New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/15 Geology of the Carrizozo quadrangle, New Mexico Robert H. Weber, 1964, pp. 100-109 in: Ruidoso Country (New Mexico), Ash, S. R.; Davis, L. R.; [eds.], New Mexico Geological Society 15th Annual Fall Field Conference Guidebook, 195 p. This is one of many related papers that were included in the 1964 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. These books have set the national standard for geologic guidebooks and are an essential geologic reference for anyone working in or around New Mexico. 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One printed copy of any materials from the NMGS website or our print and electronic publications may be made for individual use without our permission. Teachers and students may make unlimited copies for educational use. Any other use of these materials requires explicit permission. This page is intentionally left blank to maintain order of facing pages. NEW MEXICO GEOLOGICAL SOCIETY • FIFTEENTH FIELD CONFERENCE GEOLOGY OF THE CARRIZOZO QUADRANGLE, NEW MEXICO Robert H. Weber New Mexico Bureau of Mines and Mineral Resources, New Mexico Institute of Mining and Technology Socorro, New Mexico INTRODUCTION wold (1959), to whom the reader is referred for fuller coverage of the surrounding region of Lincoln County. The results of detailed geologic mapping of the Car- rizozo 15-minute quadrangle, summarized herein, are STRATIGRAPHY pertinent to both major regional features and local as- pects of physiography, stratigraphy, petrology, and struc- Exposed rock units include Permian Yeso and San ture that will be viewed during the course of the 15th Andres Formations; local equivalents of Upper Creta- Annual Field Conference. The setting of the area in ceous Dakota Sandstone, Mancos Shale, and Mesaverde relationship to nearby geographic features is shown in Group; early Tertiary Cub Mountain Formation, vol- figure 1. The geology has been highly generalized in canic; of the Sierra Blanca, and a suite of intrusive the geologic map and section (fig. 2). rocks; late Tertiary to Recent valley fill, colluvium, The mapped area includes segments of the Sacra- landslides, and talus; and Recent basalt flows. Triassic mento section of the Basin and Range Province and a rocks are concealed by the Carrizozo Malpais. An oil western lobe of the Great Plains Province. It is bounded test (Standard of Texas No. 1 Heard-Federal), just on the east by the Tertiary volcanic pile and intrusive outside the northwest corner of the quadrangle in sec. complex of the northern Sierra Blanca, and by. the west- 33, T. 6 S., R. 9 E., provides additional stratigraphic ern flanks of a series of domical intrusive bodies that control that includes Precambrian basement rock, a com- extend northward outside the quadrangle into the Ji- carilla Mountains. Sloping westward from the foot of RAE. 0.9E. RICE )/ 1 R.11E.NA. the mountainous tract into the floor of the northern end C U PA CERA "Coyote , of the Tularosa Valley, a closed intermontane basin, is I TiiTiA,LCEK W 3 i BUCK :NOrNTAEIN a broad bajada that occupies most of the central part 7.. White Ook of the area. The bajada surface is breached near its Nillj eastern edge by a discontinuous chain of hills (Chaves - 1. miziliwiammiamsar..• Mountain, Cub Mountain, Willow Hill, etc.) capped by pa small intrusive bodies. Southeastward- to eastward-dip- ocketazo ( .,/,,_,P 4y ?",.. PEAK ping Upper Cretaceous sandstones and shales, the bev- /(„lr ,-- ek -- /4,4 r 4 eled surface of which underlies most of the bajada, crop I y," , ( Carrizo out in the slopes of these hills and in a narrow cuesta ../ AI8IBIZOZ711 and scattered low hills near the foot of the slope. Recent basaltic flows of the Carrizozo Malpais mantle the floor QUAdkielit.ANG1:,,Z,,,,3 of the valley, covering the trace of Triassic redbeds and the uppermost part of the Permian sequence. Permian strata are contorted by solution collapse and folding where they emerge from beneath the western edge of the malpais, rising in elevation northwestward onto the summit of Chupadera Mesa. Elevations range from a minimum of about 5,000 feet on the floor of the Tularosa Valley to a maximum of 9,500 feet on the northern shoulder of Nogal Peak NCOLZ'S COUNTY on the crest of the Sierra Blanca. Nogal Peak, with an OTERO COUNTY "SIERRA elevation of about 10,000 feet, is in turn overshadowed BLANCA by the 12,003-foot eminence of Sierra Blanca Peak PEAK (Cerro Blanco) 8.5 miles to the south. Geologic mapping in the northeastern quarter of the quadrangle was contributed by Frederick J. Kuell- mer. The writer was assisted briefly in the field by John H. Schilling. John E. Allen aided at the plane table 0 10 Mlles during measurement of the Cub Mountain Formation type section. Line illustrations were drafted by Bob Price. Teri Ray provided editorial assistance. The geol- Figure 1. — Index map of Carrizozo quadrangle and vi- ogy of the area has been summarized recently by Gris- cinity, New Mexico. 100 EXPLANATION >– Er z Oaf cr Basalt flows Landslides Valley fill 1 I– Intrusive rocks Sills, plugs, dikes, and stocks Ill TI >- 111 rr Latite 1= 00 w I- /t/ l Andesite and basaltic andesile Cub Mountain Formation Mesaverde Group 0 Lower Mancos Shale 00 Dakota Sandstone () (7) ,7rAte///„ Chinle Formation Santa Roso Sandstone I*cr---)() 11111111J Psa 1111111111 San Andres Formation lY Yeso Formation 4- + /Tic+ + + + Igneous complex Sierra Blanco volcanics and intrusive rocks (3. rm APPROXIMATE MEAN DECLINATION 1950 0 2 4 5 Mites 9000 8000 7000 WILLOW I-ILL Ta 6000– 6000 Ovf 5000 - ............. 5000 4000 ' 111111 111111111,,,, 4000 B Figure 2. — Generalized geologic map and cross-section of the Carrizozo quadrangle, New Mexico. NEW MEXICO GEOLOGICAL SOCIETY 0 FIFTEENTH FIELD CONFERENCE plete section of the Pennsylvanian, and an abnormally Abundant arkosic beds in the Heard test have been cited thickened section of the Yeso Formation. Pre-Pennsyl- by Kottlowski (1960, 1963) as indicating that the Peder- vanian Paleozoic rocks are lacking in this section, prob- nal landmass lay only a short distance to the east. ably as a result of the combined effects of Devonian, Late Pennsylvanian sequences in central New Mexico are Pennslyvanian, and Wolfcampian erosion, and nearness commonly referred to the Magdalena Group, consisting to the Pedernal landmass to the east (Kottlowski, 1963) . of the Sandia Formation overlain by the Madera Forma- tion. Faunal equivalents of the Morrow, Derry, Des Precambrian Rocks Moines, Missouri, and Virgil Series have been recognized. Although the southward projection of the Pedernal The relatively thin section in the northern Sierra Oscura uplift lies only a short distance to the east (Foster and was subdivided by Thompson (1942) into 4 groups and Stipp, 1961), there are no outcrops of Precambrian 8 formations largely on the basis of fusilinid zones. Ad- rocks within the Carrizozo quadrangle, nor in the imme- ditional formational names have been applied to locally diate vicinity. The Heard test penetrated 310 feet of mappable lithologic units in the nearby San Andres and Precambrian gabbro with minor amounts of schist and Sacramento Mountains (Kottlowski and others, 1956; gneiss underlying Pennsylvanian rocks below 7,740 feet. Pray, 1961). Inasmuch as the problems of nomenclature, Core samples consist of a hypidiomorphic-granular ag- faunal ages, facies variations, and regional correlations gregate of medium- to coarse-grained labradorite, augite, have been discussed recently by Kottlowski (1960, 1963) olivine rimmed with pyroxene and antigorite, and mag- a thorough review seems unwarranted in this paper. netite with local reaction rims of biotite. The nearest outcrops of Precambrian rocks lie 30 Permian Rocks miles west of the town of Carrizozo in the western slopes of the Sierra Oscura. Kottlowski (1953) described brief- Strata of Permian age crop out only in the extreme ly the prevailing rock type near the northern end of the northwestern corner of the Carrizozo quadrangle, along range as a muscovite leucogranite with intrusive rela- the western edge of the Carrizozo Malpais, where they tionships with small bodies of gray quartzite. Nearly dip prevailingly eastward to southeastward beneath the equal proportions of quartz, potash feldspar (orthoclase basaltic flows. The exposed section includes only the and microcline) , and oligoclase also permit designation uppermost part of the Yeso Formation and the lower as a sodic quartz monzonite. The high degree of vari- part of the San Andres Formation. A complete section ability in lithology of the Precambrian southward along of the Yeso, underlying Abo Formation, and possible the eastern front of the San Andres Mountains has been equivalents of the Bursum Formation were cut by the shown by Kottlowski and others (1956).