Geology of the Los Pinos Mountains, New Mexico

Stark, John; Dapples, E. C.

doi:10.1130/0016-7606(1946)57[1121:gotlpm]2.0.co;2

Cited by 29 publications

(22 citation statements)

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“…Micas from both of the rock samples studied yielded metamorphic ages of about 1,350 m.y. The granitic gneisses are associated with metasedimentary and metavolcanic rocks that are probably equivalent to the sequence found in outcrop along the Los Piiios-Manzano trend (Stark and Dapples, 1946;Stark, 1956). Long (1972, p. 3425) reported ages of "about 1,600 m.y.…”

Section: Areaiv-texasandeastern New Mexicomentioning

confidence: 87%

Geology and geochronology of Precambrian rocks in the Central Interior region of the United States

Denison¹,

Lidiak²,

Bickford³

et al. 1984

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Rocks of the buried Precambrian crust in the Central Interior region range from more than 2,700 to less than 1,000 million years in age and from granite and granulitic gneiss to gabbro and basalt in rock type. The oldest rocks occur in the Dakotas and clearly are buried portions of the Canadian Shield; they are mostly older than 2,700 million years, and some may be as old as 3,600 million years.The central part of this region, including Nebraska, northern Missouri, and northern Kansas, is underlain by diverse igneous and metamorphic rocks whose ages are mostly 1,600 to 1,800 million years; scattered anorogenic granitic plutons whose ages are about 1,~1,500 million years are also known in this terrane.The most distinctive feature of the Continental Interior is the great terrane of felsic igneous rocks that makes up the basement from Ohio and Wisconsin across southern Missouri and Kansas and into the Texas Panhandle and far western Texas. These rocks, which include abundant rhyolite and mesozonal and epizonal granitic bodies, range in age from 1,500 to 1,200 million years, and the general tendency ~ for ages to decrease from northeast to southwest; older rocks are not known anywhere within this terrane. Toward the east in Ohio, eastern• Kentucky, and eastern Tennessee, and toward the south in central Texas, the basement terrane consists of medium-grade metamorphic rocks and associated granitic plutons that formed mainly 1.000-1.100 million years ago.A belt of basalt, interflow arkosic sandstone and siltstone, and related mafic intrusive rocks can be traced with the aid of geophysical data from the Lake Superior region southw~ into central Kansas.This feature, the Central North American rift system, is widely believed to be an abortive continental rift that formed about 1,100 million years ago. Geophysical data suggest that other areas in the eastem part of the interior are also underlain by rift basalts and related rocks.The Central Interior region was dominated by eugeosynclinal sedimentation and orogenic tectonics prior to about 1,600 million years ago. After that time the region apparently stabilized, and the sedimentation was characterized by the deposition of sheets of quartzose sandstone about 1,600 million years ago. Subsequent igneous activity, sedimentation, and tectonics have been dominantly anorogenic except along the margins of the stable interior.

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Section: Areaiv-texasandeastern New Mexicomentioning

confidence: 87%

Geology and geochronology of Precambrian rocks in the Central Interior region of the United States

Denison¹,

Lidiak²,

Bickford³

et al. 1984

Professional Paper

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“…Samples were collected from a series of amphibolite layers believed to have been derived from mafic dikes (Stark and Dapples, 1946) that cut the Sevilleta metarhyolite (Fig. 2).…”

Section: Amphibolitementioning

confidence: 99%

Thermal, structural, and petrological evidence for 1400-Ma metamorphism and deformation in central New Mexico

Marcoline

Heizler

Goodwin

et al. 1999

Rocky Mountain Geology

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Amphibolites from the Manzano Mountains, New Mexico, include two chemically and microstructurally distinct amphibole populations. Petrographic and electron-microprobe studies show that early actinolite is overgrown and crosscut by younger foliation-forming hornblende. An older foliation defined by actinolite porphyroclasts (S,) is discordant to the regionally extensive hornblende foliation (S,). Microstructural relationships both in amphiboles and muscovite-chlorite schists indicate that S, and S, record two distinct episodes of metamorphism and deformation, rather than a single progressive event. 40Ar/39Ar geochronologic analyses on hornblende, actinolite, muscovite, and biotite constrain timing of the youngest metamorphic/ deformational event. Most amphiboles yield complex 40Ar/39Ar age spectra, but two hornblende concentrates give preferred ages of 1410 f 12 Ma and 1399.1 f 5.4 Ma, and one actinolite has a preferred age of 1391.6 f 5.0 Ma, suggesting cooling below ~450' C at this time. These ages are interpreted to record the timing of near-peak metamorphism. Muscovite sampled over a 1.5-km vertical section of muscovite-chlorite schists shows an age discordance, with the structurally highest sample being ~5 0 m.y. older than the structurally lowest sample. This age discordance is interpreted to suggest cooling from ~3 0 0 " C at 0.5' C/m.y. following the peak of ca. 1400-Ma metamorphism. Biotites from similar structural levels yield variable preferred ages, which range from 1402.6 f 5.1 to 1267.8 f 5.7 Ma and corroborate the slow cooling suggested by the muscovite results.lbgether, the thermochronologic, structural, and petrologic data support a model of regional deformation, metamorphism, and mineral growth at ca. 1450-1400 Ma. These data add to a growing body of evidence from the southwestern United States that ca. 1400-Ma plutonism was not anorogenic, but rather was contemporaneous both with metamorphism and deformation. KEY WORDS: 40Ar/39Ar thermochronology, Manzano Mountains, metamorphism, deformation.

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“…The metavolcanic rocks of bimodal composition (p mv) (Servillita metarhyolite of Stark and Dapples, 1946) are considered the youngest of the metamorphic rocks and have an isochron age of 1.7 b.y. (Bolton, 1976;Condie and Budding, 1979).…”

Section: Geologymentioning

confidence: 99%

Mineral resource potential map of the Manzano Wilderness, Valencia and Torrance Counties, New Mexico

Maxwell¹,

Wobus²,

Light³

1983

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STUDIES RELATED TO WILDERNESSUnder the provisions of the Wilderness Act (Public Law 88-577, September 3, 1964) and related acts, the U.S. Geological Survey and the U.S. Bureau of Mines have been conducting mineral surveys of wilderness and primitive areas. Areas officially designated as "wilderness," "wild," or "canoe" when the act was passed were incorporated into the National Wilderness Preservation System, and some of them are presently being studied. The act provided that areas under consideration for wilderness designation should be studied for suitability for incorporation into the Wilderness System. The mineral surveys constitute one aspect of the suitability studies. The act directs that the results of such surveys are to be made available to the public and be submitted to the President and the Congress. This report discusses the results of a mineral survey of the Manzano Wilderness, Cibola National Forest, Valencia and Torrance Counties, N. Mex. The area was established as a wilderness by Public Law 95-Z37, February Z4, 1978. MINERAL RESOURCE POTENTIAL SUMMARY STATEMENTThere is a moderate potential for a small deposit averaging as much as 0.1 oz gold and 1 oz silver per ton in the Bartolo Canyon area as indicated by the presence of identified gold and silver mineral occurrences in the canyon. A low potential is indicated for additional small gold and silver deposits in an area of similar geology along the southwest boundary of the wilderness.No indication of significant mineral occurrences was found elsewhere in the wilderness. The few anomalous values found in stream-sediment and outcrop analyses were for samples from widely separated localities and in amounts too low to indicate a resource potential.

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Geology of the Los Pinos Mountains, New Mexico

Cited by 29 publications

References 0 publications

Geology and geochronology of Precambrian rocks in the Central Interior region of the United States

Geology and geochronology of Precambrian rocks in the Central Interior region of the United States

Thermal, structural, and petrological evidence for 1400-Ma metamorphism and deformation in central New Mexico

Mineral resource potential map of the Manzano Wilderness, Valencia and Torrance Counties, New Mexico

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