inclined beds of skeletal pack- acterizethis lithofacies, 5002;Fig. 6) is approximately 500 ft wide stone, fusulinid packstone, and cherty The unfossiliferous-siltstonelithofacies (from northwest to southeast)and ex- carbonate mudstone. These beds dip to- consists of unfossiliferous, thick-bedded poses approximately60 ft of strata. The ward the south or southeast and appear to shaly-bedded, tan and green siltstone lowestbeds exposedare cherty carbonate to be foresets filling the channelform. They

Nau Mexico Geology May 1993 of lithofaciesrecognized within the lower San Andres Formation and Cherry Canyon Tongue;A, massivecarbonate muostone1_G,t^l^t_l;911::"8:f,t"Tu"ce (localrty5uu4);6, cherty carbonatemudstone.(locality_5-002); C, skele,tal_packstone (locality 5Od2);D,"skeletal"packstone with lyttoniid brachiopod.s (lo.cality_5-002);E, unfossiliferous siltstone (locality'5004);'i, rk"l"t"l siltstone with lyttorliid brichiopods ltocialty soo+); c, fusulinid packstone (locality 5002);H, skeletal siltstone (locality 5004).

May 1993 New Merico Geology 7;

_ _ - :,,;w& rr,. ?. ::,j,1;i& "*e thus resembleepsilon crossbedsde- scribed from fluvial systems. A body of the massive carbonate-mudstonelithofacies approximately 100 ft wide and 40 ft thick abuts against the northwestern side of the channelform. Only a few crinoid- stemfragments and quesfionablesponges were observed in this unit, and no evidence of an organic frame eists. The northwestern extent of this unit could not be determined because it is covered by colluvium. The massivecarbonate-mudstone body appearsto be separatedfrom the channelform by an intraformational truncation surface. Flat-lying cherty carbonate mudstones overlie the channelform. At the Cork Draw outcrop (locality5004; Fig. 7) the lower approximately 100 ft of exposed bedrock consists of the unfossiliferous-siltstone lithofacies. A thin (10 ft) resistant layer of massivecarbonate mudstone, which grades laterally into unfossiliferoussiltstone, delineates and occupies the base of the channelform. This unit containsscattered sponge gravel and a few lyttoniids. As much as 30 ft of low-angle FIGURE 6-West Dog Canyon outcrop (ocality 5002);A, photomosaicof the entire outcrop, view inclined beds of the skeletal-packstone to the southwest; B, southeast part of outcrop exhibiting differential dips at the base of the channelform (beds dip southward in remainder lithofacies fills the lower dip northward in lowest part of exposure, beds part of the chan- of exposure);on overlay thick line indicatesbase of channelform, thin lines indicate bedding planes. nelform. On the eastside of the exposure these beds dip toward the west, whereas on the west side they dip toward the east. Lyttoniid brachiopods numerically In the massive carbonate-mudstone On the West side, however, this part of dominate faunas from the skeletal-pack- lithofacies sponges, crinoids, and lytto- (10 the channelform fill is much thinner stone and skeletal-siltstonelithofacies niids are rare, widely scattered, and not ft), resulting in a shift of the centerfrom (Cuffey, in press). In theselithofacies, fos- preserved in living positions. No evi- eastto west. As much as60 ft of low-angle sils are concentratedin tabular beds com- dence of an organic frame exists. Fur- inclined and listric beds of cherty carbon- monly inclinedat low angles(5'-15"). The thermore, no evidence of binding activity ate mudstone fills the remainder of the bedsare loose accumulations of shellsnot or sediment production by algae is ob- east side of the channelform. This litho- in living positions, and no organic frame- servable in outcrop. facies grades laterally into an equal thick- work is present. The orientation of the Further paleontologic evidence comes ness of massivecarbonate mudstone on shells appears to be random, but lytto- from examination of several other out- the west side of the channelform. Flat- niids typically are attached to each other crops outside of the channelforms. At lo- lying carbonatesof the Grayburg Forma- in clusters of three or four individuals. cality 5003, thin tabular layers of skeletal tion overlie the whole exposure. Additionally, virtually all lyttoniid speci- packstone are present within unfossilifer- mens are pedicle valves; brachial valves ous cherty carbonate mudstone. Like- Paleontology are extremely rare. Other than lyttoniids, wise, at locality 5001, thin tabular layers At the WestDog Canyonand Cork Draw few frame-building organismsare pres- of skeletalsiltstone are present within un- outcrops, fossils are abundant in the skel- ent. fossiliferous siltstone. These skeletal silt- etal-packstone,skeletal-siltstone, and fu- The fusulinid-packstone lithofacies stones contain fusulinids that exhibit sulinid-packstone lithofacies. Fossils are contains abundant fusulinids; other fos- parallel orientation. rare in the massive carbonate mudstone sils are rare. The fusulinids may exhibit and absent in the cherW carbonate-mud- parallel orientation, but the vertical na- Discussion and interpretation stone and unfossiliferous-siltstone litho- ture of the outcrops and the moldic pres- Boyd (1958)interpreted both the West facies.Table 2lists the observedfauna. ervation make this difficult to determine. Dog Canyon and Cork Draw outcrops of

Nm Mexico Geology May 1993 FIGURE 7-Cork Draw outcrop (locality 50045004), view to the south; on overlay thick line indicates base of channelform, thin lines indicate bedding planes. massive carbonate mudstone as bioherm surfaces described from carbonate slope Formation and Cherry Canyon Tongue. cores. But, careful examination proves that deposits (Wilson, 1959;Mcllreath and Basedon his discussion,we conclude that these are essentially barren carbonate James,1984; Mullins and Cook, 1986;Prav, most of those features are channelforms mudstone without any organic frame- 1988b).Specifically, Mullins and Cook and intraformational truncation surfaces work. Furthermore, neither feature ex- (1986)noted that intraformational trun- produced by submarine channeling and hibits mound-shaped geometry typical of scouring similar to that discussed here. bioherms (Heckel, tgZZ); insteid, ift" top Furthermore, Boyd (1958,pl. a, fig. B) il- surfaces of the mudstone facies are pla- lustrated a channelat the top of the Cherry nar. In contrast, all bioherms of the Glass Canyon Tongue and exposed in Cork Draw Mountains contain abundant and prom- near locality 5004.This is probably a good inent skeletal constituents and are mound analog for the channel interpretation of shaped (Bain, 1967; Cooper and Grant, nels (Walkerand Cant, 1984).Therefore, locality 5004. 1972). Moreover, in the Cork Draw out- the exposuresare interpreted as broad, Basedon the taphonomic observations crop the beds on the east side dip into the shallow submarinechannels or scourslo- presented here, the preserved faunas are massive carbonate mudstone, inconsis- interpreted as predominantly consisting tent with a flank-bed interpretation. These of allochthonous skeletalmaterial and are facts strongly suggest that this lithofacies thus transported fossil assemblages(Fa- does not represent bioherm cores. Like- gerstrom, 1964).Thus, they are analogous wise, because no organic frame is present, to the shell heaps preserved in the Glass they cannot be large boulders of reefal rock end of the exposureis interpretedas part Mountains and described by Cooper and transported downslope as is the case with of the interchannelslope that has not been Grant (1972).Presumably, the organisms carbonate lenses in the Bone Spring For- incised. In part it may be levee deposits preserved in the channelforms originally mation or Getaway Limestone (Pray and (Jackaet al., 1985),bit no conclusiveev- inhabited, andwere derived from, thebank Stehli, 1962; Harris and Wiggins,-19g5; idencefor this was observed.In Cork Draw. margin, which Sarg and Lehmann (1986) Cuffey, 1987) and some lowerteonardian the primary massivecarbonate-mudstone reported to contain abundant skeletalma- "bioherms" of the Glass Mountains (Rog- body appearsto be part of the side-chan- terial in this region. Furthermore, Son- ers, 1978). nel fill. The change upsection from silt- nenfeld (1990) reported small sponge- Based on the data presented here. the stoneto carbonatechannel fi-ll is interpreted brachiopod and bryozoan-crinoid bioh- channelforms and their skeletal-pack- to be the result of shallowing as the Gray- erms at the bank margin in the upper San stone and skeletal-siltstone fills are con- burg carbonate bank prograded basin- Andres Formation; these could have pro- cluded to be the most significant features ward into the area. The 10 ft of massive vided many of the specimensof sponges of the study outcrops. The broad concave- carbonate mudstone at the base of the and lyttoniids. However, personal obser- up (listric) geometry of these features is channel probably representsan initial vation of the bank margin failed to verify very similar to that developed in sub- channel-mantlingdeposit (Harms, 1974). the reported bioherms. Likewise, Sarg marine channels of the Brushv Canvon Boyd (1958,pp. 53-55,fig. 6) discussed (1986)did not report thesebioherms. Formation (Harms. 7974).It is aiso similar and illustrated what he termed "primary We suggestthat the strata studied were to large-scale intraformational truncation dips of uncertainorigin" in the SanAndres deposited by the following sequence of

May 1993 New Mexico Ceology TABLE 2-List of fauna observed in the San Andres and Cherry Canyon deposits under consid- events.Density currentsperiodically swept eration and relative abundances in each lithofacies; A : abundant, C : common, UC = uncom- the area, scouring the bottom, hence pro- mon, R : rare, - : absent (abundances estimated from field observations); mcm : masslve ducing broad, shallow channels and de- = : carbonate mudstone, skp skeletal packstone, fup : fusulinid packstone, sks skeletal siltstone. pressions(Harms, 1974).Some of these currents originated on the bank margin, Lithofacies were probably storm induced, and trans- Fossil group skP foP sks ported large volumes of skeletal material Foraminifera basinward into the channels.Initially, the fusulinids indet. R channelswere mantled by carbonate-mud Porifera deposits (either the cherty carbonate- calcispongesindet. R R mudstone or the massivecarbonate-mud- Cnidaria, Anthozoa stone lithofacies) similar to the initial de- solitary rugosans indet. R Formation Bryozoa posits in Brushy Canyon fenestratesindet. R channels (Harms, 1974). Subsequently, trepostomesindet. R channel filling by lateral and vertical ag- Brachiopoda gradation of skeletal-rich carbonate and/ derbyiids: or terrigenous sediments produced the Derbyiasp. R low-angle inclined beds of the skeletal- Meekellasp. R packstone, skeletal-siltstone, and fusu- productids: linid-packstone lithofacies. The currents Paucispiniferasp. C R responsible for the transportation also Kochiproductussp. R winnowed lighter, smaller, and lyttoniids: out the Collematariasp. A delicate brachial valves of the lyttoniids. Eolyttoniasp. R A Some of the creaturesmav actuallv have rhynchonellids: inhabited the current-dlposited shell Torynechussp. R heaps, as indicated by some specimens spiriferids: that are very well preserved. Neospirifersp. R 'j The Leonardian and lower Guadalu- Reticulnriinasp. R pian of the Glass Mountains, on the op- compositids: posite flank of the Permian Basin (Fig.2), Compositasp. c analog for San Andres Martinia sp. : R provide a partial retziids: Formation and Cherry Canyon Tongue Hustediasp. UC deposition and paleoecology.In the east- Mollusca, Pelecypoda ern part of the GlassMountains carbonate pectinids indet. UC R deposits prevail, with bioherms and zoo- Echinodermata, Crinozoa tikepia growing on the margin of a car- crinoids, stem fragments R UC UC bonate bank (Bain, 1967; Cooper and Grant, Arthropoda, Trilobita 1972). This eastem facies was probably DeLariasp. R similar to the bank-margin facies of the San Andres Formation, although bioherms have not been positively identified in the San Andres. Westward, the eastern facies grades and thickens into a siliciclastic sequencehaving thin, interbedded carbonates(Cooper and Grant, 1972;Cys, 1987;Ross, 1987). The carbonatesin the GlassMountains, most notably the China Tank, Willis Ranch, and Appel Ranch Limestone Members of the Word Formation, contain many shell heaps (Cooper and Grant, 1972). AIlo- chthonousboulders of biohermal rock also are present in these deposits, particularly in the Skinner Ranch Formation (Rogers, 1.978).Several authors (Cys, 1987; Ross, 1987;Rogers, 1978) interpreted theserocks as slope deposits.They are similar to the slope deposits of the San Andres For- mation and Cherry Canyon Tongue, ex- cept for the absence of allochthonous blocks in the latter two units. It remains to be determined whether the Glass Mountains region contains the large-scale intraformational truncation surfaces and channeling that are common in the Gua- dalupe Mountains. Comparison with other upper Paleozoic bioherms outside the Permian Basin does not reveal any analogs. Upper Paleozoic FIG_URF8-Paleo-oceanographic reconstruction of the West Dog Canyon area during deposition phylloid algal mounds (Toomey, 1991) of the san Andres Formalion and cherry canyon Tongue. Mod'ified from facka et al: (1985). contain readily visible phylloid-algae

Nm Mexico Ceology May 1993 Suruey, Pro- fronds. Similarly, Permian bioherms con- Drs. Frank Kottlowski and Jiri Zidek of tains, New Mexico: U.S. Geological fessional Paper M6, 69 PP. structed by various organisms, including New Mexico Bureau of Mines and Mineral Heckel, P. H., 1974,Carbonate buildups in the geo- hydrozoans (Davies, 1971)and bryozoans Resources,Dr. Roger Cuffey of Pennsyl- logic record-a review; in Laporte, L. F. (ed.), Reefs (fames, 1983), contain easily discernible vania State Universitv. and Elizabeth Lar- in time and space;selected examples from the re- macroscopicskeletal material. Neither are son of University of Oklahoma for review- cent and ancient: Society of EconornicPaleontolo- gists and Mineralogists, SpecialPublication 18, pp. the West Dog Canyon and Cork Draw ing this manuscript. 90-154. outcrops analogousto "Waulsortian mud Jacka,A. D., Thomas,C. M., Beck,R. H., Williams, mounds" of the Mississippian, which K. W., and Hanison, S. C., 1985,Guadalupian dep- contain abundant skeletal material, pre- References ositional rycles of the Delaware Basin and northwest shelf; in Cunningham, B. K., and Hedrick, dominantly fenestratebryozoans and cri- Ausich, W. I., and Meyer, D. L., 1990, Origin and C. L., Permian carbonate/clasticsedimentology, noid columnals (Pray, 1958;Cotter, 1965; composition of carbonatebuildups and associated Guadalupe Mountains-analogs for shelf and basin Ausich and Meyer, 1990),readily visible facies in the Fort Payne Formation (Lower Missis- reseryoirs:Society of EconomicPaleontologists and sippian, integrated in outcrop (Cuffey,pers. obs.). south-central Kentucky)-an Mineralogists, Pemian Basin Section, Publication sedimentologicand paleoecologicanalysis: Geolog- 85-24,pp.8l-117. ical 129- Society of America, Bulletin, v. 102, pp. James,N. P., 1983,Reef environmenq itt ftholle, P A., 146. Bebout, D. G., and Moore, C. H. (eds.), Carbonate Summary and conclusions Bain, Ii.. f., 1957, Paleoecologyof some Leonardian deoositional environments: American Association patch reefs in the GlassMountains, Texas:Brigham Examination of carbonate bodies, pre- of Petroleum Geologists,Memoir 33, pp. 345-462. YorrngUniversity, Geology Studies, v. 1.4,pp. 195- King, P. B., 1948,Geology of the southern Guadalupe viously interpreted as bioherms, in the ?36. Mountains, Texas:U.S. GeologicalSuwey, Profes- San Andres Formation and Cherry Can- Boy'd, D. W., 1958,Pemian sedimentary facies,cen- sional Paper 215, 183 pp. yon Tongue of the Brokeoff and Guada- h" I GuadalupeMountains, New Mexico:New Mex- Mcllreath, I. A., and James,N. P., 79U, Carbonate ic, 9ureau of Mines and Mineral Resources,Bulletin lupe Mountains yielded significant slopes; in Walker, R. G. (ed.), Faciesmodels, 2nd. 49, i00 pp. ed; GeoscienceCanada Reprint Series1, pp.2a5- observations and permitted reinterpreta- Cooper,G. A., andGrant, R.E.,1972,Permianbrach- 257. tion of their origin. The primary obser- iopods of west Texas,I (abs.):Smithsonian Contri- Mullins, H. T., and Cook, H. 8,, 1'986,Carbonate vations and conclusionsreached are: butions to Paleobiology,no. 1,4,231pp. apron model-alternatives to the submarine fan Cotter, E., 1955,Waulsortian-type carbonate banks in 1) six lithofacies are present: massivecar- model for paleoenvironmentalanalysis and hydro- the Mississippian Lodgepole Formation of central carbon exploration: Sedimentary Geology, v 48, PP. bonate mudstone, cherty carbonatemud- Montana:fournal of Geology,v.73, pp.881-888. 37J9. stone, fusulinid packstone, skeletal Cuffey, C. A., (in press),Preliminary note on lyttoniid Newell, N. D , Rigby,J K., Fischer,A. G., Whiteman, packstone, skeletal siltstone, and unfos- and richthofeniid brachiopods from the upper A. J., Hickox, J. E., and Bradley,J. S., 1953,The Leonardian and lower Guadalupian (Permian) of siliferous siltstone; Permian reef complex of the GuadalupeMountains southeasternNew Mexico (abs.);Geological Society region, Texasand New Mexico, a study in paleo- 2) sedimentologically, stratigraphically, of America, Abstracts with Programs. ecology: W. H. Freeman& Co., San Francisco,287 Cuffey, R. 1987,Reported possible bryozoan bio- and geometrically, the most important J., Pp. features are channelforms mantled with herms in the Guadalupe Mountains Permian, west Pray, L. C., 1958, Fenestratebryozoan core facies, Texas-megabreccialenses, sand waves, and con- Mississippian bioherms, muthwestem United States: cherty carbonate mudstone or massive (abs.): Geo- trasts with Great Lakes Silurian reefs fournal of SedimentaryPetrology, v.28, pp.251- carbonate mudstone and subsequently logical Society of America, Abshacts with Programs, 273. filled with low-angle inclined bedsof skel- v. Iy. D. ly5. Pray, L. C., 1988a,Geology of the western escarp- etal packstone, fusulinid packstone, and Cys, J. M., 1987, Prelirninary report on proposed ment, Guadalupe Mountains, Texas;in Sarg, J. F., Leonardian lectostratotype section, Glass Moun- siltstone Rossen,C., Lehmann,P. J., and Pray,L. C. (eds.), skeletal that resemble epsilon tains, west Texas;in Cromwell, D. (ed.), The Leon- Geologicguide to the western escarPment,Cua- crossbedding; ardian facies in west Texas and south-east New dalupe Mountains,Texas: Society of EconomicPa- 3) the skeletal-packstoneand skeletal- Mexico and guidebook to the Glass Mountains, west leoniologists and Mineralogists, Permian Basin siltstone lithofacies contain the only sig- Texas: Society of Economic Paleontologists and Section, Publication 88-30, pp. 1-8. Mineralogists, Pemian Basin Section, Publication nificant invertebrate faunas, which are Pray,L. C.,1988b, Trail guide-day one, Bone and 87)7, pp.35-46. Shunard Canyon area; in Reid, S. T., Bass,R. O., preserved as tabular accumulations of loose Darton, N. H., and Reeside,J. 8., Jr., 1925,Guada- and Welch, P (eds.), Guadalupe Mountains revis- skeletal material that are taphonomically lupe Group: Geological Society of America, Bulle- ited, Texasand New Mexico: WestTexas Geological interpreted as allochthonous heaps; tin, v. 37, pp. 413-428. Society,Publication 88-84, pp. 41.-60. shell Davies, G. R., 1971, A Permian hydrozoan mound, 4) the massive Prav L. C., and Stehli, F. G., 7952, Allochthonous carbonate-mudstonelith- Yukon Territory: CanadianJoumal of Earth Science, oiigin, BoneSpring "patch reefs," west Texas(abs.): ofacies does not contain evidence of in v. 8, pp. 973-988. GeologicalSociety of America, SpecialPaper 73, pp. situ biologic activity nor mound-shaped Fagerstrom,J. A., 1964,Fossil communities in paleo- 218,219. geometry; therefore, units composed of ecology-their recognition and significance:Geo- Rogers,W. 8., 1978,Megaclast-bearing conglomerate logical Societyof America, Bulletin, v.75, pp. 1197- beds in the Skinner RanchFormation, GlassMoun- this lithofacies are not bioherms; 121.6. tair.s,westTexas;inMazzrllo, S. J. (ed.),Tectonics 5) the channelforms are interpreted as Fekete,T. E., Franseen,E. K., and Pray,L. C.,1986, and Paleozoicfacies of the Marathon geosyncline, broad, shallow submarine scours and Deposition and erosion of the Grayburg Formation west Texas:Society of EconomicPaleontologists and channels filled by lateral and vertical ag- (Guadalupian, Permian) at the shelf-to-basinmar- Mineralogists, Pemian Basin Section, Publication gin, western escarpment, Guadalupe Mountains, 78-17, pp. r91J1.4. gradation of skeletal debris, which was Texas;in Moore, G. E., and Wilde, G. L. (eds.), Ross,C. A., 1987,Leonardian Series(Permian), Glass most likely transported downslope from Lower and middle Guadalupian facies, stratiSra- Mountains, west Texas;in Cromwell, D. (ed.), The the bank edge by bottom currents, prob- phy, and reseruoir geometries, San Andres/Gray- Leonardian faciesin west Texasand southeastNew ably storm generated; burg Formations, Guadalupe Mountains, New Mexico and guidebook to the Glass Mountains, west Mexico and Texas:Society of Economic Paleontol- Texas: Society of Economic Paleontologists and 6) the massivecarbonate-mudstone units ogists and Mineralogists, Permian Basin Section, Mineralogists, Permian Basin Section, Publication are reinterpreted as part of the interchan- Publication 86-25, pp. 69-a1. 8727, pp.25-j3. nel slope (possiblychannel levees in part), Harms, J. C., 1974,Brushy CanyonFomtion, Tens- Rossen,C., and Sarg,J. F., 1988,Sedimentology and part of the channel fill, or channel-man- a deep-water density-cunent deposit: Geological regional correlation of a basinally restricted deeP- Society of America, Bulletin, v. 85, pp. 1763-17U. water siliciclastic wedge-Brushy Canyon Forma- tling deposits, not as organic bioherms. Hanis, P. M., and Wiggins, W. D., 1985,Allochthon- tion-Cherry Canyon Tongue (lower Guadalupian), Acruowt-EocMEr\ns-The authors thank ous carbonatesof the Getaway Limestone, Upper Delaware Basin; in Reid, S. T., Bass, R. O., and the following people: Brant and Mary Lo- Pemian of the Delaware Basin; ln Crevello, P D., Welch, P (eds.), Guadalupe Mountains revisited, gan of Dell City, Texas,for permission to and Hanis, P. M. (eds.), Deep-water carbonates- Texasand New Mexico: West TexasGeological So- buildups, turbidites, debris flows, and chalks: So- 127-732. collect at West Dog Canyon and for pro- ciety, Publication 88-84, pp. ciety of Economic Paleontologistsand Mineralo- Sarg,J. F., 1986,Second day-facies and stratiSraPhy viding useful logistical information; Doug gists, Core Workshop no. 5, pp. 174211. of upper San Andres basin margin and lower Gray- Stavinoha of TexasA & M University for Hayes, P T.,1959, San Andres Limestoneand related burq inner shelf; in Moore, G. E., and Wilde, G. L. his assistancein the field; and Dr. William Permian rocks in Last ChanceCanyon and vicinity, (edsi.,),Lower and middle Guadalupianfacies, stra- southeastern New Mexico: American Association Ausich of Ohio Dr. Da- tigrapht and reservoir Seometries, San Andres/ State Universitv, of PetroleumGeologists, Bulletin, v.43, pp.2197- Grayburg Formations, GuadalupeMountains, New vid Brezinski of Maryland GeologicalSur- ,r)1a vey, Dr. Russell Clemons of Las Cruces, Hayes, P. T., 1964,Geology of the Guadalupe Moun- (Continueson p. 44)

May 1993 Nm MexicoGeology Upcominggeologic meetings

Tttcl;ot\, AZ

Sept.12-15 fufg^,:Ot,' ilewU.S.G.$. map products The U.S. Geological Survey National Sept. 16*19 Denv*r.,CO Mapping Division recently releasedmaps showing new and currently available map- related digital data for New Mexico. These digital products are used primarily to generate new maps using computers. Dgital elevation models (DEMs) are made by sampling elevations shown on common topographic maps at regular inter- vals (Map A,7 or 15meters). These DEMs can be used to make computer-drawn shaded relief maps. Several kinds of information commonly are printed on top of basic topographic maps and are called overlays. These overlays in digital form are called digital line graphs (DLGs). The DLG overlays available for parts of New Mexico (Maps B, C, D) include political boundaries, the public land survey sys- tem (PLSS:township, range, sectionlines), culture (human-made features),transportation (roads), hydrography (streamsand lakes), hypsography (topographic features), and vegetation (types of ground cover). Some digital orthophoto quadran- gle products with a ground resolution of about one meter are also available. Read- ers interested in obtaining more information may contact Sam Bardelson, Albuquerque Mapping Support District Office, U.S. GeologicalSurvey, P.O. Box Cuffey and Lembcke 355583,Albuquerque, NM 87176, (505)265- 7796. Readers interested in other digital (Continued p. 32) from geographicinformation may contactMike Mexico and Texas:Society of Economic Paleontol- Toomey, D F, 1997, Late Pennsylvanian phylloid- Inglis, ResourceGeographic Information ogists and Mineralogists, Permian Basin Section, algal biohems, Orogrande Basin, south-central New Publication 85-25, pp. 83-93 Mexico and west Texas:New Mexico GeologicalSo- Systems' Clearinghouse, TechnologyAp- Sarg, I F, and Lehmann, P J , 1986,Lower-middle ciety, Guidebook to 42nd Field Conference, pp 213- plication Center, University of New Mex- Guadalupian faciesand stratigrapht San Andres/ 220. ico, Albuquerque, NM 87137,(505) 277- Grayburg Formations, Permian Basin, Guadalupe Walker, R G., and Cant, D. J., 1984,Sandy fluvial 3622. Mountains,New Meico; in Mmre, G. E., and Wilde, systems;in Walker, R G (ed.), Faciesmodels, 2nd G. L. (eds.), Lower and middle Guadalupianfacies; ed : GeoscienceCanada Reprint Series l, pp 71- stratigraphy, md reseruoir geometries, Sm Andres/ 89 Grayburg Formations,Guadalupe Mountains, New Wilde, G. L., 1,985,Stratigraphic relationship of the Mexico and Texas:Society of Economic Paleontol- San Andres and Cutoff Formations, northern Gua- ogists and Mineralogists, Permian Basin Section, dalupe Mountains, New Mexico and Texas;ln Mmre, Publication 85-25, pp 1-8 G E , and Wilde, G L (eds ), Lower and middle Sarg,J F., Rossen,C., Lehmann, P J, and Pray, Guadalupian facies, stratigraphy, and reservoir L. C., editors, 1988,Geologic guide to the westem geometries, San Andres/Grayburg Formations, Guadalupe Mountains New Mexico and Texas:So- ciety of Economic Paleontologistsand Mineralo- gists, Permian BasinSection, Publication 85-25, pp. 45-63 Wilson, J. L , 1969, Microfacies and sedimentary skuctures in "deep water" lime mudstones; ir Friedman, G M. (ed ), Depositional environments in carbonaterocks: Society of Economic Paleontol- ation of Petroleum Geologists, Bulletin, v 74, p ogists and Minenlogists, Special Publication L4, pp. 768. 4-17 rr

May 1993 Nat Mexico Geology