Earth Sciences Commons^™

An Experimental Investigation Of Highly Undercooled Magnesium Silicate Chondrule-Like Spherules, Harry Nicholas Planner

Earth and Planetary Sciences ETDs

A series of experiments, involving molten magnesium silicate spherules that were subjected to high initial cooling rates and allowed to nucleate at high temperatures (985-1350°C), were performed so as to compare their thermal histories to the resulting internal features. Such comparisons could be used to decipher the thermal history of chondrules and the conditions surrounding their formation based on their mineralogy, crystal morphology, and overall texture. Various features of the spherules were correlated with the initial high cooling rate process, nucleation temperature, and the maximum temperature attained during the recalescance to demonstrate the restrictions resulting from or their sensitivities to …

Unusual Lavas From Molokai, Hawaii: Alkalic Olivine Basalts Transitional To Hawaiites And Strontium-Rich Mugearites, Paul Frank Hlava

Earth and Planetary Sciences ETDs

ABSTRACT

Systematic data has recently been published on the compositions of major mineral phases in rocks of the tholeiitic, alkalic, and nephelinic suites from the island of Maui, Hawaii. The present study was initiated to provide similar data from the rocks of Molokai, Hawaii, from which the nature of interisland variations could be established. During the study, it became obvious that many of the rocks were unusual and so this study also provides information on the bulk rock, trace element, and mineral compositions of alkalic olivine basalts transitional to hawaiites and Sr-rich mugearites.

From a total of 14 basalts collected …

Geology Of The Northern Part Of The Sierra Cuchillo, Socorro And Sierra Counties, New Mexico, Florian Maldonado

Earth and Planetary Sciences ETDs

The northern Sierra Cuchillo, Socorro and Sierra Counties, New Mexico is approximately 32 miles northwest of Truth or Consequences, New Mexico. The Sierra Cuchillo is a narrow fault-block range in the Basin-Range province and is a structurally high element west of the Rio Grande trough. It is bordered on the west by the Winston graben and the Black Range and on the east by Monticello graben and the San Mateo Mountains.

Permian rocks consist of the Yeso and San Andres Formation, with an aggregate thickness of 2100 ft (640 m). Upper Cretaceous rocks, 40 ft (10 m) thick, consist of …

Growth Line Analysis Of A Recent Scallop Population And It's [Sic] Potential For Paleoecology, John F. Dillon

Earth and Planetary Sciences ETDs

Periodic growth lines can be used to construct a record of variations in the growth rate of a fossil or recent shell. Because growth rate is largely dependent upon environmental conditions, such a record serves also as an indication of variations in the environment during the lifetime of the shell. Although the very presence of such variations is of some paleoecologic interest, the main potential of growth lines in paleoecology lies in an extension of this argument. This is the concept that the contemporaneity of fossil organisms could be tested by examining their growth rate records for similarities; these would …

A Petrologic And Quantitative Compositional Study Of Four Rocks From The Mid-Atlantic Ridge, Jonathan A. Green

Earth and Planetary Sciences ETDs

The composition of major mineral phases in four rocks from the equatorial Mid-Atlantic Ridge, as determined by electron microprobe analysis and supplemented by additional mineralogic and petrographic study, have provided data for comparison with continental mafic assemblages. The compositional range of coexisting minerals in the samples: a nepheline-normative gabbro (teschenite), an olivine tholeiite, and two uralitized norites, is similar to the ranges of comparable continental suites. The teschenite contains pyroxene (Wo_48-46 En_37-23Fs_15-31) with high amounts of CaO (20.3-22.2 wt %), Al₂O₃ (2.9-6.8 wt. %), and Ti02 (1.2-2.9 wt. %) characteristic of continental …

Geology Of The White Oaks Mining District Lincoln County, New Mexico, James R. Grainger

Earth and Planetary Sciences ETDs

The White Oaks mining district is 12 km northeast of Carrizozo, in Lincoln County, New Mexico. Hydrothermal gold and tungsten mineralization occurs in north-trending veins and breccia zones in portions of the central district. Permian sandstones, limestones, and gypsum of the San Andres Formation are upwarped marginal to and by the Lone Mountain intrusive in the northwest portion of the map area. Triassic Santa Rosa and Chinle sandstones and shales are inclined to the south with Cretaceous Dakota, Mancos, and Mesaverde sediments. Approximately 640 m of sedimentary strata is exposed in the district.

Igneous rocks in the map area range …

Structure And Stratigraphy Of The Central Cimarron Range, Colfax County, New Mexico., Craig S. Goodknight

Earth and Planetary Sciences ETDs

The Cimarron Range forms a southeastern extension of the southern Sangre de Cristo Mountains. The area mapped in this study lies mainly between Eagle Nest and Ute Park, New Mexico, and is centered around Cimarron Canyon.

Rocks ranging from Precambrian to Quaternary in age are exposed• - in the central Cimarron Range. Precambrian rocks in the core of the range consist mainly of moderately foliated, low- to medium-grade metamorphics intruded by faintly foliated bodies of meta-granodiorite and meta-diabase.

Approximately 4000 feet of sedimentary rocks ranging from the Sangre de Cristo Formation of Pennsylvanian-Permian age through the Poison Canyon Formation of …

Structure And Stratigraphy Of The San Ysidro Quadrangle, Sandoval County, New Mexico, Richard Luverne Ruetschilling

Earth and Planetary Sciences ETDs

The mapped area is in Sandoval County, New Mexico, and includes the San Ysidro 7-minute quadrangle. Precambrian rocks in the area consist mainly of quartz monzonite gneiss. Quartz diorite xenoliths and leucocratic dike rocks are less abundant.

Strata totaling 1300 meters, ranging from Morrow-age strata of Pennsylvanian age through the Zia Sand Formation of Miocene age, are exposed in area (fig. 3). Overlying the marine Pennsylvanian Morrow-age strata and Madera Formation is 900 meters of continental, marginal marine, and evaporite deposits consisting, in ascending order, of the Permian Abo Yeso, Glorieta, San Andres and Bernal Formations, the Chinle Formation of …

A Test Of The Non-Uniform Distribution Of Azimuths Of Overlapping Lunar Craters, John Richard Dickson

Earth and Planetary Sciences ETDs

The azimuths between the centers of overlapping lunar craters show a statistically strong preferred orientation over most of the lunar globe for those crater pairs where the younger crater is of relatively small diameter (10-25 km). A strong north-south preferred lineation also exists in a narrow belt along the east and northern limb of the full moon for those crater pairs involving relatively large diameter craters (45 km). Various endogenic and exogenic mechanisms which might create a preferred orientation of overlapping craters are considered in the light of these findings. The preferred orientation of the smaller craters could result from …

The Chemistry Of Groundwaters In The Jemez Area And A Magnetic Survey Of A Potential Source Of Magmatic Fluids, David Woltz

Earth and Planetary Sciences ETDs

The Jemez Mountain area of north-central New Mexico has a geologic history of intense volcanism. Active geologically related phenomena are still present in the form of hot springs and fumaroles. This thesis undertook a study of the concentration of the elements Calcium, Chlorine, Fluorine, Magnesium and Sodium, and the compound Silicon Dioxide in the groundwaters of the Jemez Mountains. The concentrations in some of the waters indicate that they may possess magmatic components. A ground magnetic survey was undertaken to investigate the possibility of intrusions in the area. Data gathered in the survey has been interpreted as an intrusion at …

Petrology And Geochemistry Of Varved Halite Ii Member, Permian Castile Formation, Delaware Basin, Texas And New Mexico, Saleh Mohammad Billo

Earth and Planetary Sciences ETDs

The Halite II Member of the Permian Castile Formation in the Delaware Basin of Texas and New Mexico constitutes a 1778-year record of evaporite laminations. They are composed of rhythmic halite-anhydrite layers interrupted by four distinct carbonate-laminated beds of anhydrite. The average thickness of the varves is 2.3 cm for the halite-anhydrite couplets and 3.9 mm for the carbonate-laminated anhydrite couplets. They are correlative over distances of 70 miles (113 km). Halite occurs either as hopper crystals, grains, or as compact masses with many inclusions, bubbles, and vacuoles. Matrix crystals, rectangular crystals, nodules, and laths are the main petrographic types …

A Study Of Trace Metal Concentrations In Two Species Of Mytilus Along The Pacific Coast Of The United States., George Harry Fullas

Earth and Planetary Sciences ETDs

An investigation of iron, zinc, copper, and cadmium concentrations in Mytilus californianus and Mytilus edulis was conducted on specimens collected along the west coast of the United States. Animals and sea water were collected at six different areas and analyzed using an Atomic Absorption Spectrophotometer. Trace metal concentrations in the animals were influenced by the collection conditions of age, species, temperature, pollution, and metal relationships. Younger animals, of both species, contained higher concentrations of all the metals. Larger, or older animals, contained the smallest metal concentrations. Copper concentrations in the animals were higher in sea water with high copper content. …

Geology Of The Country East Of The Santa Rita Mining District, Grant County, New Mexico: The San Lorenzo Area, Raymond S. Lambert Jr.

Earth and Planetary Sciences ETDs

The settlement of San Lorenzo is approximately 19 miles east of Silver City, New Mexico. The area consists of rolling hills, relatively steep slopes and the broad Mimbres River Valley. The land surface reflects partial erosion of Basin and Range fault blocks. The maximtun elevation is 7,170 feet, with relief of 1,400 feet.

The main structural feature is a northwest trending mountain range, which is a west-southwest-dipping fault block bounded on the northeast by the Mimbres fault. Vertical displacement ranges from 150 meters (500 feet) to 1,200 meters (4,000 feet). Rocks exposed along the steep northeastern escarpment range in age …

The Dacites Of The Washakie Needles, Bunsen Peak, And The Birch Hills, Wyoming, And Their Relationship To The Absaroka-Gallatin Volcanic Province, Linda Lou Anderson Love

Earth and Planetary Sciences ETDs

ABSTRACT

TI1e Washakie Needles, Bunsen Peak, and Birch Hills dacites are three of many plugs which intrude the Eocene flows and volcaniclastic rocks of the Absaroka-Gallatin volcanic province. The dacites contain phenocrysts of plagioclase (oligoclase to andesine), biotite, and resorbed quartz. The dacites of the Washakie Needles and Bunsen Peak also contain phenocrysts of hornblende. The rocks of Bunsen Peak and the Birch Hills have two feldspar phases (oligoclase to andesine and sanidine) and quartz in the groundmass. The Washakie Needles dacite groundmass is composed of one feldspar (andesine to anorthoclase) and quartz. The fission track ages of the dacites …

Gravity Survey Of The Mogolion Plateau Volcanic Province, Southwestern New Mexico., Douglas Hugh Krohn

Earth and Planetary Sciences ETDs

A regional gravity survey has been conducted over the Mogollon Plateau, a mid-Tertiary volcano-tectonic complex 125 km in diameter located in southwestern New Mexico. The complete Bouguer gravity map (3 milligal contour interval) shows gravity values ranging form -167 milligals over an outcrop of Precambrian rocks near Silver City, on the southern rim of the Plateau to -251 milligals over an alluvium filled graben east of Reserve, in the northwestern part of the Plateau giving a maximum relief of 84 milligals. Gravity data show that in general the Mogollon Plateau is an area of low density rocks: gravity values within …

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 …

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 …

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), …

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 …