Geology Commons^™

Geology And Ore Deposits Of The Southwest Nacimiento Range, Sandoval County, New Mexico, Otto L. Schumacher

Earth and Planetary Sciences ETDs

The mapped area is in Sandoval County, New Mexico, 4 miles east of La Ventana. Precambrian rocks in the core of the Nacimiento uplift in this area consist mainly of quartz monzonite gneiss which has been intruded by granite. Hornblende schist xenoliths, zones of sheared quartz-plagioclase schistose gneiss, and mafic and leucocratic dike rocks are less abundant. Strata totaling 6200 feet, ranging from the Pennsylvanian Madera Formation through the Cretaceous Mancos Formation, are exposed in the area. Overlying the marine Madera Formation is 3400 feet of continental, marginal marine, and evaporite deposits consisting in ascending order of the Permian Abo, …

Structural Geology Of The Northern Part Of The East Helena Quadrangle, Lewis And Clark County, Montana., Jon A. Durham

Earth and Planetary Sciences ETDs

The map-area is located along the northwest flank of the Big Belt Mountains, Montana and includes the Eldorado thrust which marks the zone of frontal breakthrough where thrusts of the Cordilleran foldbelt are in contact with the Rocky Mountain foreland. Sedimentary rocks range in age from Precambrian to Cretaceous. Two formations of the Precambrian Belt Series, the Greyson Shale (Oldest) and Spokane Shale are present. Overlaying the Spokane Shale are five formations of the Cambrian; Flathead Quartzite (oldest), Wolsey Shale, Meagher Limestone, Park Shale, and Pilgrim Limestone. Their total aggregate thickness is about 1200 feet.

A Geochemical Study Of Distribution Of Elements In Ores And Limestones From New Jersey Zinc Mines, Hanover, New Mexico, Dasharatham Sayala

Earth and Planetary Sciences ETDs

Limestone samples (424) from both surface and subsurface horizons in the New Jersey Zinc mines at Hanover have been analyzed by atomic absorption spectrophotometry for Ag, Cd, Mn, Pb, Zn, Cu and Sn. The lead­zinc ore bodies, occurring in Paleozoic limestones are a typical example of hydrothermal deposits; and are related to the Hanover intrusive. The distribution of trace elements in surface limestones was mainly due to primary dispersion, partly due to secondary dispersion. The depth of ore mineralization, concentration of element in ore solutions, porosity of limestones, diffusion coefficients of element, and the chemical nature of elements in the …

Precambrian Geology Of The Central Nacimiento Mountains, Sandoval County, New Mexico, Kent Richard Reed

Earth and Planetary Sciences ETDs

The oldest Precambrian rocks in the area of study are represented by abundant inclusions and schlieren of horn­blendite, plagioclase-hornblende schist, and plagioclase-­hornblende-biotite schist. These inclusions are remnants of a pre-batholithic metamorphic terrane.

The next oldest, and dominant rock in the central Nacimiento Mountains is gneiss that ranges in composition from quartz monzonite to granodiorite. Where strongly sheared, the rock is microcline-biotite-quartz-plagioclase schist. Gradational zones of schist within the gneiss were mapped separately. The gneiss and the schist are cut by metamor­phosed spessartite dikes and by leucocratic dikes of various textures and compositions.

Intruding the gneiss in the southeastern part of …

Geology Of The Rammel Mountain Area, Teton County, Wyoming, David W. Love

Earth and Planetary Sciences ETDs

The Rammel Mountain area, on the west side of the Teton Range, Wyoming, includes Precambrian metamorphic and igneous rocks; Paleozoic sandstone, shale, dolomite and limestone; and Cenozoic conglomerate, agglomerate and breccia, ash-flow tuffs and glacial deposits.

The Precambrian layered gneiss, granitic gneiss and migmatite have undergone at least two episodes of deformation and metamorphism in the sillimanite-cordierite-muscovite-almandine subfacies of the Abukuma-type facies series prior to the emplacement of quartz monzonite. Dia-base dikes, quartz-epidote and epidote veins transect these earlier rocks.

The Cambrian-Mississippian shelf-facies rocks were folded, faulted and eroded to a plain in Late Cretaceous time and were buried by …

Structure And Stratigraphy Of The Florida Mountains, Luna County, New Mexico., Lonnie Leroy Corbitt

Earth and Planetary Sciences ETDs

Precambrian rocks in the Florida Mountains have a long and complex history of orogeny and epeirogeny. The oldest recorded event is regional metamorphism (amphibolite facies) of sedimentary and igneous rocks which are intruded by granite. Following a long period of erosion, diamictite was deposited on a deeply weathered surface of igneous and metamorphic rocks.

At least 3,000 feet of Paleozoic strata is preserved above the Precambrian rock1s. The Paleozoic strata are mostly shelf carbonates; the Bliss Formation and the Devonian Percha Shale are the only major Paleozoic elastic units present. From Cambrian through Mississippian time the Florida Mountains area was …

Structure, Stratigraphy, And Ore Deposits Of The Central Nacimiento Mountains, New Mexico, William H. Kaufman

Earth and Planetary Sciences ETDs

The mapped area is in Sandoval and Rio Arriba Counties, New Mexico, 3 mi southeast of Cuba and includes the eastern margin of the San Juan Basin and the western margin of the Nacimiento Mountains. The emphasis of this report is on the stratigraphy, structure, and ore deposits of this area.

The Precambrian quartz monzonite basement rock is non-conformably overlain by approximately 6000 ft of sedimentary rocks, which range in age from Pennsylvanian to Cretaceous. The Pennsylvanian Madera Formation is predominantly marine limestone and is overlain by the clastic Permian Abo and Yeso Formations. A maximum of 1050 ft of …

Stratigraphic Analysis Of Pennsylvanian Strata In The Lucero Region Of West Central New Mexico., James L. Martin

Earth and Planetary Sciences ETDs

During Pennsylvanian time the Lucero region of west central New Mexico was located along the southeastern part of the Zuni uplift and along the western and central part of the Lucero basin. The Lucero basin is part of the broad Pennsylvanian seaway that extended north-northwestward through central New Mexico to the Paradox basin on the north and the Orogrande basin on the south. Positive elements associated with the Lucero basin were the Zuni uplift to the west, the Penasco-Uncompahgre uplifts to the northeast, the Joyita uplift. to the east,. and the Pedernal uplift farther to the east.

The Pennsylvanian strata …

Petrology And Structure Of Eastern Monte Largo Hills, New Mexico, Jan Ralph Huzarshi

Earth and Planetary Sciences ETDs

In the Monte Largo Hills in the central part of north-central New Mexico, Precambrian metamorphic and igneous rocks, Paleozoic sediments, and Tertiary intrusive and extrusive igneous rocks occur. The metamorphics consist of a series of quartzo-feldspathic gneiss, mica schist, metaquartzite, and hornblende schists. These rocks were

derived from Precambrian sediments, mostly sandstones, arkoses and impure dolomites that were subjected to amphibolite facies synkinematic metamorphism. The Precambrian alkali granite appears to have been allochthonously emplaced with evidence near the contact of the quartzofeldspathic metamorphics for a parautochthonous formation. Quartz veins and pegmatite dikes of Precambrian age are also present. The sediments …

Geology Of The Hogback Mountain Area, Northern Big Belt Mountains, Montana., William L. Shaffer

Earth and Planetary Sciences ETDs

The Hogback Mountain area is located in the northern part of the Big Belt Mountains, twenty miles northeast of Helena, Montana.

Sedimentary rocks range in age from Precambrian to Recent, and have an aggregate thickness of about 16, 500 feet. The oldest stratified rocks are two conformable formations of the Precambrian Belt Series; the Newland Formation (oldest) and the Greyson Shale. These rocks have an aggregate thickness of about 10,700 feet.

Rocks of the Belt Series are unconformably overlain by about 1,200 feet of strata of Middle and Late Cambrian age separated into five conformable formation: the Flathead Sandstone (oldest), …

Regressive And Transgressive Phenomena In The Gallup Sandstone In The Northwestern Part Of San Juan County, New Mexico., Francis Amrisar Kaharoeddin

Earth and Planetary Sciences ETDs

The sedimentary history of the Gallup Sandstone is studied through the field investigation and laboratory analysis of samples taken from four measured sections in the vicinity of the San Juan River and one section near the Red Rock Highway. In addition to field data, textural parameters and dolomite and glauconite content of sandstone samples are the basis for interpretations of the sedimentary history and environment of deposition of the Gallup Sandstone.

A plot of the mean grain-size and sorting along with stratigraphic sections reveals that most of the Gallup Sandstone was deposited in a regressive sea, and that the regression …

Geology, Geochemistry And Lava Tubes In Quaternary Basalts, Northeastern Part Of Zuni Lava Field, Valencia County, New Mexico, James Douglas Causey

Earth and Planetary Sciences ETDs

Basaltic volcanism in the northeastern part of the Zuni lava field is related to a north-northeast trending regional fracture system. This is shown by elongation of centers and their alignment. However, .the fractures do not control the direction of lava tubes.

There are three distinct stages of volcanic activity common to the Zuni lava field:

1) early pyroclastic eruptions,

2) quiescent flows or fissure eruptions􀀅

3) late pyroclastic eruptions.

Evidence for the first stage is sometimes lacking, but the second and third stages can always be seen.

The basalts range from weakly tholeiitic to alkali in nature. Potassium content varies …

Effect Of The Pedernal Axis On Permian And Triassic Sedimentation, Philip F. Hock

Earth and Planetary Sciences ETDs

The area surrounding the Pedernal Hills has been of scientific and economic interest for a number of years. The effect of the Pedernal axis on sedimentation and stratigraphy of late Paleozoic rocks is of major importance. The principal purposes of this study were to determine whether the Precambrian terrane was an active source of sediment and what effect it had on thickness of strata during Permian and Triassic time. the area was also mapped in as much detail as the scale (1:125,000) permitted.

Surface Energies In The Caso4-H2o System And The Effect Of Supersaturation On The Crystallization Of Gypsum, Sandra C. Feldman

Earth and Planetary Sciences ETDs

The surface energy of gypsum has been experimentally determined to be 70. 2 erg/cm² at 30˚ C. The value for anhydrite is calculated as 112 erg/cm². At various extrapolated supersaturations, the number of particles or ions necessary to form nuclei of gypsum and anhydrite is:

Supersaturation

No. part. or ions/nucleus

Gypsum

Anhydrite

10

60.5

1000

51

8

2

99

20

4

Crystal size measurements and crystal shapes were noted for gypsum within the range of supersaturations studied (45.6 to 131). The maximum crystal size is attained at a slightly lower supersaturation than the critical supersaturation. The shape …

Crystal Structures Of Potassium Ferric Sulfate Minerals., Edward J. Graeber

Earth and Planetary Sciences ETDs

The potassium ferric sulfate minerals, yavapaiite [KFe(so ) J and goldichite [KFe(so4) •4H2oJ were studied 42 2 using x-ray diffraction methods, and the results correlated with the mineral krausite [KFe(so4)2 ·H20J .

Yavapaiite crystallizes in space group C2/m with two formula weights in a unit cell of dimensions a= 8 .152A, b = 5, 153A, c = 7,877A and S = 911.70°. Goldichite , in space group P2 /c, contains four formula weights in a unit cell with a= 10 . 387A, b = 10.486A, c = 9.086A and 6 = 101.67°.

The structures were solved by three-dimensional Patterson syntheses …

Trace-Element Geochemistry Of Southwestern Turquoise, Anne Marguerite Colberg Sigleo

Earth and Planetary Sciences ETDs

Southwestern turquoise (CuAl₆(PO₄)₄ OH₈ · 4H₂O) is associated with Laramide intrusions along the eastern and southern margins of the Colorado Plateau in Colorado, New Mexico, and Arizona, and with a zone of Late Devonian­Mississippian tectonic activity in Nevada. A review, of the previous work on the origin of turquoise is presented. Of these, the supergene hypothesis proposed by Sidney Paige in 1912 generally remains undisputed in the literature. Much of the data presented in this study, however, suggest a hydrothermal mode of formation. The concentrations of Co in particular are most similar …

Volcanic Rocks Associated With The Western Part Of The Mogollon Plateau Volcano-Tectonic Complex, Southwestern New Mexico, Rodney Charles Rhodes

Earth and Planetary Sciences ETDs

An area of approximately 450 square miles was mapped on a reconnaissance basis, covering part of the western half of the Mogollon Plateau volcano-tectonic complex. This report deals with the geology of the area and its relationship to the regional volcano-tectonic structure of the Mogollon Plateau.

Flow Direction Of Volcanic Rocks In The Northern Part Of The Mogollon-Datil Province, New Mexico, Glenn Alan Krimsky

Earth and Planetary Sciences ETDs

The northern part of the Mogollon-Datil province is located on the margin of the mid-Tertiary volcanic province of southwest New Mexico. The techinique established b Smith (1967) for determining flow direction of volcanic rocks was applied, for the first time, to determine flow direction and source areas of volcanic rocks form uncertain centers.

The Lower volcanic Group, which contains thick sequences of rhyolltes, latites, and andesites between 38 and 29 m.y. old, originated from two volcanic centers. Source area for the Datil formation, comosed of the Spears and Hells Mesa Members, is in the northern San Mateo Mountains. The Tda …

Effective Rates Of Evaporation And Chemical Properties Of The Precipitates., John Lincoln Rasho

Earth and Planetary Sciences ETDs

An experiment was designed to simulate the evaporation of sea water in the laboratory. The experiment was conducted isothermally at 35 1. Chlorinity, salinity, and density of the solution were determined at different stages of evaporation. Also the trace element contents of Sr, Rb, K, and Li of the precipitates were determined to study the possible changes, and the significance of these changes, in the concentration of these trace elements in solution at different stages of evaporation.

The results of this experiment and the work of previous investigators indicate that the rate of crystallization from sea water, at any given …

Stratigraphic Analysis Of The Upper Permian And Lower Triassic Strata In Southern Utah, Charles Dennis Irwin Jr.

Earth and Planetary Sciences ETDs

Permian sedimentation in southwestern Utah was influenced by three principal depositional areas. These areas were the Oquirrh basin in north-central Utah, the Cordilleran geosyncline in eastern Nevada, and the Quemado-Cuchillo basin on the northern shelf of the Sonoran geosyncline in east-central Arizona and west-central New Mexico. Throughout Permian time, marine sediments and their well-developed beach and continental eolian sandstone equivalents were deposited within these basins and upon their surrounding shelves. Each of the three basins appear to have exerted their influence upon sedimentation during a discrete period of geologic time. Thus while one basin was sedimentationally active the other two …

Geology Of Part Of The Creston Range, Mora County, New Mexico, Tim T. Schowalter

Earth and Planetary Sciences ETDs

The low hills and hogback ridges of the Creston Range form the southeastern edge of the Sangre de Cristo Mountains.

Rocks ranging from Precambrian to Quaternary are exposed in the Creston Range. The Precambrian rocks consist of generally foliated, medium-grade metamorphics intruded by concordant, simple pegmatites. These rocks have been subjected to at least two episodes of deformation of Precambrian age. Approximately 9,000 feet of sedimentary rocks of Devonian (?)-Mississippian to Permian age that were deposited in an intracratonic basin to shelf environment are present. Tertiary-Quaternary rocks are represented by outliers of a basalt flow from the Ocate colcanic field …

Effect Of Supersaturation On The Kinetics Of The Gypsum-Anhydrite Transition., Pao-Chin Chao

Earth and Planetary Sciences ETDs

Gypsum and anhydrite have been found extensively in evaporite beds. Gypsum is the low-temperature, hydrous form of calcium sulfate, while anhydrite is the high-temperature, anhydrous form. The temperature of gypsum-anhydrite transition has been fixed, by both solubility measurements and thermodynamic calculations, in the range of 38 to 42°c in pure water; and at lower values with increasing NaCl content in the solutions. However, the precipitation of anhydrite has never been obtained experimentally in its own stability field, gypsum is always metastably formed instead.

Many investigators believe that the primary precipitation of anhydrite from solutions is improbable. It is usually converted …

Igneous Geology Of The Rio Puerco Necks, Sandoval And Valencia Counties, New Mexico., William Travis Brown Jr.

Earth and Planetary Sciences ETDs

In the Rio Puerco valley of Valencia and Sandoval Counties, New Mexico, immediately east of Mount Taylor and its associated lava flows are a series of ten prominent and exposed basaltic rocks. These bodies consist of alkali basalts exhibiting no systematic mineralogic or compositional trends throughout the area. The alkali basalts are composed of olivine, augite, plagioclase (labradorite), and opaques in a trachytic to felty groundmass. Each neck was emplaced by means of a convection cell mechanism that allowed the surrounding Cretaceous sediments to remain undisturbed by the intrusion. Contained in the alkali basalts are ubiquitous ultramafic inclusions of lherzolite …

Geology Of The Southern San Mateo Mountains, Socorro And Sierra Counties, New Mexico, Steven Eugene Farkas

Earth and Planetary Sciences ETDs

The San Mateo Mountains of south-central New Mexico consist of a series of uplifted blocks of Tertiary volcanic rocks which cover an area approximately 45 miles long by 20 miles wide. Faulted blocks of older, Paleozoic and Precambrian, rocks and post-volcanic intrusives are found along the eastern and southern borders of the range. Only late Paleozoic, Pennsylvanian and Permian sediments occur in the mapped area. More than 7,000 feet of Tertiary volcanic rocks unconformably overlies all older rocks, divided into the Lower Volcanic and Datil Groups. The lower Volcanic Group is composed of a series of deeply altered andesites, tuffaceous …

Stratigraphy And Structure Of The Northwestern Guadalupe Mountains, New Mexico, Klyne Headley

Earth and Planetary Sciences ETDs

The northwestern Guadalupe Mountains of southeastern New Mexico are part of a large regional cuesta that slopes gently northeast. The crest of the northern escarpment rises abruptly to more than 2,200 feet above Pinon Valley.

The rugged west-facing escarpment has been carved in an uplifted fault block composed entirely of Permian sedimentary rocks having an aggregate thickness of about 1,700 feet. Dark-red to buff siltstone, gray dolomite, and white to gray gypsum compose the Yeso Formation. Conformably overlying these rocks is the dark-brown limestone and dolomite sequence of the San Andres Formation. The Glorieta Sandstone which usually occurs between these …

Origin Of Reeflike Masses In The Upper Member Of The San Andres Formation, Central Guadalupe Mountains, Eddy County, New Mexico, Richard Lane Squires

Earth and Planetary Sciences ETDs

Several reeflike masses crop out in the upper part of the Upper member of the San Andres Formation in the Last Chance Canyon area, southeastern New Mexico. The reeflike masses are situated on the Northwest shelf adjacent to the Delaware basin of Permian age. Based on the compilation of the field and laboratory data, it was concluded that the reeflike masses are not reefs at all and such exposures are termed pseudoreefs. No criteria were found which could be used to differentiate the masses from surrounding, laterally equivalent strata since both consist of relatively unfossiliferous dolomitized mudstones and wackestones. The …

Petrography And Structure Of The Pedernal Hills, Torrance County, New Mexico, Ralph Alan Gonzales

Earth and Planetary Sciences ETDs

In the Pedernal Hills, in the eastern part of north-central New Mexico, five Precambrian metamorphic and igneous rock types occur. Stratigraphically, oldest to youngest, they include medium-grained granite gneiss; quartzite, quartz-mica schist, and quartz-specular hematite schist; schist unit consisting mainly of quartz-muscovite schist and greenstone; intrusive granite which includes rocks ranging from quartz diorite to alkali granite; and cataclasite representing dynamically metamorphosed rocks.

The Geology Of The Jicarilla Mountains, Lincoln County, New Mexico., George Ernest Ryberg

Earth and Planetary Sciences ETDs

The Jicarilla Mountains in west-central Lincoln County, New Mexico, consist of Permian, Triassic, and Cretaceous sediments intruded by Tertiary sills, dikes, laccoliths, and stocks. The upper 50 feet of the Yeso Formation is exposed and is conformably overlain by the San Andres Formation which consists of the lower Sandstone, and middle Limestone, and upper Gypsum members. The Permian Artesia Formation, which is about 300 feet thick, unconformably overlies the Gypsum member. Unconformably overlying the Artesia Formation is a 200-foot section of the Triassic Santa Rosa Formation. The boundary between the Santa Rosa Formation and the overlying Chinle Formation is gradational. …

The Geology Of The White Oaks-Patos Mountain Area, Lincoln County, New Mexico, Richard A. Haines

Earth and Planetary Sciences ETDs

The White Oaks-Patos Mountain area is in the north­ central portion of the Sierra Blanca basin in central Lincoln County, New Mexico. The rocks consist of Permian, Triassic, and Cretaceous strata intruded by early Tertiary sills, dikes, and laccoliths. The 2,900 feet of sedimentary strata include 750 to 800 feet of Permian rocks, 550 feet of Triassic rocks, and 1700 feet of Cretaceous rocks. Extensive Tertiary­ Quaternary pediments cover much of the area.

The mapped area lies in the center of a large concentra­tion of Tertiary intrusive bodies known as the ln County porphyry belt, including Patos Mountain. Igneous rocks …

Geology Of The Southern Pilot Range, Elko County, Nevada And Box Elder And Tooele Counties, Utah, John Michael O'Neill

Earth and Planetary Sciences ETDs

The southern Pilot Range is a slightly sinuous, north-trending mountain range located in the northeastern part of the Great Basin.

Approximately 18,500 feet of miogcosynclinal sedimentary rocks representing every system from late Precam­brian to Permian(?) are exposed in the southern Pilot Range. Because of intense faulting, many of the strati­graphic relationships between the formations are impossible to determine. Mesozoic and Tertiary strata are absent; however, Pleistocene Lake Bonneville deposits are wide­ spread, although thinly distributed. Small igneous stocks, dikes, and sills are common only in the southern two-thirds of the map area. Stocks are principally granodioritic. In several cases the …